Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera).

PubMed

Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

2009-09-09

Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s). We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units, even at synonymous positions, suggests that the repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

Oviposition behaviour of Phlebotomus argentipes--a laboratory-based study.

PubMed

Kumar, Vijay; Rama, Aarti; Kesari, Shreekant; Bhunia, Gouri Sankar; Dinesh, Diwakar Singh; Das, Pradeep

2013-12-01

The breeding habitat of sandflies is a little studied and poorly understood phenomenon. More importantly, oviposition behaviour is a largely neglected aspect of sandfly biology and this knowledge gap further undermines our understanding of the biology of sandflies. Pheromones released by the eggs play an important role in identifying good sites for oviposition by female insects. Several recent studies have examined the oviposition pheromone. The present study provides a preliminary report on the oviposition behaviour of Phlebotomus argentipes, the only vector of kala-azar (or visceral leishmaniasis) on the Indian sub-continent. Sandflies prefer to oviposit their eggs on surfaces that contain organic substances, especially substances with an odour of decaying animal products and the remains of conspecific eggs. The results presented here suggest that the odour released by the organic substances of old sandfly colony remains that contain dead flies, old unhatched eggs, larval food containing vertebrate faeces, frass and other organic matter serves as an attractant for the ovipositing females of P. argentipes and hence greatly increases the number of oviposited eggs compared to eggs deposited in controlled oviposition pots. This result will be helpful in maintaining an efficient colony of P. argentipes and may be a promising tool for monitoring and controlling the target insect as part of a synergistic approach.

Identification of an ant queen pheromone regulating worker sterility.

PubMed

Holman, Luke; Jørgensen, Charlotte G; Nielsen, John; d'Ettorre, Patrizia

2010-12-22

The selective forces that shape and maintain eusocial societies are an enduring puzzle in evolutionary biology. Ordinarily sterile workers can usually reproduce given the right conditions, so the factors regulating reproductive division of labour may provide insight into why eusociality has persisted over evolutionary time. Queen-produced pheromones that affect worker reproduction have been implicated in diverse taxa, including ants, termites, wasps and possibly mole rats, but to date have only been definitively identified in the honeybee. Using the black garden ant Lasius niger, we isolate the first sterility-regulating ant queen pheromone. The pheromone is a cuticular hydrocarbon that comprises the majority of the chemical profile of queens and their eggs, and also affects worker behaviour, by reducing aggression towards objects bearing the pheromone. We further show that the pheromone elicits a strong response in worker antennae and that its production by queens is selectively reduced following an immune challenge. These results suggest that the pheromone has a central role in colony organization and support the hypothesis that worker sterility represents altruistic self-restraint in response to an honest quality signal.

Mammalian Pheromones

PubMed Central

Liberles, Stephen D.

2015-01-01

Mammalian pheromones control a myriad of innate social behaviors and acutely regulate hormone levels. Responses to pheromones are highly robust, reproducible, and stereotyped and likely involve developmentally predetermined neural circuits. Here, I review several facets of pheromone transduction in mammals, including (a) chemosensory receptors and signaling components of the main olfactory epithelium and vomeronasal organ involved in pheromone detection; (b) pheromone-activated neural circuits subject to sex-specific and state-dependent modulation; and (c) the striking chemical diversity of mammalian pheromones, which range from small, volatile molecules and sulfated steroids to large families of proteins. Finally, I review (d ) molecular mechanisms underlying various behavioral and endocrine responses, including modulation of puberty and estrous; control of reproduction, aggression, suckling, and parental behaviors; individual recognition; and distinguishing of own species from predators, competitors, and prey. Deconstruction of pheromone transduction mechanisms provides a critical foundation for understanding how odor response pathways generate instinctive behaviors. PMID:23988175

Antennal transcriptome analysis of the piercing moth Oraesia emarginata (Lepidoptera: Noctuidae)

PubMed Central

Feng, Bo; Guo, Qianshuang; Zheng, Kaidi; Qin, Yuanxia; Du, Yongjun

2017-01-01

The piercing fruit moth Oraesia emarginata is an economically significant pest; however, our understanding of its olfactory mechanisms in infestation is limited. The present study conducted antennal transcriptome analysis of olfactory genes using real-time quantitative reverse transcription PCR analysis (RT-qPCR). We identified a total of 104 candidate chemosensory genes from several gene families, including 35 olfactory receptors (ORs), 41 odorant-binding proteins, 20 chemosensory proteins, 6 ionotropic receptors, and 2 sensory neuron membrane proteins. Seven candidate pheromone receptors (PRs) and 3 candidate pheromone-binding proteins (PBPs) for sex pheromone recognition were found. OemaOR29 and OemaPBP1 had the highest fragments per kb per million fragments (FPKM) values in all ORs and OBPs, respectively. Eighteen olfactory genes were upregulated in females, including 5 candidate PRs, and 20 olfactory genes were upregulated in males, including 2 candidate PRs (OemaOR29 and 4) and 2 PBPs (OemaPBP1 and 3). These genes may have roles in mediating sex-specific behaviors. Most candidate olfactory genes of sex pheromone recognition (except OemaOR29 and OemaPBP3) in O. emarginata were not clustered with those of studied noctuid species (type I pheromone). In addition, OemaOR29 was belonged to cluster PRIII, which comprise proteins that recognize type II pheromones instead of type I pheromones. The structure and function of olfactory genes that encode sex pheromones in O. emarginata might thus differ from those of other studied noctuids. The findings of the present study may help explain the molecular mechanism underlying olfaction and the evolution of olfactory genes encoding sex pheromones in O. emarginata. PMID:28614384

Binding affinity of five PBPs to Ostrinia sex pheromones

USDA-ARS?s Scientific Manuscript database

Pheromone binding proteins (PBPs) of Lepidoptera function in chemical communication, mate attraction and recognition, and may be involved in reinforcement of sexual isolation between recently diverged species. Directional selection was previously predicted between PBP3 orthologs of the corn borer si...

Aplysia attractin: biophysical characterization and modeling of a water-borne pheromone.

PubMed Central

Schein, C H; Nagle, G T; Page, J S; Sweedler, J V; Xu, Y; Painter, S D; Braun, W

2001-01-01

Attractin, a 58-residue protein secreted by the mollusk Aplysia californica, stimulates sexually mature animals to approach egg cordons. Attractin from five different Aplysia species are approximately 40% identical in sequence. Recombinant attractin, expressed in insect cells and purified by reverse-phase high-performance liquid chromatography (RP-HPLC), is active in a bioassay using A. brasiliana; its circular dichroism (CD) spectrum indicates a predominantly alpha-helical structure. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) characterization of proteolytic fragments identified disulfide bonds between the six conserved cysteines (I-VI, II-V, III-IV, where the Roman numeral indicates the order of occurrence in the primary sequence). Attractin has no significant similarity to any other sequence in the database. The protozoan Euplotes pheromones were selected by fold recognition as possible templates. These diverse proteins have three alpha-helices, with six cysteine residues disulfide-bonded in a different pattern from attractin. Model structures with good stereochemical parameters were prepared using the EXDIS/DIAMOD/FANTOM program suite and constraints based on sequence alignments with the Euplotes templates and the attractin disulfide bonds. A potential receptor-binding site is suggested based on these data. Future structural characterization of attractin will be needed to confirm these models. PMID:11423429

Multifunctional queen pheromone and maintenance of reproductive harmony in termite colonies.

PubMed

Matsuura, Kenji

2012-06-01

Pheromones are likely involved in all social activities of social insects including foraging, sexual behavior, defense, nestmate recognition, and caste regulation. Regulation of the number of fertile queens requires communication between reproductive and non-reproductive individuals. Queen-produced pheromones have long been believed to be the main factor inhibiting the differentiation of new reproductive individuals. However, since the discovery more than 50 years ago of the queen honeybee substance that inhibits the queen-rearing behavior of workers, little progress has been made in the chemical identification of inhibitory queen pheromones in other social insects. The recent identification of a termite queen pheromone and subsequent studies have elucidated the multifaceted roles of volatile pheromones, including functions such as a fertility signal, worker attractant, queen-queen communication signal, and antimicrobial agent. The proximate origin and evolutionary parsimony of the termite queen pheromone also are discussed.

Relationships between egg-recognition and egg-ejection in a grasp-ejector species.

PubMed

Soler, Manuel; Ruiz-Raya, Francisco; Roncalli, Gianluca; Ibáñez-Álamo, Juan Diego

2017-01-01

Brood parasitism frequently leads to a total loss of host fitness, which selects for the evolution of defensive traits in host species. Experimental studies have demonstrated that recognition and rejection of the parasite egg is the most common and efficient defence used by host species. Egg-recognition experiments have advanced our knowledge of the evolutionary and coevolutionary implications of egg recognition and rejection. However, our understanding of the proximate mechanisms underlying both processes remains poor. Egg rejection is a complex behavioural process consisting of three stages: egg recognition, the decision whether or not to reject the putative parasitic egg and the act of ejection itself. We have used the blackbird (Turdus merula) as a model species to explore the relationship between egg recognition and the act of egg ejection. We have manipulated the two main characteristics of parasitic eggs affecting egg ejection in this grasp-ejector species: the degree of colour mimicry (mimetic and non-mimetic, which mainly affects the egg-recognition stage of the egg-rejection process) and egg size (small, medium and large, which affects the decision to eject), while maintaining a control group of non-parasitized nests. The behaviour of the female when confronted with an experimental egg was filmed using a video camera. Our results show that egg touching is an indication of egg recognition and demonstrate that blackbirds recognized (i.e., touched) non-mimetic experimental eggs significantly more than mimetic eggs. However, twenty per cent of the experimental eggs were touched but not subsequently ejected, which confirms that egg recognition does not necessarily mean egg ejection and that accepting parasitic eggs, at least sometimes, is the consequence of acceptance decisions. Regarding proximate mechanisms, our results show that the delay in egg ejection is not only due to recognition problems as usually suggested, given that experimental eggs are not touched significantly more often. Thus, the delay in egg ejection is mainly the consequence of a delay in the decision to eject, probably triggered by mechanical constraints imposed by eggs that are harder to eject (i.e. larger). Our results offer important information on the relationships between recognition and ejection and contribute to a better understanding of host defences against brood parasites.

Relationships between egg-recognition and egg-ejection in a grasp-ejector species

PubMed Central

Soler, Manuel; Ruiz-Raya, Francisco; Roncalli, Gianluca; Ibáñez-Álamo, Juan Diego

2017-01-01

Brood parasitism frequently leads to a total loss of host fitness, which selects for the evolution of defensive traits in host species. Experimental studies have demonstrated that recognition and rejection of the parasite egg is the most common and efficient defence used by host species. Egg-recognition experiments have advanced our knowledge of the evolutionary and coevolutionary implications of egg recognition and rejection. However, our understanding of the proximate mechanisms underlying both processes remains poor. Egg rejection is a complex behavioural process consisting of three stages: egg recognition, the decision whether or not to reject the putative parasitic egg and the act of ejection itself. We have used the blackbird (Turdus merula) as a model species to explore the relationship between egg recognition and the act of egg ejection. We have manipulated the two main characteristics of parasitic eggs affecting egg ejection in this grasp-ejector species: the degree of colour mimicry (mimetic and non-mimetic, which mainly affects the egg-recognition stage of the egg-rejection process) and egg size (small, medium and large, which affects the decision to eject), while maintaining a control group of non-parasitized nests. The behaviour of the female when confronted with an experimental egg was filmed using a video camera. Our results show that egg touching is an indication of egg recognition and demonstrate that blackbirds recognized (i.e., touched) non-mimetic experimental eggs significantly more than mimetic eggs. However, twenty per cent of the experimental eggs were touched but not subsequently ejected, which confirms that egg recognition does not necessarily mean egg ejection and that accepting parasitic eggs, at least sometimes, is the consequence of acceptance decisions. Regarding proximate mechanisms, our results show that the delay in egg ejection is not only due to recognition problems as usually suggested, given that experimental eggs are not touched significantly more often. Thus, the delay in egg ejection is mainly the consequence of a delay in the decision to eject, probably triggered by mechanical constraints imposed by eggs that are harder to eject (i.e. larger). Our results offer important information on the relationships between recognition and ejection and contribute to a better understanding of host defences against brood parasites. PMID:28170402

Chemical Characterization of Young Virgin Queens and Mated Egg-Laying Queens in the Ant Cataglyphis cursor: Random Forest Classification Analysis for Multivariate Datasets.

PubMed

Monnin, Thibaud; Helft, Florence; Leroy, Chloé; d'Ettorre, Patrizia; Doums, Claudie

2018-02-01

Social insects are well known for their extremely rich chemical communication, yet their sex pheromones remain poorly studied. In the thermophilic and thelytokous ant, Cataglyphis cursor, we analyzed the cuticular hydrocarbon profiles and Dufour's gland contents of queens of different age and reproductive status (sexually immature gynes, sexually mature gynes, mated and egg-laying queens) and of workers. Random forest classification analyses showed that the four groups of individuals were well separated for both chemical sources, except mature gynes that clustered with queens for cuticular hydrocarbons and with immature gynes for Dufour's gland secretions. Analyses carried out with two groups of females only allowed identification of candidate chemicals for queen signal and for sexual attractant. In particular, gynes produced more undecane in the Dufour's gland. This chemical is both the sex pheromone and the alarm pheromone of the ant Formica lugubris. It may therefore act as sex pheromone in C. cursor, and/or be involved in the restoration of monogyny that occurs rapidly following colony fission. Indeed, new colonies often start with several gynes and all but one are rapidly culled by workers, and this process likely involves chemical signals between gynes and workers. These findings open novel opportunities for experimental studies of inclusive mate choice and queen choice in C. cursor.

Two pheromone precursor genes are transcriptionally expressed in the homothallic ascomycete Sordaria macrospora.

PubMed

Pöggeler, S

2000-06-01

In order to analyze the involvement of pheromones in cell recognition and mating in a homothallic fungus, two putative pheromone precursor genes, named ppg1 and ppg2, were isolated from a genomic library of Sordaria macrospora. The ppg1 gene is predicted to encode a precursor pheromone that is processed by a Kex2-like protease to yield a pheromone that is structurally similar to the alpha-factor of the yeast Saccharomyces cerevisiae. The ppg2 gene encodes a 24-amino-acid polypeptide that contains a putative farnesylated and carboxy methylated C-terminal cysteine residue. The sequences of the predicted pheromones display strong structural similarity to those encoded by putative pheromones of heterothallic filamentous ascomycetes. Both genes are expressed during the life cycle of S. macrospora. This is the first description of pheromone precursor genes encoded by a homothallic fungus. Southern-hybridization experiments indicated that ppg1 and ppg2 homologues are also present in other homothallic ascomycetes.

Stingless bees (Scaptotrigona pectoralis) learn foreign trail pheromones and use them to find food.

PubMed

Reichle, Christian; Aguilar, Ingrid; Ayasse, Manfred; Jarau, Stefan

2011-03-01

Foragers of several species of stingless bees (Hymenoptera, Apidae and Meliponini) deposit pheromone marks in the vegetation to guide nestmates to new food sources. These pheromones are produced in the labial glands and are nest and species specific. Thus, an important question is how recruited foragers recognize their nestmates' pheromone in the field. We tested whether naïve workers learn a specific trail pheromone composition while being recruited by nestmates inside the hive in the species Scaptotrigona pectoralis. We installed artificial scent trails branching off from trails deposited by recruiting foragers and registered whether newly recruited bees follow these trails. The artificial trails were baited with trail pheromones of workers collected from foreign S. pectoralis colonies. When the same foreign trail pheromone was presented inside the experimental hives while recruitment took place a significant higher number of bees followed the artificial trails than in experiments without intranidal presentation. Our results demonstrate that recruits of S. pectoralis can learn the composition of specific trail pheromone bouquets inside the nest and subsequently follow this pheromone in the field. We, therefore, suggest that trail pheromone recognition in S. pectoralis is based on a flexible learning process rather than being a genetically fixed behaviour.

Variation in and responses to brood pheromone of the honey bee (Apis mellifera L.).

PubMed

Metz, Bradley N; Pankiw, Tanya; Tichy, Shane E; Aronstein, Katherine A; Crewe, Robin M

2010-04-01

The 10 fatty acid ester components of brood pheromone were extracted from larvae of different populations of USA and South African honey bees and subjected to gas chromatography-mass spectrometry quantitative analysis. Extractable amounts of brood pheromone were not significantly different by larval population; however, differences in the proportions of components enabled us to classify larval population of 77% of samples correctly by discriminant analysis. Honeybee releaser and primer pheromone responses to USA, Africanized and-European pheromone blends were tested. Texas-Africanized and Georgia-European colonies responded with a significantly greater ratio of returning pollen foragers when treated with a blend from the same population than from a different population. There was a significant interaction of pheromone blend by adult population source among Georgia-European bees for modulation of sucrose response threshold, a primer response. Brood pheromone blend variation interacted with population for pollen foraging response of colonies, suggesting a self recognition cue for this pheromone releaser behavior. An interaction of pheromone blend and population for priming sucrose response thresholds among workers within the first week of adult life suggested a more complex interplay of genotype, ontogeny, and pheromone blend.

Rapid modification in the olfactory signal of ants following a change in reproductive status

NASA Astrophysics Data System (ADS)

Cuvillier-Hot, Virginie; Renault, Valérie; Peeters, Christian

2005-02-01

In insect societies, the presence and condition of egg-layers can be assessed with pheromones. Exocrine secretions are expected to vary in time in order to give up-to-date information on an individual’s reproductive physiology. In the queenless monogynous ant Streblognathus peetersi, we allowed a previously infertile high-ranking worker to accede to the alpha rank, thus triggering the onset of her oogenesis (15 replicates). We then studied her interactions with an established egg-layer from the same colony after different durations, ranging from 20 h to several days. Even though her eggs are only ready to be laid after 30 days, the new alpha was recognised within 1 2 days. Detection occurred at a distance of a few millimetres, suggesting the involvement of a pheromone with low volatility, such as cuticular hydrocarbons. When the new alpha had differentiated for >48 h, she was attacked by the established egg-layer. In all cases, low-ranking workers eventually immobilised one of the two alphas: the new alpha was the target if she had differentiated only recently, suggesting that police workers select the dominant worker with the “less fertile” odour. Using the behaviour of ants as our measure, we demonstrate that a dominant’s olfactory signal changes rapidly with a modification in her social status, and it occurs well before the onset of egg-laying.

Sex-Linked Pheromone Receptor Genes of the European Corn Borer, Ostrinia nubilalis, Are in Tandem Arrays

PubMed Central

Yasukochi, Yuji; Miura, Nami; Nakano, Ryo; Sahara, Ken; Ishikawa, Yukio

2011-01-01

Background Tuning of the olfactory system of male moths to conspecific female sex pheromones is crucial for correct species recognition; however, little is known about the genetic changes that drive speciation in this system. Moths of the genus Ostrinia are good models to elucidate this question, since significant differences in pheromone blends are observed within and among species. Odorant receptors (ORs) play a critical role in recognition of female sex pheromones; eight types of OR genes expressed in male antennae were previously reported in Ostrinia moths. Methodology/Principal Findings We screened an O. nubilalis bacterial artificial chromosome (BAC) library by PCR, and constructed three contigs from isolated clones containing the reported OR genes. Fluorescence in situ hybridization (FISH) analysis using these clones as probes demonstrated that the largest contig, which contained eight OR genes, was located on the Z chromosome; two others harboring two and one OR genes were found on two autosomes. Sequence determination of BAC clones revealed the Z-linked OR genes were closely related and tandemly arrayed; moreover, four of them shared 181-bp direct repeats spanning exon 7 and intron 7. Conclusions/Significance This is the first report of tandemly arrayed sex pheromone receptor genes in Lepidoptera. The localization of an OR gene cluster on the Z chromosome agrees with previous findings for a Z-linked locus responsible for O. nubilalis male behavioral response to sex pheromone. The 181-bp direct repeats might enhance gene duplications by unequal crossovers. An autosomal locus responsible for male response to sex pheromone in Heliothis virescens and H. subflexa was recently reported to contain at least four OR genes. Taken together, these findings support the hypothesis that generation of additional copies of OR genes can increase the potential for male moths to acquire altered specificity for pheromone components, and accordingly, facilitate differentiation of sex pheromones. PMID:21526121

Biparental defensive endowment of eggs with acquired plant alkaloid in the moth Utetheisa ornatrix.

PubMed Central

Dussourd, D E; Ubik, K; Harvis, C; Resch, J; Meinwald, J; Eisner, T

1988-01-01

The eggs of Utetheisa ornatrix contain pyrrolizidine alkaloids. These compounds are contributed by both parents, who sequester them as larvae from their food plants. Females receive alkaloid from the males at mating, apparently by seminal infusion, and transmit this alkaloid together with alkaloid of their own to the eggs. Field and laboratory tests showed that the alkaloids protect eggs from predators. The alkaloidal contribution of the male, although smaller than that of the female, itself provides significant egg protection. A previously identified pheromone, derived by the male from the alkaloid and emitted during precopulatory behavior, may announce the male alkaloidal worth to the female. PMID:3413071

Monitoring populations of saddled prominent (Lepidoptera: Notodontidae) with pheromone-baited traps.

PubMed

Spear-O'Mara, Jennifer; Allen, Douglas C

2007-04-01

Field trials with three types of pheromone traps were performed in eight northern hardwood stands in northern New York state to develop a population-monitoring tool for the saddled prominent, Heterocampa guttivitta (Walker) (Lepidoptera: Notodontidae). Lure specificity and the relationship between pheromone trap catch and subsequent egg density were examined. A study of moth emergence in relation to temperature was designed to determine whether moth activity throughout the flight season can be predicted using a growing degree-day (DD) model. Pherocon 1C wing traps were significantly more effective than the green Unitrap bucket style. Catch was not affected by position when traps were > or =20 m from an opening (road), and lures were specific to saddled prominent. Lure specificity was examined using green Multipher bucket traps, which effectively attracted and held moths. In the first year of the study, number of viable eggs per 10 leaf clusters was significantly correlated (r2 = 0.59) with average moth catch/trap in pheromone-baited Pherocon traps. When differences in stand density (basal area) and relative abundance of sugar maple (percentage of total stems per hectare), the principle host, were accounted for, the multiple regression model also was significant and r2 = 0. 83. Neither model, however, was significant the second year. Using a base temperature of 5.5 degrees C and on-site temperature data, the peak of moth flight occurred at 316 +/- 8 DD and end of flight occurred at 533 +/- 9 DD.

Optimum timing of insecticide applications against diamondback moth Plutella xylostella in cole crops using threshold catches in sex pheromone traps.

PubMed

Reddy, G V; Guerrero, A

2001-01-01

Field trials were conducted in cabbage (Brassica oleracea var capitata), cauliflower (B oleracea var botrytis) and knol khol (B oleracea gongylodes) crops at two different locations in Karnataka State (India) to optimize the timing of insecticide applications to control the diamondback moth, Plutella xylostella, using sex pheromone traps. Our results indicate that applications of cartap hydrochloride as insecticide during a 12-24 h period after the pheromone traps had caught on average 8, 12 and 16 males per trap per night in cabbage, cauliflower and knol khol, respectively, were significantly more effective than regular insecticide sprays at 7, 9, 12 or 15 days after transplantation. This was demonstrated by estimation of the mean number of eggs and larvae per plant, the percentage of holes produced, as well as the marketable yield of the three crops at each location. A good correlation between the immature stages, infestation level, the estimated crop yield and the number of moths caught in pheromone traps was also found, indicating the usefulness of pheromone-based monitoring traps to predict population densities of the pest.

Silencing the Odorant Binding Protein RferOBP1768 Reduces the Strong Preference of Palm Weevil for the Major Aggregation Pheromone Compound Ferrugineol

PubMed Central

Antony, Binu; Johny, Jibin; Aldosari, Saleh A.

2018-01-01

In insects, perception of the environment—food, mates, and prey—is mainly guided by chemical signals. The dynamic process of signal perception involves transport to odorant receptors (ORs) by soluble secretory proteins, odorant binding proteins (OBPs), which form the first stage in the process of olfactory recognition and are analogous to lipocalin family proteins in vertebrates. Although OBPs involved in the transport of pheromones to ORs have been functionally identified in insects, there is to date no report for Coleoptera. Furthermore, there is a lack of information on olfactory perception and the molecular mechanism by which OBPs participate in the transport of aggregation pheromones. We focus on the red palm weevil (RPW) Rhynchophorus ferrugineus, the most devastating quarantine pest of palm trees worldwide. In this work, we constructed libraries of all OBPs and selected antenna-specific and highly expressed OBPs for silencing through RNA interference. Aggregation pheromone compounds, 4-methyl-5-nonanol (ferrugineol) and 4-methyl-5-nonanone (ferruginone), and a kairomone, ethyl acetate, were then sequentially presented to individual RPWs. The results showed that antenna-specific RferOBP1768 aids in the capture and transport of ferrugineol to ORs. Silencing of RferOBP1768, which is responsible for pheromone binding, significantly disrupted pheromone communication. Study of odorant perception in palm weevil is important because the availability of literature regarding the nature and role of olfactory signaling in this insect may reveal likely candidates representative of animal olfaction and, more generally, of molecular recognition. Knowledge of OBPs recognizing the specific pheromone ferrugineol will allow for designing biosensors for the detection of this key compound in weevil monitoring in date palm fields. PMID:29618982

(Z)-9-Pentacosene - contact sex pheromone of the locust borer, Megacyllene robiniae

Treesearch

Matthew D. Ginzel; Jocelyn G. Miller; Lawrence M. Hanks

2003-01-01

Male locust borers, Megacyllene robiniae (Forster), responded to females only after contacting them with their antennae, indicating that mate recognition was mediated by a contact sex pheromone. GC-MS analyses of whole-body extracts of males and females determined that the profiles of compounds in the extracts were qualitatively similar, but differed...

How flies respond to honey bee pheromone: the role of the foraging gene on reproductive response to queen mandibular pheromone

NASA Astrophysics Data System (ADS)

Camiletti, Alison L.; Awde, David N.; Thompson, Graham J.

2014-01-01

In this study we test one central prediction from sociogenomic theory—that social and non-social taxa share common genetic toolkits that regulate reproduction in response to environmental cues. We exposed Drosophila females of rover ( for R) and sitter ( for s) genotypes to an ovary-suppressing pheromone derived from the honeybee Apis mellifera. Surprisingly, queen mandibular pheromone (QMP) affected several measures of fitness in flies, and in a manner comparable to the pheromone's normal effect on bee workers. QMP-treated sitter flies had smaller ovaries that contained fewer eggs than did untreated controls. QMP-treated rover flies, by contrast, showed a more variable pattern that only sometimes resulted in ovary inhibition, while a third strain of fly that contains a sitter mutant allele in a rover background ( for s2) showed no ovarian response to QMP. Taken together, our results suggest that distinctly non-social insects have some capacity to respond to social cues, but that this response varies with fly genotype. In general, the interspecific response is consistent with a conserved gene set affecting reproductive physiology. The differential response among strains in particular suggests that for is itself important for modulating the fly's pheromonal response.

A New Generation of Atmospheric Tracers - The Biological Connection

DTIC Science & Technology

1989-08-07

Butenandt, A., R. Beckmann, D. Stamai and E. Hiecker, 1959: Uber dea sexuallockstoff des seidenspinners Bombyx mori , reindarstellung und konstitution...9-16. Kaissling, K.E., 1979: Recognition of pheromones by moths especially in Saturniids and Bombyx mori , In "Chemical Ecology: Odour Communication...Special I-I---- LIST OF FIGURES Figure 1 Pheromone communication in Bombyz mori .................................. 9 Figure 2 EAG laboratory test

Isolation of pheromone precursor genes of Magnaporthe grisea.

PubMed

Shen, W C; Bobrowicz, P; Ebbole, D J

1999-01-01

In heterothallic ascomycetes one mating partner serves as the source of female tissue and is fertilized with spermatia from a partner of the opposite mating type. The role of pheromone signaling in mating is thought to involve recognition of cells of the opposite mating type. We have isolated two putative pheromone precursor genes of Magnaporthe grisea. The genes are present in both mating types of the fungus but they are expressed in a mating type-specific manner. The MF1-1 gene, expressed in Mat1-1 strains, is predicted to encode a 26-amino-acid polypeptide that is processed to produce a lipopeptide pheromone. The MF2-1 gene, expressed in Mat1-2 strains, is predicted to encode a precursor polypeptide that is processed by a Kex2-like protease to yield a pheromone with striking similarity to the predicted pheromone sequence of a close relative, Cryphonectria parasitica. Expression of the M. grisea putative pheromone precursor genes was observed under defined nutritional conditions and in field isolates. This suggests that the requirement for complex media for mating and the poor fertility of field isolates may not be due to limitation of pheromone precursor gene expression. Detection of putative pheromone precursor gene mRNA in conidia suggests that pheromones may be important for the fertility of conidia acting as spermatia. Copyright 1999 Academic Press.

Queen pheromones

PubMed Central

2010-01-01

Group-living species produce signals that alter the behavior and even the physiology of their social partners. Social insects possess especially sophisticated chemical communication systems that govern every aspect of colony life, including the defining feature of eusociality: reproductive division of labor. Current evidence hints at the central importance of queen pheromones, but progress has been hindered by the fact that such pheromones have only been isolated in honeybees. In a pair of papers on the ant Lasius niger, we identified and investigated a queen pheromone regulating worker sterility. The cuticular hydrocarbon 3-methylhentriacontane (3-MeC31) is correlated with queen maturity and fecundity and workers are also more likely to execute surplus queens that have low amounts of this chemical. Experiments with synthetic 3-MeC31 found that it inhibits ovarian development in queenless workers and lowers worker aggression towards objects coated with it. Production of 3-MeC31 by queens was depressed by an experimental immune challenge, and the same chemical was abundant on queenlaid eggs, suggesting that the workers' responses to the queen are conditional on her health and fecundity. Together with other studies, these results indicate that queen pheromones are honest signals of quality that simultaneously regulate multiple social behaviors. PMID:21331238

Monitoring and Detecting the Cigarette Beetle (Coleoptera: Anobiidae) Using Ultraviolet (LED) Direct and Reflected Lights and/or Pheromone Traps in a Laboratory and a Storehouse.

PubMed

Miyatake, Takahisa; Yokoi, Tomoyuki; Fuchikawa, Taro; Korehisa, Nobuyoshi; Kamura, Toru; Nanba, Kana; Ryouji, Shinsuke; Kamioka, Nagisa; Hironaka, Mantaro; Osada, Midori; Hariyama, Takahiko; Sasaki, Rikiya; Shinoda, Kazutaka

2016-12-01

The cigarette beetle, Lasioderma serricorne (F.), is an important stored-product pest worldwide because it damages dry foods. Detection and removal of the female L. serricorne will help to facilitate the control of the insect by removal of the egg-laying populations. In this manuscript, we examined the responses by L. serricorne to direct and reflected light in transparent cube (50 m3) set in a chamber (200 m3) and a stored facility with both direct and reflected UV-LED lights. The study also examined the responses by the beetles to light in the presence or absence of pheromone in traps that are placed at different heights. Reflected light attracted more beetles than the direct light in the experimental chamber, but the direct light traps attracted more beetles than the reflected light traps in the storehouse. Pheromone traps attracted only males; UV-LED traps attracted both sexes. The UV-LED traps with a pheromone, i.e., combined trap, attracted more males than UV-LED light traps without a pheromone, whereas the attraction of UV-LED traps with and without the pheromone was similar in females. The results suggest that UV-LED light trap combined with a sex pheromone is the best solution for monitoring and controlling L. serricorne. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Old maids have more appeal: effects of age and pheromone source on mate attraction in an orb-web spider.

PubMed

Cory, Anna-Lena; Schneider, Jutta M

2016-01-01

Background. In many insects and spider species, females attract males with volatile sex pheromones, but we know surprisingly little about the costs and benefits of female pheromone emission. Here, we test the hypothesis that mate attraction by females is dynamic and strategic in the sense that investment in mate attraction is matched to the needs of the female. We use the orb-web spider Argiope bruennichi in which females risk the production of unfertilised egg clutches if they do not receive a copulation within a certain time-frame. Methods. We designed field experiments to compare mate attraction by recently matured (young) females with females close to oviposition (old). In addition, we experimentally separated the potential sources of pheromone transmission, namely the female body and the web silk. Results. In accordance with the hypothesis of strategic pheromone production, the probability of mate attraction and the number of males attracted differed between age classes. While the bodies and webs of young females were hardly found by males, the majority of old females attracted up to two males within two hours. Old females not only increased pheromone emission from their bodies but also from their webs. Capture webs alone spun by old females were significantly more efficient in attracting males than webs of younger females. Discussion. Our results suggest that females modulate their investment in signalling according to the risk of remaining unmated and that they thereby economize on the costs associated with pheromone production and emission.

The role of multimodal signals in species recognition between tree-killing bark beetles in a narrow sympatric zone.

Treesearch

Deepa S. Pureswaran; Richard W. Hofstetter; Brian Sullivan; Kristen A. Potter

2016-01-01

When related species coexist, selection pressure should favor evolution of species recognition mechanisms to prevent interspecific pairing and wasteful reproductive encounters. We investigated the potential role of pheromone and acoustic signals in species recognition between two species of tree-killing bark beetles, the southern pine beetle, Dendroctonus frontalis...

Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA

NASA Astrophysics Data System (ADS)

Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie

2008-04-01

The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.

Contact Pheromones as Mate Recognition Cues of Four Species of Longhorned Beetles (Coleoptera: Cerambycidae)

Treesearch

Matthew D. Ginzel; Lawrence M. Hanks

2003-01-01

We tested the hypothesis that contact phermones mediate mate recognition for four species of longhorned beetles, Neoclytus mucronatus mucronatus (F.), Megacyllene caryae (Gahan), Megacyllene robiniae (Forster), and Plectrodera scalator (F.). All tested males of all four species attempted to...

Sex pheromone recognition and characterization of three pheromone-binding proteins in the legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae)

PubMed Central

Mao, Aping; Zhou, Jing; Bin Mao; Zheng, Ya; Wang, Yufeng; Li, Daiqin; Wang, Pan; Liu, Kaiyu; Wang, Xiaoping; Ai, Hui

2016-01-01

Pheromone-binding proteins (PBPs) are essential for the filtering, binding and transporting of sex pheromones across sensillum lymph to membrane-associated pheromone receptors of moths. In this study, three novel PBP genes were expressed in Escherichia coli to examine their involvement in the sex pheromone perception of Maruca vitrata. Fluorescence binding experiments indicated that MvitPBP1-3 had strong binding affinities with four sex pheromones. Moreover, molecular docking results demonstrated that six amino acid residues of three MvitPBPs were involved in the binding of the sex pheromones. These results suggested that MvitPBP1-3 might play critical roles in the perception of female sex pheromones. Additionally, the binding capacity of MvitPBP3 with the host-plant floral volatiles was high and was similar to that of MvitGOBP2. Furthermore, sequence alignment and docking analysis showed that both MvitGOBP2 and MvitPBP3 possessed an identical key binding site (arginine, R130/R140) and a similar protein pocket structure around the binding cavity. Therefore, we hypothesized that MvitPBP3 and MvitGOBP2 might have synergistic roles in binding different volatile ligands. In combination, the use of synthetic sex pheromones and floral volatiles from host-plant may be used in the exploration for more efficient monitoring and integrated management strategies for the legume pod borer in the field. PMID:27698435

Stage-dependent and temperature-controlled expression of the gene encoding the precursor protein of diapause hormone and pheromone biosynthesis activating neuropeptide in the silkworm, Bombyx mori.

PubMed

Xu, W H; Sato, Y; Ikeda, M; Yamashita, O

1995-02-24

Embryonic diapause and sex pheromone biosynthesis in the silkworm, Bombyx mori, are, respectively, induced by diapause hormone (DH) and pheromone biosynthesis activating neuropeptide (PBAN), which are produced in the subesophageal ganglion from a common polyprotein precursor (DH-PBAN precursor) encoded by a single gene (DH-PBAN gene). Using DH-PBAN cDNA as a probe, we quantitatively measured DH-PBAN mRNA content throughout embryonic and postembryonic development and observed the effects of incubation temperature, which is a key factor for determination of diapause, on DH-PBAN gene expression. The silkworm, which is programmed to lay diapause eggs by being incubated at 25 degrees C, showed peaks of DH-PBAN mRNA content at five different stages throughout the life cycle: at the late embryonic stage, at the middle of the fourth and the fifth larval instars, and at early and late stages of pupal-adult development. In the non-diapause type silkworms programmed by a 15 degrees C incubation, only the last peak of DH-PBAN mRNA in pupal-adult development was found, and the other peaks were absent. Furthermore, interruption of the incubation period at 25 degrees C by incubation at 15 degrees C decreased both DH-PBAN mRNA content in mature embryos and in subesophageal ganglia of day 3 pupae and the incidence of diapause eggs. Thus, there were two types of regulatory mechanisms for DH-PBAN gene expression. One is a temperature-controlled expression that is responsible for diapause induction, and the other is a temperature-independent, stage-dependent expression related to pheromone production.

Food odors trigger Drosophila males to deposit a pheromone that guides aggregation and female oviposition decisions

PubMed Central

Lin, Chun-Chieh; Prokop-Prigge, Katharine A; Preti, George; Potter, Christopher J

2015-01-01

Animals use olfactory cues for navigating complex environments. Food odors in particular provide crucial information regarding potential foraging sites. Many behaviors occur at food sites, yet how food odors regulate such behaviors at these sites is unclear. Using Drosophila melanogaster as an animal model, we found that males deposit the pheromone 9-tricosene upon stimulation with the food-odor apple cider vinegar. This pheromone acts as a potent aggregation pheromone and as an oviposition guidance cue for females. We use genetic, molecular, electrophysiological, and behavioral approaches to show that 9-tricosene activates antennal basiconic Or7a receptors, a receptor activated by many alcohols and aldehydes such as the green leaf volatile E2-hexenal. We demonstrate that loss of Or7a positive neurons or the Or7a receptor abolishes aggregation behavior and oviposition site-selection towards 9-tricosene and E2-hexenal. 9-Tricosene thus functions via Or7a to link food-odor perception with aggregation and egg-laying decisions. DOI: http://dx.doi.org/10.7554/eLife.08688.001 PMID:26422512

Conserved queen pheromones in bumblebees: a reply to Amsalem et al.

PubMed

Holman, Luke; van Zweden, Jelle S; Oliveira, Ricardo C; van Oystaeyen, Annette; Wenseleers, Tom

2017-01-01

In a recent study, Amsalem, Orlova & Grozinger (2015) performed experiments with Bombus impatiens bumblebees to test the hypothesis that saturated cuticular hydrocarbons are evolutionarily conserved signals used to regulate reproductive division of labor in many Hymenopteran social insects. They concluded that the cuticular hydrocarbon pentacosane (C 25 ), previously identified as a queen pheromone in a congeneric bumblebee, does not affect worker reproduction in B. impatiens . Here we discuss some shortcomings of Amsalem et al.'s study that make its conclusions unreliable. In particular, several confounding effects may have affected the results of both experimental manipulations in the study. Additionally, the study's low sample sizes (mean n per treatment = 13.6, range: 4-23) give it low power, not 96-99% power as claimed, such that its conclusions may be false negatives. Inappropriate statistical tests were also used, and our reanalysis found that C 25 substantially reduced and delayed worker egg laying in B. impatiens . We review the evidence that cuticular hydrocarbons act as queen pheromones, and offer some recommendations for future queen pheromone experiments.

Hitch-hiking parasitic wasp learns to exploit butterfly antiaphrodisiac

PubMed Central

Huigens, Martinus E.; Pashalidou, Foteini G.; Qian, Ming-Hui; Bukovinszky, Tibor; Smid, Hans M.; van Loon, Joop J. A.; Dicke, Marcel; Fatouros, Nina E.

2009-01-01

Many insects possess a sexual communication system that is vulnerable to chemical espionage by parasitic wasps. We recently discovered that a hitch-hiking (H) egg parasitoid exploits the antiaphrodisiac pheromone benzyl cyanide (BC) of the Large Cabbage White butterfly Pieris brassicae. This pheromone is passed from male butterflies to females during mating to render them less attractive to conspecific males. When the tiny parasitic wasp Trichogramma brassicae detects the antiaphrodisiac, it rides on a mated female butterfly to a host plant and then parasitizes her freshly laid eggs. The present study demonstrates that a closely related generalist wasp, Trichogramma evanescens, exploits BC in a similar way, but only after learning. Interestingly, the wasp learns to associate an H response to the odors of a mated female P. brassicae butterfly with reinforcement by parasitizing freshly laid butterfly eggs. Behavioral assays, before which we specifically inhibited long-term memory (LTM) formation with a translation inhibitor, reveal that the wasp has formed protein synthesis-dependent LTM at 24 h after learning. To our knowledge, the combination of associatively learning to exploit the sexual communication system of a host and the formation of protein synthesis-dependent LTM after a single learning event has not been documented before. We expect it to be widespread in nature, because it is highly adaptive in many species of egg parasitoids. Our finding of the exploitation of an antiaphrodisiac by multiple species of parasitic wasps suggests its use by Pieris butterflies to be under strong selective pressure. PMID:19139416

Hitch-hiking parasitic wasp learns to exploit butterfly antiaphrodisiac.

PubMed

Huigens, Martinus E; Pashalidou, Foteini G; Qian, Ming-Hui; Bukovinszky, Tibor; Smid, Hans M; van Loon, Joop J A; Dicke, Marcel; Fatouros, Nina E

2009-01-20

Many insects possess a sexual communication system that is vulnerable to chemical espionage by parasitic wasps. We recently discovered that a hitch-hiking (H) egg parasitoid exploits the antiaphrodisiac pheromone benzyl cyanide (BC) of the Large Cabbage White butterfly Pieris brassicae. This pheromone is passed from male butterflies to females during mating to render them less attractive to conspecific males. When the tiny parasitic wasp Trichogramma brassicae detects the antiaphrodisiac, it rides on a mated female butterfly to a host plant and then parasitizes her freshly laid eggs. The present study demonstrates that a closely related generalist wasp, Trichogramma evanescens, exploits BC in a similar way, but only after learning. Interestingly, the wasp learns to associate an H response to the odors of a mated female P. brassicae butterfly with reinforcement by parasitizing freshly laid butterfly eggs. Behavioral assays, before which we specifically inhibited long-term memory (LTM) formation with a translation inhibitor, reveal that the wasp has formed protein synthesis-dependent LTM at 24 h after learning. To our knowledge, the combination of associatively learning to exploit the sexual communication system of a host and the formation of protein synthesis-dependent LTM after a single learning event has not been documented before. We expect it to be widespread in nature, because it is highly adaptive in many species of egg parasitoids. Our finding of the exploitation of an antiaphrodisiac by multiple species of parasitic wasps suggests its use by Pieris butterflies to be under strong selective pressure.

Queen pheromones: The chemical crown governing insect social life.

PubMed

Holman, Luke

2010-11-01

Group-living species produce signals that alter the behavior and even the physiology of their social partners. Social insects possess especially sophisticated chemical communication systems that govern every aspect of colony life, including the defining feature of eusociality: reproductive division of labor. Current evidence hints at the central importance of queen pheromones, but progress has been hindered by the fact that such pheromones have only been isolated in honeybees. In a pair of papers on the ant Lasius niger, we identified and investigated a queen pheromone regulating worker sterility. The cuticular hydrocarbon 3-methylhentriacontane (3-MeC(31)) is correlated with queen maturity and fecundity and workers are also more likely to execute surplus queens that have low amounts of this chemical. Experiments with synthetic 3-MeC(31) found that it inhibits ovarian development in queenless workers and lowers worker aggression towards objects coated with it. Production of 3-MeC(31) by queens was depressed by an experimental immune challenge, and the same chemical was abundant on queenlaid eggs, suggesting that the workers' responses to the queen are conditional on her health and fecundity. Together with other studies, these results indicate that queen pheromones are honest signals of quality that simultaneously regulate multiple social behaviors.

Fitness cost of pheromone production in signaling female moths.

PubMed

Harari, Ally R; Zahavi, Tirtza; Thiéry, Denis

2011-06-01

A secondary sexual character may act as an honest signal of the quality of the individual if the trait bears a cost and if its expression is phenotypically condition dependent. The cost of increasing the trait should be tolerable for individuals in good condition but not for those in a poor condition. The trait thus provides an honest signal of quality that enables the receiver to choose higher quality mates. Evidence for sex pheromones, which play a major role in shaping sexual evolution, inflicting a signaling cost is scarce. Here, we demonstrate that the amount of the major component of the pheromone in glands of Lobesia botrana (Lepidoptera) females at signaling time was significantly greater in large than in small females, that male moths preferred larger females as mates when responding to volatile signals, and small virgin females, but not large ones, exposed to conspecific pheromone, produced, when mated, significantly fewer eggs than nonexposed females. The latter indicates a condition-dependent cost of signaling. These results are in accordance with the predictions of condition-dependent honest signals. We therefore suggest that female signaling for males using sex pheromones bears a cost and thus calling may serve as honest advertisement for female quality. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Fertility signals in the bumblebee Bombus terrestris (Hymenoptera: Apidae)

NASA Astrophysics Data System (ADS)

Sramkova, A.; Schulz, C.; Twele, R.; Francke, W.; Ayasse, M.

2008-06-01

In eusocial Hymenoptera, queen control over workers is probably inseparable from the mechanism of queen recognition. In primitively eusocial bumblebees ( Bombus), worker reproduction is controlled not only by the presence or absence of a dominant queen but also by other dominant workers. Furthermore, it was shown that the queen dominance is maintained by pheromonal cues. We investigated whether there is a similar odor signal released by egg-laying queens and workers that may have a function as a fertility signal. We collected cuticular surface extracts from nest-searching and breeding Bombus terrestris queens and workers that were characterized by their ovarian stages. In chemical analyses, we identified 61 compounds consisting of aldehydes, alkanes, alkenes, and fatty acid esters. Nest-searching queens and all groups of breeding females differed significantly in their odor bouquets. Furthermore, workers before the competition point (time point of colony development where workers start to develop ovaries and lay eggs) differed largely from queens and all other groups of workers. Breeding queens showed a unique bouquet of chemical compounds and certain queen-specific compounds, and the differences toward workers decrease with an increasing development of the workers’ ovaries, hinting the presence of a reliable fertility signal. Among the worker groups, the smallest differences were found after the competition point. Egg-laying females contained higher total amounts of chemical compounds and of relative proportions of wax-type esters and aldehydes than nest-searching queens and workers before the competition point. Therefore, these compounds may have a function as a fertility signal present in queens and workers.

Genetic dissection of pheromone processing reveals main olfactory system-mediated social behaviors in mice.

PubMed

Matsuo, Tomohiko; Hattori, Tatsuya; Asaba, Akari; Inoue, Naokazu; Kanomata, Nobuhiro; Kikusui, Takefumi; Kobayakawa, Reiko; Kobayakawa, Ko

2015-01-20

Most mammals have two major olfactory subsystems: the main olfactory system (MOS) and vomeronasal system (VNS). It is now widely accepted that the range of pheromones that control social behaviors are processed by both the VNS and the MOS. However, the functional contributions of each subsystem in social behavior remain unclear. To genetically dissociate the MOS and VNS functions, we established two conditional knockout mouse lines that led to either loss-of-function in the entire MOS or in the dorsal MOS. Mice with whole-MOS loss-of-function displayed severe defects in active sniffing and poor survival through the neonatal period. In contrast, when loss-of-function was confined to the dorsal MOB, sniffing behavior, pheromone recognition, and VNS activity were maintained. However, defects in a wide spectrum of social behaviors were observed: attraction to female urine and the accompanying ultrasonic vocalizations, chemoinvestigatory preference, aggression, maternal behaviors, and risk-assessment behaviors in response to an alarm pheromone. Functional dissociation of pheromone detection and pheromonal induction of behaviors showed the anterior olfactory nucleus (AON)-regulated social behaviors downstream from the MOS. Lesion analysis and neural activation mapping showed pheromonal activation in multiple amygdaloid and hypothalamic nuclei, important regions for the expression of social behavior, was dependent on MOS and AON functions. Identification of the MOS-AON-mediated pheromone pathway may provide insights into pheromone signaling in animals that do not possess a functional VNS, including humans.

Effects of flour conditioning on cannibalism of T. castaneum eggs and pupae

USDA-ARS?s Scientific Manuscript database

Cannibalism is a very important factor regulating population dynamics of the red flour beetle. After several days of feeding, the flour becomes conditioned by the beetles, which can affect rates of cannibalism. Flour conditioning is caused by an accumulation of feces, pheromones, and ethylquinone, w...

Identification of the ubiquitous antioxidant tripeptide glutathione as a fruit fly semiochemical

USDA-ARS?s Scientific Manuscript database

Many insects mark their oviposition sites with a host marking pheromone (HMP) to deter other females from over-exploiting these sites for egg-laying. Previous studies have identified and used HMPs to manage certain fruit fly species. However, few examples are known for African indigenous fruit flie...

Single mutation to a sex pheromone receptor provides adaptive specificity between closely related moth species

PubMed Central

Leary, Greg P.; Allen, Jean E.; Bunger, Peggy L.; Luginbill, Jena B.; Linn, Charles E.; Macallister, Irene E.; Kavanaugh, Michael P.; Wanner, Kevin W.

2012-01-01

Sex pheromone communication, acting as a prezygotic barrier to mating, is believed to have contributed to the speciation of moths and butterflies in the order Lepidoptera. Five decades after the discovery of the first moth sex pheromone, little is known about the molecular mechanisms that underlie the evolution of pheromone communication between closely related species. Although Asian and European corn borers (ACB and ECB) can be interbred in the laboratory, they are behaviorally isolated from mating naturally by their responses to subtly different sex pheromone isomers, (E)-12- and (Z)-12-tetradecenyl acetate and (E)-11- and (Z)-11-tetradecenyl acetate (ACB: E12, Z12; ECB; E11, Z11). Male moth olfactory systems respond specifically to the pheromone blend produced by their conspecific females. In vitro, ECB(Z) odorant receptor 3 (OR3), a sex pheromone receptor expressed in male antennae, responds strongly to E11 but also generally to the Z11, E12, and Z12 pheromones. In contrast, we show that ACB OR3, a gene that has been subjected to positive selection (ω = 2.9), responds preferentially to the ACB E12 and Z12 pheromones. In Ostrinia species the amino acid residue corresponding to position 148 in transmembrane domain 3 of OR3 is alanine (A), except for ACB OR3 that has a threonine (T) in this position. Mutation of this residue from A to T alters the pheromone recognition pattern by selectively reducing the E11 response ∼14-fold. These results suggest that discrete mutations that narrow the specificity of more broadly responsive sex pheromone receptors may provide a mechanism that contributes to speciation. PMID:22891317

Effects of flour conditioning on cannibalism of T. castaneum eggs and pupae.

PubMed

Flinn, Paul W; Campbell, James F

2012-12-01

Cannibalism is a very important factor regulating population dynamics of the red flour beetle. After several days of feeding, the flour becomes conditioned by the beetles, which can affect rates of cannibalism. Flour conditioning is caused by an accumulation of feces, pheromones, and ethylquinone, which is a repellent produced by the beetles. We determined the effect of five different levels of flour conditioning on cannibalism of red flour beetle eggs and pupae by adult and larval stages. Larvae had the highest rates of egg cannibalism (12 eggs eaten over the 4-d period) followed by female adults (seven eggs consumed). Adult males had the lowest rates of cannibalism with only two eggs consumed. Cannibalism of eggs by females was correlated negatively with the level of flour conditioning. There was no effect of flour conditioning on egg or pupal cannibalism by larvae or adult males. Cannibalism by adult females may decrease as the level of flour conditioning increases because females may spend less time tunneling in highly conditioned flour and more time trying to disperse to other areas that are better for oviposition.

A male-specific odorant receptor conserved through the evolution of sex pheromones in Ostrinia moth species

PubMed Central

Miura, Nami; Nakagawa, Tatsuro; Tatsuki, Sadahiro; Touhara, Kazushige; Ishikawa, Yukio

2009-01-01

In many moths, mate-finding communication is mediated by the female sex pheromones. Since differentiation of sex pheromones is often associated with speciation, it is intriguing to know how the changes in female sex pheromone have been tracked by the pheromone recognition system of the males. A male-specific odorant receptor was found to have been conserved through the evolution of sex pheromone communication systems in the genus Ostrinia (Lepidoptera: Crambidae). In an effort to characterize pheromone receptors of O. scapulalis, which uses a mixture of (E)-11- and (Z)-11-tetradecenyl acetates as a sex pheromone, we cloned a gene (OscaOR1) encoding a male-specific odorant receptor. In addition, we cloned a gene of the Or83b family (OscaOR2). Functional assays using Xenopus oocytes co-expressing OscaOR1 and OscaOR2 have shown that OscaOR1 is, unexpectedly, a receptor of (E)-11-tetradecenol (E11-14:OH), a single pheromone component of a congener O. latipennis. Subsequent studies on O. latipennis showed that this species indeed has a gene orthologous to OscaOR1 (OlatOR1), a functional assay of which confirmed it to be a gene encoding the receptor of E11-14:OH. Furthermore, investigations of six other Ostrinia species have revealed that all of them have a gene orthologous to OscaOR1, although none of these species, except O. ovalipennis, a species most closely related to O. latipennis, uses E11-14:OH as the pheromone component. The present findings suggest that the male-specific receptor of E11-14:OH was acquired before the divergence of the genus Ostrinia, and functionally retained through the evolution of this genus. PMID:19421342

A cuckoo-like parasitic moth leads African weaver ant colonies to their ruin

PubMed Central

Dejean, Alain; Orivel, Jérôme; Azémar, Frédéric; Hérault, Bruno; Corbara, Bruno

2016-01-01

In myrmecophilous Lepidoptera, mostly lycaenids and riodinids, caterpillars trick ants into transporting them to the ant nest where they feed on the brood or, in the more derived “cuckoo strategy”, trigger regurgitations (trophallaxis) from the ants and obtain trophic eggs. We show for the first time that the caterpillars of a moth (Eublemma albifascia; Noctuidae; Acontiinae) also use this strategy to obtain regurgitations and trophic eggs from ants (Oecophylla longinoda). Females short-circuit the adoption process by laying eggs directly on the ant nests, and workers carry just-hatched caterpillars inside. Parasitized colonies sheltered 44 to 359 caterpillars, each receiving more trophallaxis and trophic eggs than control queens. The thus-starved queens lose weight, stop laying eggs (which transport the pheromones that induce infertility in the workers) and die. Consequently, the workers lay male-destined eggs before and after the queen’s death, allowing the colony to invest its remaining resources in male production before it vanishes. PMID:27021621

Use of a pheromone to cause copulation between two species of cerambycids

Treesearch

Jimmy R. Galford

1980-01-01

The painted hickory borer, Megacyllene caryae (Gahan) and the locust borer Megacyllene robiniae (Forster) will not attempt to interbreed in the laboratory. However, male locust borers copulated with painted hickory borer females painted with an alcohol extract of female locust borers. No eggs were laid by treated or untreated...

CRISPR/Cas9 editing of the codling moth (Lepidoptera: Tortricidae) CpomOR1 gene affects egg production and viability

USDA-ARS?s Scientific Manuscript database

The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is a major pest of pome fruit worldwide. The inclusion of semiochemicals, including the main sex pheromone (codlemone), in codling moth IPM programs has drastically reduced the amount of chemical insecticides needed to control this ...

Leading edge gypsy moth population dynamics

Treesearch

M. R. Carter; F. W. Ravlin; M. L. McManus

1991-01-01

Leading edge gypsy moth populations have been the focus of several intervention programs (MDIPM, AIPM). Knowledge of gypsy moth population dynamics in leading edge area is crucial for effective management. Populations in these areas tend to reach outbreak levels (noticeable defoliation) within three to four years after egg masses are first detected. Pheromone traps...

Molecular identification of a pancreatic lipase-like gene involved in sex pheromone biosynthesis of Bombyx mori.

PubMed

Zhang, Song-Dou; Li, Xun; Bin, Zhu; Du, Meng-Fang; Yin, Xin-Ming; An, Shi-Heng

2014-08-01

Cytoplasmic lipid droplet (LD) lipolysis is regulated by pheromone biosynthesis activating neuropeptide (PBAN) in Bombyx mori. To elucidate the molecular mechanism of cytoplasm LD lipolysis, the pancreatic lipase-like gene in B. mori pheromone glands (PGs), designated as B. mori pancreatic lipase-like gene (BmPLLG), was identified in this study. Spatial expression analysis revealed that BmPLLG is a ubiquitous gene present in all studied tissues, such as PGs, brain, epidermis, egg, midgut, flight muscle and fat body. Temporal expression analysis showed that the BmPLLG transcript begins to express 96 h before eclosion (-96 h), continues to increase, peaks in newly emerged females and steadily decreases after eclosion. Translational expression analysis of BmPLLG using a prepared antiserum demonstrated that BmPLLG was expressed in an age-dependent pattern at different development stages in B. mori. This finding was similar to the transcript expression pattern. Further RNA interference-mediated knockdown of BmPLLG significantly inhibited bombykol production. Overall, these results demonstrated that BmPLLG is involved in PBAN-induced sex pheromone biosynthesis and release. © 2013 Institute of Zoology, Chinese Academy of Sciences.

General odorant-binding proteins and sex pheromone guide larvae of Plutella xylostella to better food.

PubMed

Zhu, Jiao; Ban, Liping; Song, Li-Mei; Liu, Yang; Pelosi, Paolo; Wang, Guirong

2016-05-01

Olfaction of Lepidopteran larvae has received little attention, compared to the damage to crops done by insects at this stage. We report that larvae of the diamondback moth Plutella xylostella are attracted to their natural sex pheromone and to their major component (Z)-11-hexadecenal, but only in a food context. For such task they use two general odorant-binding proteins (GOBPs), abundantly expressed in the three major sensilla basiconica of the larval antenna, as shown by whole-mount immunostaining and immunocytochemistry experiments. None of the three genes encoding pheromone-binding proteins (PBPs) are expressed at this stage. Both recombinant GOBPs bind (Z)-11-hexadecenal and the corresponding alcohol, but not the acetate. Binding experiments performed with five mutants of GOBP2, where aromatic residues in the binding pocket were replaced with leucine showed that only one or two amino acid substitutions can completely abolish binding to the pheromone shifting the affinity to plant-derived compounds. We hypothesise that detection of their species-specific pheromone may direct larvae to the sites of foraging chosen by their mother when laying eggs, to find better food, as well as to reduce competition with individuals of the same or other species sharing the same host plant. We also provide evidence that GOBP2 is a narrowly tuned binding protein, whose affinity can be easily switched from linear pheromones to branched plants terpenoids, representing a tool better suited for the simple olfactory system of larvae, as compared to the more sophisticated organ of adults. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Roles of sialic acids in sperm maturation and capacitation and sperm-egg recognition].

PubMed

Feng, Ying; Wang, Lin; Wu, Yi-Lun; Liu, Hong-Hua; Ma, Fang

2016-10-01

Sialic acids are a subset of nine-carbon alpha-keto aldonic acids involved in various biological functions. Sialic acid on the sperm surface is closely related to sperm maturation and capacitation and sperm-egg recognition, which makes sperm negatively charged to avoid accumulation and covers some antigenic determinants there to increase the survival rate of sperm in the female reproductive tract. The loss of sialic acids is an important factor mediating sperm capacitation. Moreover, the sialic acid at the extremity of the protein polymer is involved in signal identification in sperm-egg recognition. Here, we review the current understanding of sialic acids in sperm maturation and capacitation and sperm-egg recognition.

Various Bee Pheromones Binding Affinity, Exclusive Chemosensillar Localization, and Key Amino Acid Sites Reveal the Distinctive Characteristics of Odorant-Binding Protein 11 in the Eastern Honey Bee, Apis cerana.

PubMed

Song, Xin-Mi; Zhang, Lin-Ya; Fu, Xiao-Bin; Wu, Fan; Tan, Jing; Li, Hong-Liang

2018-01-01

Odorant-binding proteins (OBPs) are the critical elements responsible for binding and transporting odors and pheromones in the sensitive olfactory system in insects. Honey bees are representative social insects that have complex odorants and pheromone communication systems relative to solitary insects. Here, we first cloned and characterized OBP11 ( AcerOBP11 ), from the worker bees antennae of Eastern honey bee, Apis cerana . Based on sequence and phylogenetic analysis, most sequences homologous to AcerOBP11 belong to the typical OBPs family. The transcriptional expression profiles showed that AcerOBP11 was expressed throughout the developmental stages and highly specifically expressed in adult antennae. Using immunofluorescence localization, AcerOBP11 in worker bee's antennae was only localized in the sensilla basiconica (SB) near the fringe of each segment. Fluorescence ligand-binding assay showed that AcerOBP11 protein had strong binding affinity with the tested various bee pheromones components, including the main queen mandibular pheromones (QMPs), methyl p-hydroxybenzoate (HOB), and ( E )-9-oxo-2-decanoic acid (9-ODA), alarm pheromone (n-hexanol), and worker pheromone components. AcerOBP11 also had strong binding affinity to plant volatiles, such as 4-Allylveratrole. Based on the docking and site-directed mutagenesis, two key amino acid residues (Ile97 and Ile140) were involved in the binding of AcerOBP11 to various bee pheromones. Taken together, we identified that AcerOBP11 was localized in a single type of antennal chemosensilla and had complex ligand-binding properties, which confer the dual-role with the primary characteristics of sensing various bee pheromones and secondary characteristics of sensing general odorants. This study not only prompts the theoretical basis of OBPs-mediated bee pheromones recognition of honey bee, but also extends the understanding of differences in pheromone communication between social and solitary insects.

Gene expression and molecular phylogenetic analyses of beta-glucosidase in the termite Reticulitermes speratus (Isoptera: Rhinotermitidae).

PubMed

Shimada, Keisuke; Maekawa, Kiyoto

2014-06-01

Beta-glucosidase (BG) is known as a multifunctional enzyme for social maintenance in terms of both cellulose digestion and social communication in termites. However, the expression profiles of each BG gene and their evolutionary history are not well understood. First, we cloned two types of BG homologs (RsBGI and RsBGII) from the termite Reticulitermes speratus (Kolbe). Gene expression analyses showed that RsBGI expression levels of primary queens and kings from 30 to 100 days after colony foundation were high, but those of reproductives dropped after day 400. Extremely low gene expression levels of RsBGI were observed in eggs, whereas workers had significantly higher expression levels than those of soldiers and other colony members. Consequently, RsBGI gene expression levels changed among each developmental stage, and RsBGI was shown to be involved in cellulose digestion. On the other hand, the RsBGII gene was consistently expressed in all castes and developmental stages examined, and notable expression changes were not observed among them, including in eggs. It was indicated that RsBGII is a main component involved in social communication, for example, the egg-recognition pheromone shown in this species previously. Finally, we obtained partial gene homologs from other termite and cockroach species, including the woodroach (genus Cryptocercus), which is the sister group to termites, and performed molecular phylogenetic analyses. The results showed that the origin of the BG gene homologs preceded the divergence of termites and cockroaches, suggesting that the acquisition of multifunctionality of the BG gene also occurred in cockroach lineages. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Background of a Volatile Plant Compound Alters Neural and Behavioral Responses to the Sex Pheromone Blend in a Moth.

PubMed

Dupuy, Fabienne; Rouyar, Angéla; Deisig, Nina; Bourgeois, Thomas; Limousin, Denis; Wycke, Marie-Anne; Anton, Sylvia; Renou, Michel

2017-01-01

Recognition of intra-specific olfactory signals within a complex environment of plant-related volatiles is crucial for reproduction in male moths. Sex pheromone information is detected by specific olfactory receptor neurons (Phe-ORNs), highly abundant on the male antenna. The information is then transmitted to the pheromone processing macroglomerular complex (MGC) within the primary olfactory center, the antennal lobe, where it is processed by local interneurons and projection neurons. Ultimately a behavioral response, orientation toward the pheromone source, is elicited. Volatile plant compounds (VPCs) are detected by other functional types of olfactory receptor neurons (ORNs) projecting in another area of the antennal lobe. However, Phe-ORNs also respond to some VPCs. Female-produced sex pheromones are emitted within a rich environment of VPCs, some of which have been shown to interfere with the detection and processing of sex pheromone information. As interference between the different odor sources might depend on the spatial and temporal features of the two types of stimuli, we investigated here behavioral and neuronal responses to a brief sex pheromone blend pulse in a VPC background as compared to a control background in the male noctuid moth Agrotis ipsilon . We observed male orientation behavior in a wind tunnel and recorded responses of Phe-ORNs and MGC neurons to a brief sex pheromone pulse within a background of individual VPCs. We also recorded the global input signal to the MGC using in vivo calcium imaging with the same stimulation protocol. We found that VPCs eliciting a response in Phe-ORNs and MGC neurons masked responses to the pheromone and decreased the contrast between background odor and the sex pheromone at both levels, whereas α-pinene did not interfere with first order processing. The calcium signal produced in response to a VPC background was tonic, lasting longer than the VPC stimulus duration, and masked entirely the pheromone response. One percent heptanal and linalool, in addition to the masking effect, caused a clear delay in responses of MGC neurons to the sex pheromone. Upwind flight toward the pheromone in a wind tunnel was also delayed but otherwise not altered by different doses of heptanal.

Contribution of pheromones processed by the main olfactory system to mate recognition in female mammals

PubMed Central

Baum, Michael J.

2012-01-01

Until recently it was widely believed that the ability of female mammals (with the likely exception of women) to identify and seek out a male breeding partner relied on the detection of non-volatile male pheromones by the female's vomeronasal organ (VNO) and their subsequent processing by a neural circuit that includes the accessory olfactory bulb (AOB), vomeronasal amygdala, and hypothalamus. Emperical data are reviewed in this paper that demonstrate the detection of volatile pheromones by the main olfactory epithelium (MOE) of female mice which, in turn, leads to the activation of a population of glomeruli and abutting mitral cells in the main olfactory bulb (MOB). Anatomical results along with functional neuroanatomical data demonstrate that some of these MOB mitral cells project to the vomeronasal amygdala. These particular MOB mitral cells were selectively activated (i.e., expressed Fos protein) by exposure to male as opposed to female urinary volatiles. A similar selectivity to opposite sex urinary volatiles was also seen in mitral cells of the AOB of female mice. Behavioral data from female mouse, ferret, and human are reviewed that implicate the main olfactory system, in some cases interacting with the accessory olfactory system, in mate recognition. PMID:22679420

Egg discrimination along a gradient of natural variation in eggshell coloration.

PubMed

Hanley, Daniel; Grim, Tomáš; Igic, Branislav; Samaš, Peter; López, Analía V; Shawkey, Matthew D; Hauber, Mark E

2017-02-08

Accurate recognition of salient cues is critical for adaptive responses, but the underlying sensory and cognitive processes are often poorly understood. For example, hosts of avian brood parasites have long been assumed to reject foreign eggs from their nests based on the total degree of dissimilarity in colour to their own eggs, regardless of the foreign eggs' colours. We tested hosts' responses to gradients of natural (blue-green to brown) and artificial (green to purple) egg colours, and demonstrate that hosts base rejection decisions on both the direction and degree of colour dissimilarity along the natural, but not artificial, gradient of egg colours. Hosts rejected brown eggs and accepted blue-green eggs along the natural egg colour gradient, irrespective of the total perceived dissimilarity from their own egg's colour. By contrast, their responses did not vary along the artificial colour gradient. Our results demonstrate that egg recognition is specifically tuned to the natural gradient of avian eggshell colour and suggest a novel decision rule. These results highlight the importance of considering sensory reception and decision rules when studying perception, and illustrate that our understanding of recognition processes benefits from examining natural variation in phenotypes. © 2017 The Authors.

Egg discrimination along a gradient of natural variation in eggshell coloration

PubMed Central

Grim, Tomáš; Igic, Branislav; Samaš, Peter; López, Analía V.; Shawkey, Matthew D.; Hauber, Mark E.

2017-01-01

Accurate recognition of salient cues is critical for adaptive responses, but the underlying sensory and cognitive processes are often poorly understood. For example, hosts of avian brood parasites have long been assumed to reject foreign eggs from their nests based on the total degree of dissimilarity in colour to their own eggs, regardless of the foreign eggs' colours. We tested hosts' responses to gradients of natural (blue-green to brown) and artificial (green to purple) egg colours, and demonstrate that hosts base rejection decisions on both the direction and degree of colour dissimilarity along the natural, but not artificial, gradient of egg colours. Hosts rejected brown eggs and accepted blue-green eggs along the natural egg colour gradient, irrespective of the total perceived dissimilarity from their own egg's colour. By contrast, their responses did not vary along the artificial colour gradient. Our results demonstrate that egg recognition is specifically tuned to the natural gradient of avian eggshell colour and suggest a novel decision rule. These results highlight the importance of considering sensory reception and decision rules when studying perception, and illustrate that our understanding of recognition processes benefits from examining natural variation in phenotypes. PMID:28179521

Predation and parasitism by native and exotic natural enemies of Halyomorpha halys (Hemiptera: Pentatomidae) eggs augmented with semiochemicals and differing host stimuli

USDA-ARS?s Scientific Manuscript database

The brown marmorated stink bug, or Halyomorpha halys, is an invasive species in the United States, and causes severe agricultural damage to a variety of crops. Prior research with other stink bugs has shown that various stimuli, including the aggregation pheromone of a pest can be an important kairo...

Queen-specific volatile in a higher termite Nasutitermes takasagoensis (Isoptera: Termitidae).

PubMed

Himuro, Chihiro; Yokoi, Tomoyuki; Matsuura, Kenji

2011-07-01

In social insect colonies, queen-produced pheromones have important functions in social regulation. These substances influence the behavior and physiology of colony members. A queen-produced volatile that inhibits differentiation of new neotenic reproductives was recently identified in the lower termite Reticulitermes speratus. However, there are no known queen-specific volatiles of this type in any other termite species. Here, we report volatile compounds emitted by live queens of the higher termite Nasutitermes takasagoensis. We used headspace gas chromatography mass spectroscopy (HS GC-MS) to analyze volatiles emitted by live primary queens, workers, soldiers, alates, and eggs collected in a Japanese subtropical forest. Among 14 detected compounds, 7 were soldier-specific, 1 was alate-specific, 1 was egg-specific, and 1 was queen-specific. The queen-specific volatile was phenylethanol, which is different than the compound identified in R. speratus. The identification of this queen-specific volatile is the first step in determining its functions in higher termite social regulation. Comparisons of queen pheromone substances regulating caste differentiation among various termite taxa will contribute to a better understanding of the evolution of social systems in termites. Copyright © 2011 Elsevier Ltd. All rights reserved.

Refining the dual olfactory hypothesis: pheromone reward and odour experience.

PubMed

Martínez-García, Fernando; Martínez-Ricós, Joana; Agustín-Pavón, Carmen; Martínez-Hernández, Jose; Novejarque, Amparo; Lanuza, Enrique

2009-06-25

In rodents, sexual advertisement and gender recognition are mostly (if not exclusively) mediated by chemosignals. Specifically, there is ample evidence indicating that female mice are 'innately' attracted by male sexual pheromones that have critical non-volatile components and are detected by the vomeronasal organ. These pheromones can only get access to the vomeronasal organ by active pumping mechanisms that require close contact with the source of the stimulus (e.g. urine marks) during chemoinvestigation. We have hypothesised that male sexual pheromones are rewarding to female mice. Indeed, male-soiled bedding can be used as a reinforcer to induce conditioned place preference, provided contact with the bedding is allowed. The neural mechanisms of pheromone reward seem, however, different from those employed by other natural reinforcers, such as the sweetness or postingestive effects of sucrose. In contrast to vomeronasal-detected male sexual pheromones, male-derived olfactory stimuli (volatiles) are not intrinsically attractive to female mice. However, after repeated exposure to male-soiled bedding, intact female mice develop an acquired preference for male odours. On the contrary, in females whose accessory olfactory bulbs have been lesioned, exposure to male-soiled bedding induces aversion to male odorants. These considerations, together with data on the different properties of olfactory and vomeronasal receptors, lead us to make a proposal for the complementary roles that the olfactory and vomeronasal systems play in intersexual attraction and in other forms of intra- or inter-species communication.

Plants and insect eggs: how do they affect each other?

PubMed

Hilker, Monika; Meiners, Torsten

2011-09-01

Plant-insect interactions are not just influenced by interactions between plants and the actively feeding stages, but also by the close relationships between plants and insect eggs. Here, we review both effects of plants on insect eggs and, vice versa, effects of eggs on plants. We consider the influence of plants on the production of insect eggs and address the role of phytochemicals for the biosynthesis and release of insect sex pheromones, as well as for insect fecundity. Effects of plants on insect oviposition by contact and olfactory plant cues are summarised. In addition, we consider how the leaf boundary layer influences both insect egg deposition behaviour and development of the embryo inside the egg. The effects of eggs on plants involve egg-induced changes of photosynthetic activity and of the plant's secondary metabolism. Except for gall-inducing insects, egg-induced changes of phytochemistry were so far found to be detrimental to the eggs. Egg deposition can induce hypersensitive-like plant response, formation of neoplasms or production of ovicidal plant substances; these plant responses directly harm the eggs. In addition, egg deposition can induce a change of the plant's odour and leaf surface chemistry which serve indirect plant defence with the help of antagonists of the insect eggs. These egg-induced changes lead to attraction of egg parasitoids and their arrestance on a leaf, respectively. Finally, we summarise knowledge of the elicitors of egg-induced plant changes and address egg-induced effects on the plant's transcriptional pattern. Copyright © 2011 Elsevier Ltd. All rights reserved.

Aggression and courtship in Drosophila: pheromonal communication and sex recognition.

PubMed

Fernández, María Paz; Kravitz, Edward A

2013-11-01

Upon encountering a conspecific in the wild, males have to rapidly detect, integrate and process the most relevant signals to evoke an appropriate behavioral response. Courtship and aggression are the most important social behaviors in nature for procreation and survival: for males, making the right choice between the two depends on the ability to identify the sex of the other individual. In flies as in most species, males court females and attack other males. Although many sensory modalities are involved in sex recognition, chemosensory communication mediated by specific molecules that serve as pheromones plays a key role in helping males distinguish between courtship and aggression targets. The chemosensory signals used by flies include volatile and non-volatile compounds, detected by the olfactory and gustatory systems. Recently, several putative olfactory and gustatory receptors have been identified that play key roles in sex recognition, allowing investigators to begin to map the neuronal circuits that convey this sensory information to higher processing centers in the brain. Here, we describe how Drosophila melanogaster males use taste and smell to make correct behavioral choices.

Aggression and Courtship in Drosophila: Pheromonal Communication and Sex Recognition

PubMed Central

Fernández, María Paz; Kravitz, Edward A.

2013-01-01

Upon encountering a conspecific in the wild, males have to rapidly detect, integrate and process the most relevant signals to evoke an appropriate behavioral response. Courtship and aggression are the most important social behaviors in nature for procreation and survival: for males, making the right choice between the two depends on the ability to identify the sex of the other individual. In flies as in most species, males court females and attack other males. Although many sensory modalities are involved in sex recognition, chemosensory communication mediated by specific molecules that serve as pheromones plays a key role in helping males distinguish between courtship and aggression targets. The chemosensory signals used by flies include volatile and non-volatile compounds, detected by the olfactory and gustatory systems. Recently, several putative olfactory and gustatory receptors have been identified that play key roles in sex recognition, allowing investigators to begin to map the neuronal circuits that convey this sensory information to higher processing centers in the brain. Here, we describe how Drosophila melanogaster males use taste and smell to make correct behavioral choices. PMID:24043358

Association between molecular markers and behavioral phenotypes in the immatures of a butterfly.

PubMed

De Nardin, Janaína; Buffon, Vanessa; Revers, Luís Fernando; de Araújo, Aldo Mellender

2018-01-01

Newly hatched caterpillars of the butterfly Heliconius erato phyllis routinely cannibalize eggs. In a manifestation of kin recognition they cannibalize sibling eggs less frequently than unrelated eggs. Previous work has estimated the heritability of kin recognition in H. erato phyllis to lie between 14 and 48%. It has furthermore been shown that the inheritance of kin recognition is compatible with a quantitative model with a threshold. Here we present the results of a preliminary study, in which we tested for associations between behavioral kin recognition phenotypes and AFLP and SSR markers. We implemented two experimental approaches: (1) a cannibalism test using sibling eggs only, which allowed for only two behavioral outcomes (cannibal and non-cannibal), and (2) a cannibalism test using two sibling eggs and one unrelated egg, which allowed four outcomes [cannibal who does not recognize siblings, cannibal who recognizes siblings, "super-cannibal" (cannibal of both eggs), and "super non-cannibal" (does not cannibalize eggs at all)]. Single-marker analyses were performed using χ2 tests and logistic regression with null markers as covariates. Results of the χ2 tests identified 72 associations for experimental design 1 and 73 associations for design 2. Logistic regression analysis of the markers found to be significant in the χ2 test resulted in 20 associations for design 1 and 11 associations for design 2. Experiment 2 identified markers that were more frequently present or absent in cannibals who recognize siblings and super non-cannibals; i.e. in both phenotypes capable of kin recognition.

Association between molecular markers and behavioral phenotypes in the immatures of a butterfly

PubMed Central

De Nardin, Janaína; Buffon, Vanessa; Revers, Luís Fernando; de Araújo, Aldo Mellender

2018-01-01

Abstract Newly hatched caterpillars of the butterfly Heliconius erato phyllis routinely cannibalize eggs. In a manifestation of kin recognition they cannibalize sibling eggs less frequently than unrelated eggs. Previous work has estimated the heritability of kin recognition in H. erato phyllis to lie between 14 and 48%. It has furthermore been shown that the inheritance of kin recognition is compatible with a quantitative model with a threshold. Here we present the results of a preliminary study, in which we tested for associations between behavioral kin recognition phenotypes and AFLP and SSR markers. We implemented two experimental approaches: (1) a cannibalism test using sibling eggs only, which allowed for only two behavioral outcomes (cannibal and non-cannibal), and (2) a cannibalism test using two sibling eggs and one unrelated egg, which allowed four outcomes [cannibal who does not recognize siblings, cannibal who recognizes siblings, “super-cannibal” (cannibal of both eggs), and “super non-cannibal” (does not cannibalize eggs at all)]. Single-marker analyses were performed using χ2 tests and logistic regression with null markers as covariates. Results of the χ2 tests identified 72 associations for experimental design 1 and 73 associations for design 2. Logistic regression analysis of the markers found to be significant in the χ2 test resulted in 20 associations for design 1 and 11 associations for design 2. Experiment 2 identified markers that were more frequently present or absent in cannibals who recognize siblings and super non-cannibals; i.e. in both phenotypes capable of kin recognition. PMID:29583155

Chemical communication in isoptera.

PubMed

Costa-Leonardo, Ana M; Casarin, Fabiana E; Lima, Juliana T

2009-01-01

The semiochemicals produced by termites have been little studied compared to those of ants and bees. Among the limiting factors are the cryptic habits of termites, together with the difficulty in maintaining many species in the laboratory. The semiochemicals of Isoptera include trail, sex and alarm pheromones and a complex mixture of substances responsible for the recognition of nestmates. Although little is known about the semiochemicals of termites, available data indicate a strategy of pheromonal parsimony in the chemistry communication of these insects, i.e., the same compound is sometimes secreted by different glands, different species and for different functions.

Selection on male sex pheromone composition contributes to butterfly reproductive isolation

PubMed Central

Bacquet, P. M. B.; Brattström, O.; Wang, H.-L.; Allen, C. E.; Löfstedt, C.; Brakefield, P. M.; Nieberding, C. M.

2015-01-01

Selection can facilitate diversification by inducing character displacement in mate choice traits that reduce the probability of maladaptive mating between lineages. Although reproductive character displacement (RCD) has been demonstrated in two-taxa case studies, the frequency of this process in nature is still debated. Moreover, studies have focused primarily on visual and acoustic traits, despite the fact that chemical communication is probably the most common means of species recognition. Here, we showed in a large, mostly sympatric, butterfly genus, a strong pattern of recurrent RCD for predicted male sex pheromone composition, but not for visual mate choice traits. Our results suggest that RCD is not anecdotal, and that selection for divergence in male sex pheromone composition contributed to reproductive isolation within the Bicyclus genus. We propose that selection may target olfactory mate choice traits as a more common sensory modality to ensure reproductive isolation among diverging lineages than previously envisaged. PMID:25740889

Resinosis Inhibits Monochamus spp. (Coleoptera: Cerambycidae) Colonization of Healthy Shortleaf Pines in Southeastern United States.

PubMed

Ethington, Matthew W; Galligan, Larry D; Stephen, Fred M

2018-05-14

The genus Monochamus Dejean (Coleoptera: Cerambycidae) includes large, woodboring, longhorned beetles, which colonize pine trees in North America. Many authors have classified the genus as saprophagous, but one recent study reported successful colonization of standing jack pine trees (Pinus banksiana Lamb.) (Pinales: Pinaceae) following severe wind disturbance in Minnesota. We tested whether two Monochamus species native to the southeastern United States (M. titillator (Fabricius) and M. carolinensis (Olivier)) could successfully colonize healthy shortleaf pines (Pinus echinata Mill.) (Pinales: Pinaceae) in recently harvested stands without coincident abiotic or biotic stressors, such as lightning strikes or bark beetle attacks. We attached commercially available semiochemical lures, including monochamol, ethanol, and ipsenol, to healthy shortleaf pine trees and observed Monochamus spp. oviposition response. Egg development was monitored following oviposition by harvesting attacked trees and dissecting oviposition pits. High numbers of oviposition pits were observed on trees treated with lures containing the bark beetle pheromone ipsenol and pits were highly concentrated on the tree bole near lures. Although egg deposition occurred, pit dissection revealed large amounts of resin present in almost all dissected pits and that egg hatch and subsequent larval development were rare. Our results demonstrate that southeastern Monochamus spp. are unlikely to be primary pests of healthy shortleaf pines due to resinosis. To better understand the host finding behavior of these two Monochamus species, we also conducted trapping trials with several semiochemical combinations. Both species and sexes demonstrated similar attraction to compounds, and the most attractive lure combined host volatiles, pheromone, and sympatric insect kairomone.

Accelerated evolution of CES7, a gene encoding a novel major urinary protein in the cat family.

PubMed

Li, Gang; Janecka, Jan E; Murphy, William J

2011-02-01

Cauxin is a novel urinary protein recently identified in the domestic cat that regulates the excretion of felinine, a pheromone precursor involved in sociochemical communication and territorial marking of domestic and wild felids. Understanding the evolutionary history of cauxin may therefore illuminate molecular adaptations involved in the evolution of pheromone-based communication, recognition, and mate selection in wild animals. We sequenced the gene encoding cauxin, CES7, in 22 species representing all major felid lineages, and multiple outgroups and showed that it has undergone rapid evolutionary change preceding and during the diversification of the cat family. A comparison between feline cauxin and orthologous carboxylesterases from other mammalian lineages revealed evidence of strong positive Darwinian selection within and between several cat lineages, enriched at functionally important sites of the protein. The higher rate of radical amino acid replacements in small felids, coupled with the lack of felinine and extremely low levels of cauxin in the urine of the great cats (Panthera), correlates with functional divergence of this gene in Panthera, and its putative loss in the snow leopard. Expression studies found evidence for several alternatively spliced transcripts in testis and brain, suggesting additional roles in male reproductive fitness and behavior. Our work presents the first report of strong positive natural selection acting on a major urinary protein of nonrodent mammals, providing evidence for parallel selection pressure on the regulation of pheromones in different mammalian lineages, despite the use of different metabolic pathways. Our results imply that natural selection may drive rapid changes in the regulation of pheromones in urine among the different cat species, which in turn may influence social behavior, such as territorial marking and conspecific recognition, therefore serving as an important mechanism for the radiation of this group of mammals.

Antennal transcriptome analysis of the Asian longhorned beetle Anoplophora glabripennis

PubMed Central

Hu, Ping; Wang, Jingzhen; Cui, Mingming; Tao, Jing; Luo, Youqing

2016-01-01

Olfactory proteins form the basis of insect olfactory recognition, which is crucial for host identification, mating, and oviposition. Using transcriptome analysis of Anoplophora glabripennis antenna, we identified 42 odorant-binding proteins (OBPs), 12 chemosensory proteins (CSPs), 14 pheromone-degrading enzymes (PDEs), 1 odorant-degrading enzymes (ODE), 37 odorant receptors (ORs), 11 gustatory receptors (GRs), 2 sensory neuron membrane proteins (SNMPs), and 4 ionotropic receptor (IR). All CSPs and PBPs were expressed in antennae, confirming the authenticity of the transcriptome data. CSP expression profiles showed that AglaCSP3, AglaCSP6, and AglaCSP12 were expressed preferentially in maxillary palps and AglaCSP7 and AglaCSP9 were strongly expressed in antennae. The vast majority of CSPs were highly expressed in multiple chemosensory tissues, suggesting their participation in olfactory recognition in almost all olfactory tissues. Intriguingly, the PBP AglaPBP2 was preferentially expressed in antenna, indicating that it is the main protein involved in efficient and sensitive pheromone recognition. Phylogenetic analysis of olfactory proteins indicated AglaGR1 may detect CO2. This study establishes a foundation for determining the chemoreception molecular mechanisms of A. glabripennis, which would provide a new perspective for controlling pest populations, especially those of borers. PMID:27222053

Looking for a similar partner: host plants shape mating preferences of herbivorous insects by altering their contact pheromones.

PubMed

Geiselhardt, Sven; Otte, Tobias; Hilker, Monika

2012-09-01

The role of phenotypical plasticity in ecological speciation and the evolution of sexual isolation remains largely unknown. We investigated whether or not divergent host plant use in an herbivorous insect causes assortative mating by phenotypically altering traits involved in mate recognition. We found that males of the mustard leaf beetle Phaedon cochleariae preferred to mate with females that were reared on the same plant species to females provided with a different plant species, based on divergent cuticular hydrocarbon profiles that serve as contact pheromones. The cuticular hydrocarbon phenotypes of the beetles were host plant specific and changed within 2 weeks after a shift to a novel host plant species. We suggest that plant-induced phenotypic divergence in mate recognition cues may act as an early barrier to gene flow between herbivorous insect populations on alternative host species, preceding genetic divergence and thus, promoting ecological speciation. © 2012 Blackwell Publishing Ltd/CNRS.

Simultaneously hermaphroditic shrimp use lipophilic cuticular hydrocarbons as contact sex pheromones.

PubMed

Zhang, Dong; Terschak, John A; Harley, Maggy A; Lin, Junda; Hardege, Jörg D

2011-04-20

Successful mating is essentially a consequence of making the right choices at the correct time. Animals use specific strategies to gain information about a potential mate, which is then applied to decision-making processes. Amongst the many informative signals, odor cues such as sex pheromones play important ecological roles in coordinating mating behavior, enabling mate and kin recognition, qualifying mate choice, and preventing gene exchange among individuals from different populations and species. Despite overwhelming behavioral evidence, the chemical identity of most cues used in aquatic organisms remains unknown and their impact and omnipresence have not been fully recognized. In many crustaceans, including lobsters and shrimps, reproduction happens through a cascade of events ranging from initial attraction to formation of a mating pair eventually leading to mating. We examined the hypothesis that contact pheromones on the female body surface of the hermaphroditic shrimp Lysmata boggessi are of lipophilic nature, and resemble insect cuticular hydrocarbon contact cues. Via chemical analyses and behavioural assays, we show that newly molted euhermaphrodite-phase shrimp contain a bouquet of odor compounds. Of these, (Z)-9-octadecenamide is the key odor with hexadecanamide and methyl linoleate enhancing the bioactivity of the pheromone blend. Our results show that in aquatic systems lipophilic, cuticular hydrocarbon contact sex pheromones exist; this raises questions on how hydrocarbon contact signals evolved and how widespread these are in the marine environment.

Natural History of the Southern Pine Beetle

Treesearch

Fred P. Hain; Adrian J. Duehl; Micah J. Gardner; Thomas L. Payne

2011-01-01

The southern pine beetle (SPB) is a tree killer of southern yellow pines. All life stages—eggs, larvae, pupae, and adults—infest the inner bark or phloem tissue of the host tree. Adult beetles overcome the tree’s defenses through a mass-attack phenomenon. They are attracted to the tree by a pheromone system consisting of volatiles produced by the beetles and the host....

Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

NASA Astrophysics Data System (ADS)

Li, Jing; Pang, Shaojun; Liu, Feng; Shan, Tifeng; Gao, Suqin

2013-07-01

During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization success. Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions, the potential life-span of the sperm of two seaweeds, Saccharina japonica and Undaria pinnatifida, was assessed by their ability to fertilize eggs. Results show that within 20-30 min after being discharged, sperm of both species could complete fertilization without an apparent decline in fertilization rate. Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species, some sperm were viable enough to fertilize the eggs. In S. japonica, at 12°C, some sperm were able to fertilize eggs up to 12 h after discharge. In both species, egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups. Doubling the seeded male gametophytes of S. japonica in the SGT tests significantly increased the EDR, further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.

Egg size matching by an intraspecific brood parasite

USGS Publications Warehouse

Lemons, Patrick R.; Sedinger, James S.

2011-01-01

Avian brood parasitism provides an ideal system with which to understand animal recognition and its affect on fitness. This phenomenon of laying eggs in the nests of other individuals has classically been framed from the perspective of interspecific brood parasitism and host recognition of parasitic eggs. Few examples exist of strategies adopted by intraspecific brood parasites to maximize success of parasitic eggs. Intraspecific brood parasitism within precocial birds can be a risky strategy in that hatch synchrony is essential to reproductive success. Given that egg size is positively correlated with incubation time, parasitic birds would benefit by recognizing and selecting hosts with a similar egg size. Intraspecific brood parasitism is an alternative reproductive strategy in black brant (Branta bernicla nigricans), a colonial nesting goose with precocial young. Based on a randomization test, parasitic eggs in this study differed less in size from eggs in their host's nests than did random eggs placed in random nests. Parasitic eggs were remarkably similar in size to hosts’ eggs, differing by <2% of volume on average from host eggs, whereas randomly paired eggs in random nests differed by nearly 8%. The precision with which parasitic brant match the egg size of hosts in our study supports our hypothesis that brant match egg size of hosts, thereby maximizing hatching success of their parasitic eggs.

Dietary lufenuron reduces egg hatch and influences protein expression in the fruit fly Bactrocera latifrons (Hendel).

PubMed

Chang, Chiou Ling; Geib, Scott; Cho, Il Kyu; Li, Qing X; Stanley, David

2014-08-01

Lufenuron (LFN), a chitin synthase inhibitor, impacts the fertility of Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons. We posed the hypothesis that LFN curtails egg hatch in the solanaceous fruit fly, B. latifrons. In this study, newly emerged virgin adults were sexed and fed for 12 days with varying concentrations of LFN-laced agar diets until sexual maturation. Eggs were collected from 12-d-old adults and the egg hatch was assessed. Egg hatch decreased in adults reared on LFN-treated diets. LFN-treated media did not influence fertility after one gender was reared on experimental and the other on control media before mating. Exposure to LFN-treated medium after mating led to reduced egg hatch. We infer that LFN is not a permanent sterilant, and reduced egg hatch depends on continuous exposure to dietary LFN after mating. Proteomic analysis identified two differentially expressed proteins, a pheromone binding protein and a chitin binding protein, between adults maintained on LFN-treated and control diets. Expression of two genes encoding chitin synthase 2, and chitin binding protein, was altered in adults exposed to dietary LFN. LFN treatments also led to increased expression of two odorant binding proteins one in females and one in males. We surmise these data support our hypothesis and provide insight into LFN actions. © 2014 Wiley Periodicals, Inc.

Effect of Brood Pheromone on Survival and Nutrient Intake of African Honey Bees (Apis mellifera scutellata) under Controlled Conditions.

PubMed

Démares, Fabien J; Yusuf, Abdullahi A; Nicolson, Susan W; Pirk, Christian W W

2017-05-01

The influence of pheromones on insect physiology and behavior has been thoroughly reported for numerous aspects, such as attraction, gland development, aggregation, mate and kin recognition. Brood pheromone (BP) is released by honey bee larvae to indicate their protein requirements to the colony. Although BP is known to modulate pollen and protein consumption, which in turn can affect physiological and morphological parameters, such as hypopharyngeal gland (HPG) development and ovarian activation, few studies have focused on the effect of BP on nutritional balance. In this study, we exposed newly emerged worker bees for 14 d and found that BP exposure increased protein intake during the first few days, with a peak in consumption at day four following exposure. BP exposure decreased survival of caged honey bees, but did not affect either the size of the HPG acini or ovarian activation stage. The uncoupling of the BP releaser effect, facilitated by working under controlled conditions, and the presence of larvae as stimulating cues are discussed.

Foraging behavior of Anastrepha Ludens, A. obliqua, and A. serpentina in response to feces extracts containing host marking pheromone.

PubMed

Aluja, Martin; Díaz-Fleischer, Francisco

2006-02-01

Following oviposition, females of many Tephritid flies deposit host marking pheromones (HMPs) to indicate that the host fruit has been occupied. We describe the foraging behavior of these three economically important species (Anastrepha ludens and A. obliqua from the fraterculus species group and A. serpentina from the serpentina species group) when they encounter an artificial fruit (green agar spheres wrapped in Parafilm) marked with intra- and interspecific feces extracts that contain, among other substances, host marking pheromone. When flies encountered fruit treated with either 1 or 100 mg/ml feces extract, there were drastic and statistically significant reductions in tree residence time, mean time spent on fruit, and in the number of oviposition attempts or actual ovipositions when compared to the control treatment (clean fruit). These responses were almost identical irrespective of extract origin (i.e., fly species), indicating complete interspecific HMP cross-recognition by all three Anastrepha species tested. We discuss the ecological and practical implications of our findings.

SNMP is a signaling component required for pheromone sensitivity in Drosophila.

PubMed

Jin, Xin; Ha, Tal Soo; Smith, Dean P

2008-08-05

The only known volatile pheromone in Drosophila, 11-cis-vaccenyl acetate (cVA), mediates a variety of behaviors including aggregation, mate recognition, and sexual behavior. cVA is detected by a small set of olfactory neurons located in T1 trichoid sensilla on the antennae of males and females. Two components known to be required for cVA reception are the odorant receptor Or67d and the extracellular pheromone-binding protein LUSH. Using a genetic screen for cVA-insensitive mutants, we have identified a third component required for cVA reception: sensory neuron membrane protein (SNMP). SNMP is a homolog of CD36, a scavenger receptor important for lipoprotein binding and uptake of cholesterol and lipids in vertebrates. In humans, loss of CD36 is linked to a wide range of disorders including insulin resistance, dyslipidemia, and atherosclerosis, but how CD36 functions in lipid transport and signal transduction is poorly understood. We show that SNMP is required in pheromone-sensitive neurons for cVA sensitivity but is not required for sensitivity to general odorants. Using antiserum to SNMP infused directly into the sensillum lymph, we show that SNMP function is required on the dendrites of cVA-sensitive neurons; this finding is consistent with a direct role in cVA signal transduction. Therefore, pheromone perception in Drosophila should serve as an excellent model to elucidate the role of CD36 members in transmembrane signaling.

Binding Specificity of Two PBPs in the Yellow Peach Moth Conogethes punctiferalis (Guenée)

PubMed Central

Ge, Xing; Ahmed, Tofael; Zhang, Tiantao; Wang, Zhenying; He, Kanglai; Bai, Shuxiong

2018-01-01

Pheromone binding proteins (PBPs) play an important role in olfaction of insects by transporting sex pheromones across the sensillum lymph to odorant receptors. To obtain a better understanding of the molecular basis between PBPs and semiochemicals, we have cloned, expressed, and purified two PBPs (CpunPBP2 and CpunPBP5) from the antennae of Conogethes punctiferalis. Fluorescence competitive binding assays were used to investigate binding affinities of CpunPBP2 and CpunPBP5 to sex pheromone and volatiles. Results indicate both CpunPBP2 and CpunPBP5 bind sex pheromones E10-16:Ald, Z10-16:Ald and hexadecanal with higher affinities. In addition, CpunPBP2 and CpunPBP5 also could bind some odorants, such as 1-tetradecanol, trans-caryopyllene, farnesene, and β-farnesene. Homology modeling to predict 3D structure and molecular docking to predict key binding sites were used, to better understand interactions of CpunPBP2 and CpunPBP5 with sex pheromones E10-16:Ald and Z10-16:Ald. According to the results, Phe9, Phe33, Ser53, and Phe115 were key binding sites predicted for CpunPBP2, as were Ser9, Phe12, Val115, and Arg120 for CpunPBP5. Binding affinities of four mutants of CpunPBP2 and four mutants of CpunPBP5 with the two sex pheromones were investigated by fluorescence competitive binding assays. Results indicate that single nucleotides mutation may affect interactions between PBPs and sex pheromones. Expression levels of CpunPBP2 and CpunPBP5 in different tissues were evaluated using qPCR. Results show that CpunPBP2 and CpunPBP5 were largely amplified in the antennae, with low expression levels in other tissues. CpunPBP2 was expressed mainly in male antennae, whereas CpunPBP5 was expressed mainly in female antennae. These results provide new insights into understanding the recognition between PBPs and ligands. PMID:29666585

Does contrast between eggshell ground and spot coloration affect egg rejection?

PubMed

Dainson, Miri; Hauber, Mark E; López, Analía V; Grim, Tomáš; Hanley, Daniel

2017-08-01

Obligate avian brood parasitic species impose the costs of incubating foreign eggs and raising young upon their unrelated hosts. The most common host defence is the rejection of parasitic eggs from the nest. Both egg colours and spot patterns influence egg rejection decisions in many host species, yet no studies have explicitly examined the role of variation in spot coloration. We studied the American robin Turdus migratorius, a blue-green unspotted egg-laying host of the brown-headed cowbird Molothrus ater, a brood parasite that lays non-mimetic spotted eggs. We examined host responses to model eggs with variable spot coloration against a constant robin-mimetic ground colour to identify patterns of rejection associated with perceived contrast between spot and ground colours. By using avian visual modelling, we found that robins were more likely to reject eggs whose spots had greater chromatic (hue) but not achromatic (brightness) contrast. Therefore, egg rejection decision rules in the American robin may depend on the colour contrast between parasite eggshell spot and host ground coloration. Our study also suggests that egg recognition in relation to spot coloration, like ground colour recognition, is tuned to the natural variation of avian eggshell spot colours but not to unnatural spot colours.

A role for carbohydrate recognition in mammalian sperm-egg binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, Gary F., E-mail: clarkgf@health.missouri.edu

Highlights: • Mammalian sperm-egg binding as a carbohydrate dependent species recognition event. • The role of carbohydrate recognition in human, mouse and pig sperm-egg binding. • Historical perspective and future directions for research focused on gamete binding. - Abstract: Mammalian fertilization usually requires three sequential cell–cell interactions: (i) initial binding of sperm to the specialized extracellular matrix coating the egg known as the zona pellucida (ZP); (ii) binding of sperm to the ZP via the inner acrosomal membrane that is exposed following the induction of acrosomal exocytosis; and (iii) adhesion of acrosome-reacted sperm to the plasma membrane of the eggmore » cell, enabling subsequent fusion of these gametes. The focus of this review is on the initial binding of intact sperm to the mammalian ZP. Evidence collected over the past fifty years has confirmed that this interaction relies primarily on the recognition of carbohydrate sequences presented on the ZP by lectin-like egg binding proteins located on the plasma membrane of sperm. There is also evidence that the same carbohydrate sequences that mediate binding also function as ligands for lectins on lymphocytes that can inactivate immune responses, likely protecting the egg and the developing embryo up to the stage of blastocyst hatching. The literature related to initial sperm-ZP binding in the three major mammalian models (human, mouse and pig) is discussed. Historical perspectives and future directions for research related to this aspect of gamete adhesion are also presented.« less

A new approach to determine the capture conditions of bark beetles in pheromone-baited traps

PubMed Central

Ozcan, Gonca Ece; Cicek, Osman; Enez, Korhan; Yildiz, Mustafa

2014-01-01

Forests form an organic unity with a great number of organic and inorganic components and tend to maintain the sustainability of their existing balance. However, some factors which adversely affect the balance of nature may interrupt this sustainability. The epidemic which is formed by bark beetles in their spreading region, due to various factors, changes the stability so much that interference is required. One of the most common methods used to monitor these beetles is pheromone-baited traps. The recognition of parameters, such as date (day/month/year), temperature and humidity, when bark beetles are captured in pheromone-baited traps, especially those used for monitoring will help to increase the trap efficiency on land and to develop an effective strategy for combating pests. In this study, an electronic control unit was added to pheromone-baited traps in order to obtain all of the above mentioned parameters. This unit operates with microcontrollers and data related to the parameters is saved in a storage unit. This is triggered by the beetle at the moment it is captured in the trap. A photovoltaic system was used to meet the energy needed for the system functioning and to complete the counting process in due time. PMID:26019592

Specialized odorant receptors in social insects that detect cuticular hydrocarbon cues and candidate pheromones.

PubMed

Pask, Gregory M; Slone, Jesse D; Millar, Jocelyn G; Das, Prithwiraj; Moreira, Jardel A; Zhou, Xiaofan; Bello, Jan; Berger, Shelley L; Bonasio, Roberto; Desplan, Claude; Reinberg, Danny; Liebig, Jürgen; Zwiebel, Laurence J; Ray, Anandasankar

2017-08-17

Eusocial insects use cuticular hydrocarbons as components of pheromones that mediate social behaviours, such as caste and nestmate recognition, and regulation of reproduction. In ants such as Harpegnathos saltator, the queen produces a pheromone which suppresses the development of workers' ovaries and if she is removed, workers can transition to a reproductive state known as gamergate. Here we functionally characterize a subfamily of odorant receptors (Ors) with a nine-exon gene structure that have undergone a massive expansion in ants and other eusocial insects. We deorphanize 22 representative members and find they can detect cuticular hydrocarbons from different ant castes, with one (HsOr263) that responds strongly to gamergate extract and a candidate queen pheromone component. After systematic testing with a diverse panel of hydrocarbons, we find that most Harpegnathos saltator Ors are narrowly tuned, suggesting that several receptors must contribute to detection and discrimination of different cuticular hydrocarbons important in mediating eusocial behaviour.Cuticular hydrocarbons (CHC) mediate the interactions between individuals in eusocial insects, but the sensory receptors for CHCs are unclear. Here the authors show that in ants such as H. saltator, the 9-exon subfamily of odorant receptors (HsOrs) responds to CHCs, and ectopic expression of HsOrs in Drosophila neurons imparts responsiveness to CHCs.

Ratiometric Decoding of Pheromones for a Biomimetic Infochemical Communication System.

PubMed

Wei, Guangfen; Thomas, Sanju; Cole, Marina; Rácz, Zoltán; Gardner, Julian W

2017-10-30

Biosynthetic infochemical communication is an emerging scientific field employing molecular compounds for information transmission, labelling, and biochemical interfacing; having potential application in diverse areas ranging from pest management to group coordination of swarming robots. Our communication system comprises a chemoemitter module that encodes information by producing volatile pheromone components and a chemoreceiver module that decodes the transmitted ratiometric information via polymer-coated piezoelectric Surface Acoustic Wave Resonator (SAWR) sensors. The inspiration for such a system is based on the pheromone-based communication between insects. Ten features are extracted from the SAWR sensor response and analysed using multi-variate classification techniques, i.e., Linear Discriminant Analysis (LDA), Probabilistic Neural Network (PNN), and Multilayer Perception Neural Network (MLPNN) methods, and an optimal feature subset is identified. A combination of steady state and transient features of the sensor signals showed superior performances with LDA and MLPNN. Although MLPNN gave excellent results reaching 100% recognition rate at 400 s, over all time stations PNN gave the best performance based on an expanded data-set with adjacent neighbours. In this case, 100% of the pheromone mixtures were successfully identified just 200 s after they were first injected into the wind tunnel. We believe that this approach can be used for future chemical communication employing simple mixtures of airborne molecules.

Ratiometric Decoding of Pheromones for a Biomimetic Infochemical Communication System

PubMed Central

Wei, Guangfen; Thomas, Sanju; Cole, Marina; Rácz, Zoltán

2017-01-01

Biosynthetic infochemical communication is an emerging scientific field employing molecular compounds for information transmission, labelling, and biochemical interfacing; having potential application in diverse areas ranging from pest management to group coordination of swarming robots. Our communication system comprises a chemoemitter module that encodes information by producing volatile pheromone components and a chemoreceiver module that decodes the transmitted ratiometric information via polymer-coated piezoelectric Surface Acoustic Wave Resonator (SAWR) sensors. The inspiration for such a system is based on the pheromone-based communication between insects. Ten features are extracted from the SAWR sensor response and analysed using multi-variate classification techniques, i.e., Linear Discriminant Analysis (LDA), Probabilistic Neural Network (PNN), and Multilayer Perception Neural Network (MLPNN) methods, and an optimal feature subset is identified. A combination of steady state and transient features of the sensor signals showed superior performances with LDA and MLPNN. Although MLPNN gave excellent results reaching 100% recognition rate at 400 s, over all time stations PNN gave the best performance based on an expanded data-set with adjacent neighbours. In this case, 100% of the pheromone mixtures were successfully identified just 200 s after they were first injected into the wind tunnel. We believe that this approach can be used for future chemical communication employing simple mixtures of airborne molecules. PMID:29084158

Biological complexity and adaptability of simple mammalian olfactory memory systems.

PubMed

Brennan, P; Keverne, E B

2015-03-01

Chemosensory systems play vital roles in the lives of most mammals, including the detection and identification of predators, as well as sex and reproductive status and the identification of individual conspecifics. All of these capabilities require a process of recognition involving a combination of innate (kairomonal/pheromonal) and learned responses. Across very different phylogenies, the mechanisms for pheromonal and odour learning have much in common. They are frequently associated with plasticity of GABA-ergic feedback at the initial level of processing the chemosensory information, which enhances its pattern separation capability. Association of odourant features into an odour object primarily involves anterior piriform cortex for non-social odours. However, the medial amygdala appears to be involved in both the recognition of social odours and their association with chemosensory information sensed by the vomeronasal system. Unusually not only the sensory neurons themselves, but also the GABA-ergic interneurons in the olfactory bulb are continually being replaced, with implications for the induction and maintenance of learned chemosensory responses. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Brain modulation of Dufour's gland ester biosynthesis in vitro in the honeybee ( Apis mellifera)

NASA Astrophysics Data System (ADS)

Katzav-Gozansky, Tamar; Hefetz, Abraham; Soroker, Victoria

2007-05-01

Caste-specific pheromone biosynthesis is a prerequisite for reproductive skew in the honeybee. Nonetheless, this process is not hardwired but plastic, in that egg-laying workers produce a queen-like pheromone. Studies with Dufour’s gland pheromone revealed that, in vivo, workers’ gland biosynthesis matches the social status of the worker, i.e., sterile workers showed a worker-like pattern whereas fertile workers showed a queen-like pattern (production of the queen-specific esters). However, when incubated in vitro, the gland spontaneously exhibits the queen-like pattern, irrespective of its original worker type, prompting the notion that ester production in workers is under inhibitory control that is queen-dependent. We tested this hypothesis by exposing queen or worker Dufour’s glands in vitro to brain extracts of queens, queenright (sterile) workers and males. Unexpectedly, worker brain extracts activated the queen-like esters biosynthesis in workers’ Dufour’s gland. This stimulation was gender-specific; queen or worker brains demonstrated a stimulatory activity, but male brains did not. Queen gland could not be further stimulated. Bioassays with heated and filtered extracts indicate that the stimulatory brain factor is below 3,000 Da. We suggest that pheromone production in Dufour’s gland is under dual, negative positive control. Under queenright conditions, the inhibitor is released and blocks ester biosynthesis, whereas under queenless conditions, the activator is released, activating ester biosynthesis in the gland. This is consistent with the hypothesis that queenright workers are unequivocally recognized as non-fertile, whereas queenless workers try to become “false queens” as part of the reproductive competition.

Which egg features predict egg rejection responses in American robins? Replicating Rothstein's (1982) study.

PubMed

Luro, Alec B; Igic, Branislav; Croston, Rebecca; López, Analía V; Shawkey, Matthew D; Hauber, Mark E

2018-02-01

Rothstein (Behavioral Ecology and Sociobiology, 11, 1982, 229) was one of the first comprehensive studies to examine how different egg features influence egg rejection behaviors of avian brood parasite-hosts. The methods and conclusions of Rothstein (1982) laid the foundation for subsequent experimental brood parasitism studies over the past thirty years, but its results have never been evaluated with replication. Here, we partially replicated Rothstein's (1982) experiments using parallel artificial model egg treatments to simulate cowbird ( Molothrus ater ) parasitism in American robin ( Turdus migratorius ) nests. We compared our data with those of Rothstein (1982) and confirmed most of its original findings: (1) robins reject model eggs that differ from the appearance of a natural robin egg toward that of a natural cowbird egg in background color, size, and maculation; (2) rejection responses were best predicted by model egg background color; and (3) model eggs differing by two or more features from natural robin eggs were more likely to be rejected than model eggs differing by one feature alone. In contrast with Rothstein's (1982) conclusion that American robin egg recognition is not specifically tuned toward rejection of brown-headed cowbird eggs, we argue that our results and those of other recent studies of robin egg rejection suggest a discrimination bias toward rejection of cowbird eggs. Future work on egg recognition will benefit from utilizing a range of model eggs varying continuously in background color, maculation patterning, and size in combination with avian visual modeling, rather than using model eggs which vary only discretely.

Pre-Release Consumption of Methyl Eugenol Increases the Mating Competitiveness of Sterile Males of the Oriental Fruit Fly, Bactrocera dorsalis, in Large Field Enclosures

PubMed Central

Shelly, Todd E.; Edu, James; McInnis, Donald

2010-01-01

The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1–4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost-effectiveness of the sterile insect technique. PMID:20569140

Different recognition cues reveal the decision rules used for egg rejection by hosts of a variably mimetic avian brood parasite.

PubMed

de la Colina, M Alicia; Pompilio, Lorena; Hauber, Mark E; Reboreda, Juan C; Mahler, Bettina

2012-09-01

Brood parasitism imposes several fitness costs on the host species. To reduce these costs, hosts of avian brood parasites have evolved various defenses, of which egg rejection is the most prevalent. In the face of variable host-parasite mimicry and the costs of egg discrimination itself, many hosts reject only some foreign eggs. Here, we experimentally varied the recognition cues to study the underlying cognitive mechanisms used by the Chalk-browed Mockingbird (Mimus saturninus) to reject the white immaculate eggs laid by the parasitic Shiny Cowbird (Molothrus bonariensis). Immaculate eggs are the only parasite eggs rejected by this host, as it accepts all polymorphic, spotted eggs laid by cowbirds. Using a within-breeding pair experimental design, we tested for the salience of spotting, UV reflectance, and brightness in eliciting rejection. We found that the presence of spotting significantly decreased the probability of rejection while increments in brightness significantly increased rejection frequencies. The cognitive rules underlying mockingbird rejection behavior can be explained by a decision-making model which predicts changes in the levels of rejection in direct relation to the number of relevant attributes shared between host and parasite eggs.

The role of egg-nest contrast in the rejection of brood parasitic eggs.

PubMed

Aidala, Zachary; Croston, Rebecca; Schwartz, Jessica; Tong, Lainga; Hauber, Mark E

2015-04-15

Hosts of avian brood parasites can avoid the reproductive costs of raising genetically unrelated offspring by rejecting parasitic eggs. The perceptual cues and controls mediating parasitic egg discrimination and ejection are well studied: hosts are thought to use differences in egg color, brightness, maculation, size and shape to discriminate between their own and foreign eggs. Most theories of brood parasitism implicitly assume that the primary criteria to which hosts attend when discriminating eggs are differences between the eggs themselves. However, this assumption is confounded by the degree to which chromatic and achromatic characteristics of the nest lining co-vary with egg coloration, so that egg-nest contrast per se might be the recognition cue driving parasitic egg detection. Here, we systematically tested whether and how egg-nest contrast itself contributes to foreign egg discrimination. In an artificial parasitism experiment, we independently manipulated egg color and nest lining color of the egg-ejector American robin (Turdus migratorius), a host of the obligate brood parasitic brown-headed cowbird (Molothrus ater). We hypothesized that the degree of contrast between foreign eggs and the nest background would affect host egg rejection behavior. We predicted that experimentally decreasing egg-nest chromatic and achromatic contrast (i.e. rendering parasitic eggs more cryptic against the nest lining) would decrease rejection rates, while increasing egg-nest contrast would increase rejection rates. In contrast to our predictions, egg-nest contrast was not a significant predictor of egg ejection patterns. Instead, egg color significantly predicted responses to parasitism. We conclude that egg-egg differences are the primary drivers of egg rejection in this system. Future studies should test for the effects of egg-nest contrast per se in predicting parasitic egg recognition in other host-parasite systems, including those hosts building enclosed nests and those parasites laying cryptic eggs, as an alternative to hypothesized effects of egg-egg contrast. © 2015. Published by The Company of Biologists Ltd.

Caste-, sex-, and age-dependent expression of immune-related genes in a Japanese subterranean termite, Reticulitermes speratus

PubMed Central

Kobayashi, Kazuya; Matsuura, Kenji

2017-01-01

Insects protect themselves from microbial infections through innate immune responses, including pathogen recognition, phagocytosis, the activation of proteolytic cascades, and the synthesis of antimicrobial peptides. Termites, eusocial insects inhabiting microbe-rich wood, live in closely-related family groups that are susceptible to shared pathogen infections. To resist pathogenic infection, termite families have evolved diverse immune adaptations at both individual and societal levels, and a strategy of trade-offs between reproduction and immunity has been suggested. Although termite immune-inducible genes have been identified, few studies have investigated the differential expression of these genes between reproductive and neuter castes, and between sexes in each caste. In this study, we compared the expression levels of immune-related genes among castes, sexes, and ages in a Japanese subterranean termite, Reticulitermes speratus. Using RNA-seq, we found 197 immune-related genes, including 40 pattern recognition proteins, 97 signalling proteins, 60 effectors. Among these genes, 174 showed differential expression among castes. Comparing expression levels between males and females in each caste, we found sexually dimorphic expression of immune-related genes not only in reproductive castes, but also in neuter castes. Moreover, we identified age-related differential expression of 162 genes in male and/or female reproductives. In addition, although R. speratus is known to use the antibacterial peptide C-type lysozyme as an egg recognition pheromone, we determined that R. speratus has not only C-type, but also P-type and I-type lysozymes, as well as other termite species. Our transcriptomic analyses revealed immune response plasticity among all castes, and sex-biased expression of immune genes even in neuter castes, suggesting a sexual division of labor in the immune system of R. speratus. This study heightens the understanding of the evolution of antimicrobial strategies in eusocial insects, and of sexual roles in insect societies as a whole. PMID:28410430

Caste-, sex-, and age-dependent expression of immune-related genes in a Japanese subterranean termite, Reticulitermes speratus.

PubMed

Mitaka, Yuki; Kobayashi, Kazuya; Matsuura, Kenji

2017-01-01

Insects protect themselves from microbial infections through innate immune responses, including pathogen recognition, phagocytosis, the activation of proteolytic cascades, and the synthesis of antimicrobial peptides. Termites, eusocial insects inhabiting microbe-rich wood, live in closely-related family groups that are susceptible to shared pathogen infections. To resist pathogenic infection, termite families have evolved diverse immune adaptations at both individual and societal levels, and a strategy of trade-offs between reproduction and immunity has been suggested. Although termite immune-inducible genes have been identified, few studies have investigated the differential expression of these genes between reproductive and neuter castes, and between sexes in each caste. In this study, we compared the expression levels of immune-related genes among castes, sexes, and ages in a Japanese subterranean termite, Reticulitermes speratus. Using RNA-seq, we found 197 immune-related genes, including 40 pattern recognition proteins, 97 signalling proteins, 60 effectors. Among these genes, 174 showed differential expression among castes. Comparing expression levels between males and females in each caste, we found sexually dimorphic expression of immune-related genes not only in reproductive castes, but also in neuter castes. Moreover, we identified age-related differential expression of 162 genes in male and/or female reproductives. In addition, although R. speratus is known to use the antibacterial peptide C-type lysozyme as an egg recognition pheromone, we determined that R. speratus has not only C-type, but also P-type and I-type lysozymes, as well as other termite species. Our transcriptomic analyses revealed immune response plasticity among all castes, and sex-biased expression of immune genes even in neuter castes, suggesting a sexual division of labor in the immune system of R. speratus. This study heightens the understanding of the evolution of antimicrobial strategies in eusocial insects, and of sexual roles in insect societies as a whole.

Mass Release of Trichogramma evanescens and T. cacoeciae Can Reduce Damage by the Apple Codling Moth Cydia pomonella in Organic Orchards under Pheromone Disruption

PubMed Central

Sigsgaard, Lene; Herz, Annette; Korsgaard, Maren; Wührer, Bernd

2017-01-01

Cydia pomonella is a major pest in apples in Denmark. Trichogramma spp. are known biocontrol agents of C. pomonella eggs and two naturally occurring species in Denmark, which are also both commercially available, were chosen for mass-release trials. Trichogramma evanescens, T. cacoeciae or a mix of the two species were evaluated for mass-release to control C. pomonella in two commercial organic apple orchards, one in 2012 and one in 2013, using a complete randomized block design. Pheromone disruption was used in both orchards, making the study one of the first to evaluate Trichogramma release under a mating disruption regime. Trichogramma activity was assessed using bait cards with Sitotroga cerealella eggs. The percent C. pomonella damaged fruit was recorded and the fruit yield was estimated. In 2012 cool and wet weather conditions resulted in low Trichogramma activity (<16% bait cards parasitized) and only T. evanescens was recovered from bait cards. The conditions in 2013 were warmer but T. evanescens was still >10 times more frequently found in bait cards than T. cacoeciae. There was a significant effect of the treatment and year (p = 0.009) and of the sampling period (p = 0.0008) on Trichogramma activity (proportion bait cards parasitized), with no significant difference between treatments in 2012. In 2013 the highest activity was found in T. evanescens and mixed treatments, in July reaching 69% and 47% bait cards parasitized, respectively. Fruit damage was highest in the control plots (7.1%) compared with Trichogramma treatments (T. evanescens 2.8%, T. cacoeciae 3.8%, mixed 3.3%) (p = 0.028). Yield did not differ significantly between treatments. In conclusion, Trichogramma mass release is a promising biocontrol method for use in the Danish climate, but further studies are needed regarding the performance of the two Trichogramma species (and potential other Trichogramma species) towards C. pomonella eggs in the field to identify the best biocontrol candidate. PMID:28375171

Mass Release of Trichogramma evanescens and T. cacoeciae Can Reduce Damage by the Apple Codling Moth Cydia pomonella in Organic Orchards under Pheromone Disruption.

PubMed

Sigsgaard, Lene; Herz, Annette; Korsgaard, Maren; Wührer, Bernd

2017-04-04

Cydia pomonella is a major pest in apples in Denmark. Trichogramma spp. are known biocontrol agents of C. pomonella eggs and two naturally occurring species in Denmark, which are also both commercially available, were chosen for mass-release trials. Trichogramma evanescens , T. cacoeciae or a mix of the two species were evaluated for mass-release to control C. pomonella in two commercial organic apple orchards, one in 2012 and one in 2013, using a complete randomized block design. Pheromone disruption was used in both orchards, making the study one of the first to evaluate Trichogramma release under a mating disruption regime. Trichogramma activity was assessed using bait cards with Sitotroga cerealella eggs. The percent C. pomonella damaged fruit was recorded and the fruit yield was estimated. In 2012 cool and wet weather conditions resulted in low Trichogramma activity (<16% bait cards parasitized) and only T. evanescens was recovered from bait cards. The conditions in 2013 were warmer but T. evanescens was still >10 times more frequently found in bait cards than T. cacoeciae . There was a significant effect of the treatment and year ( p = 0.009) and of the sampling period ( p = 0.0008) on Trichogramma activity (proportion bait cards parasitized), with no significant difference between treatments in 2012. In 2013 the highest activity was found in T. evanescens and mixed treatments, in July reaching 69% and 47% bait cards parasitized, respectively. Fruit damage was highest in the control plots (7.1%) compared with Trichogramma treatments ( T. evanescens 2.8%, T. cacoeciae 3.8%, mixed 3.3%) ( p = 0.028). Yield did not differ significantly between treatments. In conclusion, Trichogramma mass release is a promising biocontrol method for use in the Danish climate, but further studies are needed regarding the performance of the two Trichogramma species (and potential other Trichogramma species) towards C. pomonella eggs in the field to identify the best biocontrol candidate.

Queen pheromones in Temnothorax ants: control or honest signal?

PubMed Central

2011-01-01

Background The division of reproductive labor among group members in insect societies is regulated by "queen pheromones". However, it remains controversial whether these are manipulative, i.e., actively suppress worker reproduction, or honestly signal the fertility status of the queen to which workers react in their own interest by refraining from laying eggs. Manipulative queen control is thought to lead to an evolutionary arms race between queens and workers, resulting in complex queen bouquets that diverge strongly among different populations and species. In contrast, honest signals would evolve more slowly and might therefore differ less strongly within and among species. Results We aimed at determining the tempo of the evolution of queen signals in two ways. First, we investigated whether queens of Temnothorax ants are capable of controlling egg laying by workers of their own, closely, and distantly related species. Second, we compared the species- and caste-specific patterns of cuticular hydrocarbons, which are assumed to convey information on reproductive status. In mixed-species colonies, queens were not able to fully suppress egg-laying and male production by workers of unrelated species, while workers did not reproduce under the influence of a queen from their own species. Furthermore, the chemical profiles differed more strongly among queens of different species than among the respective workers. Conclusions Our results suggest that cuticular hydrocarbons associated with fecundity are not fully conserved in evolution and evolve slightly faster than worker-specific components in the blend of cuticular hydrocarbons. While this higher rate of evolution might reflect an arms race between queens and workers, the observation that workers still respond to the presence of a queen from another species support the honest signal hypothesis. Future studies need to examine alternative explanations for a higher rate of evolution of queen-specific substances, such as an involvement of such compounds in mating. PMID:21356125

A direct main olfactory bulb projection to the ‘vomeronasal’ amygdala in female mice selectively responds to volatile pheromones from males

PubMed Central

Kang, Ningdong; Baum, Michael J.; Cherry, James A.

2009-01-01

The main olfactory system, like the accessory olfactory system, responds to pheromones involved in social communication. Whereas pheromones detected by the accessory system are transmitted to the hypothalamus via the medial (‘vomeronasal’) amygdala, the pathway by which pheromones are detected and transmitted by the main system is not well understood. We examined in female mice whether a direct projection from mitral/tufted (M/T) cells in the main olfactory bulb (MOB) to the medial amygdala exists, and whether medial amygdala-projecting M/T cells are activated by volatile urinary odors from conspecifics or a predator (cat). Simultaneous anterograde tracing using Phaseolus vulgaris leucoagglutinin and Fluoro-Ruby placed in the MOB and accessory olfactory bulb (AOB), respectively, revealed that axons of MOB M/T cells projected to superficial laminae of layer Ia in anterior and posterodorsal subdivisions of the medial amygdala, whereas projection neurons from the AOB sent axons to non-overlapping, deeper layer Ia laminae of the same subdivisions. Placement of the retrograde tracer cholera toxin B into the medial amygdala labeled M/T cells that were concentrated in the ventral MOB. Urinary volatiles from male mice, but not from female conspecifics or cat, induced Fos in medial amygdala-projecting MOB M/T cells of female subjects, suggesting that information about male odors is transmitted directly from the MOB to the ‘vomeronasal’ amygdala. The presence of a direct MOB-to-medial amygdala pathway in mice and other mammals could enable volatile, opposite-sex pheromones to gain privileged access to diencephalic structures that control mate recognition and reproduction. PMID:19187265

Sex-pairing pheromones and reproductive isolation in three sympatric Cornitermes species (Isoptera, Termitidae, Syntermitinae).

PubMed

Bordereau, Christian; Cancello, Eliana M; Sillam-Dussès, David; Sémon, Etienne

2011-04-01

The species-specificity of pairing has been studied in three sympatric Neotropical termites: Cornitermes bequaerti, Cornitermes cumulans and Cornitermes silvestrii (Termitidae, Syntermitinae). Bioassays showed that sex attraction was highly species-specific between C. bequaerti and C. cumulans but not between C. cumulans and C. silvestrii. The sex-pairing pheromone of the three species is secreted by the tergal glands of female alates. It consists of a common compound (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. In C. bequaerti, this polyunsaturated alcohol is the only compound of the sex-pairing pheromone, whereas it is associated with the oxygenated sesquiterpene (E)-nerolidol in C. cumulans, and with (E)-nerolidol and (Z)-dodec-3-en-1-ol in C. silvestrii. (3Z,6Z,8E)-Dodeca-3,6,8-trien-1-ol is responsible for sexual attraction, whereas (E)-nerolidol, which is inactive in eliciting attraction of male alates, is responsible for the species-specificity of the attraction. This is the first time that a multicomponent sex-pairing pheromone has been identified in termites. The role of (Z)-dodec-3-en-1-ol present on the surface of the tergal glands of the female alates of C. silvestrii could not be definitively determined, but it is suggested that this compound could be involved in the species-specificity of sex attraction with other sympatric species of Cornitermes. Our study shows that the reproductive isolation in termites is due to a succession of factors, as the chronology of dispersal flights, the species-specificity of sex-pairing pheromones and the species-specific recognition. Copyright © 2011 Elsevier Ltd. All rights reserved.

Human sperm bind to the N-terminal domain of ZP2 in humanized zonae pellucidae in transgenic mice

PubMed Central

Baibakov, Boris; Boggs, Nathan A.; Yauger, Belinda; Baibakov, Galina

2012-01-01

Fertilization requires taxon-specific gamete recognition, and human sperm do not bind to zonae pellucidae (ZP1–3) surrounding mouse eggs. Using transgenesis to replace endogenous mouse proteins with human homologues, gain-of-function sperm-binding assays were established to evaluate human gamete recognition. Human sperm bound only to zonae pellucidae containing human ZP2, either alone or coexpressed with other human zona proteins. Binding to the humanized matrix was a dominant effect that resulted in human sperm penetration of the zona pellucida and accumulation in the perivitelline space, where they were unable to fuse with mouse eggs. Using recombinant peptides, the site of gamete recognition was located to a defined domain in the N terminus of ZP2. These results provide experimental evidence for the role of ZP2 in mediating sperm binding to the zona pellucida and support a model in which human sperm–egg recognition is dependent on an N-terminal domain of ZP2, which is degraded after fertilization to provide a definitive block to polyspermy. PMID:22734000

Sperm-attractant peptide influences the spermatozoa swimming behavior in internal fertilization in Octopus vulgaris.

PubMed

De Lisa, Emilia; Salzano, Anna Maria; Moccia, Francesco; Scaloni, Andrea; Di Cosmo, Anna

2013-06-15

Marine invertebrates exhibit both chemokinesis and chemotaxis phenomena, induced in most cases by the release of water-borne peptides or pheromones. In mollusks, several peptides released during egg-laying improve both male attraction and mating. Unlike other cephalopods, Octopus vulgaris adopts an indirect internal fertilization strategy. We here report on the identification and characterization of a chemoattractant peptide isolated from mature eggs of octopus females. Using two-chamber and time-lapse microscopy assays, we demonstrate that this bioactive peptide is able to increase sperm motility and induce chemotaxis by changing the octopus spermatozoa swimming behavior in a dose-dependent manner. We also provide evidence that chemotaxis in the octopus requires the presence of extracellular calcium and membrane protein phophorylation at tyrosine. This study is the first report on a sperm-activating factor in a non-free-spawning marine animal.

A juvenile mouse pheromone inhibits sexual behaviour through the vomeronasal system.

PubMed

Ferrero, David M; Moeller, Lisa M; Osakada, Takuya; Horio, Nao; Li, Qian; Roy, Dheeraj S; Cichy, Annika; Spehr, Marc; Touhara, Kazushige; Liberles, Stephen D

2013-10-17

Animals display a repertoire of different social behaviours. Appropriate behavioural responses depend on sensory input received during social interactions. In mice, social behaviour is driven by pheromones, chemical signals that encode information related to age, sex and physiological state. However, although mice show different social behaviours towards adults, juveniles and neonates, sensory cues that enable specific recognition of juvenile mice are unknown. Here we describe a juvenile pheromone produced by young mice before puberty, termed exocrine-gland secreting peptide 22 (ESP22). ESP22 is secreted from the lacrimal gland and released into tears of 2- to 3-week-old mice. Upon detection, ESP22 activates high-affinity sensory neurons in the vomeronasal organ, and downstream limbic neurons in the medial amygdala. Recombinant ESP22, painted on mice, exerts a powerful inhibitory effect on adult male mating behaviour, which is abolished in knockout mice lacking TRPC2, a key signalling component of the vomeronasal organ. Furthermore, knockout of TRPC2 or loss of ESP22 production results in increased sexual behaviour of adult males towards juveniles, and sexual responses towards ESP22-deficient juveniles are suppressed by ESP22 painting. Thus, we describe a pheromone of sexually immature mice that controls an innate social behaviour, a response pathway through the accessory olfactory system and a new role for vomeronasal organ signalling in inhibiting sexual behaviour towards young. These findings provide a molecular framework for understanding how a sensory system can regulate behaviour.

Sex-pairing pheromone of Ancistrotermes dimorphus (Isoptera: Macrotermitinae).

PubMed

Wen, Ping; Mo, Jianchu; Lu, Chunwen; Tan, Ken; Šobotník, Jan; Sillam-Dussès, David

2015-12-01

Ancistrotermes dimorphus is a common Macrotermitinae representative, facultative inquiline by its life-style, occurring in South-East China. Sex pheromone is used for couple formation and maintenance, and it is produced by and released from the female sternal gland and is highly attractive to males. Based on our combined behavioral, chemical and electrophysiological analyses, we identified (3Z,6Z)-dodeca-3,6-dien-1-ol as the female sex pheromone of A. dimorphus as it evoked the tandem behavior at short distance, and the active quantities ranged from 0.01ng to 10ng. Interestingly, GC-MS analyses of SPME extracts showed another compound specific to the female sternal gland, (3Z)-dodec-3-en-1-ol, which showed a clear GC-EAD response. However, this compound has no behavioral function in natural concentrations (0.1ng), while higher amounts (1ng) inhibit the attraction achieved by (3Z,6Z)-dodeca-3,6-dien-1-ol. The function of (3Z)-dodec-3-en-1-ol is not fully understood, but might be linked to recognition from sympatric species using the same major compound, enhancing the long-distance attraction, or informing about presence of other colonies using the compound as a trail-following pheromone. The sternal gland secretion of Ancistrotermes females contains additional candidate compounds, namely (3E,6Z)-dodeca-3,6-dien-1-ol and (6Z)-dodec-6-en-1-ol, which are not perceived by males' antennae in biologically relevant amounts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evidence for partial overlap of male olfactory cues in lampreys

USGS Publications Warehouse

Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

2016-01-01

Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

Learned recognition of maternal signature odors mediates the first suckling episode in mice

PubMed Central

Logan, Darren W.; Brunet, Lisa J.; Webb, William R.; Cutforth, Tyler; Ngai, John; Stowers, Lisa

2012-01-01

Summary Background Soon after birth all mammals must initiate milk suckling to survive. In rodents, this innate behavior is critically dependent on uncharacterized maternally-derived chemosensory ligands. Recently the first pheromone sufficient to initiate suckling was isolated from the rabbit. Identification of the olfactory cues that trigger first suckling in the mouse would provide the means to determine the neural mechanisms that generate innate behavior. Results Here we use behavioral analysis, metabolomics, and calcium imaging of primary sensory neurons and find no evidence of ligands with intrinsic bioactivity, such as pheromones, acting to promote first suckling in the mouse. Instead, we find that the initiation of suckling is dependent on variable blends of maternal ‘signature odors’ that are learned and recognized prior to first suckling. Conclusions As observed with pheromone-mediated behavior, the response to signature odors releases innate behavior. However, this mechanism tolerates variability in both the signaling ligands and sensory neurons which may maximize the probability that this first essential behavior is successfully initiated. These results suggest that mammalian species have evolved multiple strategies to ensure the onset of this critical behavior. PMID:23041191

Signalling of Arabidopsis thaliana response to Pieris brassicae eggs shares similarities with PAMP-triggered immunity

PubMed Central

Reymond, Philippe

2013-01-01

Insect egg deposition activates plant defence, but very little is known about signalling events that control this response. In Arabidopsis thaliana, oviposition by Pieris brassicae triggers salicylic acid (SA) accumulation and induces the expression of defence genes. This is similar to the recognition of pathogen-associated molecular patterns (PAMPs), which are involved in PAMP-triggered immunity (PTI). Here, the involvement of known signalling components of PTI in response to oviposition was studied. Treatment with P. brassicae egg extract caused a rapid induction of early PAMP-responsive genes. In addition, expression of the defence gene PR-1 required EDS1, SID2, and, partially, NPR1, thus implicating the SA pathway downstream of egg recognition. PR-1 expression was triggered by a non-polar fraction of egg extract and by an oxidative burst modulated through the antagonistic action of EDS1 and NUDT7, but which did not depend on the NADPH oxidases RBOHD and RBOHF. Searching for receptors of egg-derived elicitors, a receptor-like kinase mutant, lecRK-I.8, was identified which shows a much reduced induction of PR-1 in response to egg extract treatment. These results demonstrate the importance of the SA pathway in response to egg-derived elicitor(s) and unravel intriguing similarities between the detection of insect eggs and PTI in Arabidopsis. PMID:23264520

The Molecular Chaperone HSPA2 Plays a Key Role in Regulating the Expression of Sperm Surface Receptors That Mediate Sperm-Egg Recognition

PubMed Central

Redgrove, Kate A.; Nixon, Brett; Baker, Mark A.; Hetherington, Louise; Baker, Gordon; Liu, De-Yi; Aitken, R. John

2012-01-01

A common defect encountered in the spermatozoa of male infertility patients is an idiopathic failure of sperm–egg recognition. In order to resolve the molecular basis of this condition we have compared the proteomic profiles of spermatozoa exhibiting an impaired capacity for sperm-egg recognition with normal cells using label free mass spectrometry (MS)-based quantification. This analysis indicated that impaired sperm–zona binding was associated with reduced expression of the molecular chaperone, heat shock 70 kDa protein 2 (HSPA2), from the sperm proteome. Western blot analysis confirmed this observation in independent patients and demonstrated that the defect did not extend to other members of the HSP70 family. HSPA2 was present in the acrosomal domain of human spermatozoa as a major component of 5 large molecular mass complexes, the most dominant of which was found to contain HSPA2 in close association with just two other proteins, sperm adhesion molecule 1 (SPAM1) and arylsulfatase A (ARSA), both of which that have previously been implicated in sperm-egg interaction. The interaction between SPAM1, ARSA and HSPA2 in a multimeric complex mediating sperm-egg interaction, coupled with the complete failure of this process when HSPA2 is depleted in infertile patients, provides new insights into the mechanisms by which sperm function is impaired in cases of male infertility. PMID:23209833

Maternal manipulation of hatching asynchrony limits sibling cannibalism in the predatory mite Phytoseiulus persimilis.

PubMed

Schausberger, P; Hoffmann, D

2008-11-01

1. Sibling cannibalism is a common phenomenon in the animal kingdom but entails a high risk of direct and inclusive fitness loss for the mother and her offspring. Therefore, mechanisms limiting sibling cannibalism are expected to be selected for. One way of maternal manipulation of sibling cannibalism is to influence hatching asynchrony between nearby laid eggs. This has rarely been tested experimentally. 2. We examined the ability of ovipositing females of the cannibalistic predatory mite Phytoseiulus persimilis to influence the occurrence of sibling cannibalism among offspring by manipulating hatching asynchrony of nearby laid eggs. 3. In the first experiment, we assessed the occurrence of sibling cannibalism in relation to the hatching interval (24 h and 48 h) between nearby laid eggs. In the second experiment, we tested whether ovipositing females discriminate sites containing young (24-h old) and old (48-h old) eggs, fresh and old traces (metabolic waste products and possibly pheromones) left by the same female (24 h and 48 h ago), or young eggs plus fresh female traces and old eggs plus old female traces. Both experiments were conducted with and without prey. 4. Without prey, siblings were more likely to cannibalize each other if the hatching interval between nearby laid eggs was short (24 h). Cannibalism occurred less often when senior siblings (protonymphs) experienced a delay in the opportunity to cannibalize junior siblings (larvae). 5. Independent of prey availability, females preferentially added new eggs to sites containing old eggs plus old female traces but did neither distinguish between young and old eggs presented without own traces nor between fresh and old traces presented without eggs. 6. We discuss cue perception and use by P. persimilis females and contrast the outcome of our experiments and theoretical predictions of sibling cannibalism. We conclude that P. persimilis mothers increase hatching asynchrony of nearby laid eggs to prevent sibling cannibalism on the last produced offspring. Such a behaviour may be considered a simple form of maternal care increasing the survival prospects of offspring.

Peripheral Coding of Sex Pheromone Blends with Reverse Ratios in Two Helicoverpa Species

PubMed Central

Huang, Ling-Qiao; Yan, Fu-Shun; Wang, Chen-Zhu

2013-01-01

The relative proportions of components in a pheromone blend play a major role in sexual recognition in moths. Two sympatric species, Helicoverpa armigera and Helicoverpa assulta, use (Z)-11-hexadecenal (Z11–16: Ald) and (Z)-9-hexadecenal (Z9–16: Ald) as essential sex pheromone components but in very different ratios, 97∶3 and 7∶93 respectively. Using wind tunnel tests, single sensillum recording and in vivo calcium imaging, we comparatively studied behavioral responses and physiological activities at the level of antennal sensilla and antennal lobe (AL) in males of the two species to blends of the two pheromone components in different ratios (100∶0, 97∶3, 50∶50, 7∶93, 0∶100). Z11–16: Ald and Z9–16: Ald were recognized by two populations of olfactory sensory neurons (OSNs) in different trichoid sensilla on antennae of both species. The ratios of OSNs responding to Z11–16:Ald and Z9–16:Ald OSNs were 100∶28.9 and 21.9∶100 in H. armigera and H. assulta, respectively. The Z11–16:Ald OSNs in H. armigera exhibited higher sensitivity and efficacy than those in H. assulta, while the Z9–16:Ald OSNs in H. armigera had the same sensitivity but lower efficacy than those in H. assulta. At the dosage of 10 µg, Z11–16: Ald and Z9–16: Ald evoked calcium activity in 8.5% and 3.0% of the AL surface in H. armigera, while 5.4% and 8.6% of AL in H. assulta, respectively. The calcium activities in the AL reflected the peripheral input signals of the binary pheromone mixtures and correlated with the behavioral output. These results demonstrate that the binary pheromone blends were precisely coded by the firing frequency of individual OSNs tuned to Z11–16: Ald or Z9–16: Ald, as well as their population sizes. Such information was then accurately reported to ALs of H. armigera and H. assulta, eventually producing different behaviors. PMID:23894593

The species recognition system: a new corollary for the human fetoembryonic defense system hypothesis.

PubMed

Clark, G F; Dell, A; Morris, H R; Patankar, M S; Easton, R L

2001-01-01

We have previously suggested that the human fetus is protected during human development by a system of both soluble and cell surface associated glycoconjugates that utilize their carbohydrate sequences as functional groups to enable them to evoke tolerance. The proposed model has been referred to as the human fetoembryonic defense system hypothesis (hu-FEDS). In this paradigm, it has previously been proposed that similar oligosaccharides are used to mediate crucial recognition events required during both human sperm-egg binding and immune-inflammatory cell interactions. This vertical integration suggested to us that the sperm-egg binding itself is related to universal recognition events that occur between immune and inflammatory cells, except that in this case recognition of 'species' rather than recognition of 'self' is being manifested. In this paper, we have designated this component of hu-FEDS as the species recognition system (SRS). We propose that the SRS is an integral component of the hu-FEDS used to enable sperm-egg recognition and protection of the gametes from potential immune responses. Recent structural data indicates that the glycan sequences implicated in mediating murine gamete recognition are also expressed on CD45 in activated murine T lymphocytes and cytotoxic T lymphocytes. This overlap supports our contention that there is an overlap between the immune and gamete recognition systems. Therefore the hu-FEDS paradigm may be a subset of a larger model that also applies to other placental mammals. We therefore propose that the hu-FEDS model for protection should in the future be referred to as the eutherian fetoembryonic defense system hypothesis (eu-FEDS) to account for this extension. The possibility exists that the SRS component of eu-FEDS could predate eutherians and extend to all sexually reproducing organisms. Future investigation of the interactions between the immune and gamete recognition system will be required to determine the degree of overlap. Copyright 2001 S. Karger AG, Basel

Molecular evolution of candidate male reproductive genes in the brown algal model Ectocarpus.

PubMed

Lipinska, Agnieszka P; Van Damme, Els J M; De Clerck, Olivier

2016-01-05

Evolutionary studies of genes that mediate recognition between sperm and egg contribute to our understanding of reproductive isolation and speciation. Surface receptors involved in fertilization are targets of sexual selection, reinforcement, and other evolutionary forces including positive selection. This observation was made across different lineages of the eukaryotic tree from land plants to mammals, and is particularly evident in free-spawning animals. Here we use the brown algal model species Ectocarpus (Phaeophyceae) to investigate the evolution of candidate gamete recognition proteins in a distant major phylogenetic group of eukaryotes. Male gamete specific genes were identified by comparing transcriptome data covering different stages of the Ectocarpus life cycle and screened for characteristics expected from gamete recognition receptors. Selected genes were sequenced in a representative number of strains from distant geographical locations and varying stages of reproductive isolation, to search for signatures of adaptive evolution. One of the genes (Esi0130_0068) showed evidence of selective pressure. Interestingly, that gene displayed domain similarities to the receptor for egg jelly (REJ) protein involved in sperm-egg recognition in sea urchins. We have identified a male gamete specific gene with similarity to known gamete recognition receptors and signatures of adaptation. Altogether, this gene could contribute to gamete interaction during reproduction as well as reproductive isolation in Ectocarpus and is therefore a good candidate for further functional evaluation.

Synthesis and olfactory activity of unnatural, sulfated 5β-bile acid derivatives in the sea lamprey (Petromyzon marinus)

PubMed Central

Burns, Aaron C.; Sorensen, Peter W.

2011-01-01

A variety of unnatural bile acid derivatives (9a–9f) were synthesized and used to examine the specificity with which the sea lamprey (Petromyzon marinus) olfactory system detects these compounds. These compounds are analogs of petromyzonol sulfate (PS, 1), a component of the sea lamprey migratory pheromone. Both the stereochemical configuration at C5 (i.e., 5α vs. 5β) and the extent and sites of oxygenation (hydroxylation or ketonization) of the bile acid derived steroid skeleton were evaluated by screening the compounds for olfactory activity using electro-olfactogram recording. 5β-Petromyzonol sulfate (9a) elicited a considerable olfactory response at sub-nanomolar concentration. In addition, less oxygenated systems (i.e., 9b–9e) elicited olfactory responses, albeit with less potency. The sea lamprey sex pheromone mimic 9f (5β-3-ketopetromyzonol sulfate) was also examined and found to produce a much lower olfactory response. Mixture studies conducted with 9a and PS (1) suggest that stimulation is occurring via similar modes of activation, demonstrating a relative lack of specificity for recognition of the allo-configuration (i.e., 5α) in sea lamprey olfaction. This attribute could facilitate design of pheromone analogs to control this invasive species. PMID:21145335

Structural Basis of Egg Coat-Sperm Recognition at Fertilization.

PubMed

Raj, Isha; Sadat Al Hosseini, Hamed; Dioguardi, Elisa; Nishimura, Kaoru; Han, Ling; Villa, Alessandra; de Sanctis, Daniele; Jovine, Luca

2017-06-15

Recognition between sperm and the egg surface marks the beginning of life in all sexually reproducing organisms. This fundamental biological event depends on the species-specific interaction between rapidly evolving counterpart molecules on the gametes. We report biochemical, crystallographic, and mutational studies of domain repeats 1-3 of invertebrate egg coat protein VERL and their interaction with cognate sperm protein lysin. VERL repeats fold like the functionally essential N-terminal repeat of mammalian sperm receptor ZP2, whose structure is also described here. Whereas sequence-divergent repeat 1 does not bind lysin, repeat 3 binds it non-species specifically via a high-affinity, largely hydrophobic interface. Due to its intermediate binding affinity, repeat 2 selectively interacts with lysin from the same species. Exposure of a highly positively charged surface of VERL-bound lysin suggests that complex formation both disrupts the organization of egg coat filaments and triggers their electrostatic repulsion, thereby opening a hole for sperm penetration and fusion. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Conservation of Bio synthetic pheromone pathways in honeybees Apis

NASA Astrophysics Data System (ADS)

Martin, Stephen J.; Jones, Graeme R.

Social insects use complex chemical communication systems to govern many aspects of their life. We studied chemical changes in Dufour's gland secretions associated with ovary development in several genotypes of honeybees. We found that C28-C38 esters were associated only with cavity nesting honeybee queens, while the alcohol eicosenol was associated only with their non-laying workers. In contrast, both egg-laying anarchistic workers and all parasitic Cape workers from queenright colonies showed the typical queen pattern (i.e. esters present and eicosenol absent), while egg-laying wild-type and anarchistic workers in queenless colonies showed an intermediate pattern, producing both esters and eicosenol but at intermediate levels. Furthermore, neither esters nor eicosenol were found in aerial nesting honeybee species. Both esters and eicosenol are biosynthetically similar compounds since both are recognizable products of fatty acid biosynthesis. Therefore, we propose that in honeybees the biosynthesis of esters and eicosenol in the Dufour's gland is caste-regulated and this pathway has been conserved over evolutionary time.

Relationships of Reproductive Traits With the Phylogeny of the African Noctuid Stem Borers

PubMed Central

Calatayud, Paul-André; Dupas, Stéphane; Frérot, Brigitte; Genestier, Gilles; Ahuya, Peter; Capdevielle-Dulac, Claire; Le Ru, Bruno

2016-01-01

The display of the reproductive behavior in most noctuid Lepidoptera follows a diel periodicity and is limited to a precise period of either the day or the night. These behavioral traits and the sex pheromone chemistry can be species specific and thus might be linked to the phylogeny. The objective of this study was to test the relationship of these reproductive traits with phylogeny. The study was undertaken using eight closely related species of noctuid stem borers, which are easy to rear under artificial conditions, namely, Busseola fusca, B. nairobica, B. sp. nr. segeta, Manga melanodonta, M. sp. nr. nubifera, Pirateolea piscator, Sesamia calamistis, and S. nonagrioides. For each species, the adult emergence period, the mating time, and the oviposition period were estimated, referred as biological traits. The components of the sex pheromones emitted by the females of each species were also analyzed by gas chromatography–mass spectrometry. Among the biological traits measured, only those linked to the oviposition pattern (timing and egg loads per night) were significantly correlated with the phylogeny of these species. For the sex pheromone components, among the 13 components identified in all species, only four, namely, Z9-tetradecenyl acetate (Z9-TDA), Z11-TDA, E11-TDA, and Z11-hexadecenyl acetate (Z11-HDA), showed the highest significant correlations with the phylogeny. These results suggest that among the different reproductive traits evaluated, only few are phylogenetically constrained. Their involvement in the reinforcement of ecological speciation in noctuid stem borers is discussed. PMID:27867304

Blue petrels recognize the odor of their egg.

PubMed

Leclaire, Sarah; Bourret, Vincent; Bonadonna, Francesco

2017-09-01

Most studies on avian olfactory communication have focused on mate choice, and the importance of olfaction in subsequent nesting stages has been poorly explored. In particular, the role of olfactory cues in egg recognition has received little attention, despite eggs potentially being spread with parental odorous secretions known to elicit individual discrimination. Here, we used behavioral choice tests to determine whether female blue petrels ( Halobaena caerulea ) can discriminate the odor of their own egg from the odor of a conspecific egg. Females preferentially approached the odor of their own egg, suggesting that blue petrels can recognize their own egg using odor cues. This finding raises the question of the adaptive value of this mechanism, and may inspire further research on odor-based egg discrimination in species suffering brood parasitism. © 2017. Published by The Company of Biologists Ltd.

Identification and Characterization of Pheromone Receptors and Interplay between Receptors and Pheromone Binding Proteins in the Diamondback Moth, Plutella xyllostella

PubMed Central

Sun, Mengjing; Liu, Yang; Walker, William B.; Liu, Chengcheng; Lin, Kejian; Gu, Shaohua; Zhang, Yongjun; Zhou, Jingjiang; Wang, Guirong

2013-01-01

Moths depend on olfactory cues such as sex pheromones to find and recognize mating partners. Pheromone receptors (PRs) and Pheromone binding proteins (PBPs) are thought to be associated with olfactory signal transduction of pheromonal compounds in peripheral olfactory reception. Here six candidate pheromone receptor genes in the diamondback moth, Plutella xyllostella were identified and cloned. All of the six candidate PR genes display male-biased expression, which is a typical characteristic of pheromone receptors. In the Xenopus-based functional study and in situ hybridization, PxylOR4 is defined as another pheromone receptor in addition to the previously characterized PxylOR1. In the study of interaction between PRs and PBPs, PxylPBPs could increase the sensitivity of the complex expressing oocyte cells to the ligand pheromone component while decreasing the sensitivity to pheromone analogs. We deduce that activating pheromone receptors in olfactory receptor neurons requires some role of PBPs to pheromone/PBP complex. If the chemical signal is not the pheromone component, but instead, a pheromone analog with a similar structure, the complex would have a decreased ability to activate downstream pheromone receptors. PMID:23626773

The Use of F2 Screening for Detection of Resistance to Emamectin Benzoate, Chlorantraniliprole, and Indoxacarb in Australian Populations of Helicoverpa armigera (Lepidoptera: Noctuidae).

PubMed

Bird, L J; Drynan, L J; Walker, P W

2017-04-01

The ability to effectively detect changes in susceptibility to insecticides is an integral component of resistance management strategies and is highly dependent upon precision of methods deployed. Between 2013 and 2016, F2 screens were performed for detection of resistance alleles in Helicoverpa armigera (Hübner) to emamectin benzoate, chlorantraniliprole, and indoxacarb in major cropping regions of eastern Australia. Resistance to emamectin benzoate was not detected. There were low but detectable levels of survival at discriminating concentrations of chlorantraniliprole and indoxacarb. Alleles conferring an advantage to chlorantraniliprole were present at a frequency of 0.0027 (95% CI 0.0012-0.0064; n = 1,817). Alleles conferring an advantage to indoxacarb were present at a frequency of 0.027 (95% CI 0.020-0.035; n = 1,863). Complementation tests for allelism in six of seven positive indoxacarb tests indicated that resistance was due to alleles present at the same locus. The majority (88%) of lines that tested positive for indoxacarb resistance deviated from a model of recessive inheritance. Pheromone-caught male moths contributed significantly greater numbers of F2 lines compared with moths derived from field-collected eggs or larvae. There was no difference in the detectability of indoxacarb resistance in F2 lines from pheromone-caught moths compared with moths derived from immature stages collected from the field and reared to adult under laboratory conditions. Therefore, we recommend the use of pheromone traps for sourcing insects for F2 screening as a more cost- and time-efficient alternative to traditional methods of sampling. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Regulation of onset of female mating and sex pheromone production by juvenile hormone in Drosophila melanogaster

PubMed Central

Bilen, Julide; Atallah, Jade; Azanchi, Reza; Levine, Joel D.; Riddiford, Lynn M.

2013-01-01

Juvenile hormone (JH) coordinates timing of female reproductive maturation in most insects. In Drosophila melanogaster, JH plays roles in both mating and egg maturation. However, very little is known about the molecular pathways associated with mating. Our behavioral analysis of females genetically lacking the corpora allata, the glands that produce JH, showed that they were courted less by males and mated later than control females. Application of the JH mimic, methoprene, to the allatectomized females just after eclosion rescued both the male courtship and the mating delay. Our studies of the null mutants of the JH receptors, Methoprene tolerant (Met) and germ cell-expressed (gce), showed that lack of Met in Met27 females delayed the onset of mating, whereas lack of Gce had little effect. The Met27 females were shown to be more attractive but less behaviorally receptive to copulation attempts. The behavioral but not the attractiveness phenotype was rescued by the Met genomic transgene. Analysis of the female cuticular hydrocarbon profiles showed that corpora allata ablation caused a delay in production of the major female-specific sex pheromones (the 7,11-C27 and -C29 dienes) and a change in the cuticular hydrocarbon blend. In the Met27 null mutant, by 48 h, the major C27 diene was greatly increased relative to wild type. In contrast, the gce2.5k null mutant females were courted similarly to control females despite changes in certain cuticular hydrocarbons. Our findings indicate that JH acts primarily via Met to modulate the timing of onset of female sex pheromone production and mating. PMID:24145432

Periodicity of sex pheromone biosynthesis, release and degradation in the lightbrown apple moth, Epiphyas postvittana (Walker).

PubMed

Foster, S P

2000-03-01

Pheromone titer in moths is a product of three processes occurring in or at the surface of the pheromone gland: biosynthesis, release, and intraglandular degradation, of pheromone. Changes in titers of sex pheromone, the fatty acyl pheromone analog (FAPA), and tetradecanoate, a pheromone biosynthetic intermediate, were studied in detail in the lightbrown apple moth, Epiphyas postvittana (Walker). Although changes in the pheromone titers in a day were relatively small, with the peak titer being 2-3 times greater than that at the trough, pheromone titer did show a distinct diel periodicity. Titer of the FAPA showed a similar, but less variable, diel pattern, but tetradecanoate titer showed little or no diel pattern. The pattern of pheromone titer suggested that females biosynthesize pheromone at two different rates during the photoperiod: a high rate during the latter half of the photophase and most of the scotophase, which is associated with a high pheromone titer, and a low rate throughout the first half of the photophase, which is associated with a low titer. Consistent with data on commencement of copulation, pheromone was released from the second hour of the scotophase through to the eighth hour. Pheromone release rate during this period appeared to be similar to the rate of pheromone biosynthesis. In contrast to the other two processes, pheromone degradation did not appear to have a diel pattern. Females decapitated at different times of the photoperiod showed a similar decline in pheromone titer, consistent with the reaction kinetics being first order in pheromone titer.

Juno is the egg Izumo receptor and is essential for mammalian fertilisation

PubMed Central

Bianchi, Enrica; Doe, Brendan; Goulding, David; Wright, Gavin J.

2014-01-01

Fertilisation occurs when sperm and egg recognise each other and fuse to form a new, genetically distinct organism. The molecular basis of sperm-egg recognition is unknown, but is likely to require interactions between receptor proteins displayed on their surface. Izumo1 is an essential sperm cell surface protein, but its egg receptor has remained a mystery. Here, we identify Juno as the receptor for Izumo1 on mouse eggs, and show this interaction is conserved within mammals. Female mice lacking Juno are infertile and Juno-deficient eggs do not fuse with normal sperm. Rapid shedding of Juno from the oolemma after fertilisation suggests a mechanism for the membrane block to polyspermy, ensuring eggs normally fuse with just a single sperm. Our discovery of an essential receptor pair at the nexus of conception provides opportunities for the rational development of new fertility treatments and contraceptives. PMID:24739963

Production of human monoclonal antibody in eggs of chimeric chickens.

PubMed

Zhu, Lei; van de Lavoir, Marie-Cecile; Albanese, Jenny; Beenhouwer, David O; Cardarelli, Pina M; Cuison, Severino; Deng, David F; Deshpande, Shrikant; Diamond, Jennifer H; Green, Lynae; Halk, Edward L; Heyer, Babette S; Kay, Robert M; Kerchner, Allyn; Leighton, Philip A; Mather, Christine M; Morrison, Sherie L; Nikolov, Zivko L; Passmore, David B; Pradas-Monne, Alicia; Preston, Benjamin T; Rangan, Vangipuram S; Shi, Mingxia; Srinivasan, Mohan; White, Steven G; Winters-Digiacinto, Peggy; Wong, Susan; Zhou, Wen; Etches, Robert J

2005-09-01

The tubular gland of the chicken oviduct is an attractive system for protein expression as large quantities of proteins are deposited in the egg, the production of eggs is easily scalable and good manufacturing practices for therapeutics from eggs have been established. Here we examined the ability of upstream and downstream DNA sequences of ovalbumin, a protein produced exclusively in very high quantities in chicken egg white, to drive tissue-specific expression of human mAb in chicken eggs. To accommodate these large regulatory regions, we established and transfected lines of chicken embryonic stem (cES) cells and formed chimeras that express mAb from cES cell-derived tubular gland cells. Eggs from high-grade chimeras contained up to 3 mg of mAb that possesses enhanced antibody-dependent cellular cytotoxicity (ADCC), nonantigenic glycosylation, acceptable half-life, excellent antigen recognition and good rates of internalization.

Sex and Aggregation-Sex Pheromones of Cerambycid Beetles: Basic Science and Practical Applications.

PubMed

Hanks, Lawrence M; Millar, Jocelyn G

2016-07-01

Research since 2004 has shown that the use of volatile attractants and pheromones is widespread in the large beetle family Cerambycidae, with pheromones now identified from more than 100 species, and likely pheromones for many more. The pheromones identified to date from species in the subfamilies Cerambycinae, Spondylidinae, and Lamiinae are all male-produced aggregation-sex pheromones that attract both sexes, whereas all known examples for species in the subfamilies Prioninae and Lepturinae are female-produced sex pheromones that attract only males. Here, we summarize the chemistry of the known pheromones, and the optimal methods for their collection, analysis, and synthesis. Attraction of cerambycids to host plant volatiles, interactions between their pheromones and host plant volatiles, and the implications of pheromone chemistry for invasion biology are discussed. We also describe optimized traps, lures, and operational parameters for practical applications of the pheromones in detection, sampling, and management of cerambycids.

A plant factory for moth pheromone production

PubMed Central

Ding, Bao-Jian; Hofvander, Per; Wang, Hong-Lei; Durrett, Timothy P.; Stymne, Sten; Löfstedt, Christer

2014-01-01

Moths depend on pheromone communication for mate finding and synthetic pheromones are used for monitoring or disruption of pheromone communication in pest insects. Here we produce moth sex pheromone, using Nicotiana benthamiana as a plant factory, by transient expression of up to four genes coding for consecutive biosynthetic steps. We specifically produce multicomponent sex pheromones for two species. The fatty alcohol fractions from the genetically modified plants are acetylated to mimic the respective sex pheromones of the small ermine moths Yponomeuta evonymella and Y. padella. These mixtures are very efficient and specific for trapping of male moths, matching the activity of conventionally produced pheromones. Our long-term vision is to design tailor-made production of any moth pheromone component in genetically modified plants. Such semisynthetic preparation of sex pheromones is a novel and cost-effective way of producing moderate to large quantities of pheromones with high purity and a minimum of hazardous waste. PMID:24569486

[Identification of special quality eggs with NIR spectroscopy technology based on symbol entropy feature extraction method].

PubMed

Zhao, Yong; Hong, Wen-Xue

2011-11-01

Fast, nondestructive and accurate identification of special quality eggs is an urgent problem. The present paper proposed a new feature extraction method based on symbol entropy to identify near infrared spectroscopy of special quality eggs. The authors selected normal eggs, free range eggs, selenium-enriched eggs and zinc-enriched eggs as research objects and measured the near-infrared diffuse reflectance spectra in the range of 12 000-4 000 cm(-1). Raw spectra were symbolically represented with aggregation approximation algorithm and symbolic entropy was extracted as feature vector. An error-correcting output codes multiclass support vector machine classifier was designed to identify the spectrum. Symbolic entropy feature is robust when parameter changed and the highest recognition rate reaches up to 100%. The results show that the identification method of special quality eggs using near-infrared is feasible and the symbol entropy can be used as a new feature extraction method of near-infrared spectra.

Identification of the pheromone biosynthesis genes from the sex pheromone gland transcriptome of the diamondback moth, Plutella xylostella.

PubMed

Chen, Da-Song; Dai, Jian-Qing; Han, Shi-Chou

2017-11-24

The diamondback moth was estimated to increase costs to the global agricultural economy as the global area increase of Brassica vegetable crops and oilseed rape. Sex pheromones traps are outstanding tools available in Integrated Pest Management for many years and provides an effective approach for DBM population monitoring and control. The ratio of two major sex pheromone compounds shows geographical variations. However, the limitation of our information in the DBM pheromone biosynthesis dampens our understanding of the ratio diversity of pheromone compounds. Here, we constructed a transcriptomic library from the DBM pheromone gland and identified genes putatively involved in the fatty acid biosynthesis, pheromones functional group transfer, and β-oxidation enzymes. In addition, odorant binding protein, chemosensory protein and pheromone binding protein genes encoded in the pheromone gland transcriptome, suggest that female DBM moths may receive odors or pheromone compounds via their pheromone gland and ovipositor system. Tissue expression profiles further revealed that two ALR, three DES and one FAR5 genes were pheromone gland tissue biased, while some chemoreception genes expressed extensively in PG, pupa, antenna and legs tissues. Finally, the candidate genes from large-scale transcriptome information may be useful for characterizing a presumed biosynthetic pathway of the DBM sex pheromone.

Pheromones affecting ovary activation and ovariole loss in the Asian honey bee Apis cerana.

PubMed

Tan, Ken; Liu, Xiwen; Dong, Sihao; Wang, Chao; Oldroyd, Benjamin P

2015-03-01

The Asian hive bee Apis cerana has similar queen mandibular pheromones (QMP) to the Western honey bee Apismellifera. However the effects of individual QMP components have never been tested to determine their effects on the reproductive physiology of A. cerana workers. We fed one queen equivalent of each of the major components of A. cerana QMP to groups of c.a. 500 day-old, caged, workers twice a day until the workers were 10 days old. Half of the cages were also provided with 10% royal jelly in the food. Workers were sampled each day and dissected to determine the number of ovarioles and the degree of ovary activation (egg development). In cages treated with 9-carbon fatty acids ovary activation was minimal, whereas the 10-carbon acids suppressed ovary activation very little. Royal jelly enhanced ovary activation, especially in cages treated with 10-carbon acids. The number of ovarioles declined with bee age, but the rate of decline was slowed by the 9-carbon acids in particular. The results show conservation of the composition and function of QMP between A. cerana and A. mellifera and support the hypothesis that QMP is an honest signal of queen fecundity rather than a chemical castrator of workers. Copyright © 2015 Elsevier Ltd. All rights reserved.

European corn borer sex pheromone : Inhibition and elicitation of behavioral response by analogs.

PubMed

Schwarz, M; Klun, J A; Uebel, E C

1990-05-01

The male sexual behavior-stimulating and inhibiting properties of a series of analogs of the European corn borer sex pheromone were determined in a flight tunnel. The structural requirements for inhibition of pheromonal response were far less restrictive than those for elicitation of that response. Analogs that by themselves elicited upwind flight response from males at a low dose were generally less inhibitory to male response than many of the analogs that had no pheromonal activity. These findings suggest that many pheromone analogs bind to pheromone receptors without provoking behavioral response and possibly undergo slower degradation on the antenna than pheromonally active compounds. The disparity of response to analogs by two pheromonal types of the European corn borer indicates that the pheromone receptor and pheromone catabolic systems are biochemically very different in the two types.

Discovery and characterization of natural products that act as pheromones in fish.

PubMed

Li, Ke; Buchinger, Tyler J; Li, Weiming

2018-06-20

Covering: up to 2018 Fish use a diverse collection of molecules to communicate with conspecifics. Since Karlson and Lüscher termed these molecules 'pheromones', chemists and biologists have joined efforts to characterize their structures and functions. In particular, the understanding of insect pheromones developed at a rapid pace, set, in part, by the use of bioassay-guided fractionation and natural product chemistry. Research on vertebrate pheromones, however, has progressed more slowly. Initially, biologists characterized fish pheromones by screening commercially available compounds suspected to act as pheromones based upon their physiological function. Such biology-driven screening has proven a productive approach to studying pheromones in fish. However, the many functions of fish pheromones and diverse metabolites that fish release make predicting pheromone identity difficult and necessitate approaches led by chemistry. Indeed, the few cases in which pheromone identification was led by natural product chemistry indicated novel or otherwise unpredicted compounds act as pheromones. Here, we provide a brief review of the approaches to identifying pheromones, placing particular emphasis on the promise of using natural product chemistry together with assays of biological activity. Several case studies illustrate bioassay-guided fractionation as an approach to pheromone identification in fish and the unexpected diversity of pheromone structures discovered by natural product chemistry. With recent advances in natural product chemistry, bioassay-guided fractionation is likely to unveil an even broader collection of pheromone structures and enable research that spans across disciplines.

Chemical Communication and Reproduction Partitioning in Social Wasps.

PubMed

Dani, Francesca Romana; Turillazzi, Stefano

2018-05-22

Social wasps encompass species displaying diverse social organization regarding colony cycle, nest foundation, caste differences (from none to significant dimorphism) and number of reproductive queens. Current phylogenetic data suggests that sociality occured independently in the subfamily Stenogastrinae and in the Polistinae+Vespinae clade. In most species, including those with the simplest social organization, colony reproduction is monopolised by a single or few females. Since their nest mates can also develop ovaries and lay eggs, dominant females must somehow inhibit them from reproducing. Physical interactions in the form of open aggression or, usually, ritualised dominance by the fertile females contribute to fertility inhibition in several species, but it is unlikely to function in large colonies. In the latter case, reproduction within the colony is likely to be regulated through pheromones. Relatively little is known about these semiochemicals. Studies on all the three social wasp subfamilies, revealed that cuticular hydrocarbon components differ in abundance between egg-laying and not egg-laying females and that their composition depends on fertility status. In several species, females have been reported to manifestly react towards females with activated ovaries, but there is little evidence to support the hypothesis that fertile individuals are either recognized through their CHC composition, or that over-represented CHC constituents can inhibit fertility. Moreover, very little information exists on the possibility that exocrine glands release fertility signals or chemicals inhibiting fertility.

Isolation of a pyrazine alarm pheromone component from the fire ant, Solenopsis invicta.

PubMed

Vander Meer, Robert K; Preston, Catherine A; Choi, Man-Yeon

2010-02-01

Alarm pheromones in social insects are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality. The alarm pheromones of ants were among the first examples of animal pheromones identified, primarily because of the large amount of chemical produced and the distinctive responses of ants to the pheromone. However, the alarm pheromone of the fire ant, Solenopsis invicta, eluded identification for over four decades. We identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of S. invicta. Worker fire ants detect the pyrazine alarm pheromone at 30 pg/ml, which is comparable to alarm pheromone sensitivities reported for other ant species. The source of this alarm pheromone are the mandibular glands, which, in fire ants, are not well developed and contain only about 300 pg of the compound, much less than the microgram quantities of alarm pheromones reported for several other ant species. Female and male sexuals and workers produce the pyrazine, which suggests that it may be involved in fire ant mating flight initiation, as well as the typical worker alarm response. This is the first report of 2-ethyl-3,6-dimethylpyrazine from a Solenopsis species and the first example of this alkaloid functioning as an alarm pheromone.

Ant Trail Pheromone Biosynthesis Is Triggered by a Neuropeptide Hormone

PubMed Central

Choi, Man-Yeon; Vander Meer, Robert K.

2012-01-01

Our understanding of insect chemical communication including pheromone identification, synthesis, and their role in behavior has advanced tremendously over the last half-century. However, endocrine regulation of pheromone biosynthesis has progressed slowly due to the complexity of direct and/or indirect hormonal activation of the biosynthetic cascades resulting in insect pheromones. Over 20 years ago, a neurohormone, pheromone biosynthesis activating neuropeptide (PBAN) was identified that stimulated sex pheromone biosynthesis in a lepidopteran moth. Since then, the physiological role, target site, and signal transduction of PBAN has become well understood for sex pheromone biosynthesis in moths. Despite that PBAN-like peptides (∼200) have been identified from various insect Orders, their role in pheromone regulation had not expanded to the other insect groups except for Lepidoptera. Here, we report that trail pheromone biosynthesis in the Dufour's gland (DG) of the fire ant, Solenopsis invicta, is regulated by PBAN. RNAi knock down of PBAN gene (in subesophageal ganglia) or PBAN receptor gene (in DG) expression inhibited trail pheromone biosynthesis. Reduced trail pheromone was documented analytically and through a behavioral bioassay. Extension of PBAN's role in pheromone biosynthesis to a new target insect, mode of action, and behavioral function will renew research efforts on the involvement of PBAN in pheromone biosynthesis in Insecta. PMID:23226278

Access to the odor world: olfactory receptors and their role for signal transduction in insects.

PubMed

Fleischer, Joerg; Pregitzer, Pablo; Breer, Heinz; Krieger, Jürgen

2018-02-01

The sense of smell enables insects to recognize and discriminate a broad range of volatile chemicals in their environment originating from prey, host plants and conspecifics. These olfactory cues are received by olfactory sensory neurons (OSNs) that relay information about food sources, oviposition sites and mates to the brain and thus elicit distinct odor-evoked behaviors. Research over the last decades has greatly advanced our knowledge concerning the molecular basis underlying the reception of odorous compounds and the mechanisms of signal transduction in OSNs. The emerging picture clearly indicates that OSNs of insects recognize odorants and pheromones by means of ligand-binding membrane proteins encoded by large and diverse families of receptor genes. In contrast, the mechanisms of the chemo-electrical transduction process are not fully understood; the present status suggests a contribution of ionotropic as well as metabotropic mechanisms. In this review, we will summarize current knowledge on the peripheral mechanisms of odor sensing in insects focusing on olfactory receptors and their specific role in the recognition and transduction of odorant and pheromone signals by OSNs.

Dual role of preputial gland secretion and its major components in sex recognition of mice.

PubMed

Zhang, Jian-Xu; Liu, Ying-Juan; Zhang, Jin-Hua; Sun, Lixing

2008-10-20

This study was aimed at validating the sexual attractiveness of hexadecanol and hexadecyl acetate, two putative pheromone compounds, from preputial gland secretion of mice. These two compounds have been reported to be among the major components of preputial gland secretion in both sexes but higher in quantity in males than females. In this study, we show that castration suppressed the production of the two compounds, further suggesting their association with maleness. Adding preputial gland secretion and the synthetic analogs of the two compounds to castrated male urine at their physiological levels in intact males increased the attractiveness of castrated male urine to female mice, showing that the two compounds were indeed male pheromones. Furthermore, their sexual attractiveness disappeared upon removing the vomeronasal organs (VNOs) from female recipients. Replenishing castrated male urine with preputial gland secretion and the two compounds at their physiological levels in females increased the attractiveness of castrated male urine to males. Such a reversal of sexual attractiveness for hexadecanol and hexadecyl acetate suggests that they had opposing dual effects in sexual attractiveness in a dosage-dependent manner.

A simple rule reduces costs of extragroup parasitism in a communally breeding bird.

PubMed

Riehl, Christina

2010-10-26

How do cooperatively breeding groups resist invasion by parasitic "cheaters," which dump their eggs in the communal nest but provide no parental care [1,2]? Here I show that Greater Anis (Crotophaga major), Neotropical cuckoos that nest in social groups containing several breeding females [3], use a simple rule based on the timing of laying to recognize and reject eggs laid by extragroup parasites. I experimentally confirmed that Greater Anis cannot recognize parasitic eggs based on the appearance of host egg phenotypes or on the number of eggs in the clutch. However, they can discriminate between freshly laid eggs and those that have already been incubated, and they accordingly eject asynchronous eggs. This mechanism is reliable in naturally parasitized nests, because group members typically lay their eggs in tight synchrony, whereas the majority of parasitic eggs are laid several days later. Rejection of asynchronous eggs therefore provides a rare empirical example of a complex, group-level behavior that arises through relatively simple "rules of thumb" without requiring advanced cognitive mechanisms such as learning, counting, or individual recognition. Copyright © 2010 Elsevier Ltd. All rights reserved.

Becoming a mother by non-anonymous egg donation: secrecy and the relationship between egg recipient, egg donor and egg donation child.

PubMed

van Berkel, D; Candido, A; Pijffers, W H

2007-06-01

The object of the study was to investigate secrecy in non-anonymous egg donation, to explore some characteristics of this kind of egg donation arrangement and the relationship of the recipient with her non-genetic child. Forty-four egg recipients and 62 IVF patients with a child conceived through egg donation and/or IVF were recruited. A semi-structured questionnaire was sent to all the participants. Chi-square and T-tests were used to examine the differences between the groups. There were no significant differences on the following aspects. The same high proportion of egg donation mothers (77%) and IVF mothers (87%) had the intention of telling their child about the conception but most women thought disclosure at a later time preferable. Two thirds of the recipients and IVF mothers said the way of conception had no influence on the relationship with their child. The two groups differed however in their argumentation about secrecy and named different feelings. Egg donation mothers expressed more denial and showed more defensive reactions, anxieties and uncertainty. It is suggested that recognition of a certain difference between a natural conception and egg donation could be helpful in early disclosure and could help to diminish anxieties in egg donation mothers.

An End-to-End Model of Plant Pheromone Channel for Long Range Molecular Communication.

PubMed

Unluturk, Bige D; Akyildiz, Ian F

2017-01-01

A new track in molecular communication is using pheromones which can scale up the range of diffusion-based communication from μm meters to meters and enable new applications requiring long range. Pheromone communication is the emission of molecules in the air which trigger behavioral or physiological responses in receiving organisms. The objective of this paper is to introduce a new end-to-end model which incorporates pheromone behavior with communication theory for plants. The proposed model includes both the transmission and reception processes as well as the propagation channel. The transmission process is the emission of pheromones from the leaves of plants. The dispersion of pheromones by the flow of wind constitutes the propagation process. The reception process is the sensing of pheromones by the pheromone receptors of plants. The major difference of pheromone communication from other molecular communication techniques is the dispersion channel acting under the laws of turbulent diffusion. In this paper, the pheromone channel is modeled as a Gaussian puff, i.e., a cloud of pheromone released instantaneously from the source whose dispersion follows a Gaussian distribution. Numerical results on the performance of the overall end-to-end pheromone channel in terms of normalized gain and delay are provided.

Glycerol-3-phosphate O-acyltransferase is required for PBAN-induced sex pheromone biosynthesis in Bombyx mori

PubMed Central

Du, Mengfang; Liu, Xiaoguang; Liu, Xiaoming; Yin, Xinming; Han, Shuangyin; Song, Qisheng; An, Shiheng

2015-01-01

Female moths employ their own pheromone blends as a communicational medium in mating behavior. The biosynthesis and release of sex pheromone in female moths are regulated by pheromone biosynthesis activating neuropeptide (PBAN) and the corresponding action of PBAN has been well elucidated in Bombyx mori. However, very little is known about the molecular mechanism regarding the biosynthesis of sex pheromone precursor. In this study, quantitative proteomics was utilized to comprehensively elucidate the expression dynamics of pheromone glands (PGs) during development. Proteomic analysis revealed a serial of differentially expressed sex pheromone biosynthesis-associated proteins at the different time points of B. mori development. Most interestingly B. mori glycerol-3-phosphate O-acyltransferase (BmGPAT) was found to be expressed during the key periods of sex pheromone biosynthesis. RNAi knockdown of BmGPAT confirmed the important function of this protein in the biosynthesis of sex pheromone precursor, triacylglcerol (TAG), and subsequently PBAN-induced production of sex pheromone, bombykol. Behavioral analysis showed that RNAi knockdown of GPAT significantly impaired the ability of females to attract males. Our findings indicate that GPAT acts to regulate the biosynthesis of sex pheromone precursor, TAG, thus influencing PBAN-induced sex pheromone production and subsequent mating behavior. PMID:25630665

Pheromone Autodetection: Evidence and Implications

PubMed Central

Holdcraft, Robert; Rodriguez-Saona, Cesar; Stelinski, Lukasz L.

2016-01-01

Olfactory communication research with insects utilizing sex pheromones has focused on the effects of pheromones on signal receivers. Early pheromone detection studies using the silkworm moth, Bombyx mori L., and Saturniids led to the assumption that emitters, especially females, are unable to detect their own pheromone. Pheromone anosmia, i.e., the inability of females to detect their conspecific sex pheromone, was often assumed, and initially little attention was paid to female behaviors that may result from autodetection, i.e., the ability of females to detect their sex pheromone. Detection of conspecific pheromone plumes from nearby females may provide information to improve chances of mating success and progeny survival. Since the first documented example in 1972, numerous occurrences of autodetection have been observed and verified in field and laboratory studies. We summarize here a significant portion of research relating to autodetection. Electrophysiological and behavioral investigations, as well as expression patterns of proteins involved in pheromone autodetection are included. We discuss problems inherent in defining a boundary between sex and aggregation pheromones considering the occurrence of autodetection, and summarize hypothesized selection pressures favoring autodetection. Importance of including autodetection studies in future work is emphasized by complications arising from a lack of knowledge combined with expanding the use of pheromones in agriculture. PMID:27120623

Binding Properties of General Odorant Binding Proteins from the Oriental Fruit Moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae)

PubMed Central

Li, Guangwei; Chen, Xiulin; Li, Boliao; Zhang, Guohui; Li, Yiping; Wu, Junxiang

2016-01-01

Background The oriental fruit moth Grapholita molesta is a host-switching pest species. The adults highly depend on olfactory cues in locating optimal host plants and oviposition sites. Odorant binding proteins (OBPs) are thought to be responsible for recognizing and transporting hydrophobic odorants across the aqueous sensillum lymph to stimulate the odorant receptors (ORs) within the antennal sensilla and activate the olfactory signal transduction pathway. Exploring the physiological function of these OBPs could facilitate understanding insect chemical communications. Methodology/Principal Finding Two antennae-specific general OBPs (GOBPs) of G. molesta were expressed and purified in vitro. The binding affinities of G. molesta GOBP1 and 2 (GmolGOBP1 and 2) for sex pheromone components and host plant volatiles were measured by fluorescence ligand-binding assays. The distribution of GmolGOBP1 and 2 in the antennal sensillum were defined by whole mount fluorescence immunohistochemistry (WM-FIHC) experiments. The binding sites of GmolGOBP2 were predicted using homology modeling, molecular docking and site-directed mutagenesis. Both GmolGOBP1 and 2 are housing in sensilla basiconica and with no differences in male and female antennae. Recombinant GmolGOBP1 (rGmolGOBP1) exhibited broad binding properties towards host plant volatiles and sex pheromone components; rGmolGOBP2 could not effectively bind host plant volatiles but showed specific binding affinity with a minor sex pheromone component dodecanol. We chose GmolGOBP2 and dodecanol for further homology modeling, molecular docking, and site-directed mutagenesis. Binding affinities of mutants demonstrated that Thr9 was the key binding site and confirmed dodecanol bonding to protein involves a hydrogen bond. Combined with the pH effect on binding affinities of rGmolGOBP2, ligand binding and release of GmolGOBP2 were related to a pH-dependent conformational transition. Conclusion Two rGmolGOBPs exhibit different binding characteristics for tested ligands. rGmolGOBP1 has dual functions in recognition of host plant volatiles and sex pheromone components, while rGmolGOBP2 is mainly involved in minor sex pheromone component dodecanol perception. This study also provides empirical evidence for the predicted functions of key amino acids in recombinant protein ligand-binding characteristics. PMID:27152703

Interspecific interaction between Telenomus remus (Hymenoptera: Platygastridae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) on Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs.

PubMed

Carneiro, Tatiana R; Fernandes, Odair A

2012-12-01

This work aims to evaluate the interspecific interaction between Trichogramma pretiosum and Telenomus remus, two biological control agents of fall armyworm (Spodoptera frugiperda) eggs. Eggs of Spodoptera frugiperda previously parasitized by Telenomus remus were offered to Trichogramma pretiosum, and those parasitized by Trichogramma pretiosum were offered to Telenomus remus. The previously parasitized eggs were tested at different embryonic development stages for each parasitoid. In addition, to evaluate the competition between species, Spodoptera frugiperda eggs were offered to the parasitoids simultaneously. The behavior of the insects was recorded under a stereomicroscope. When Spodoptera frugiperda eggs were previously exposed to either parasitoid, there was no emergence of the other parasitoid. When the Telenomus remus and Trichogramma pretiosum females were placed together with Spodoptera frugiperda eggs, Telenomus remus had a greater parasitism rate. Except searching time, all Trichogramma pretiosum behaviors took a longer time than Telenomus remus behaviors. Thus, despite belonging to different families, each of these parasitoids is able to recognize host eggs previously parasitized by the other. So, this suggests that the recognition mechanism involved is not exclusively specific.

Pheromone Signalling

ERIC Educational Resources Information Center

Hart, Adam G.

2011-01-01

Pheromones are chemicals used to communicate with members of the same species. First described in insects, pheromones are often used to attract mates but in social insects, such as ants and bees, pheromone use is much more sophisticated. For example, ants use pheromones to make foraging trails and the chemical and physical properties of the…

Sex pheromone and trail pheromone of the sand termite Psammotermes hybostoma.

PubMed

Sillam-Dussès, David; Hanus, Robert; Abd El-Latif, Ashraf Oukasha; Jiroš, Pavel; Krasulová, Jana; Kalinová, Blanka; Valterová, Irena; Sobotník, Jan

2011-02-01

Within the complex network of chemical signals used by termites, trail pheromones and sex pheromones are among the best known. Numerous recent papers map the chemical identity and glandular origin of these pheromones in nearly all major isopteran taxa. In this study, we aimed to describe the sex pheromone and the trail pheromone of a poorly known sand termite, Psammotermes hybostoma. We identified (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol (dodecatrienol) as the sex pheromone released by tergal and sternal glands of female imagos and, at the same time, as the trail pheromone secreted from the sternal gland of workers. We conclude that chemical communication in Psammotermes does not differ from that of most other Rhinotermitidae, such as Reticulitermes, despite the presence of a diterpene as a major component of the trail pheromone of Prorhinotermes to which Psammotermes is presumed to be phylogenetically close. Our findings underline once again the conservative nature of chemical communication in termites, with dodecatrienol being a frequent component of pheromonal signals in trail following and sex attraction and, at the same time, a tight evolutionary relationship between the trail following of working castes and the sex attraction of imagos.

Turning workers into false queens- the role of exogenous pheromones in regulating reproduction in worker honey bees.

PubMed

Yusuf, Abdullahi A; Crewe, Robin M; Pirk, Christian W W

2018-05-18

One of the responses that honey bee workers can make in the event of queen loss is to develop into false queens. False queens are workers that exhibit both behavioural and physiological traits similar to those of a true queen. However, the presence of more than one false queen in a colony distorts the established hierarchies. As transformation into a false queen occurs after emergence as an adult, we tested the effect of worker mobile pheromone carriers (PCs) treated with exogenously supplied pheromones on their nestmates. The PCs carried either synthetic mandibular gland pheromones or pheromones extracted from capensis parasitic workers . Only PCs attracted retinues of workers, increased pheromone production, and activated their ovaries becoming false queens. Pheromones from capensis workers were more effective than extracts of commercially available synthetic queen pheromones in eliciting these effects. Using this simple mobile pheromone delivery system, we have shown that, carrying amounts of exogenous pheromone can induce pheromone production in the carrier resulting in the production of false queens within experimental groups. Possible implications of using this technique to modify and regulate worker reproduction in colonies are discussed. © 2018. Published by The Company of Biologists Ltd.

Pheromones and pheromone receptors are required for proper sexual development in the homothallic ascomycete Sordaria macrospora.

PubMed

Mayrhofer, Severine; Weber, Jan M; Pöggeler, Stefanie

2006-03-01

The homothallic, filamentous ascomycete Sordaria macrospora is self-fertile and produces sexual fruiting bodies (perithecia) without a mating partner. Even so, S. macrospora transcriptionally expresses two pheromone-precursor genes (ppg1 and ppg2) and two pheromone-receptor genes (pre1 and pre2). The proteins encoded by these genes are similar to alpha-factor-like and a-factor-like pheromones and to G-protein-coupled pheromone receptors of the yeast Saccharomyces cerevisiae. It has been suggested that in S. macrospora, PPG1/PRE2 and PPG2/PRE1 form two cognate pheromone-receptor pairs. To investigate their function, we deleted (delta) pheromone-precursor genes (delta ppg1, delta ppg2) and receptor genes (delta pre1, delta pre2) and generated single- as well as double-knockout strains. No effect on vegetative growth, fruiting-body, and ascospore development was seen in the single pheromone-mutant and receptor-mutant strains, respectively. However, double-knockout strains lacking any compatible pheromone-receptor pair (delta pre2/delta ppg2, delta pre1/delta ppg1) and the double-pheromone mutant (delta ppg1/delta ppg2) displayed a drastically reduced number of perithecia and sexual spores, whereas deletion of both receptor genes (delta pre1/delta pre2) completely eliminated fruiting-body and ascospore formation. The results suggest that pheromones and pheromone receptors are required for optimal sexual reproduction of the homothallic S. macrospora.

Utilization of pheromones in the population management of moth pests.

PubMed Central

Cardé, R T

1976-01-01

Pheromones are substances emitted by one individual of a species and eliciting a specific response in a second individual of the same species. In moths (Lepidoptera) generally females lure males for mating by emission of a sex attractant pheromone comprised of either one or more components. Since 1966 the identification of the pheromone blends of many moth pests has allowed investigations into the use of these messengers for population manipulation. Pheromone-baited traps may be used both to detect pest presence and to estimate population density, so that conventional control tactics can be employed only as required and timed precisely for maximum effectiveness. Attractant traps also can be utilized for direct population suppression when the traps are deployed at a density effective in reducing mating success sufficiently to achieve control. A third use pattern of pheromones and related compounds is disruption of pheromone communication via atmospheric permeation with synthetic disruptants. The behavioral modifications involved in disruption of communication may include habituation of the normal response sequence (alteration of the pheromone response threshold) and "confusion" (inability of the organism to perceive and orient to the naturally emitted lure). Disruption of communication employing the natural pheromone components as the disruptant has been most successful, although nonattractant behavioral modifiers structurally similar to the pheromone components also may prove useful. Possible future resistance to direct pheromone manipulation may be expected to involve the evolution of behavioral and sensory changes that minimize the informational overlap between the natural pheromone system and the pheromone control technique. PMID:789060

Polychlorinated biphenyls in Great Lakes lake trout and their eggs: relations to survival and congener composition 1979-1988

USGS Publications Warehouse

Mac, Michael J.; Schwartz, Ted R.; Edsall, Carol C.; Frank, Anthony M.

1993-01-01

Eggs taken from lake trout (Salvelinus namaycush) captured from various Great Lakes between 1979 and 1988 were analyzed for individual polychlorinated biphenyl (PCB) congeners. Eggs from the same fish had been previously reared through hatching and early fry development to ascertain egg quality. Tissues from a subsample of the adult females that provided eggs were similarly analyzed. Significant relations were found between embryonic mortality (eggs dying between fertilization and hatch) and the concentrations of total PCBs in both the eggs and adults. PCB concentrations were also negatively correlated with the percentage of normal fry that successfully hatched, but no relation was found between PCB residues and fry mortality. Pattern recognition analysis indicated that the PCB congener fingerprint for eggs from Lake Superior was different than that of eggs from Lakes Michigan, Huron, and Ontario. A difference between PCB residue patterns was also identified between eggs and the parent fish. While this difference indicated some preferential deposition of congeners in the eggs, the difference was not attributed to the toxic AHH-active congeners. No difference in the PCB pattern was observed over the 10 years of sample collection, demonstrating that concentrations of individual congeners are declining at similar rates.

Controlled release of insect sex pheromones from paraffin wax and emulsions.

PubMed

Atterholt, C A; Delwiche, M J; Rice, R E; Krochta, J M

1999-02-22

Paraffin wax and aqueous paraffin emulsions can be used as controlled release carriers for insect sex pheromones for mating disruption of orchard pests. Paraffin can be applied at ambient temperature as an aqueous emulsion, adheres to tree bark or foliage, releases pheromone for an extended period of time, and will slowly erode from bark and biodegrade in soil. Pheromone emulsions can be applied with simple spray equipment. Pheromone release-rates from paraffin were measured in laboratory flow-cell experiments. Pheromone was trapped from an air stream with an adsorbent, eluted periodically, and quantified by gas chromatography. Pheromone release from paraffin was partition-controlled, providing a constant (zero-order) release rate. A typical paraffin emulsion consisted of 30% paraffin, 4% pheromone, 4% soy oil, 1% vitamin E, 2% emulsifier, and the balance water. Soy oil and vitamin E acted as volatility suppressants. A constant release of oriental fruit moth pheromone from paraffin emulsions was observed in the laboratory for more than 100 days at 27 degreesC, with release-rates ranging from 0.4 to 2 mg/day, depending on the concentration and surface area of the dried emulsion. The use of paraffin emulsions is a viable method for direct application of insect pheromones for mating disruption. Sprayable formulations can be designed to release insect pheromones to the environment at a rate necessary for insect control by mating disruption. At temperatures below 38 degreesC, zero-order release was observed. At 38 degreesC and higher, pheromone oxidation occurred. A partition-controlled release mechanism was supported by a zero-order pheromone release-rate, low air/wax partition coefficients, and pheromone solubility in paraffin.

Functional characterization of an alpha-factor-like Sordaria macrospora peptide pheromone and analysis of its interaction with its cognate receptor in Saccharomyces cerevisiae.

PubMed

Mayrhofer, Severine; Pöggeler, Stefanie

2005-04-01

The homothallic filamentous ascomycete Sordaria macrospora possesses genes which are thought to encode two pheromone precursors and two seven-transmembrane pheromone receptors. The pheromone precursor genes are termed ppg1 and ppg2. The putative products derived from the gene sequence show structural similarity to the alpha-factor precursors and a-factor precursors of the yeast Saccharomyces cerevisiae. Likewise, sequence similarity has been found between the putative products of the pheromone receptor genes pre2 and pre1 and the S. cerevisiae Ste2p alpha-factor receptor and Ste3p a-factor receptor, respectively. To investigate whether the alpha-factor-like pheromone-receptor pair of S. macrospora is functional, a heterologous yeast assay was used. Our results show that the S. macrospora alpha-factor-like pheromone precursor PPG1 is processed into an active pheromone by yeast MATalpha cells. The S. macrospora PRE2 protein was demonstrated to be a peptide pheromone receptor. In yeast MATa cells lacking the endogenous Ste2p receptor, the S. macrospora PRE2 receptor facilitated all aspects of the pheromone response. Using a synthetic peptide, we can now predict the sequence of one active form of the S. macrospora peptide pheromone. We proved that S. macrospora wild-type strains secrete an active pheromone into the culture medium and that disruption of the ppg1 gene in S. macrospora prevents pheromone production. However, loss of the ppg1 gene does not affect vegetative growth or fertility. Finally, we established the yeast assay as an easy and useful system for analyzing pheromone production in developmental mutants of S. macrospora.

Field and Laboratory Responses of Male Leaf Roller Moths, Choristoneura rosaceana and Pandemis pyrusana, to Pheromone Concentrations in an Attracticide Paste Formulation

PubMed Central

Curkovic, Tomislav; Brunner, Jay F.; Landolt, Peter J.

2009-01-01

Male leafroller moths, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) and Pandemis pyrusana (Kearfott), were evaluated for responses to a paste formulation loaded with a range of concentrations of the two species' pheromone blends and evaluated in a laboratory wind tunnel and in the field. Response criteria were flight, flight towards the pheromone source, and contact with the pheromone source for the wind tunnel assays, and capture of moths in traps for the field tests. In the wind tunnel and field, responses of males of both species to the paste generally increased as the pheromone concentration in the paste was increased. There was little response by either species to paste with less than 0.16% pheromone. The relationship between pheromone concentration and response for P. pyrusana was linear and for C. rosaceana was sinusoidal over the range of pheromone concentrations tested. These patterns were seen both in the wind tunnel and in the field. Initial release rates from the paste of (Z)-11-tetradecenyl acetate, the main component of the pheromone blends of both species was 3.6–3.8 ng/h. Inhibitory thresholds for responses were not reached for either species, using pheromone concentrations as high as 16%, in either the wind tunnel or the field. For both species, response of males to rubber septa with one mg pheromone loads was similar to the response to the paste with pheromone at concentrations greater than 3–4%. For C. rosaceana, rates of contact with the paste in the wind tunnel were statistically similar to rates of contact in response to conspecific females, with paste pheromone concentrations above 1.6%. Response rates for males of P. pyrusana were significantly lower to the paste than to conspecific females at all paste pheromone concentrations tested. Overall, the optimum pheromone concentration in the paste for moth attraction to contact was 3.2 % for C. rosaceana and 8% for P. pyrusana. PMID:19619030

Regulatory Role of PBAN in Sex Pheromone Biosynthesis of Heliothine Moths

PubMed Central

Jurenka, Russell; Rafaeli, Ada

2011-01-01

Both males and females of heliothine moths utilize sex-pheromones during the mating process. Females produce and release a sex pheromone for the long–range attraction of males for mating. Production of sex pheromone in females is controlled by the peptide hormone (pheromone biosynthesis activating neuropeptide, PBAN). This review will highlight what is known about the role PBAN plays in controlling pheromone production in female moths. Male moths produce compounds associated with a hairpencil structure associated with the aedaegus that are used as short-range aphrodisiacs during the mating process. We will discuss the role that PBAN plays in regulating male production of hairpencil pheromones. PMID:22654810

Is parasite pressure a driver of chemical cue diversity in ants?

PubMed Central

Martin, Stephen J.; Helanterä, Heikki; Drijfhout, Falko P.

2011-01-01

Parasites and pathogens are possibly key evolutionary forces driving recognition systems. However, empirical evidence remains sparse. The ubiquitous pioneering ant Formica fusca is exploited by numerous socially parasitic ant species. We compared the chemical cue diversity, egg and nest mate recognition abilities in two Finnish and two UK populations where parasite pressure is high or absent, respectively. Finnish populations had excellent egg and nest mate discrimination abilities, which were lost in the UK populations. The loss of discrimination behaviour correlates with a loss in key recognition compounds (C25-dimethylalkanes). This was not owing to genetic drift or different ecotypes since neutral gene diversity was the same in both countries. Furthermore, it is known that the cuticular hydrocarbon profiles of non-host ant species remain stable between Finland and the UK. The most parsimonious explanation for the striking difference in the cue diversity (number of C25-dimethylalkanes isomers) between the UK and Finland populations is the large differences in parasite pressure experienced by F. fusca in the two countries. These results have strong parallels with bird (cuckoo) studies and support the hypothesis that parasites are driving recognition cue diversity. PMID:20610426

The influence of volatile semiochemicals from stink bug eggs and oviposition-damaged plants on the foraging behaviour of the egg parasitoid Telenomus podisi.

PubMed

Michereff, M F F; Borges, M; Aquino, M F S; Laumann, R A; Mendes Gomes, A C M; Blassioli-Moraes, M C

2016-10-01

During host selection, physical and chemical stimuli provide important cues that modify search behaviours of natural enemies. We evaluated the influence of volatiles released by eggs and egg extracts of the stink bug Euschistus heros and by soybean plants treated with the eggs and egg extracts on Telenomus podisi foraging behaviour. Responses to volatiles were evaluated in Y-tube olfactometers after exposure to (1) one egg cluster for 24 h; (2) plants with eggs laid by the stink bug, tested at 24, 48, and 72 h after treatment; (3) plants with eggs laid artificially, tested at 24, 48, and 72 h after treatment; and (4) plants treated with acetone or hexane extracts of eggs. Telenomus podisi was attracted to volatiles emitted by one egg cluster and to acetone extracts of one egg cluster, but not to air or acetone controls. There were no responses to odours of plants treated with eggs or egg extracts. Analysis of acetone extracts of egg clusters by gas chromatography revealed the major components were saturated and unsaturated fatty acids, including hexadecanoic acid, linoleic acid, and (Z)-9-octadecenoic acid. Our results suggest that one egg cluster and the acetone extract of one egg cluster contain volatile compounds that can modify T. podisi foraging behaviour, and that the amounts of these compounds, probably together with some minor compounds, are important for host recognition by T. podisi. Also, the oviposition damage or egg extracts on the plant did not elicit indirect defences that attracted Telenomus podisi.

Impacts of biological control and invasive species on a non-target native Hawaiian insect.

PubMed

Johnson, M Tracy; Follett, Peter A; Taylor, Andrew D; Jones, Vincent P

2005-02-01

The potential for classical biological control to cause unintended harm to native species was evaluated in the case of the endemic Hawaiian koa bug, Coleotichus blackburniae White (Hemiptera: Scutelleridae), and parasitoids introduced to Hawaii for control of an agricultural pest, the southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae). Parasitism of C. blackburniae eggs, nymphs and adults by biocontrol agents was quantified across a wide range of habitats and compared to other sources of mortality. Egg mortality due to the biocontrol agent Trissolcus basalis Wollaston (Hymenoptera: Scelionidae) was low (maximum 26%) and confined to elevations below 500 m on a single host plant. Predation, mainly by alien spiders and ants, was the greatest source of egg mortality (maximum 87%). Parasitism of adult C. blackburniae by the biocontrol agent Trichopoda pilipes (F.) (Diptera: Tachinidae) was near zero at 21 of 24 sites surveyed. Three sites with high bug density had higher levels of T. pilipes parasitism, reaching maxima of 70% among adult female bugs, 100% among males and 50% among fifth instars. Male-biased parasitism indicated that T. pilipes is adapted to using male aggregation pheromone for finding C. blackburniae hosts. The relative impacts of biocontrol agents and other sources of mortality were compared using life tables. Invasive species, particularly generalist egg predators, had the greatest impacts on C. blackburniae populations. Effects of intentionally introduced parasitoids were relatively minor, although the tachinid T. pilipes showed potential for large impacts at individual sites. In retrospect, non-target attacks by biological control agents on C. blackburniae were predictable, but the environmental range and magnitude of impacts would have been difficult to foresee.

Differential recognition of geometric isomers by the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae): Evidence for only three essential components in aggregation pheromone.

PubMed

Dickens, J C; Prestwich, G D

1989-02-01

For two decades, the aggregation pheromone of the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae), was thought to consist of four compounds: I [(+)-(Z)-2-isopropenyl-1-methylcyclobutane ethanol]; II [(Z)-3,3-dimethyl-Δ(I,β)-cyclohexane ethanol]; III [(Z)-3,3-dimethyl-Δ(1,α)-cyclohexane acetaldehyde); and IV [(E)-3,3-dimethyl-Δ(1,α)-cyclohexane acetaldehyde). Evidence is presented from behavioral and electrophysiological studies to show that only three of these components, I, II, and IV, are essential for attraction. Competitive field tests, in which each possible three-component blend was tested against the four-component mixture, demonstrated that omission of I, II. or IV resulted in decreased trap captures (P < 0.01). Trap captures by these blends lacking I, II, or IV resembled those by the hexane solvent alone in a similar experiment. However, omission of III did not significantly alter field attractiveness of the blend. Dosage-response curves constructed from electroantennogram responses of both males and females to serial dilutions of III, IV, and a 50∶50 mixture of the geometric isomers III and IV showed both sexes to be 10- to 100-fold more sensitive to IV than III. Data from the electrophysiological studies were consistent with a single acceptor type for the (E)-cyclohexylidene aldehyde, IV, for males, and possibly one or two acceptor types for III and IV for females. Possible roles for the (Z)-cyclohexylidene aldehyde, III, and implications for the pheromonal attractant currently used in boll weevil eradication/suppression programs are discussed.

Pretreatment with CP-154526 blocks the modifying effects of alarm pheromone on components of sexual behavior in male, but not in female, rats.

PubMed

Kobayashi, Tatsuya; Kiyokawa, Yasushi; Takeuchi, Yukari; Mori, Yuji

2011-09-01

We previously demonstrated that an alarm pheromone released from male donor Wistar rats evoked several physiological and behavioral responses in recipient rats. However, the pheromone effects on social behavior were not analyzed. In the present study, we examined whether the alarm pheromone affects sexual behavior in male or female rats. When a pair of male and female subjects was exposed to the alarm pheromone during sexual behavior, the ejaculation latency was elongated, the number of mounts was increased, and the hit rate (number of intromissions/number of mounts and intromissions) was decreased in the male subject. In contrast, female sexual behavior was not affected by the alarm pheromone. When we exposed only the male or female subject of the pair to the pheromone just before sexual behavior, the results were similar: the pheromone effects were evident in male, but not in female, subjects. In addition, when we pretreated with corticotropin-releasing factor (CRF) antagonist (CP-154526) before exposing the male subject to the alarm pheromone, the pheromone effects were attenuated in a dose-dependent manner. These results indicate that the alarm pheromone modifies male, but not female, components of sexual behavior and that CRF participates in the effects.

Queen pheromones affecting the production of queen-like secretion in workers.

PubMed

Tamar, Katzav-Gozansky; Raphaël, Boulay; Victoria, Soroker; Abraham, Hefetz

2006-07-01

The honeybee queen pheromones promote both worker sterility and worker-like pheromone composition; in their absence workers become fertile and express the queen pheromones. Which of the queen pheromones regulate worker pheromone expression and how, is still elusive. Here we investigated how two queen pheromones, the mandibular and Dufour's, singly or combined, affect worker ovarian activation and occurrence of queen-like Dufour's esters. Although queen mandibular pheromone (QMP) alone, or combined with Dufour's secretion, inhibited to some extent worker reproduction, neither was as effective as the queen. The effect of the queen pheromones on worker pheromone expression was limited to workers with developed ovaries. Here too, QMP and Dufour's combined had the greatest inhibitory effect. In contrast, treatment with Dufour's alone resulted in augmentation of esters in the workers. This is another demonstration that a pheromone emitted by one individual affects the rates of its production in another individual. Ester production was tightly coupled to ovarian development. However fertile workers from queenright or QMP-treated colonies had significantly higher amounts of esters in their Dufour's gland than untreated queenless colonies. The fact that the queen or QMP exert greater suppression on signal production than on ovary activation, suggests disparate regulatory pathways, and presents a challenging ultimate as well as proximate questions.

Evolved differences in larval social behavior mediated by novel pheromones

PubMed Central

Mast, Joshua D; De Moraes, Consuelo M; Alborn, Hans T; Lavis, Luke D; Stern, David L

2014-01-01

Pheromones, chemical signals that convey social information, mediate many insect social behaviors, including navigation and aggregation. Several studies have suggested that behavior during the immature larval stages of Drosophila development is influenced by pheromones, but none of these compounds or the pheromone-receptor neurons that sense them have been identified. Here we report a larval pheromone-signaling pathway. We found that larvae produce two novel long-chain fatty acids that are attractive to other larvae. We identified a single larval chemosensory neuron that detects these molecules. Two members of the pickpocket family of DEG/ENaC channel subunits (ppk23 and ppk29) are required to respond to these pheromones. This pheromone system is evolving quickly, since the larval exudates of D. simulans, the sister species of D. melanogaster, are not attractive to other larvae. Our results define a new pheromone signaling system in Drosophila that shares characteristics with pheromone systems in a wide diversity of insects. DOI: http://dx.doi.org/10.7554/eLife.04205.001 PMID:25497433

Pheromones and Pheromone Receptors Are Required for Proper Sexual Development in the Homothallic Ascomycete Sordaria macrospora

PubMed Central

Mayrhofer, Severine; Weber, Jan M.; Pöggeler, Stefanie

2006-01-01

The homothallic, filamentous ascomycete Sordaria macrospora is self-fertile and produces sexual fruiting bodies (perithecia) without a mating partner. Even so, S. macrospora transcriptionally expresses two pheromone-precursor genes (ppg1 and ppg2) and two pheromone-receptor genes (pre1 and pre2). The proteins encoded by these genes are similar to α-factor-like and a-factor-like pheromones and to G-protein-coupled pheromone receptors of the yeast Saccharomyces cerevisiae. It has been suggested that in S. macrospora, PPG1/PRE2 and PPG2/PRE1 form two cognate pheromone–receptor pairs. To investigate their function, we deleted (Δ) pheromone-precursor genes (Δppg1, Δppg2) and receptor genes (Δpre1, Δpre2) and generated single- as well as double-knockout strains. No effect on vegetative growth, fruiting-body, and ascospore development was seen in the single pheromone-mutant and receptor-mutant strains, respectively. However, double-knockout strains lacking any compatible pheromone-receptor pair (Δpre2/Δppg2, Δpre1/Δppg1) and the double-pheromone mutant (Δppg1/Δppg2) displayed a drastically reduced number of perithecia and sexual spores, whereas deletion of both receptor genes (Δpre1/Δpre2) completely eliminated fruiting-body and ascospore formation. The results suggest that pheromones and pheromone receptors are required for optimal sexual reproduction of the homothallic S. macrospora. PMID:16387884

Automated egg grading system using computer vision: Investigation on weight measure versus shape parameters

NASA Astrophysics Data System (ADS)

Nasir, Ahmad Fakhri Ab; Suhaila Sabarudin, Siti; Majeed, Anwar P. P. Abdul; Ghani, Ahmad Shahrizan Abdul

2018-04-01

Chicken egg is a source of food of high demand by humans. Human operators cannot work perfectly and continuously when conducting egg grading. Instead of an egg grading system using weight measure, an automatic system for egg grading using computer vision (using egg shape parameter) can be used to improve the productivity of egg grading. However, early hypothesis has indicated that more number of egg classes will change when using egg shape parameter compared with using weight measure. This paper presents the comparison of egg classification by the two above-mentioned methods. Firstly, 120 images of chicken eggs of various grades (A–D) produced in Malaysia are captured. Then, the egg images are processed using image pre-processing techniques, such as image cropping, smoothing and segmentation. Thereafter, eight egg shape features, including area, major axis length, minor axis length, volume, diameter and perimeter, are extracted. Lastly, feature selection (information gain ratio) and feature extraction (principal component analysis) are performed using k-nearest neighbour classifier in the classification process. Two methods, namely, supervised learning (using weight measure as graded by egg supplier) and unsupervised learning (using egg shape parameters as graded by ourselves), are conducted to execute the experiment. Clustering results reveal many changes in egg classes after performing shape-based grading. On average, the best recognition results using shape-based grading label is 94.16% while using weight-based label is 44.17%. As conclusion, automated egg grading system using computer vision is better by implementing shape-based features since it uses image meanwhile the weight parameter is more suitable by using weight grading system.

Is dauer pheromone of Caenorhabditis elegans really a pheromone?

NASA Astrophysics Data System (ADS)

Viney, M. E.; Franks, N. R.

Animals respond to signals and cues in their environment. The difference between a signal (e.g. a pheromone) and a cue (e.g. a waste product) is that the information content of a signal is subject to natural selection, whereas that of a cue is not. The model free-living nematode Caenorhabditis elegans forms an alternative developmental morph (the dauer larva) in response to a so-called `dauer pheromone', produced by all worms. We suggest that the production of `dauer pheromone' has no fitness advantage for an individual worm and therefore we propose that `dauer pheromone' is not a signal, but a cue. Thus, it should not be called a pheromone.

Parasitic egg rejection decisions of chalk-browed mockingbirds Mimus saturninus are independent of clutch composition.

PubMed

de la Colina, M A; Pompilio, L; Hauber, M E; Reboreda, J C; Mahler, B

2018-03-01

Obligate avian brood parasites lay their eggs in nests of other host species, which assume all the costs of parental care for the foreign eggs and chicks. The most common defensive response to parasitism is the rejection of foreign eggs by hosts. Different cognitive mechanisms and decision-making rules may guide both egg recognition and rejection behaviors. Classical optimization models generally assume that decisions are based on the absolute properties of the options (i.e., absolute valuation). Increasing evidence shows instead that hosts' rejection decisions also depend on the context in which options are presented (i.e., context-dependent valuation). Here we study whether the chalk-browed mockingbird's (Mimus saturninus) rejection of parasitic shiny cowbird (Molothrus bonariensis) eggs is a fixed behavior or varies with the context of the clutch. We tested three possible context-dependent mechanisms: (1) range effect, (2) habituation to variation, and (3) sensitization to variation. We found that mockingbird rejection of parasitic eggs does not change according to the characteristics of the other eggs in the nest. Thus, rejection decisions may exclusively depend on the objective characteristics of the eggs, meaning that the threshold of acceptance or rejection of a foreign egg is context-independent in this system.

Sexy DEG/ENaC channels involved in gustatory detection of fruit fly pheromones.

PubMed

Pikielny, Claudio W

2012-11-06

Hydrocarbon pheromones on the cuticle of Drosophila melanogaster modulate the complex courtship behavior of males. Recently, three members of the degenerin/epithelial Na+ channel (DEG/ENaC) family of sodium channel subunits, Ppk25, Ppk23, and Ppk29 (also known as Nope), have been shown to function in gustatory perception of courtship-modulating contact pheromones. All three proteins are required for the activation of male courtship by female pheromones. Specific interactions between two of them have been demonstrated in cultured cells, suggesting that, in a subset of cells where they are coexpressed, these three subunits function within a common heterotrimeric DEG/ENaC channel. Such a DEG/ENaC channel may be gated by pheromones, either directly or indirectly, or alternatively may control the excitability of pheromone-sensing cells. In addition, these studies identify taste neurons that respond specifically to courtship-modulating pheromones and mediate their effects on male behavior. Two types of pheromone-sensing taste neurons, F and M cells, have been defined on the basis of their specific response to either female or male pheromones. These reports set the stage for the dissection of the molecular and cellular mechanisms that mediate gustatory detection of contact pheromones.

Modeling the suppression of sea lamprey populations by use of the male sex pheromone

USGS Publications Warehouse

Klassen, Waldemar; Adams, Jean V.; Twohey, Michael B.

2005-01-01

The suppression of sea lamprey populations, Petromyzon marinus (Linnaeus), was modeled using four different applications of the male sex pheromone: (1) pheromone-baited traps that remove females from the spawning population, (2) pheromone-baited decoys that exhaust females before they are able to spawn, (3) pheromone-enhanced sterile males that increase the proportion of non-fertile matings, and (4) camouflaging of the pheromone emitted by calling males to make it difficult for females to find a mate. The models indicated that thousands of traps or hundreds of thousands of decoys would be required to suppress a population of 100,000 animals. The potential efficacy of pheromone camouflages is largely unknown, and additional research is required to estimate how much pheromone is needed to camouflage the pheromone plumes of calling males. Pheromone-enhanced sterile males appear to be a promising application in the Great Lakes. Using this technique for three generations each of ca. 7 years duration could reduce sea lamprey populations by 90% for Lakes Huron and Ontario and by 98% for Lake Michigan, based on current trapping operations that capture 20 to 30% of the population each year.

Heritable variation of sex pheromone composition and the potential for evolution of resistance to pheromone-based control of the Indian meal moth, Plodia interpunctella.

PubMed

Svensson, Glenn P; Ryne, Camilla; Löfstedt, Christer

2002-07-01

The short-term evolutionary effect of pheromone-based mating disruption on the mating ability of the Indian meal moth, Plodia interpunctella, was investigated. Three independent selection lines were established, and the mating ability of moths in plastic tents treated with high doses of pheromone and in control tents was compared for two consecutive generations. In addition, the heritability of the sex pheromone blend, measured as the ratio of two major pheromone components (Z,E)-9,12-tetradecadienyl acetate and (Z,E)-9,12-tetradecadienol, was estimated. Based on a mother-daughter regression analysis including 21 families, the heritability of the pheromone blend was 0.65 +/- 0.14, indicating a potential for evolutionary change of the character. However, no increase in mating ability of females in pheromone-treated tents or alteration of the pheromone blend was observed in any selection line when compared with control lines, indicating no or weak selection on the pheromone blend as well as other traits influencing mating ability of this species under the created mating disruption conditions. Factors contributing to the lack of selection effects are discussed.

2,3-Hexanediols as Sex Attractants and a Female-produced Sex Pheromone for Cerambycid Beetles in the Prionine Genus Tragosoma

PubMed Central

Barbour, James D.; McElfresh, J. Steven; Moreira, Jardel A.; Swift, Ian; Wright, Ian M.; Žunič, Alenka; Mitchell, Robert F.; Graham, Elizabeth E.; Alten, Ronald L.; Millar, Jocelyn G.; Hanks, Lawrence M.

2013-01-01

Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium “sp. nov. Laplante” is (2R,3R)-2,3-hex-anediol, and provide evidence from field bioassays and electro-antennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T depsarium “harrisi” LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines. PMID:22923142

Cloning and functional characterization of a fatty acid transport protein (FATP) from the pheromone gland of a lichen moth, Eilema japonica, which secretes an alkenyl sex pheromone.

PubMed

Qian, Shuguang; Fujii, Takeshi; Ito, Katsuhiko; Nakano, Ryo; Ishikawa, Yukio

2011-01-01

Sex pheromones of moths are largely classified into two types based on the presence (Type I) or absence (Type II) of a terminal functional group. While Type-I sex pheromones are synthesized from common fatty acids in the pheromone gland (PG), Type-II sex pheromones are derived from hydrocarbons produced presumably in the oenocytes and transported to the PG via the hemolymph. Recently, a fatty acid transport protein (BmFATP) was identified from the PG of the silkworm Bombyx mori, which produces a Type-I sex pheromone (bombykol). BmFATP was shown to facilitate the uptake of extracellular fatty acids into PG cells for the synthesis of bombykol. To elucidate the presence and function of FATP in the PG of moths that produce Type-II sex pheromones, we explored fatp homologues expressed in the PG of a lichen moth, Eilema japonica, which secretes an alkenyl sex pheromone (Type II). A fatp homologue cloned from E. japonica (Ejfatp) was predominantly expressed in the PG, and its expression is upregulated shortly after eclosion. Functional expression of EjFATP in Escherichia coli enhanced the uptake of long chain fatty acids (C₁₈ and C₂₀), but not pheromone precursor hydrocarbons. To the best of our knowledge, this is the first report of the cloning and functional characterization of a FATP in the PG of a moth producing a Type-II sex pheromone. Although EjFATP is not likely to be involved in the uptake of pheromone precursors in E. japonica, the expression pattern of Ejfatp suggests a role for EjFATP in the PG not directly linked to pheromone biosynthesis. Copyright © 2010 Elsevier Ltd. All rights reserved.

The Effect of Trail Pheromone and Path Confinement on Learning of Complex Routes in the Ant Lasius niger

PubMed Central

Czaczkes, Tomer J.; Weichselgartner, Tobias; Bernadou, Abel; Heinze, Jürgen

2016-01-01

Route learning is key to the survival of many central place foragers, such as bees and many ants. For ants which lay pheromone trails, the presence of a trail may act as an important source of information about whether an error has been made. The presence of trail pheromone has been demonstrated to support route learning, and the effect of pheromones on route choice have been reported to persist even after the pheromones have been removed. This could be explained in two ways: the pheromone may constrain the ants onto the correct route, thus preventing errors and aiding learning. Alternatively, the pheromones may act as a ‘reassurance’, signalling that the learner is on the right path and that learning the path is worthwhile. Here, we disentangle pheromone presence from route confinement in order to test these hypotheses, using the ant Lasius niger as a model. Unexpectedly, we did not find any evidence that pheromones support route learning. Indeed, there was no evidence that ants confined to the correct route learned at all. Thus, while we cannot support the ‘reassurance’ hypothesis, we can rule out the ‘confinement’ hypothesis. Other findings, such as a reduction in pheromone deposition in the presence of trail pheromones, are remarkably consistent with previous experiments. As previously reported, ants which make errors on their outward journey upregulate pheromone deposition on their return. Surprisingly, ants which would go on to make an error down-regulate pheromone deposition on their outward journey, hinting at a capacity for ants to gauge the quality of their own memories. PMID:26959996

Characterization of comQ and comX, Two Genes Required for Production of ComX Pheromone in Bacillus subtilis

PubMed Central

Schneider, Katherine Bacon; Palmer, Tanya M.; Grossman, Alan D.

2002-01-01

Many microbes use secreted peptide-signaling molecules to stimulate changes in gene expression in response to high population density, a process called quorum sensing. ComX pheromone is a modified 10-amino-acid peptide used by Bacillus subtilis to modulate changes in gene expression in response to crowding. comQ and comX are required for production of ComX pheromone. We found that accumulation of ComX pheromone in culture supernatant paralleled cell growth, indicating that there was no autoinduction of production of ComX pheromone. We overexpressed comQ and comX separately and together and found that overexpression of comX alone was sufficient to cause an increase in production of ComX pheromone and early induction of a quorum-responsive promoter. These results indicate that the extracellular concentration of ComX pheromone plays a major role in determining the timing of the quorum response and that expression of comX is limiting for production of ComX pheromone. We made alanine substitutions in the residues that comprise the peptide backbone of ComX pheromone. Analysis of these mutants highlighted the importance of the modification for ComX pheromone function and identified three residues (T50, G54, and D55) that are unlikely to interact with proteins involved in production of or response to ComX pheromone. We have also identified and mutated a putative isoprenoid binding domain of ComQ. Mutations in this domain eliminated production of ComX pheromone, consistent with the hypothesis that ComQ is involved in modifying ComX pheromone and that the modification is likely to be an isoprenoid. PMID:11751817

Putative pathway of sex pheromone biosynthesis and degradation by expression patterns of genes identified from female pheromone gland and adult antenna of Sesamia inferens (Walker).

PubMed

Zhang, Ya-Nan; Xia, Yi-Han; Zhu, Jia-Yao; Li, Sheng-Yun; Dong, Shuang-Lin

2014-05-01

The general pathway of biosynthesis and degradation for Type-I sex pheromones in moths is well established, but some genes involved in this pathway remain to be characterized. The purple stem borer, Sesamia inferens, employs a pheromone blend containing components with three different terminal functional groups (Z11-16:OAc, Z11-16:OH, and Z11-16:Ald) of Type-I sex pheromones. Thus, it provides a good model to study the diversity of genes involved in pheromone biosynthesis and degradation pathways. By analyzing previously obtained transcriptomic data of the sex pheromone glands and antennae, we identified 73 novel genes that are possibly related to pheromone biosynthesis (46 genes) or degradation (27 genes). Gene expression patterns and phylogenetic analysis revealed that one desaturase (SinfDes4), one fatty acid reductase (SinfFAR2), and one fatty acid xtransport protein (SinfFATP1) genes were predominantly expressed in pheromone glands, and clustered with genes involved in pheromone synthesis in other moth species. Ten genes including five carboxylesterases (SinfCXE10, 13, 14, 18, and 20), three aldehyde oxidases (SinfAOX1, 2 and 3), and two alcohol dehydrogenases (SinfAD1 and 3) were expressed specifically or predominantly in antennae, and could be candidate genes involved in pheromone degradation. SinfAD1 and 3 are the first reported alcohol dehydrogenase genes with antennae-biased expression. Based on these results we propose a pathway involving these potential enzyme-encoding gene candidates in sex pheromone biosynthesis and degradation in S. inferens. This study provides robust background information for further elucidation of the genetic basis of sex pheromone biosynthesis and degradation, and ultimately provides potential targets to disrupt sexual communication in S. inferens for control purposes.

Novel sex cells and evidence for sex pheromones in diatoms.

PubMed

Sato, Shinya; Beakes, Gordon; Idei, Masahiko; Nagumo, Tamotsu; Mann, David G

2011-01-01

Diatoms belong to the stramenopiles, one of the largest groups of eukaryotes, which are primarily characterized by a presence of an anterior flagellum with tubular mastigonemes and usually a second, smooth flagellum. Based on cell wall morphology, diatoms have historically been divided into centrics and pennates, of which only the former have flagella and only on the sperm. Molecular phylogenies show the pennates to have evolved from among the centrics. However, the timing of flagellum loss--whether before the evolution of the pennate lineage or after--is unknown, because sexual reproduction has been so little studied in the 'araphid' basal pennate lineages, to which Pseudostaurosira belongs. Sexual reproduction of an araphid pennate, Pseudostaurosira trainorii, was studied with light microscopy (including time lapse observations and immunofluorescence staining observed under confocal scanning laser microscopy) and SEM. We show that the species produces motile male gametes. Motility is mostly associated with the extrusion and retrieval of microtubule-based 'threads', which are structures hitherto unknown in stramenopiles, their number varying from one to three per cell. We also report experimental evidence for sex pheromones that reciprocally stimulate sexualization of compatible clones and orientate motility of the male gametes after an initial 'random walk'. The threads superficially resemble flagella, in that both are produced by male gametes and contain microtubules. However, one striking difference is that threads cannot beat or undulate and have no motility of their own, and they do not bear mastigonemes. Threads are sticky and catch and draw objects, including eggs. The motility conferred by the threads is probably crucial for sexual reproduction of P. trainorii, because this diatom is non-motile in its vegetative stage but obligately outbreeding. Our pheromone experiments are the first studies in which gametogenesis has been induced in diatoms by cell-free exudates, opening new possibilities for molecular 'dissection' of sexualization.

Gender-typical olfactory regulation of sexual behavior in goldfish

PubMed Central

Kawaguchi, Yutaro; Nagaoka, Akira; Kitami, Asana; Mitsuhashi, Tomomi; Hayakawa, Youichi; Kobayashi, Makito

2014-01-01

It is known that olfaction is essential for the occurrence of sexual behavior in male goldfish. Sex pheromones from ovulatory females elicit male sexual behavior, chasing, and sperm releasing act. In female goldfish, ovarian prostaglandin F2α (PGF) elicits female sexual behavior, egg releasing act. It has been considered that olfaction does not affect sexual behavior in female goldfish. In the present study, we re-examined the involvement of olfaction in sexual behavior of female goldfish. Olfaction was blocked in male and female goldfish by two methods: nasal occlusion (NO) which blocks the reception of olfactants, and olfactory tract section (OTX) which blocks transmission of olfactory information from the olfactory bulb to the telencephalon. Sexual behavior of goldfish was induced by administration of PGF to females, an established method for inducing goldfish sexual behavior in both sexes. Sexual behavior in males was suppressed by NO and OTX as previously reported because of lack of pheromone stimulation. In females, NO suppressed sexual behavior but OTX did not affect the occurrence of sexual behavior. Females treated with both NO and OTX performed sexual behavior normally. These results indicate that olfaction is essential in female goldfish to perform sexual behavior as in males but in a different manner. The lack of olfaction in males causes lack of pheromonal stimulation, resulting in no behavior elicited. Whereas the results of female experiments suggest that lack of olfaction in females causes strong inhibition of sexual behavior mediated by the olfactory pathway. Olfactory tract section is considered to block the pathway and remove this inhibition, resulting in the resumption of the behavior. By subtract sectioning of the olfactory tract, it was found that this inhibition was mediated by the medial olfactory tracts, not the lateral olfactory tracts. Thus, it is concluded that goldfish has gender-typical olfactory regulation for sexual behavior. PMID:24817840

Molecular evolution of the odorant and gustatory receptor genes in lepidopteran insects: implications for their adaptation and speciation.

PubMed

Engsontia, Patamarerk; Sangket, Unitsa; Chotigeat, Wilaiwan; Satasook, Chutamas

2014-08-01

Lepidoptera (comprised of butterflies and moths) is one of the largest groups of insects, including more than 160,000 described species. Chemoreception plays important roles in the adaptation of these species to a wide range of niches, e.g., plant hosts, egg-laying sites, and mates. This study investigated the molecular evolution of the lepidopteran odorant (Or) and gustatory receptor (Gr) genes using recently identified genes from Bombyx mori, Danaus plexippus, Heliconius melpomene, Plutella xylostella, Heliothis virescens, Manduca sexta, Cydia pomonella, and Spodoptera littoralis. A limited number of cases of large lineage-specific gene expansion are observed (except in the P. xylostella lineage), possibly due to selection against tandem gene duplication. There has been strong purifying selection during the evolution of both lepidopteran odorant and gustatory genes, as shown by the low ω values estimated through CodeML analysis, ranging from 0.0093 to 0.3926. However, purifying selection has been relaxed on some amino acid sites in these receptors, leading to sequence divergence, which is a precursor of positive selection on these sequences. Signatures of positive selection were detected only in a few loci from the lineage-specific analysis. Estimation of gene gains and losses suggests that the common ancestor of the Lepidoptera had fewer Or genes compared to extant species and an even more reduced number of Gr genes, particularly within the bitter receptor clade. Multiple gene gains and a few gene losses occurred during the evolution of Lepidoptera. Gene family expansion may be associated with the adaptation of lepidopteran species to plant hosts, especially after angiosperm radiation. Phylogenetic analysis of the moth sex pheromone receptor genes suggested that chromosomal translocations have occurred several times. New sex pheromone receptors have arisen through tandem gene duplication. Positive selection was detected at some amino acid sites predicted to be in the extracellular and transmembrane regions of the newly duplicated genes, which might be associated with the evolution of the new pheromone receptors.

Chemical fingerprints encode mother–offspring similarity, colony membership, relatedness, and genetic quality in fur seals

PubMed Central

Stoffel, Martin A.; Caspers, Barbara A.; Forcada, Jaume; Giannakara, Athina; Baier, Markus; Eberhart-Phillips, Luke; Müller, Caroline; Hoffman, Joseph I.

2015-01-01

Chemical communication underpins virtually all aspects of vertebrate social life, yet remains poorly understood because of its highly complex mechanistic basis. We therefore used chemical fingerprinting of skin swabs and genetic analysis to explore the chemical cues that may underlie mother–offspring recognition in colonially breeding Antarctic fur seals. By sampling mother–offspring pairs from two different colonies, using a variety of statistical approaches and genotyping a large panel of microsatellite loci, we show that colony membership, mother–offspring similarity, heterozygosity, and genetic relatedness are all chemically encoded. Moreover, chemical similarity between mothers and offspring reflects a combination of genetic and environmental influences, the former partly encoded by substances resembling known pheromones. Our findings reveal the diversity of information contained within chemical fingerprints and have implications for understanding mother–offspring communication, kin recognition, and mate choice. PMID:26261311

Sex pheromone in the moth Heliothis virescens is produced as a mixture of two pools: de novo and via precursor storage in glycerolipids.

PubMed

Foster, Stephen P; Anderson, Karin G; Casas, Jérôme

2017-08-01

Most species of moths use a female-produced volatile sex pheromone, typically produced via de novo fatty acid synthesis in a specialized gland, for communication among mates. While de novo biosynthesis of pheromone (DNP) is rapid, suggesting transient precursor acids, substantial amounts of pheromone precursor (and other) acids are stored, predominantly in triacylglycerols in the pheromone gland. Whether these stored acids are converted to pheromone later or not has been the subject of some debate. Using a tracer/tracee approach, in which we fed female Heliothis virescens U- 13 C-glucose, we were able to distinguish two pools of pheromone, in which precursors were temporally separated (after and before feeding on labeled glucose): DNP synthesized from a mixed tracer/tracee acetyl CoA pool after feeding, and pheromone made from precursor acids primarily synthesized before feeding, which we call recycled precursor fat pheromone (RPP). DNP titer varied from high (during scotophase) to low (photophase) and with presence/absence of pheromone biosynthesis activating neuropeptide (PBAN), in accord with native pheromone titer previously observed. By contrast, RPP was constant throughout the photoperiod and did not change with PBAN presence/absence. The amount of RPP (6.3-10.3 ng/female) was typically much lower than that of DNP, especially during the scotophase (peak DNP, 105 ng/female). We propose an integral role for stored fats in pheromone biosynthesis, in which they are hydrolyzed and re-esterified throughout the photoperiod, with a small proportion of liberated precursor acyl CoAs being converted to pheromone. During the sexually active period, release of PBAN results in increased flux of glucose (from trehalose) and hydrolyzed acids entering the mitochondria, producing acetyl CoA precursor for de novo fat and pheromone biosynthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Monitoring of European corn borer with pheromone-baited traps: review of trapping system basics and remaining problems.

PubMed

Laurent, Pélozuelo; Frérot, Brigitte

2007-12-01

Since the identification of female European corn borer, Ostrinia nubilalis (Hübner) pheromone, pheromone-baited traps have been regarded as a promising tool to monitor populations of this pest. This article reviews the literature produced on this topic since the 1970s. Its aim is to provide extension entomologists and other researchers with all the necessary information to establish an efficient trapping procedure for this moth. The different pheromone races of the European corn borer are described, and research results relating to the optimization of pheromone blend, pheromone bait, trap design, and trap placement are summarized followed by a state-of-the-art summary of data comparing blacklight trap and pheromone-baited trap techniques to monitor European corn borer flight. Finally, we identify the information required to definitively validate/invalidate the pheromone-baited traps as an efficient decision support tool in European corn borer control.

The Harvest and Management of Migratory Bird Eggs by Inuit in Nunatsiavut, Labrador

NASA Astrophysics Data System (ADS)

Natcher, David; Felt, Larry; Chaulk, Keith; Procter, Andrea

2012-12-01

This paper presents the results of collaborative research conducted in 2007 on the harvest of migratory bird eggs by Inuit households of Nunatsiavut, Labrador. Harvest variability between communities and species is examined, as is the social and ecological factors affecting the 2007 Inuit egg harvest. Representing the first comprehensive account of Inuit egg use in Labrador, this information should be valuable to agencies responsible for managing migratory bird populations in North America and will contribute to a more informed understanding of the complexity and temporal variability in subsistence harvesting among Labrador Inuit. It is argued that the recognition of this complexity will be critical as the Nunatsiavut Government and other wildlife management agencies formulate management policies that are supportive rather, than constraining, to Inuit resource use in the future.

Trail pheromones: an integrative view of their role in social insect colony organization.

PubMed

Czaczkes, Tomer J; Grüter, Christoph; Ratnieks, Francis L W

2015-01-07

Trail pheromones do more than simply guide social insect workers from point A to point B. Recent research has revealed additional ways in which they help to regulate colony foraging, often via positive and negative feedback processes that influence the exploitation of the different resources that a colony has knowledge of. Trail pheromones are often complementary or synergistic with other information sources, such as individual memory. Pheromone trails can be composed of two or more pheromones with different functions, and information may be embedded in the trail network geometry. These findings indicate remarkable sophistication in how trail pheromones are used to regulate colony-level behavior, and how trail pheromones are used and deployed at the individual level.

Optimizing Aerosol Dispensers for Mating Disruption of Codling Moth, Cydia pomonella L.

PubMed

McGhee, Peter S; Miller, James R; Thomson, Donald R; Gut, Larry J

2016-07-01

Experiments were conducted in commercial apple orchards to determine if improved efficiencies in pheromone delivery may be realized by using aerosol pheromone dispensers for codling moth (CM), Cydia pomonella L., mating disruption. Specifically, we tested how reducing: pheromone concentration, period of dispenser operation, and frequency of pheromone emission from aerosol dispensers affected orientational disruption of male CM to pheromone-baited monitoring traps. Isomate® CM MIST formulated with 50 % less codlemone (3.5 mg/ emission) provided orientation disruption equal to the standard commercial formulation (7 mg / emission). Decreased periods of dispenser operation (3 and 6 h) and frequency of pheromone emission (30 and 60 min) provided a level of orientational disruption similar to the current standard protocol of releasing pheromone over a 12 h period on a 15 min cycle, respectively. These three modifications provide a means of substantially reducing the amount of pheromone necessary for CM disruption. The savings accompanying pheromone conservation could lead to increased adoption of CM mating disruption and, moreover, provide an opportunity for achieving higher levels of disruption by increasing dispenser densities.

Gene Identification of Pheromone Gland Genes Involved in Type II Sex Pheromone Biosynthesis and Transportation in Female Tea Pest Ectropis grisescens

PubMed Central

Li, Zhao-Qun; Ma, Long; Yin, Qian; Cai, Xiao-Ming; Luo, Zong-Xiu; Bian, Lei; Xin, Zhao-Jun; He, Peng; Chen, Zong-Mao

2018-01-01

Moths can biosynthesize sex pheromones in the female sex pheromone glands (PGs) and can distinguish species-specific sex pheromones using their antennae. However, the biosynthesis and transportation mechanism for Type II sex pheromone components has rarely been documented in moths. In this study, we constructed a massive PG transcriptome database (14.72 Gb) from a moth species, Ectropis grisescens, which uses type II sex pheromones and is a major tea pest in China. We further identified putative sex pheromone biosynthesis and transportation-related unigenes: 111 cytochrome P450 monooxygenases (CYPs), 25 odorant-binding proteins (OBPs), and 20 chemosensory proteins (CSPs). Tissue expression and phylogenetic tree analyses showed that one CYP (EgriCYP341-fragment3), one OBP (EgriOBP4), and one CSP (EgriCSP10) gene displayed an enriched expression in the PGs, and that EgriOBP2, 3, and 25 are clustered in the moth pheromone-binding protein clade. We considered these our candidate genes. Our results yielded large-scale PG sequence information for further functional studies. PMID:29317471

Evaporation rate of emulsion and oil-base emulsion pheromones

USDA-ARS?s Scientific Manuscript database

Knowledge of pheromone evaporation rate is critical to distribute pheromone containers effectively in the forest, orchard and field. There are several factors influencing the pheromone evaporation rate that include wind speed, container size and porosity, release area, temperature, humidity, pherom...

Pheromone lures to monitor sparse populations of spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)

Treesearch

David G. Grimble

1988-01-01

Four types of spruce budworm pheromone lures were field-tested in sparse spruce budworm populations in Maine. BioLures® with constant pheromone emission rates less than 1.0, ca. 1.0-1.5, and ca. 15.0 micrograms of pheromone per day were compared to polyvinyl chloride (PVC) lures with rapidly decreasing pheromone emission rates. Mean trap catch was roughly proportional...

Identifying Possible Pheromones of Cerambycid Beetles by Field Testing Known Pheromone Components in Four Widely Separated Regions of the United States

Treesearch

Jocelyn G Millar; Robert F Mitchell; Judith A Mongold-Diers; Yunfan Zou; Carlos E Bográn; Melissa K Fierke; Matthew D Ginzel; Crawford W Johnson; James R Meeker; Therese M Poland; Iral Ragenovich; Lawrence M Hanks

2017-01-01

The pheromone components of many cerambycid beetles appear to be broadly shared among related species, including species native to different regions of the world. This apparent conservation of pheromone structures within the family suggests that field trials of common pheromone components could be used as a means of attracting multiple species, which then could be...

Antennal transcriptome analysis and comparison of olfactory genes in two sympatric defoliators, Dendrolimus houi and Dendrolimus kikuchii (Lepidoptera: Lasiocampidae).

PubMed

Zhang, Sufang; Zhang, Zhen; Wang, Hongbin; Kong, Xiangbo

2014-09-01

The Yunnan pine and Simao pine caterpillar moths, Dendrolimus houi Lajonquière and Dendrolimus kikuchii Matsumura (Lepidoptera: Lasiocampidae), are two closely related and sympatric pests of coniferous forests in southwestern China, and olfactory communication systems of these two insects have received considerable attention because of their economic importance. However, there is little information on the molecular aspect of odor detection about these insects. Furthermore, although lepidopteran species have been widely used in studies of insect olfaction, few work made comparison between sister moths on the olfactory recognition mechanisms. In this study, next-generation sequencing of the antennal transcriptome of these two moths were performed to identify the major olfactory genes. After comparing the antennal transcriptome of these two moths, we found that they exhibit highly similar transcripts-associated GO terms. Chemosensory gene families were further analyzed in both species. We identified 23 putative odorant binding proteins (OBP), 17 chemosensory proteins (CSP), two sensory neuron membrane proteins (SNMP), 33 odorant receptors (OR), and 10 ionotropic receptors (IR) in D. houi; and 27 putative OBPs, 17 CSPs, two SNMPs, 33 ORs, and nine IRs in D. kikuchii. All these transcripts were full-length or almost full-length. The predicted protein sequences were compared with orthologs in other species of Lepidoptera and model insects, including Bombyx mori, Manduca sexta, Heliothis virescens, Danaus plexippus, Sesamia inferens, Cydia pomonella, and Drosophila melanogaster. The sequence homologies of the orthologous genes in D. houi and D. kikuchii are very high. Furthermore, the olfactory genes were classed according to their expression level, and the highly expressed genes are our target for further function investigation. Interestingly, many highly expressed genes are ortholog gene of D. houi and D. kikuchii. We also found that the Classic OBPs were further separated into three groups according to their motifs, which will help future functional researches. Surprisingly, no pheromone receptor was identified in the two Dendrolimus species, which may indicate a special pheromone identification mechanism in Dendrolimus. Our work allows for further functional studies of pheromones and host volatile recognition genes, and give novel candidate targets for pest management. Copyright © 2014 Elsevier Ltd. All rights reserved.

Collection of pheromone from atmosphere surrounding boll weevils,Anthonomus grandis.

PubMed

Chang, J F; Benedict, J H; Payne, T L; Camp, B J; Vinson, S B

1989-02-01

An effluvial method was developed to collect the pheromone, grandlure from actively calling male boll weevils,Anthonomus grandis Boheman. The adsorbant, Porapak Q (ethylvinylbenzene-divinylbenzene), was utilized to trap and concentrate the pheromone. Captured pheromone was desorbed from columns packed with Porapak Q by elution withn-pentane and quantified by capillary column gas-liquid chromatography. In recovery studies with known amounts of synthetic grandlure, we found that the amount of each pheromone component collected was a function of collection duration, elution volume, and initial concentration. This effluvial method was capable of recovering as much as 94.9% of a known quantity (80 μg) of grandlure. The chromatograms were free of extraneous peaks. In studies of insect-produced pheromone, the effluvial method was used to collect pheromone from the air space surrounding male boll weevils as they fed on flower buds from CAMD-E cotton. The quantity and quality of boll-weevil-produced pheromone was determined for days 6, 8, 10, 11, 12, 13, and 14 of boll weevil adulthood. The maximum quantity of natural pheromone was produced on day 13 (4.2 μg/weevil) with a pheromone component ratio of 2.41∶2.29∶0.95∶1 for components I, II, III, and IV, respectively. The effluvial method described in this report is an efficient method to collect and quantify boll weevil pheromone from the atmosphere surrounding actively calling insects. Other applications of this method are suggested.

Antennally mediated negative feedback regulation of pheromone production in the pine engraver beetle, Ips pini

NASA Astrophysics Data System (ADS)

Ginzel, Matthew D.; Bearfield, Jeremy C.; Keeling, Christopher I.; McCormack, Colin C.; Blomquist, Gary J.; Tittiger, Claus

2007-01-01

Bark beetles use monoterpenoid aggregation pheromones to coordinate host colonization and mating. These chemical signals are produced de novo in midgut cells via the mevalonate pathway, and pheromone production may be regulated by a negative feedback system mediated through the antennae. In this study, we explored the effect of antennectomy on pheromone production and transcript levels of key mevalonate pathway genes in juvenile hormone III-treated male pine engraver beetles, Ips pini (Say). Antennectomized males produced significantly greater amounts of pheromone than podectomized males and those with intact antennae. Likewise, mRNA levels of three mevalonate pathway genes important in pheromone biosynthesis were measured by quantitative real-time PCR and found to be induced to a greater extent with antennectomy, suggesting a transcriptional regulation of pheromone production.

Pheromone disruption of Argentine ant trail integrity.

PubMed

Suckling, D M; Peck, R W; Manning, L M; Stringer, L D; Cappadonna, J; El-Sayed, A M

2008-12-01

Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m(2)) to 1- and 4-m(2) plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected.

Pheromone disruption of Argentine ant trail integrity

USGS Publications Warehouse

Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

2008-01-01

Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

The RING domain of the scaffold protein Ste5 adopts a molten globular character with high thermal and chemical stability.

PubMed

Walczak, Michal J; Samatanga, Brighton; van Drogen, Frank; Peter, Matthias; Jelesarov, Ilian; Wider, Gerhard

2014-01-27

Ste5 is a scaffold protein that controls the pheromone response of the MAP-kinase cascade in yeast cells. Upon pheromone stimulation, Ste5 (through its RING-H2 domain) interacts with the β and γ subunits of an activated heterodimeric G protein and promotes activation of the MAP-kinase cascade. With structural and biophysical studies, we show that the Ste5 RING-H2 domain exists as a molten globule under native buffer conditions, in yeast extracts, and even in denaturing conditions containing urea (7 M). Furthermore, it exhibits high thermal stability in native conditions. Binding of the Ste5 RING-H2 domain to the physiological Gβ/γ (Ste4/Ste18) ligand is accompanied by a conformational transition into a better folded, more globular structure. This study reveals novel insights into the folding mechanism and recruitment of binding partners by the Ste5 RING-H2 domain. We speculate that many RING domains may share a similar mechanism of substrate recognition and molten-globule-like character. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

QuantiFly: Robust Trainable Software for Automated Drosophila Egg Counting.

PubMed

Waithe, Dominic; Rennert, Peter; Brostow, Gabriel; Piper, Matthew D W

2015-01-01

We report the development and testing of software called QuantiFly: an automated tool to quantify Drosophila egg laying. Many laboratories count Drosophila eggs as a marker of fitness. The existing method requires laboratory researchers to count eggs manually while looking down a microscope. This technique is both time-consuming and tedious, especially when experiments require daily counts of hundreds of vials. The basis of the QuantiFly software is an algorithm which applies and improves upon an existing advanced pattern recognition and machine-learning routine. The accuracy of the baseline algorithm is additionally increased in this study through correction of bias observed in the algorithm output. The QuantiFly software, which includes the refined algorithm, has been designed to be immediately accessible to scientists through an intuitive and responsive user-friendly graphical interface. The software is also open-source, self-contained, has no dependencies and is easily installed (https://github.com/dwaithe/quantifly). Compared to manual egg counts made from digital images, QuantiFly achieved average accuracies of 94% and 85% for eggs laid on transparent (defined) and opaque (yeast-based) fly media. Thus, the software is capable of detecting experimental differences in most experimental situations. Significantly, the advanced feature recognition capabilities of the software proved to be robust to food surface artefacts like bubbles and crevices. The user experience involves image acquisition, algorithm training by labelling a subset of eggs in images of some of the vials, followed by a batch analysis mode in which new images are automatically assessed for egg numbers. Initial training typically requires approximately 10 minutes, while subsequent image evaluation by the software is performed in just a few seconds. Given the average time per vial for manual counting is approximately 40 seconds, our software introduces a timesaving advantage for experiments starting with as few as 20 vials. We also describe an optional acrylic box to be used as a digital camera mount and to provide controlled lighting during image acquisition which will guarantee the conditions used in this study.

QuantiFly: Robust Trainable Software for Automated Drosophila Egg Counting

PubMed Central

Waithe, Dominic; Rennert, Peter; Brostow, Gabriel; Piper, Matthew D. W.

2015-01-01

We report the development and testing of software called QuantiFly: an automated tool to quantify Drosophila egg laying. Many laboratories count Drosophila eggs as a marker of fitness. The existing method requires laboratory researchers to count eggs manually while looking down a microscope. This technique is both time-consuming and tedious, especially when experiments require daily counts of hundreds of vials. The basis of the QuantiFly software is an algorithm which applies and improves upon an existing advanced pattern recognition and machine-learning routine. The accuracy of the baseline algorithm is additionally increased in this study through correction of bias observed in the algorithm output. The QuantiFly software, which includes the refined algorithm, has been designed to be immediately accessible to scientists through an intuitive and responsive user-friendly graphical interface. The software is also open-source, self-contained, has no dependencies and is easily installed (https://github.com/dwaithe/quantifly). Compared to manual egg counts made from digital images, QuantiFly achieved average accuracies of 94% and 85% for eggs laid on transparent (defined) and opaque (yeast-based) fly media. Thus, the software is capable of detecting experimental differences in most experimental situations. Significantly, the advanced feature recognition capabilities of the software proved to be robust to food surface artefacts like bubbles and crevices. The user experience involves image acquisition, algorithm training by labelling a subset of eggs in images of some of the vials, followed by a batch analysis mode in which new images are automatically assessed for egg numbers. Initial training typically requires approximately 10 minutes, while subsequent image evaluation by the software is performed in just a few seconds. Given the average time per vial for manual counting is approximately 40 seconds, our software introduces a timesaving advantage for experiments starting with as few as 20 vials. We also describe an optional acrylic box to be used as a digital camera mount and to provide controlled lighting during image acquisition which will guarantee the conditions used in this study. PMID:25992957

A reference gene set for sex pheromone biosynthesis and degradation genes from the diamondback moth, Plutella xylostella, based on genome and transcriptome digital gene expression analyses.

PubMed

He, Peng; Zhang, Yun-Fei; Hong, Duan-Yang; Wang, Jun; Wang, Xing-Liang; Zuo, Ling-Hua; Tang, Xian-Fu; Xu, Wei-Ming; He, Ming

2017-03-01

Female moths synthesize species-specific sex pheromone components and release them to attract male moths, which depend on precise sex pheromone chemosensory system to locate females. Two types of genes involved in the sex pheromone biosynthesis and degradation pathways play essential roles in this important moth behavior. To understand the function of genes in the sex pheromone pathway, this study investigated the genome-wide and digital gene expression of sex pheromone biosynthesis and degradation genes in various adult tissues in the diamondback moth (DBM), Plutella xylostella, which is a notorious vegetable pest worldwide. A massive transcriptome data (at least 39.04 Gb) was generated by sequencing 6 adult tissues including male antennae, female antennae, heads, legs, abdomen and female pheromone glands from DBM by using Illumina 4000 next-generation sequencing and mapping to a published DBM genome. Bioinformatics analysis yielded a total of 89,332 unigenes among which 87 transcripts were putatively related to seven gene families in the sex pheromone biosynthesis pathway. Among these, seven [two desaturases (DES), three fatty acyl-CoA reductases (FAR) one acetyltransferase (ACT) and one alcohol dehydrogenase (AD)] were mainly expressed in the pheromone glands with likely function in the three essential sex pheromone biosynthesis steps: desaturation, reduction, and esterification. We also identified 210 odorant-degradation related genes (including sex pheromone-degradation related genes) from seven major enzyme groups. Among these genes, 100 genes are new identified and two aldehyde oxidases (AOXs), one aldehyde dehydrogenase (ALDH), five carboxyl/cholinesterases (CCEs), five UDP-glycosyltransferases (UGTs), eight cytochrome P450 (CYP) and three glutathione S-transferases (GSTs) displayed more robust expression in the antennae, and thus are proposed to participate in the degradation of sex pheromone components and plant volatiles. To date, this is the most comprehensive gene data set of sex pheromone biosynthesis and degradation enzyme related genes in DBM created by genome- and transcriptome-wide identification, characterization and expression profiling. Our findings provide a basis to better understand the function of genes with tissue enriched expression. The results also provide information on the genes involved in sex pheromone biosynthesis and degradation, and may be useful to identify potential gene targets for pest control strategies by disrupting the insect-insect communication using pheromone-based behavioral antagonists.

A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex.

PubMed

González, Mikel A; Bandi, Krishna K; Bell, Melissa J; Brazil, Reginaldo P; Dilger, Erin; Guerrero, Angel; Courtenay, Orin; Hamilton, James G C

2017-12-01

Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL). Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex. We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS). Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7-9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S)-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male) followed by Sobral 2S males (diterpene; 199.9 ± 34.3) and Jacobina males ((1S,3S,7R)-3-methyl-α-himachalene; 128.8 ± 30.3) at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4-5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype. Accumulation of pheromone appears to occur at different rates in the different chemotypes examined and results in differing amounts being present in glands over time. Release of accumulated pheromone is not passive, but depends on biotic (presence of females) and abiotic (light) circumstances. There are marked differences in content and release between the members of the complex suggesting important behavioural, biosynthetic and ecological differences between them.

A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex

PubMed Central

González, Mikel A.; Bandi, Krishna K.; Bell, Melissa J.; Brazil, Reginaldo P.; Dilger, Erin; Guerrero, Angel; Courtenay, Orin

2017-01-01

Background Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL). Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex. Methodology/Principal findings We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS). Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7–9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S)-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male) followed by Sobral 2S males (diterpene; 199.9 ± 34.3) and Jacobina males ((1S,3S,7R)-3-methyl-α-himachalene; 128.8 ± 30.3) at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4–5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype. Conclusions/Significance Accumulation of pheromone appears to occur at different rates in the different chemotypes examined and results in differing amounts being present in glands over time. Release of accumulated pheromone is not passive, but depends on biotic (presence of females) and abiotic (light) circumstances. There are marked differences in content and release between the members of the complex suggesting important behavioural, biosynthetic and ecological differences between them. PMID:29194438

Diel periodicity of pheromone release by females of Planococcus citri and Planococcus ficus and the temporal flight activity of their conspecific males

NASA Astrophysics Data System (ADS)

Levi-Zada, Anat; Fefer, Daniela; David, Maayan; Eliyahu, Miriam; Franco, José Carlos; Protasov, Alex; Dunkelblum, Ezra; Mendel, Zvi

2014-08-01

The diel periodicity of sex pheromone release was monitored in two mealybug species, Planococcus citri and Planococcus ficus (Hemiptera; Pseudococcidae), using sequential SPME/GCMS analysis. A maximal release of 2 ng/h pheromone by 9-12-day-old P. citri females occurred 1-2 h before the beginning of photophase. The highest release of pheromone by P. ficus females was 1-2 ng/2 h of 10-20-day-old females, approximately 2 h after the beginning of photophase. Mating resulted in termination of the pheromone release in both mealybug species. The temporal flight activity of the males was monitored in rearing chambers using pheromone baited delta traps. Males of both P. citri and P. ficus displayed the same flight pattern and began flying at 06:00 hours when the light was turned on, reaching a peak during the first and second hour of the photophase. Our results suggest that other biparental mealybug species display also diel periodicities of maximal pheromone release and response. Direct evaluation of the diel periodicity of the pheromone release by the automatic sequential analysis is convenient and will be very helpful in optimizing the airborne collection and identification of other unknown mealybug pheromones and to study the calling behavior of females. Considering this behavior pattern may help to develop more effective pheromone-based management strategies against mealybugs.

Two chemoreceptors mediate developmental effects of dauer pheromone in C. elegans.

PubMed

Kim, Kyuhyung; Sato, Koji; Shibuya, Mayumi; Zeiger, Danna M; Butcher, Rebecca A; Ragains, Justin R; Clardy, Jon; Touhara, Kazushige; Sengupta, Piali

2009-11-13

Intraspecific chemical communication is mediated by signals called pheromones. Caenorhabditis elegans secretes a mixture of small molecules (collectively termed dauer pheromone) that regulates entry into the alternate dauer larval stage and also modulates adult behavior via as yet unknown receptors. Here, we identify two heterotrimeric GTP-binding protein (G protein)-coupled receptors (GPCRs) that mediate dauer formation in response to a subset of dauer pheromone components. The SRBC-64 and SRBC-66 GPCRs are members of the large Caenorhabditis-specific SRBC subfamily and are expressed in the ASK chemosensory neurons, which are required for pheromone-induced dauer formation. Expression of both, but not each receptor alone, confers pheromone-mediated effects on heterologous cells. Identification of dauer pheromone receptors will allow a better understanding of the signaling cascades that transduce the context-dependent effects of ecologically important chemical signals.

Effects of natural and synthetic alarm pheromone and individual pheromone components on foraging behavior of the giant Asian honey bee, Apis dorsata.

PubMed

Li, Jianjun; Wang, Zhengwei; Tan, Ken; Qu, Yufeng; Nieh, James C

2014-10-01

Social pollinators such as honey bees face attacks from predators not only at the nest, but also during foraging. Pollinating honey bees can therefore release alarm pheromones that deter conspecifics from visiting dangerous inflorescences. However, the effect of alarm pheromone and its chemical components upon bee avoidance of dangerous food sources remains unclear. We tested the responses of giant honey bee foragers, Apis dorsata, presented with alarm pheromone at a floral array. Foragers investigated the inflorescence with natural alarm pheromone, but 3.3-fold more foragers preferred to land on the 'safe' inflorescence without alarm pheromone. Using gas chromatography-mass spectrometry analysis, we identified eight chemical components in the alarm pheromone, of which three components (1-octanol, decanal and gamma-octanoic lactone) have not previously been reported in this species. We bioassayed six major compounds and found that a synthetic mixture of these compounds elicited behaviors statistically indistinguishable from responses to natural alarm pheromone. By testing each compound separately, we show that gamma-octanoic lactone, isopentyl acetate and (E)-2-decen-1-yl acetate are active compounds that elicit significant alarm responses. Gamma-octanoic lactone elicited the strongest response to a single compound and has not been previously reported in honey bee alarm pheromone. Isopentyl acetate is widely found in the alarm pheromones of sympatric Asian honey bee species, and thus alarmed A. dorsata foragers may produce information useful for conspecifics and heterospecifics, thereby broadening the effects of alarm information on plant pollination. © 2014. Published by The Company of Biologists Ltd.

Identification of receptors of main sex-pheromone components of three Lepidopteran species.

PubMed

Mitsuno, Hidefumi; Sakurai, Takeshi; Murai, Masatoshi; Yasuda, Tetsuya; Kugimiya, Soichi; Ozawa, Rika; Toyohara, Haruhiko; Takabayashi, Junji; Miyoshi, Hideto; Nishioka, Takaaki

2008-09-01

Male moths discriminate conspecific female-emitted sex pheromones. Although the chemical components of sex pheromones have been identified in more than 500 moth species, only three components in Bombyx mori and Heliothis virescens have had their receptors identified. Here we report the identification of receptors for the main sex-pheromone components in three moth species, Plutella xylostella, Mythimna separata and Diaphania indica. We cloned putative sex-pheromone receptor genes PxOR1, MsOR1 and DiOR1 from P. xylostella, M. separata and D. indica, respectively. Each of the three genes was exclusively expressed with an Or83b orthologous gene in male olfactory receptor neurons (ORNs) that are surrounded by supporting cells expressing pheromone-binding-protein (PBP) genes. By two-electrode voltage-clamp recording, we tested the ligand specificity of Xenopus oocytes co-expressing PxOR1, MsOR1 or DiOR1 with an OR83b family protein. Among the seven sex-pheromone components of the three moth species, the oocytes dose-dependently responded only to the main sex-pheromone component of the corresponding moth species. In our study, PBPs were not essential for ligand specificity of the receptors. On the phylogenetic tree of insect olfactory receptors, the six sex-pheromone receptors identified in the present and previous studies are grouped in the same subfamily but have no relation with the taxonomy of moths. It is most likely that sex-pheromone receptors have randomly evolved from ancestral sex-pheromone receptors before the speciation of moths and that their ligand specificity was modified by mutations of local amino acid sequences after speciation.

Pheromone production, male abundance, body size, and the evolution of elaborate antennae in moths

PubMed Central

Symonds, Matthew RE; Johnson, Tamara L; Elgar, Mark A

2012-01-01

The males of some species of moths possess elaborate feathery antennae. It is widely assumed that these striking morphological features have evolved through selection for males with greater sensitivity to the female sex pheromone, which is typically released in minute quantities. Accordingly, females of species in which males have elaborate (i.e., pectinate, bipectinate, or quadripectinate) antennae should produce the smallest quantities of pheromone. Alternatively, antennal morphology may be associated with the chemical properties of the pheromone components, with elaborate antennae being associated with pheromones that diffuse more quickly (i.e., have lower molecular weights). Finally, antennal morphology may reflect population structure, with low population abundance selecting for higher sensitivity and hence more elaborate antennae. We conducted a phylogenetic comparative analysis to test these explanations using pheromone chemical data and trapping data for 152 moth species. Elaborate antennae are associated with larger body size (longer forewing length), which suggests a biological cost that smaller moth species cannot bear. Body size is also positively correlated with pheromone titre and negatively correlated with population abundance (estimated by male abundance). Removing the effects of body size revealed no association between the shape of antennae and either pheromone titre, male abundance, or mean molecular weight of the pheromone components. However, among species with elaborate antennae, longer antennae were typically associated with lower male abundances and pheromone compounds with lower molecular weight, suggesting that male distribution and a more rapidly diffusing female sex pheromone may influence the size but not the general shape of male antennae. PMID:22408739

Interspecific Sex in Grass Smuts and the Genetic Diversity of Their Pheromone-Receptor System

PubMed Central

Kellner, Ronny; Vollmeister, Evelyn; Feldbrügge, Michael; Begerow, Dominik

2011-01-01

The grass smuts comprise a speciose group of biotrophic plant parasites, so-called Ustilaginaceae, which are specifically adapted to hosts of sweet grasses, the Poaceae family. Mating takes a central role in their life cycle, as it initiates parasitism by a morphological and physiological transition from saprobic yeast cells to pathogenic filaments. As in other fungi, sexual identity is determined by specific genomic regions encoding allelic variants of a pheromone-receptor (PR) system and heterodimerising transcription factors. Both operate in a biphasic mating process that starts with PR–triggered recognition, directed growth of conjugation hyphae, and plasmogamy of compatible mating partners. So far, studies on the PR system of grass smuts revealed diverse interspecific compatibility and mating type determination. However, many questions concerning the specificity and evolutionary origin of the PR system remain unanswered. Combining comparative genetics and biological approaches, we report on the specificity of the PR system and its genetic diversity in 10 species spanning about 100 million years of mating type evolution. We show that three highly syntenic PR alleles are prevalent among members of the Ustilaginaceae, favouring a triallelic determination as the plesiomorphic characteristic of this group. Furthermore, the analysis of PR loci revealed increased genetic diversity of single PR locus genes compared to genes of flanking regions. Performing interspecies sex tests, we detected a high potential for hybridisation that is directly linked to pheromone signalling as known from intraspecies sex. Although the PR system seems to be optimised for intraspecific compatibility, the observed functional plasticity of the PR system increases the potential for interspecific sex, which might allow the hybrid-based genesis of newly combined host specificities. PMID:22242007

Egg shape mimicry in parasitic cuckoos.

PubMed

Attard, M R G; Medina, I; Langmore, N E; Sherratt, E

2017-11-01

Parasitic cuckoos lay their eggs in nests of host species. Rejection of cuckoo eggs by hosts has led to the evolution of egg mimicry by cuckoos, whereby their eggs mimic the colour and pattern of their host eggs to avoid egg recognition and rejection. There is also evidence of mimicry in egg size in some cuckoo-host systems, but currently it is unknown whether cuckoos can also mimic the egg shape of their hosts. In this study, we test whether there is evidence of mimicry in egg form (shape and size) in three species of Australian cuckoos: the fan-tailed cuckoo Cacomantis flabelliformis, which exploits dome nesting hosts, the brush cuckoo Cacomantis variolosus, which exploits both dome and cup nesting hosts, and the pallid cuckoo Cuculus pallidus, which exploits cup nesting hosts. We found evidence of size mimicry and, for the first time, evidence of egg shape mimicry in two Australian cuckoo species (pallid cuckoo and brush cuckoo). Moreover, cuckoo-host egg similarity was higher for hosts with open nests than for hosts with closed nests. This finding fits well with theory, as it has been suggested that hosts with closed nests have more difficulty recognizing parasitic eggs than open nests, have lower rejection rates and thus exert lower selection for mimicry in cuckoos. This is the first evidence of mimicry in egg shape in a cuckoo-host system, suggesting that mimicry at different levels (size, shape, colour pattern) is evolving in concert. We also confirm the existence of egg size mimicry in cuckoo-host systems. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

The cell biology of mammalian fertilization.

PubMed

Okabe, Masaru

2013-11-01

Fertilization is the process by which eggs and spermatozoa interact, achieve mutual recognition, and fuse to create a zygote, which then develops to form a new individual, thus allowing for the continuity of a species. Despite numerous studies on mammalian fertilization, the molecular mechanisms underpinning the fertilization event remain largely unknown. However, as I summarize here, recent work using both gene-manipulated animals and in vitro studies has begun to elucidate essential sperm and egg molecules and to establish predictive models of successful fertilization.

Moth pheromone binding proteins contribute to the excitation of olfactory receptor cells

NASA Astrophysics Data System (ADS)

Pophof, Blanka

2002-10-01

Pheromone binding proteins (PBPs) occur in high concentrations in the sensillum lymph surrounding the sensory dendrites of moth pheromone-sensitive sensilla. They were shown to transport the lipophilic odorants through the aqueous sensillum lymph to the receptor cells. The sensilla trichodea of the silkmoth Antheraea polyphemus are supplied with three types of receptor cells responding specifically to three pheromone components. The sensillum lymph of these sensilla contains three different types of PBPs. In this study, recombinant PBPs in various combinations with pheromone components were applied to the receptor cells via tip-opened sensilla during electrophysiological recordings. The responses of receptor cells were shown to depend on both the pheromone component and the PBP. Pheromone components artificially bound to particular PBPs elicited nerve impulses in receptor cell types which they do not activate under natural conditions. This is the first electrophysiological study to suggest that the PBPs contribute to the activation of receptor molecules.

Synthetic pheromones disrupt male Dioryctria spp. moths in a loblolly pine seed orchard

Treesearch

Gary L. DeBarr; James L. Hanula; Christine G. Niwa; John C Nord

2000-01-01

Synthetic sex pheromones released in a loblolly pine, Pinus taeda L. (Pinaceae), seed orchard interfered with the ability of male coneworm moths, Dioryctria Zeller spp. (Lepidoptera: Pyralidae), to locate traps baited with sex pheromones or live females. Pherocon 1 C® traps baited with synthetic pheromones or live conspecific...

Pheromone interruption of pine engraver, Ips pini, by pheromones of mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Scolytidae)

Treesearch

Daniel R. Miller; John H. Borden

2000-01-01

The effect of pheromones of Dendroctonus ponderosae Hopkins on the attraction of Ips pini (Say) to its pheromone, ipsdienol, was investigated in stands of lodgepole pine. The mixture of cis- and trans-verbenol significantly reduced catches of I. pini in traps baited with...

Pheromone-based disruption of Eucosma sonomana and Rhyacionia zozana (Lepidoptera: Tortricidae) using aerially applied microencapsulated pheromone

Treesearch

Nancy E. Gillette; John D. Stein; Donald R. Owen; Jeffrey N. Webster; Sylvia R. Mori

2006-01-01

Two aerial applications of microencapsulated pheromone were conducted on five 20.2 ha plots to disrupt western pine shoot borer (Eucosma sonomana Kearfott) and ponderosa pine tip moth (Rhyacionia zowna (Kearfott): Lepidoptera: Tortricidae) orientation to pheromones and oviposition in ponderosa pine plantations in 2002 and 2004...

Re-evaluation of the PBAN receptor molecule: characterization of PBANR variants expressed in the pheromone glands of moths

USDA-ARS?s Scientific Manuscript database

Sex pheromone production in most moths is initiated following pheromone biosynthesis activating neuropeptide receptor (PBANR) activation. PBANR was initially cloned from pheromone glands (PGs) of Helicoverpa zea and Bombyx mori. The B. mori PBANR is characterized by a relatively long C-terminus that...

A new class of mealybug pheromones: a hemiterpene ester in the sex pheromone of Crisicoccus matsumotoi

NASA Astrophysics Data System (ADS)

Tabata, Jun; Narai, Yutaka; Sawamura, Nobuo; Hiradate, Syuntaro; Sugie, Hajime

2012-07-01

Mealybugs, which include several agricultural pests, are small sap feeders covered with a powdery wax. They exhibit clear sexual dimorphism; males are winged but fragile and short lived, whereas females are windless and less mobile. Thus, sex pheromones emitted by females facilitate copulation and reproduction by serving as a key navigation tool for males. Although the structures of the hitherto known mealybug pheromones vary among species, they have a common structural motif; they are carboxylic esters of monoterpene alcohols with irregular non-head-to-tail linkages. However, in the present study, we isolated from the Matsumoto mealybug, Crisicoccus matsumotoi (Siraiwa), a pheromone with a completely different structure. Using gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy, we identified the pheromone as 3-methyl-3-butenyl 5-methylhexanoate. Its attractiveness to males was confirmed in a series of field trapping experiments involving comparison between the isolated natural product and a synthetic sample. This is the first report of a hemiterpene mealybug pheromone. In addition, the acid moiety (5-methylhexanoate) appears to be rare in insect pheromones.

A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans.

PubMed

Neal, Scott J; Park, JiSoo; DiTirro, Danielle; Yoon, Jason; Shibuya, Mayumi; Choi, Woochan; Schroeder, Frank C; Butcher, Rebecca A; Kim, Kyuhyung; Sengupta, Piali

2016-05-03

Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer) mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation. Copyright © 2016 Neal et al.

Mutations in a gene encoding the. cap alpha. subunit of a Saccharomyces cerevisiae G protein indicate a role in mating pheromone signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jahng, K.Y.; Ferguson, J.; Reed, S.I.

1988-06-01

Mutations which allowed conjugation by Saccharomyces cerevisiae cells lacking a mating pheromone receptor gene were selected. One of the genes defined by such mutations was isolated from a yeast genomic library by complementation of a temperature-sensitive mutation and is identically to the gene GPA1 (also known as SCG1), recently shown to be highly homologous to gene encoding the ..cap alpha.. subunits of mammalian G proteins. Physiological analysis of temperature-sensitive gpal mutations suggests that the encoded G protein is involved in signaling in response to mating pheromones. Mutational disruption of G-protein activity causes cell-cycle arrest in G/sub 1/, deposition of mating-specificmore » cell surface aggultinins, and induction of pheromone-specific mRNa, all of which are responses to pheromone in wild-type cells. In addition, mutants can conjugate without the benefit of mating pheromone or pheromone receptor. A model is presented where the activated G protein has a negative impact on a constitutive signal which normally keeps the pheromone response repressed.« less

RNA interference of pheromone biosynthesis-activating neuropeptide receptor suppresses mating behavior by inhibiting sex pheromone production in Plutella xylostella (L.).

PubMed

Lee, Dae-Weon; Shrestha, Sony; Kim, A Young; Park, Seok Joo; Yang, Chang Yeol; Kim, Yonggyun; Koh, Young Ho

2011-04-01

Sex pheromone production is regulated by pheromone biosynthesis-activating neuropeptide (PBAN) in many lepidopteran species. We cloned a PBAN receptor (Plx-PBANr) gene from the female pheromone gland of the diamondback moth, Plutella xylostella (L.). Plx-PBANr encodes 338 amino acids and has conserved structural motifs implicating in promoting G protein coupling and tyrosine-based sorting signaling along with seven transmembrane domains, indicating a typical G protein-coupled receptor. The expression of Plx-PBANr was found only in the pheromone gland of female adults among examined tissues and developmental stages. Heterologous expression in human uterus cervical cancer cells revealed that Plx-PBANr induced significant calcium elevation when challenged with Plx-PBAN. Female P. xylostella injected with double-stranded RNA specific to Plx-PBANr showed suppression of the receptor gene expression and exhibited significant reduction in pheromone biosynthesis, which resulted in loss of male attractiveness. Taken together, the identified PBAN receptor is functional in PBAN signaling via calcium secondary messenger, which leads to activation of pheromone biosynthesis and male attraction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pheromone-modulated behavioral suites influence colony growth in the honey bee (Apis mellifera)

NASA Astrophysics Data System (ADS)

Pankiw, Tanya; Roman, Roman; Sagili, Ramesh R.; Zhu-Salzman, Keyan

2004-12-01

The success of a species depends on its ability to assess its environment and to decide accordingly which behaviors are most appropriate. Many animal species, from bacteria to mammals, are able to communicate using interspecies chemicals called pheromones. In addition to exerting physiological effects on individuals, for social species, pheromones communicate group social structure. Communication of social structure is important to social insects for the allocation of its working members into coordinated suites of behaviors. We tested effects of long-term treatment with brood pheromone on suites of honey bee brood rearing and foraging behaviors. Pheromone-treated colonies reared significantly greater brood areas and more adults than controls, while amounts of stored pollen and honey remained statistically similar. Brood pheromone increased the number of pollen foragers and the pollen load weights they returned. It appeared that the pheromone-induced increase in pollen intake was directly canalized into more brood rearing. A two-way pheromone priming effect was observed, such that some workers from the same age cohorts showed an increased and extended capacity to rear larvae, while others were recruited at significantly younger ages into pollen-specific foraging. Brood pheromone affected suites of nursing and foraging behaviors allocating worker and pollen resources associated with an important fitness trait, colony growth.

With or without pheromone habituation: possible differences between insect orders?

PubMed

Suckling, David Maxwell; Stringer, Lloyd D; Jiménez-Pérez, Alfredo; Walter, Gimme H; Sullivan, Nicola; El-Sayed, Ashraf M

2018-06-01

Habituation to sex pheromones is one of the key mechanisms in mating disruption, an insect control tactic. Male moths often show reduced sexual response after pre-exposure to female sex pheromone. Mating disruption is relatively rare in insect orders other than Lepidoptera. As a positive control we confirmed habituation in a moth (Epiphyas postvittana) using 24 h pre-exposure to sex pheromone to reduce subsequent activation behaviour. We then tested the impact of pre-exposure to sex or trail pheromone on subsequent behavioural response with insects from three other orders. Similar pre-exposure for 24 h to either sex pheromone [Pseudococcus calceolariae (Homoptera) and apple leaf curling midge Dasineura mali (Diptera), or trail pheromone of Argentine ants (Linepithema humile (Hymenoptera)], followed by behavioural assay in clean air provided no evidence of habituation after pre-exposure in these latter cases. The moths alone were affected by pre-exposure to pheromone. For pests without habituation, sustained attraction to a point source may make lure and kill more economical. Improved knowledge of behavioural processes should lead to better success in pest management and mechanisms should be investigated further to inform studies and practical efforts generally enhancing effectiveness of pheromone-based management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Pheromone-modulated behavioral suites influence colony growth in the honey bee (Apis mellifera).

PubMed

Pankiw, Tanya; Roman, Roman; Sagili, Ramesh R; Zhu-Salzman, Keyan

2004-12-01

The success of a species depends on its ability to assess its environment and to decide accordingly which behaviors are most appropriate. Many animal species, from bacteria to mammals, are able to communicate using interspecies chemicals called pheromones. In addition to exerting physiological effects on individuals, for social species, pheromones communicate group social structure. Communication of social structure is important to social insects for the allocation of its working members into coordinated suites of behaviors. We tested effects of long-term treatment with brood pheromone on suites of honey bee brood rearing and foraging behaviors. Pheromone-treated colonies reared significantly greater brood areas and more adults than controls, while amounts of stored pollen and honey remained statistically similar. Brood pheromone increased the number of pollen foragers and the pollen load weights they returned. It appeared that the pheromone-induced increase in pollen intake was directly canalized into more brood rearing. A two-way pheromone priming effect was observed, such that some workers from the same age cohorts showed an increased and extended capacity to rear larvae, while others were recruited at significantly younger ages into pollen-specific foraging. Brood pheromone affected suites of nursing and foraging behaviors allocating worker and pollen resources associated with an important fitness trait, colony growth.

Chemosensory Gene Families in Ectropis grisescens and Candidates for Detection of Type-II Sex Pheromones.

PubMed

Li, Zhao-Qun; Luo, Zong-Xiu; Cai, Xiao-Ming; Bian, Lei; Xin, Zhao-Jun; Liu, Yan; Chu, Bo; Chen, Zong-Mao

2017-01-01

Tea grey geometrid ( Ectropis grisescens ), a devastating chewing pest in tea plantations throughout China, produces Type-II pheromone components. Little is known about the genes encoding proteins involved in the perception of Type-II sex pheromone components. To investigate the olfaction genes involved in E . grisescens sex pheromones and plant volatiles perception, we sequenced female and male antennae transcriptomes of E . grisescens . After assembly and annotation, we identified 153 candidate chemoreception genes in E. grisescens , including 40 odorant-binding proteins (OBPs), 30 chemosensory proteins (CSPs), 59 odorant receptors (ORs), and 24 ionotropic receptors (IRs). The results of phylogenetic, qPCR, and mRNA abundance analyses suggested that three candidate pheromone-binding proteins (EgriOBP2, 3, and 25), two candidate general odorant-binding proteins (EgriOBP1 and 29), six pheromone receptors (EgriOR24, 25, 28, 31, 37, and 44), and EgriCSP8 may be involved in the detection of Type-II sex pheromone components. Functional investigation by heterologous expression in Xenopus oocytes revealed that EgriOR31 was robustly tuned to the E . grisescens sex pheromone component (Z,Z,Z)-3,6,9-octadecatriene and weakly to the other sex pheromone component (Z,Z)-3,9-6,7-epoxyoctadecadiene. Our results represent a systematic functional analysis of the molecular mechanism of olfaction perception in E . grisescens with an emphasis on gene encoding proteins involved in perception of Type-II sex pheromones, and provide information that will be relevant to other Lepidoptera species.

Pheromone modulates two phenotypically plastic traits - adult reproduction and larval diapause - in the nematode Caenorhabditis elegans.

PubMed

Wharam, Barney; Weldon, Laura; Viney, Mark

2017-08-22

Animals use information from their environment to make decisions, ultimately to maximize their fitness. The nematode C. elegans has a pheromone signalling system, which hitherto has principally been thought to be used by worms in deciding whether or not to arrest their development as larvae. Recent studies have suggested that this pheromone can have other roles in the C. elegans life cycle. Here we demonstrate a new role for the C. elegans pheromone, showing that it accelerates hermaphrodites' reproductive rate, a phenomenon which we call pheromone-dependent reproductive plasticity (PDRP). We also find that pheromone accelerates larval growth rates, but this depends on a live bacterial food source, while PDRP does not. Different C. elegans strains all show PDRP, though the magnitude of these effects differ among the strains, which is analogous to the diversity of arrested larval phenotypes that this pheromone also induces. Using a selection experiment we also show that selection for PDRP or for larval arrest affects both the target and the non-target trait, suggesting that there is cross-talk between these two pheromone-dependent traits. Together, these results show that C. elegans' pheromone is a signal that acts at two key life cycle points, controlling alternative larval fates and affecting adult hermaphrodites' reproduction. More broadly, these results suggest that to properly understand and interpret the biology of pheromone signalling in C. elegans and other nematodes, the life-history biology of these organisms in their natural environment needs to be considered.

Chemosensory Gene Families in Ectropis grisescens and Candidates for Detection of Type-II Sex Pheromones

PubMed Central

Li, Zhao-Qun; Luo, Zong-Xiu; Cai, Xiao-Ming; Bian, Lei; Xin, Zhao-Jun; Liu, Yan; Chu, Bo; Chen, Zong-Mao

2017-01-01

Tea grey geometrid (Ectropis grisescens), a devastating chewing pest in tea plantations throughout China, produces Type-II pheromone components. Little is known about the genes encoding proteins involved in the perception of Type-II sex pheromone components. To investigate the olfaction genes involved in E. grisescens sex pheromones and plant volatiles perception, we sequenced female and male antennae transcriptomes of E. grisescens. After assembly and annotation, we identified 153 candidate chemoreception genes in E. grisescens, including 40 odorant-binding proteins (OBPs), 30 chemosensory proteins (CSPs), 59 odorant receptors (ORs), and 24 ionotropic receptors (IRs). The results of phylogenetic, qPCR, and mRNA abundance analyses suggested that three candidate pheromone-binding proteins (EgriOBP2, 3, and 25), two candidate general odorant-binding proteins (EgriOBP1 and 29), six pheromone receptors (EgriOR24, 25, 28, 31, 37, and 44), and EgriCSP8 may be involved in the detection of Type-II sex pheromone components. Functional investigation by heterologous expression in Xenopus oocytes revealed that EgriOR31 was robustly tuned to the E. grisescens sex pheromone component (Z,Z,Z)-3,6,9-octadecatriene and weakly to the other sex pheromone component (Z,Z)-3,9-6,7-epoxyoctadecadiene. Our results represent a systematic functional analysis of the molecular mechanism of olfaction perception in E. grisescens with an emphasis on gene encoding proteins involved in perception of Type-II sex pheromones, and provide information that will be relevant to other Lepidoptera species. PMID:29209233

Pheromone gland development and pheromone production in lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae).

PubMed

Spiegel, Carolina N; Batista-Pereira, Luciane G; Bretas, Jorge A C; Eiras, Alvaro E; Hooper, Antony M; Peixoto, Alexandre A; Soares, Maurilio J

2011-05-01

The sand fly Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae: Phlebotominae) is the main vector of American visceral leishmaniasis. Adult males produce a terpenoid sex pheromone that in some cases also acts as male aggregation pheromone. We have analyzed the correlation between male pheromone production levels and pheromone gland cell morphogenesis after adult emergence from pupae. The abdominal tergites of L. longipalpis males were dissected and fixed in glutaraldehyde for transmission electron microscopy, or the pheromone was extracted in analytical grade hexane. Pheromone chemical analysis was carried out at 3- to 6-h intervals during the first 24 h after emergence and continued daily until the seventh day. All extracts were analyzed by gas chromatography. For the morphological analysis, we used insects collected at 0-6, 9-12, 12-14, and 96 h after emergence. Ultrastructural data from 0- to 6-h-old adult males revealed smaller pheromone gland cells with small microvilli at the end apparatus. Lipid droplets and peroxisomes were absent or very rare, but a large number of mitochondria could be seen. Lipid droplets started to appear in the gland cells cytoplasm approximately 9 h after adult emergence, and their number and size increased with age, together with the presence of several peroxisomes, suggesting a role for these organelles in pheromone biosynthesis. At 12-15 h after emergence, the lipid droplets were mainly distributed near the microvilli but were smaller than those in mature older males (4 d old). Pheromone biosynthesis started around 12 h after emergence and increased continuously during the first 3 d, stabilizing thereafter, coinciding with the period when males are more able to attract females.

High individual variation in pheromone production by tree-killing bark beetles (Coleoptera: Curculionidae: Scolytinae)

NASA Astrophysics Data System (ADS)

Pureswaran, Deepa S.; Sullivan, Brian T.; Ayres, Matthew P.

2008-01-01

Aggregation via pheromone signalling is essential for tree-killing bark beetles to overcome tree defenses and reproduce within hosts. Pheromone production is a trait that is linked to fitness, so high individual variation is paradoxical. One explanation is that the technique of measuring static pheromone pools overestimates true variation among individuals. An alternative hypothesis is that aggregation behaviour dilutes the contribution of individuals to the trait under selection and reduces the efficacy of natural selection on pheromone production by individuals. We compared pheromone measurements from traditional hindgut extractions of female southern pine beetles with those obtained by aerating individuals till they died. Aerations showed greater total pheromone production than hindgut extractions, but coefficients of variation (CV) remained high (60-182%) regardless of collection technique. This leaves the puzzle of high variation unresolved. A novel but simple explanation emerges from considering bark beetle aggregation behaviour. The phenotype visible to natural selection is the collective pheromone plume from hundreds of colonisers. The influence of a single beetle on this plume is enhanced by high variation among individuals but constrained by large group sizes. We estimated the average contribution of an individual to the pheromone plume across a range of aggregation sizes and showed that large aggregation sizes typical in mass attacks limit the potential of natural selection because each individual has so little effect on the overall plume. Genetic variation in pheromone production could accumulate via mutation and recombination, despite strong effects of the pheromone plume on the fitness of individuals within the aggregation. Thus, aggregation behaviour, by limiting the efficacy of natural selection, can allow the persistence of extreme phenotypes in nature.

A novel mechanism regulating a sexual signal: the testosterone-based inhibition of female sex pheromone expression in garter snakes.

PubMed

Parker, M Rockwell; Mason, Robert T

2014-08-01

Vertebrates communicate their sex to conspecifics through the use of sexually dimorphic signals, such as ornaments, behaviors and scents. Furthermore, the physiological connection between hormones and secondary sexual signal expression is key to understanding their dimorphism, seasonality and evolution. The red-sided garter snake (Thamnophis sirtalis parietalis) is the only reptile for which a described pheromone currently exists, and because garter snakes rely completely on the sexual attractiveness pheromone for species identification and mate choice, they constitute a unique model species for exploring the relationship between pheromones and the endocrine system. We recently demonstrated that estrogen can activate female pheromone production in male garter snakes. The purpose of this study was to determine the mechanism(s) acting to prevent female pheromone production in males. We found that castrated males (GX) are courted by wild males in the field and produce appreciable amounts of female sex pheromone. Furthermore, pheromone production is inhibited in castrates given testosterone implants (GX+T), suggesting that pheromone production is actively inhibited by the presence of testosterone. Lastly, testosterone supplementation alone (T) increased the production of several saturated methyl ketones in the pheromone but not the unsaturated ketones; this may indicate that saturated ketones are testosterone-activated components of the garter snake's skin lipid milieu. Collectively, our research has shown that pheromone expression in snakes results from two processes: activation by the feminizing steroid estradiol and inhibition by testosterone. We suggest that basal birds and garter snakes share common pathways of activation that modulate crucial intraspecific signals that originate from skin. Copyright © 2013 Elsevier Inc. All rights reserved.

Fatty acid and sex pheromone changes and the role of glandular lipids in the Z-strain of the European corn borer, Ostrinia nubilalis (Hübner).

PubMed

Foster, S P

2004-06-01

Lipids in the sex pheromone gland of females of the Z-strain of Ostrinia nubilalis were analyzed for fatty acyl pheromone analogs (FAPAs) and other potential biosynthetic intermediates. More than 80% of the FAPAs were found in the triacylglycerols (TGs), with smaller amounts found in the phosphatidyl cholines, ethanolamines, and serines. Analysis of the TGs by lipase revealed that the two FAPAs were distributed fairly evenly among all three stereospecific positions. Comparison of changes in titers of key glandular fatty acids with those of pheromone components, with respect to photoperiodic time and age of females, showed that both FAPA and pheromone titers exhibited a cyclical pattern with peaks in the scotophase and valleys in the photophase. However, whereas pheromone titer tended to peak in the first half of the scotophase, FAPA titer peaked at the end of the scotophase. Significantly, the titer of the FAPA of the minor component, (E)-11-tetradecenyl acetate (3% of pheromone), was always much greater than the titer of the FAPA of the major component, (Z)-11-tetradecenyl acetate (97%), of the pheromone. Titer of myristate, an intermediate in pheromone biosynthesis, was also higher during the scotophase than the photophase. However, myristate titer showed a pronounced dip in the middle of the scotophase. These data suggest two roles for glandular lipids in sex pheromone biosynthesis in O. nubilalis. Firstly, they remove excess FAPA of the minor component so the fatty acid reductase system is not presented with a high ratio of this isomer (which would otherwise result from the reductase's own selectivity), which could cause changes in the final pheromone ratio. Secondly, hydrolysis of the large amounts of stored saturated fatty acids from the TGs may provide substrate for pheromone biosynthesis. Copyright 2004 Wiley-Liss, Inc.

Transcriptome exploration of the sex pheromone gland of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae).

PubMed

González-Caballero, Natalia; Valenzuela, Jesus G; Ribeiro, José M C; Cuervo, Patricia; Brazil, Reginaldo P

2013-03-07

Molecules involved in pheromone biosynthesis may represent alternative targets for insect population control. This may be particularly useful in managing the reproduction of Lutzomyia longipalpis, the main vector of the protozoan parasite Leishmania infantum in Latin America. Besides the chemical identity of the major components of the L. longipalpis sex pheromone, there is no information regarding the molecular biology behind its production. To understand this process, obtaining information on which genes are expressed in the pheromone gland is essential. In this study we used a transcriptomic approach to explore the pheromone gland and adjacent abdominal tergites in order to obtain substantial general sequence information. We used a laboratory-reared L. longipalpis (one spot, 9-Methyl GermacreneB) population, captured in Lapinha Cave, state of Minas Gerais, Brazil for this analysis. From a total of 3,547 cDNA clones, 2,502 high quality sequences from the pheromone gland and adjacent tissues were obtained and assembled into 1,387 contigs. Through blast searches of public databases, a group of transcripts encoding proteins potentially involved in the production of terpenoid precursors were identified in the 4th abdominal tergite, the segment containing the pheromone gland. Among them, protein-coding transcripts for four enzymes of the mevalonate pathway such as 3-hydroxyl-3-methyl glutaryl CoA reductase, phosphomevalonate kinase, diphosphomevalonate descarboxylase, and isopentenyl pyrophosphate isomerase were identified. Moreover, transcripts coding for farnesyl diphosphate synthase and NADP+ dependent farnesol dehydrogenase were also found in the same tergite. Additionally, genes potentially involved in pheromone transportation were identified from the three abdominal tergites analyzed. This study constitutes the first transcriptomic analysis exploring the repertoire of genes expressed in the tissue containing the L. longipalpis pheromone gland as well as the flanking tissues. Using a comparative approach, a set of molecules potentially present in the mevalonate pathway emerge as interesting subjects for further study regarding their association to pheromone biosynthesis. The sequences presented here may be used as a reference set for future research on pheromone production or other characteristics of pheromone communication in this insect. Moreover, some matches for transcripts of unknown function may provide fertile ground of an in-depth study of pheromone-gland specific molecules.

Pheromone Recognition and Selectivity by ComR Proteins among Streptococcus Species

PubMed Central

Morrison, Donald A.; Talagas, Antoine; Nessler, Sylvie; Federle, Michael J.; Prehna, Gerd

2016-01-01

Natural transformation, or competence, is an ability inherent to bacteria for the uptake of extracellular DNA. This process is central to bacterial evolution and allows for the rapid acquirement of new traits, such as antibiotic resistance in pathogenic microorganisms. For the Gram-positive bacteria genus Streptococcus, genes required for competence are under the regulation of quorum sensing (QS) mediated by peptide pheromones. One such system, ComRS, consists of a peptide (ComS) that is processed (XIP), secreted, and later imported into the cytoplasm, where it binds and activates the transcription factor ComR. ComR then engages in a positive feedback loop for the expression of ComS and the alternative sigma-factor SigX. Although ComRS are present in the majority of Streptococcus species, the sequence of both ComS/XIP and ComR diverge significantly, suggesting a mechanism for species-specific communication. To study possible cross-talk between streptococcal species in the regulation of competence, and to explore in detail the molecular interaction between ComR and XIP we undertook an interdisciplinary approach. We developed a ‘test-bed’ assay to measure the activity of different ComR proteins in response to cognate and heterologous XIP peptides in vivo, revealing distinct ComR classes of strict, intermediate, and promiscuous specificity among species. We then solved an X-ray crystal structure of ComR from S. suis to further understand the interaction with XIP and to search for structural features in ComR proteins that may explain XIP recognition. Using the structure as a guide, we probed the apo conformation of the XIP-binding pocket by site-directed mutagenesis, both in test-bed cultures and biochemically in vitro. In alignments with ComR proteins from other species, we find that the pocket is lined by a variable and a conserved face, where residues of the conserved face contribute to ligand binding and the variable face discriminate among XIP peptides. Together, our results not only provide a model for XIP recognition and specificity, but also allow for the prediction of novel XIP peptides that induce ComR activity. PMID:27907154

Naïve hosts of avian brood parasites accept foreign eggs, whereas older hosts fine-tune foreign egg discrimination during laying

PubMed Central

2014-01-01

Background Many potential hosts of social parasites recognize and reject foreign intruders, and reduce or altogether escape the negative impacts of parasitism. The ontogenetic basis of whether and how avian hosts recognize their own and the brood parasitic eggs remains unclear. By repeatedly parasitizing the same hosts with a consistent parasitic egg type, and contrasting the responses of naïve and older breeders, we studied ontogenetic plasticity in the rejection of foreign eggs by the great reed warbler (Acrocephalus arundinaceus), a host species of the common cuckoo (Cuculus canorus). Results In response to experimental parasitism before the onset of laying, first time breeding hosts showed almost no egg ejection, compared to higher rates of ejection in older breeders. Young birds continued to accept foreign eggs when they were subjected to repeated parasitism, whereas older birds showed even higher ejection rates later in the same laying cycle. Conclusions Our results are consistent with the hypotheses that (i) naïve hosts need to see and learn the appearance of their own eggs to discriminate and reject foreign eggs, whereas (ii) experienced breeders possess a recognition template of their own eggs and reject parasitic eggs even without having to see their own eggs. However, we cannot exclude the possibility that other external cues and internal processes, accumulated simply with increasing age, may also modify age-specific patterns in egg rejection (e.g. more sightings of the cuckoo by older breeders). Future research should specifically track the potential role of learning in responses of individual hosts between first and subsequent breeding attempts by testing whether imprinting on a parasitized clutch reduces the rates of rejecting foreign eggs in subsequent parasitized clutches. PMID:25024736

40 CFR 180.1064 - Tomato pinworm insect pheromone; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Tomato pinworm insect pheromone... RESIDUES IN FOOD Exemptions From Tolerances § 180.1064 Tomato pinworm insect pheromone; exemption from the... residues of both components of the tomato pinworm insect pheromone (E)-4-tridecen-1-yl acetate and (Z)-4...

40 CFR 180.1064 - Tomato pinworm insect pheromone; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Tomato pinworm insect pheromone... RESIDUES IN FOOD Exemptions From Tolerances § 180.1064 Tomato pinworm insect pheromone; exemption from the... residues of both components of the tomato pinworm insect pheromone (E)-4-tridecen-1-yl acetate and (Z)-4...

40 CFR 180.1064 - Tomato pinworm insect pheromone; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Tomato pinworm insect pheromone... RESIDUES IN FOOD Exemptions From Tolerances § 180.1064 Tomato pinworm insect pheromone; exemption from the... residues of both components of the tomato pinworm insect pheromone (E)-4-tridecen-1-yl acetate and (Z)-4...

40 CFR 180.1064 - Tomato pinworm insect pheromone; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Tomato pinworm insect pheromone... RESIDUES IN FOOD Exemptions From Tolerances § 180.1064 Tomato pinworm insect pheromone; exemption from the... residues of both components of the tomato pinworm insect pheromone (E)-4-tridecen-1-yl acetate and (Z)-4...

High individual variation in pheromone production by tree-killing bark beetles (Coleoptera: Curculionidae: Scolytinae)

Treesearch

Deepa S. Pureswaran; Brian T. Sullivan; Matthew P. Ayres

2008-01-01

Aggregation via pheromone signaling is essential for tree-killing bark beetles to overcome tree defenses and reproduce within hosts. Pheromone production is a trait that is linked to fitness, so high individual variation is paradoxica1. One explanation is that the technique of measuring static pheromone pools overestimates true variation among individuals. An...

40 CFR 180.1064 - Tomato pinworm insect pheromone; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Tomato pinworm insect pheromone... RESIDUES IN FOOD Exemptions From Tolerances § 180.1064 Tomato pinworm insect pheromone; exemption from the... residues of both components of the tomato pinworm insect pheromone (E)-4-tridecen-1-yl acetate and (Z)-4...

Nest desertion and cowbird parasitism: evidence for evolved responses and evolutionary lag.

PubMed

Hosoi; Rothstein

2000-04-01

Nest desertion with subsequent renesting is a frequently cited response to parasitism by the brown-headed cowbird, Molothrus ater, yet the role of desertion as an antiparasite defence is widely debated. To determine whether desertion represents an evolutionary response to brown-headed cowbird parasitism, we searched the primary literature, yielding data on the desertion frequencies of 60 host populations from 35 species. Species were categorized according to three habitat types (forest, intermediate and nonforest). Because cowbirds prefer open habitat and rarely penetrate deeply into forests, nonforest species have long been exposed to widespread cowbird parasitism, whereas forest species have not. However, due to increased forest fragmentation, forest species are being increasingly exposed to extensive parasitism. The frequency of desertion of parasitized nests was significantly higher in nonforest than forest species, suggesting that the latter experience evolutionary lag. We also considered whether desertion is affected by predation frequency, degree of current or recent sympatry with cowbirds, parasitism frequency, length of host laying season, phylogenetic relationships, and potential cost of cowbird parasitism. None of these variables created biases that could account for the observed difference in desertion frequencies of nonforest and forest species. However, species that incur large costs when parasitized had higher desertion rates among nonforest species but not among forest species. These results indicate that increased nest desertion is an evolved response to cowbird parasitism, as one would otherwise expect no relationship between desertion frequency and thezx costs and length of exposure to cowbird parasitism. Although nearly all hosts have eggs easily distinguished from cowbird eggs, few or none desert in response to cowbird eggs. Instead, desertion may be a response to adult cowbirds. The scarcity of species that desert in response to cowbird eggs suggests that egg recognition is more difficult to evolve than heightened desertion tendencies and that egg recognition quickly leads to ejection behaviour once it does develop. Copyright 2000 The Association for the Study of Animal Behaviour.

Factors Influencing Male Plutella xylostella (Lepidoptera: Plutellidae) Capture Rates in Sex Pheromone-Baited Traps on Canola in Western Canada.

PubMed

Miluch, C E; Dosdall, L M; Evenden, M L

2014-12-01

Optimization of male moth trapping rates in sex pheromone-baited traps plays a key role in managing Plutella xylostella (L.). We investigated various ways to increase the attractiveness of pheromone-baited traps to P. xylostella in canola agroecosystems in AB, Canada. Factors tested included pheromone blend and dose, addition of a green leaf volatile to the pheromone at different times during the season, lure type, trap color, and height. The industry standard dose of 100 μg of pheromone (four-component blend) per lure (ConTech Enterprises Inc., Delta, British Columbia [BC], Canada) captured the most moths in the two lure types tested. Traps baited with pheromone released from gray rubber septa captured more males than those baited with red rubber septa. Traps baited with lures in which Z11-16: Ac is the main component attracted significantly more moths than those in which Z11-16: Ald is the main component. The addition of the green leaf volatile, (Z)-3-hexenyl acetate, to pheromone at a range of doses, did not increase moth capture at any point during the canola growing season. Unpainted white traps captured significantly more male moths than pheromone-baited traps that were painted yellow. Trap height had no significant effect on moth capture. Recommendations for monitoring P. xylostella in canola agroecosystems of western Canada include using a pheromone blend with Z11-16: Ac as the main component released from gray rubber septa at a dose of 100 μg. © 2014 Entomological Society of America.

Increased pheromone signaling by small male sea lamprey has distinct effects on female mate search and courtship

USGS Publications Warehouse

Buchinger, Tyler J.; Bussy, Ugo; Buchinger, Ethan G.; Fissette, Skye D.; Li, Weiming; Johnson, Nicholas

2017-01-01

Male body size affects access to mates in many animals. Attributes of sexual signals often correlate with body size due to physiological constraints on signal production. Larger males generally produce larger signals, but costs of being large or compensation by small males can result in smaller males producing signals of equal or greater magnitude. Female choice following multiple male traits with different relationships to size might further complicate the effect of male body size on access to mates. We report the relationship between male body size and pheromone signaling, and the effects on female mate search and courtship in the sea lamprey (Petromyzon marinus). We predicted that pheromone production in the liver and the liver mass to body mass ratio would remain constant across sizes, resulting in similar mass-adjusted pheromone release rates across sizes but a positive relationship between absolute pheromone release and body mass. Our results confirmed positive relationships between body mass and liver mass, and liver mass and the magnitude of the pheromone signal. Surprisingly, decreasing body mass was correlated with higher pheromone concentrations in the liver, liver mass to body mass ratios, and mass-adjusted pheromone release rates. In a natural stream, females more often entered nests treated with small versus large male odors. However, close-proximity courtship behaviors were similar in nests treated with small or large male odors. We conclude that small males exhibit increased release of the main pheromone component, but female discrimination of male pheromones follows several axes of variation with different relationships to size.

Pheromone modulates plant odor responses in the antennal lobe of a moth.

PubMed

Chaffiol, Antoine; Dupuy, Fabienne; Barrozo, Romina B; Kropf, Jan; Renou, Michel; Rospars, Jean-Pierre; Anton, Sylvia

2014-06-01

In nature, male moths are exposed to a complex plant odorant environment when they fly upwind to a sex pheromone source in their search for mates. Plant odors have been shown to affect responses to pheromone at various levels but how does pheromone affects plant odor perception? We recorded responses from neurons within the non-pheromonal "ordinary glome ruli" of the primary olfactory center, the antennal lobe (AL), to single and pulsed stimulations with the plant odorant heptanal, the pheromone, and their mixture in the male moth Agrotis ipsilon. We identified 3 physiological types of neurons according to their activity patterns combining excitatory and inhibitory phases. Both local and projection neurons were identified in each physiological type. Neurons with excitatory responses to heptanal responded also frequently to the pheromone and showed additive responses to the mixture. Moreover, the neuron's ability of resolving successive pulses generally improved with the mixture. Only some neurons with combined excitatory/inhibitory, or purely inhibitory responses to heptanal, also responded to the pheromone. Although individual mixture responses were not significantly different from heptanal responses in these neurons, pulse resolution was improved with the mixture as compared with heptanal alone. These results demonstrate that the pheromone and the general odorant subsystems interact more intensely in the moth AL than previously thought. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pheromone-sensitive glomeruli in the primary olfactory centre of ants.

PubMed

Yamagata, Nobuhiro; Nishino, Hiroshi; Mizunami, Makoto

2006-09-07

Tremendous evolutional success and the ecological dominance of social insects, including ants, termites and social bees, are due to their efficient social organizations and their underlying communication systems. Functional division into reproductive and sterile castes, cooperation in defending the nest, rearing the young and gathering food are all regulated by communication by means of various kinds of pheromones. No brain structures specifically involved in the processing of non-sexual pheromone have been physiologically identified in any social insects. By use of intracellular recording and staining techniques, we studied responses of projection neurons of the antennal lobe (primary olfactory centre) of ants to alarm pheromone, which plays predominant roles in colony defence. Among 23 alarm pheromone-sensitive projection neurons recorded and stained in this study, eight were uniglomerular projection neurons with dendrites in one glomerulus, a structural unit of the antennal lobe, and the remaining 15 were multiglomerular projection neurons with dendrites in multiple glomeruli. Notably, all alarm pheromone-sensitive uniglomerular projection neurons had dendrites in one of five 'alarm pheromone-sensitive (AS)' glomeruli that form a cluster in the dorsalmost part of the antennal lobe. All alarm pheromone-sensitive multiglomerular projection neurons had dendrites in some of the AS glomeruli as well as in glomeruli in the anterodorsal area of the antennal lobe. The results suggest that components of alarm pheromone are processed in a specific cluster of glomeruli in the antennal lobe of ants.

Activity of male pheromone of Melanesian rhinoceros beetle Scapanes australis.

PubMed

Rochat, Didier; Morin, Jean-Paul; Kakul, Titus; Beaudoin-Ollivier, Laurence; Prior, Robert; Renou, Michel; Malosse, Isabelle; Stathers, Tanya; Embupa, Sebastian; Laup, Samson

2002-03-01

Laboratory and field investigations were carried out to investigate the nature and role of the male pheromone emitted by the Dynast beetle Scapanes australis and to develop a mass trapping technique against this major coconut pest in Papua New Guinea. We report the biological data obtained from natural and synthetic pheromone, previously described as an 84:12:4 (w/w) mixture of 2-butanol (1), 3-hydoxy-2-butanone (2), and 2,3-butanediol (3). EAG recordings from natural and synthetic pheromone and a pitfall olfactometer were poorly informative. In contrast, extensive field trapping trials with various synthetic pheromone mixtures and doses showed that 1 and 2 (formulated in polyethylene sachets in 90:5 v/v ratio) were necessary and sufficient for optimum long-range attraction. Beetles were captured in traps baited with racemic 1 plus 2, with or without a stereoisomer mixture of 3 (2.5- to 2500-mg/day doses). Plant pieces, either sugarcane or coconut, enhanced captures by the synthetic pheromone, which was active alone. Traps with the pheromone caught both sexes in a 3:2 female-male ratio. A pheromone-based mass trapping led to the capture of 2173 beetles in 14 traps surrounding 40 ha of a cocoa-coconut plantation. The captures followed a log-linear decrease during the 125-week trapping program. The role of the male pheromone and its potential for crop protection are discussed.

Identification and Expression Profiles of Sex Pheromone Biosynthesis and Transport Related Genes in Spodoptera litura

PubMed Central

Zhang, Ya-Nan; Zhu, Xiu-Yun; Fang, Li-Ping; He, Peng; Wang, Zhi-Qiang; Chen, Geng; Sun, Liang; Ye, Zhan-Feng; Deng, Dao-Gui; Li, Jin-Bu

2015-01-01

Although the general pathway of sex pheromone synthesis in moth species has been established, the molecular mechanisms remain poorly understood. The common cutworm Spodoptera litura is an important agricultural pest worldwide and causes huge economic losses annually. The female sex pheromone of S. litura comprises Z9,E11-14:OAc, Z9,E12-14:OAc, Z9-14:OAc, and E11-14:OAc. By sequencing and analyzing the transcriptomic data of the sex pheromone glands, we identified 94 candidate genes related to pheromone biosynthesis (55 genes) or chemoreception (39 genes). Gene expression patterns and phylogenetic analysis revealed that two desaturase genes (SlitDes5 and SlitDes11) and one fatty acyl reductase gene (SlitFAR3) showed pheromone gland (PG) biased or specific expression, and clustered with genes known to be involved in pheromone synthesis in other moth species. Furthermore, 4 chemoreception related genes (SlitOBP6, SlitOBP11, SlitCSP3, and SlitCSP14) also showed higher expression in the PG, and could be additional candidate genes involved in sex pheromone transport. This study provides the first solid background information that should facilitate further elucidation of sex pheromone biosynthesis and transport, and indicates potential targets to disrupt sexual communication in S. litura for a novel pest management strategy. PMID:26445454

Expert Assessment of Human-Human Stigmergy

DTIC Science & Technology

2005-10-01

paradigm for marker based stigmergy is the use of pheromones by certain social insects to coordinate their actions. Most insect species use a few...dozen distinct pheromone “flavors,” and thus use qualitative as well as quantitative decision-making. In engineered systems, stigmergic markers can...Gradient following in a single pheromone field Ant cemetery clustering Qualitative Decisions based on combinations of pheromones Wasp nest

A potent dauer pheromone component in Caenorhabditis elegans that acts synergistically with other components.

PubMed

Butcher, Rebecca A; Ragains, Justin R; Kim, Edward; Clardy, Jon

2008-09-23

In the model organism Caenorhabditis elegans, the dauer pheromone is the primary cue for entry into the developmentally arrested, dauer larval stage. The dauer is specialized for survival under harsh environmental conditions and is considered "nonaging" because larvae that exit dauer have a normal life span. C. elegans constitutively secretes the dauer pheromone into its environment, enabling it to sense its population density. Several components of the dauer pheromone have been identified as derivatives of the dideoxy sugar ascarylose, but additional unidentified components of the dauer pheromone contribute to its activity. Here, we show that an ascaroside with a 3-hydroxypropionate side chain is a highly potent component of the dauer pheromone that acts synergistically with previously identified components. Furthermore, we show that the active dauer pheromone components that are produced by C. elegans vary depending on cultivation conditions. Identifying the active components of the dauer pheromone, the conditions under which they are produced, and their mechanisms of action will greatly extend our understanding of how chemosensory cues from the environment can influence such fundamental processes as development, metabolism, and aging in nematodes and in higher organisms.

Alarm pheromone is detected by the vomeronasal organ in male rats.

PubMed

Kiyokawa, Yasushi; Kodama, Yuka; Kubota, Takahiro; Takeuchi, Yukari; Mori, Yuji

2013-10-01

It is widely known that a stressed animal releases specific pheromones, possibly for alarming nearby conspecifics. We previously investigated an alarm pheromone in male rats and found that this alarm pheromone evokes several responses, including increases in the defensive and risk assessment behaviors in a modified open-field test, and enhancement of the acoustic startle reflex. However, the role of the vomeronasal organ in these pheromone effects remains unclear. To clarify this point, vomeronasal organ-excising or sham surgeries were performed in male rats for use in 2 experimental models, after which they were exposed to alarm pheromone. We found that the vomeronasal organ-excising surgery blocked the effects of this alarm pheromone in both the modified open-field test and acoustic startle reflex test. In addition, the results of habituation/dishabituation test and soybean agglutinin binding to the accessory olfactory bulb suggested that the vomeronasal organ-excising surgery completely ablated the vomeronasal organ while preserving the functioning of the main olfactory system. From the above results, we showed that the vomeronasal organ plays an important role in alarm pheromone effects in the modified open-field test and acoustic startle reflex test.

Effects of Two Conventional Insecticides on Male-Specific Sex Pheromone Discrimination and Mate Choice in Trichogramma chilonis (Hymenoptera: Trichogrammatidae).

PubMed

Wang, Desen; Lü, Lihua; He, Yurong

2017-04-01

Trichogramma chilonis Ishii is an important natural enemy of many lepidopterous pests on vegetables and field crops. The effects of two conventional insecticides on male-specific sex pheromone discrimination and mate choice in T. chilonis was evaluated in the laboratory. Beta-cypermethrin LC20 exposure induced decreases in male conspecific sex pheromone discrimination and mating rate in T. chilonis, and these decreases were not due to the lower locomotor activity of the surviving T. chilonis males. Spinosad LC20 exposure caused a significant decrease in male locomotor activity of T. chilonis, but did not affect male-specific sex pheromone discrimination (conspecific sex pheromone discrimination or virgin sex pheromone discrimination) or mating rate. However, there was no significant difference in specific sex pheromone discrimination, mate choice, and locomotor activity between control males and males exposed to the low concentration (LC1) of insecticide (beta-cypermethrin or spinosad). In conclusion, beta-cypermethrin LC20 exposure was harmful to male-specific sex pheromone discrimination and mate choice in T. chilonis. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Chiral discrimination of the Japanese beetle sex pheromone and a behavioral antagonist by a pheromone-degrading enzyme.

PubMed

Ishida, Yuko; Leal, Walter S

2008-07-01

The sophistication of the insect olfactory system is elegantly demonstrated by the reception of sex pheromone by the Japanese beetle. In this insect, two olfactory receptor neurons housed in antennal sensilla placodea are highly sensitive. One neuron specifically detects the sex pheromone produced by conspecific females (R,Z)-5-(-)-(1-decenyl)oxacyclopentan-2-one [(R)-japonilure]. The other neuron is tuned to (S)-japonilure, a sex pheromone from a closely related species and a behavioral antagonist for the Japanese beetle. These chemical signals are enzymatically terminated by antennal esterases that open the lactone rings to form physiologically inactive hydroxyacids. We have isolated a pheromone-degrading enzyme, PjapPDE, from >100,000 antennae of the Japanese beetle. PjapPDE was demonstrated to be expressed only in the antennal tissues housing the pheromone-detecting sensilla placodea. Baculovirus expression generated recombinant PjapPDE with likely the same posttranslational modifications as the native enzyme. Kinetic studies with pure native and recombinant PjapPDE showed a clear substrate preference, with an estimated half-life in vivo for the sex pheromone and a behavioral antagonist of approximately 30 and approximately 90 ms, respectively.

Primer and short-range releaser pheromone properties of premolt female urine from the shore crab Carcinus maenas.

PubMed

Ekerholm, Mattias; Hallberg, Eric

2005-08-01

The European shore crab Carcinus maenas is considered to rely on a female pheromone when mating. Evidence, however, is scarce on how the urine pheromone in itself affects males. We investigated male primer and releaser responses to female pheromones with methods that minimized effects from females, delivering female urine either as a pump-generated plume or deposited on a polyurethane sponge. We delivered the pheromone at different concentrations in far, near, and close/contact range to get a picture of how distance affects behavioral response. Our results show that substances in premolt female urine (PMU) function as primer and potent short-range releaser pheromones. Based on the olfactometer and sponge tests, we conclude that PMU stimulus in itself is sufficient to elicit increased search and mating-specific behaviors such as posing, posing search, cradle carrying, and stroking. Pheromone concentrations do not seem to be important for attenuating search and posing as long as the level is above a certain threshold concentration. Instead, pheromone levels seem to play a role in male acceptance of females, recruiting more males to respond, and generating better responses with increasing concentration.

Temporary inactivation of the anterior part of the bed nucleus of the stria terminalis blocks alarm pheromone-induced defensive behavior in rats

PubMed Central

Breitfeld, Tino; Bruning, Johann E. A.; Inagaki, Hideaki; Takeuchi, Yukari; Kiyokawa, Yasushi; Fendt, Markus

2015-01-01

Rats emit an alarm pheromone in threatening situations. Exposure of rats to this alarm pheromone induces defensive behaviors, such as head out behavior, and increases c-Fos expression in brain areas involved in the mediation of defensive behaviors. One of these brain areas is the anterior bed nucleus of the stria terminalis (aBNST). The goal of the present study was to investigate if pharmacological inactivation of the aBNST by local microinjections of the GABAA receptor-agonist muscimol modulates alarm pheromone-induced defensive behaviors. We first established the behavioral paradigm of alarm pheromone-induced defensive behaviors in Sprague-Dawley rats in our laboratory. In a second experiment, we inactivated the aBNST, then exposed rats to one of four different odors (neck odor, female urine, alarm pheromone, fox urine) and tested the effects of the aBNST inactivation on the behavior in response to these odors. Our data show that temporary inactivation of the aBNST blocked head out behavior in response to the alarm pheromone. This indicates that the aBNST plays an important role in the mediation of the alarm pheromone-induced defensive behavior in rats. PMID:26441496

Trail pheromone disruption of Argentine ant trail formation and foraging.

PubMed

Suckling, David Maxwell; Peck, Robert W; Stringer, Lloyd D; Snook, Kirsten; Banko, Paul C

2010-01-01

Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2–3 m s−1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments.

Mimicking Insect Communication: Release and Detection of Pheromone, Biosynthesized by an Alcohol Acetyl Transferase Immobilized in a Microreactor

PubMed Central

Muñoz, Lourdes; Dimov, Nikolay; Carot-Sans, Gerard; Bula, Wojciech P.; Guerrero, Angel; Gardeniers, Han J. G. E.

2012-01-01

Infochemical production, release and detection of (Z,E)-9,11-tetradecadienyl acetate, the major component of the pheromone of the moth Spodoptera littoralis, is achieved in a novel microfluidic system designed to mimic the final step of the pheromone biosynthesis by immobilized recombinant alcohol acetyl transferase. The microfluidic system is part of an “artificial gland”, i.e., a chemoemitter that comprises a microreactor connected to a microevaporator and is able to produce and release a pre-defined amount of the major component of the pheromone from the corresponding (Z,E)-9,11-tetradecadienol. Performance of the entire chemoemitter has been assessed in electrophysiological and behavioral experiments. Electroantennographic depolarizations of the pheromone produced by the chemoemitter were ca. 40% relative to that evoked by the synthetic pheromone. In a wind tunnel, the pheromone released from the evaporator elicited on males a similar attraction behavior as 3 virgin females in most of the parameters considered. PMID:23155372

Biosynthesis of the Caenorhabditis elegans dauer pheromone.

PubMed

Butcher, Rebecca A; Ragains, Justin R; Li, Weiqing; Ruvkun, Gary; Clardy, Jon; Mak, Ho Yi

2009-02-10

To sense its population density and to trigger entry into the stress-resistant dauer larval stage, Caenorhabditis elegans uses the dauer pheromone, which consists of ascaroside derivatives with short, fatty acid-like side chains. Although the dauer pheromone has been studied for 25 years, its biosynthesis is completely uncharacterized. The daf-22 mutant is the only known mutant defective in dauer pheromone production. Here, we show that daf-22 encodes a homolog of human sterol carrier protein SCPx, which catalyzes the final step in peroxisomal fatty acid beta-oxidation. We also show that dhs-28, which encodes a homolog of the human d-bifunctional protein that acts just upstream of SCPx, is also required for pheromone production. Long-term daf-22 and dhs-28 cultures develop dauer-inducing activity by accumulating less active, long-chain fatty acid ascaroside derivatives. Thus, daf-22 and dhs-28 are required for the biosynthesis of the short-chain fatty acid-derived side chains of the dauer pheromone and link dauer pheromone production to metabolic state.

A host beetle pheromone regulates development and behavior in the nematode Pristionchus pacificus.

PubMed

Cinkornpumin, Jessica K; Wisidagama, Dona R; Rapoport, Veronika; Go, James L; Dieterich, Christoph; Wang, Xiaoyue; Sommer, Ralf J; Hong, Ray L

2014-10-15

Nematodes and insects are the two most speciose animal phyla and nematode-insect associations encompass widespread biological interactions. To dissect the chemical signals and the genes mediating this association, we investigated the effect of an oriental beetle sex pheromone on the development and behavior of the nematode Pristionchus pacificus. We found that while the beetle pheromone is attractive to P. pacificus adults, the pheromone arrests embryo development, paralyzes J2 larva, and inhibits exit of dauer larvae. To uncover the mechanism that regulates insect pheromone sensitivity, a newly identified mutant, Ppa-obi-1, is used to reveal the molecular links between altered attraction towards the beetle pheromone, as well as hypersensitivity to its paralyzing effects. Ppa-obi-1 encodes lipid-binding domains and reaches its highest expression in various cell types, including the amphid neuron sheath and excretory cells. Our data suggest that the beetle host pheromone may be a species-specific volatile synomone that co-evolved with necromeny.

Bumblebee size polymorphism and worker response to queen pheromone.

PubMed

Holman, Luke

2014-01-01

Queen pheromones are chemical signals produced by reproductive individuals in social insect colonies. In many species they are key to the maintenance of reproductive division of labor, with workers beginning to reproduce individually once the queen pheromone disappears. Recently, a queen pheromone that negatively affects worker fecundity was discovered in the bumblebee Bombus terrestris, presenting an exciting opportunity for comparisons with analogous queen pheromones in independently-evolved eusocial lineages such as honey bees, ants, wasps and termites. I set out to replicate this discovery and verify its reproducibility. Using blind, controlled experiments, I found that n-pentacosane (C25) does indeed negatively affect worker ovary development. Moreover, the pheromone affects both large and small workers, and applies to workers from large, mature colonies as well as young colonies. Given that C25 is readily available and that bumblebees are popular study organisms, I hope that this replication will encourage other researchers to tackle the many research questions enabled by the discovery of a queen pheromone.

Short-chain alkanes synergise responses of moth pests to their sex pheromones.

PubMed

Gurba, Alexandre; Guerin, Patrick M

2016-05-01

The use of sex pheromones for mating disruption of moth pests of crops is increasing worldwide. Efforts are under way to augment the efficiency and reliability of this control method by adding molecules derived from host plants to the sex attractants in dispensers. We show how attraction of the European grapevine moth, Lobesia botrana Den. & Schiff., and the codling moth, Cydia pomonella L., males to underdosed levels of their sex pheromones is increased by adding heptane or octane over a range of release rates. Pheromone-alkane mixtures enhance male recruitment by up to 30%, reaching levels induced by calling females, and shorten the flight time to the sex attractant by a factor of 2. The findings show the promise of using short-chain alkanes as pheromone synergists for mating disruption of insect pests of food crops. Alkane-pheromone combinations are expected to increase the competitiveness of dispensers with females, and to reduce the amount of pheromone needed for the control of these pests. © 2015 Society of Chemical Industry.

Pheromone Binding Protein EhipPBP1 Is Highly Enriched in the Male Antennae of the Seabuckthorn Carpenterworm and Is Binding to Sex Pheromone Components

PubMed Central

Hu, Ping; Gao, Chenglong; Zong, Shixiang; Luo, Youqing; Tao, Jing

2018-01-01

The seabuckthorn carpenterworm moth Eogystia hippophaecolus is a major threat to seabuckthorn plantations, causing considerable ecological and economic losses in China. Transcriptomic analysis of E. hippophaecolus previously identified 137 olfactory proteins, including three pheromone-binding proteins (PBPs). We investigated the function of E. hippophaecolus PBP1 by studying its mRNA and protein expression profiles and its binding ability with different compounds. The highest levels of expression were in the antennae, particularly in males, with much lower levels of expression in the legs and external genitals. Recombinant PBP1 showed strong binding to sex-pheromone components, suggesting that antennal EhipPBP1 is involved in binding sex-pheromone components during pheromone communication. PMID:29755369

Assessing the potential for egg chemoattractants to mediate sexual selection in a broadcast spawning marine invertebrate

PubMed Central

Evans, Jonathan P.; Garcia-Gonzalez, Francisco; Almbro, Maria; Robinson, Oscar; Fitzpatrick, John L.

2012-01-01

In numerous species, egg chemoattractants play a critical role in guiding sperm towards unfertilized eggs (sperm chemotaxis). Until now, the known functions of sperm chemotaxis include increasing the effective target size of eggs, thereby promoting sperm–egg encounters, and facilitating species recognition. Here, we report that in the broadcast spawning mussel, Mytilus galloprovincialis, egg chemoattractants may play an unforeseen role in sexual selection by enabling sperm to effectively ‘choose’ between the eggs of different conspecific females. In an initial experiment, we confirmed that sperm chemotaxis occurs in M. galloprovincialis by showing that sperm are attracted towards unfertilized eggs when given the choice of eggs or no eggs in a dichotomous chamber. We then conducted two cross-classified mating experiments, each comprising the same individual males and females crossed in identical male × female combinations, but under experimental conditions that offered sperm ‘no-choice’ (each fertilization trial took place in a Petri dish and involved a single male and female) or a ‘choice’ of a female's eggs (sperm were placed in the centre of a dichotomous choice chamber and allowed to choose eggs from different females). We show that male-by-female interactions characterized fertilization rates in both experiments, and that there was remarkable consistency between patterns of sperm migration in the egg-choice experiment and fertilization rates in the no-choice experiment. Thus, sperm appear to exploit chemical cues to preferentially swim towards eggs with which they are most compatible during direct sperm-to-egg encounters. These results reveal that sperm differentially select eggs on the basis of chemical cues, thus exposing the potential for egg chemoattractants to mediate mate choice for genetically compatible partners. Given the prevalence of sperm chemotaxis across diverse taxa, our findings may have broad implications for sexual selection in other mating systems. PMID:22438495

Transcriptome exploration of the sex pheromone gland of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae)

PubMed Central

2013-01-01

Background Molecules involved in pheromone biosynthesis may represent alternative targets for insect population control. This may be particularly useful in managing the reproduction of Lutzomyia longipalpis, the main vector of the protozoan parasite Leishmania infantum in Latin America. Besides the chemical identity of the major components of the L. longipalpis sex pheromone, there is no information regarding the molecular biology behind its production. To understand this process, obtaining information on which genes are expressed in the pheromone gland is essential. Methods In this study we used a transcriptomic approach to explore the pheromone gland and adjacent abdominal tergites in order to obtain substantial general sequence information. We used a laboratory-reared L. longipalpis (one spot, 9-Methyl GermacreneB) population, captured in Lapinha Cave, state of Minas Gerais, Brazil for this analysis. Results From a total of 3,547 cDNA clones, 2,502 high quality sequences from the pheromone gland and adjacent tissues were obtained and assembled into 1,387 contigs. Through blast searches of public databases, a group of transcripts encoding proteins potentially involved in the production of terpenoid precursors were identified in the 4th abdominal tergite, the segment containing the pheromone gland. Among them, protein-coding transcripts for four enzymes of the mevalonate pathway such as 3-hydroxyl-3-methyl glutaryl CoA reductase, phosphomevalonate kinase, diphosphomevalonate descarboxylase, and isopentenyl pyrophosphate isomerase were identified. Moreover, transcripts coding for farnesyl diphosphate synthase and NADP+ dependent farnesol dehydrogenase were also found in the same tergite. Additionally, genes potentially involved in pheromone transportation were identified from the three abdominal tergites analyzed. Conclusion This study constitutes the first transcriptomic analysis exploring the repertoire of genes expressed in the tissue containing the L. longipalpis pheromone gland as well as the flanking tissues. Using a comparative approach, a set of molecules potentially present in the mevalonate pathway emerge as interesting subjects for further study regarding their association to pheromone biosynthesis. The sequences presented here may be used as a reference set for future research on pheromone production or other characteristics of pheromone communication in this insect. Moreover, some matches for transcripts of unknown function may provide fertile ground of an in-depth study of pheromone-gland specific molecules. PMID:23497448

Aggregation Pheromone System: A Real-parameter Optimization Algorithm using Aggregation Pheromones as the Base Metaphor

NASA Astrophysics Data System (ADS)

Tsutsui, Shigeyosi

This paper proposes an aggregation pheromone system (APS) for solving real-parameter optimization problems using the collective behavior of individuals which communicate using aggregation pheromones. APS was tested on several test functions used in evolutionary computation. The results showed APS could solve real-parameter optimization problems fairly well. The sensitivity analysis of control parameters of APS is also studied.

Synthetic sex pheromone attracts the leishmaniasis vector Lutzomyia longipalpis to experimental chicken sheds treated with insecticide

PubMed Central

2010-01-01

Background Current strategies for controlling American visceral leishmaniasis (AVL) have been unable to prevent the spread of the disease across Brazil. With no effective vaccine and culling of infected dogs an unpopular and unsuccessful alternative, new tools are urgently needed to manage populations of the sand fly vector, Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae). Here, we test two potential strategies for improving L. longipalpis control using the synthetic sand fly pheromone (±)-9-methylgermacrene-B: the first in conjunction with spraying of animal houses with insecticide, the second using coloured sticky traps. Results Addition of synthetic pheromone resulted in greater numbers of male and female sand flies being caught and killed at experimental chicken sheds sprayed with insecticide, compared to pheromone-less controls. Furthermore, a ten-fold increase in the amount of sex pheromone released from test sheds increased the number of females attracted and subsequently killed. Treating sheds with insecticide alone resulted in a significant decrease in numbers of males attracted to sheds (compared to pre-spraying levels), and a near significant decrease in numbers of females. However, this effect was reversed through addition of synthetic pheromone at the time of insecticide spraying, leading to an increase in number of flies attracted post-treatment. In field trials of commercially available different coloured sticky traps, yellow traps caught more males than blue traps when placed in chicken sheds. In addition, yellow traps fitted with 10 pheromone lures caught significantly more males than pheromone-less controls. However, while female sand flies showed a preference for both blue and yellow pheromone traps sticky traps over white traps in the laboratory, neither colour caught significant numbers of females in chicken sheds, either with or without pheromone. Conclusions We conclude that synthetic pheromone could currently be most effectively deployed for sand fly control through combination with existing insecticide spraying regimes. Development of a standalone pheromone trap remains a possibility, but such devices may require an additional attractive host odour component to be fully effective. PMID:20222954

Trail communication regulated by two trail pheromone components in the fungus-growing termite Odontotermes formosanus (Shiraki).

PubMed

Wen, Ping; Ji, Bao-Zhong; Sillam-Dussès, David

2014-01-01

The eusocial termites are well accomplished in chemical communication, but how they achieve the communication using trace amount of no more than two pheromone components is mostly unknown. In this study, the foraging process and trail pheromones of the fungus-growing termite Odontotermes formosanus (Shiraki) were systematically studied and monitored in real-time using a combination of techniques, including video analysis, solid-phase microextraction, gas chromatography coupled with either mass spectrometry or an electroantennographic detector, and bioassays. The trail pheromone components in foraging workers were (3Z)-dodec-3-en-1-ol and (3Z,6Z)-dodeca-3,6-dien-1-ol secreted by their sternal glands. Interestingly, ratio of the two components changed according to the behaviors that the termites were displaying. This situation only occurs in termites whereas ratios of pheromone components are fixed and species-specific for other insect cuticular glands. Moreover, in bioassays, the active thresholds of the two components ranged from 1 fg/cm to 10 pg/cm according to the behavioral contexts or the pheromonal exposure of tested workers. The two components did not act in synergy. (3Z)-Dodec-3-en-1-ol induced orientation behavior of termites that explore their environment, whereas (3Z,6Z)-dodeca-3,6-dien-1-ol had both an orientation effect and a recruitment effect when food was discovered. The trail pheromone of O. formosanus was regulated both quantitatively by the increasing number of workers involved in the early phases of foraging process, and qualitatively by the change in ratio of the two pheromone components on sternal glandular cuticle in the food-collecting workers. In bioassays, the responses of workers to the pheromone were also affected by the variation in pheromone concentration and component ratio in the microenvironment. Thus, this termite could exchange more information with nestmates using the traces of the two trail pheromone components that can be easily regulated within a limited microenvironment formed by the tunnels or chambers.

A Single Sex Pheromone Receptor Determines Chemical Response Specificity of Sexual Behavior in the Silkmoth Bombyx mori

PubMed Central

Sakurai, Takeshi; Mitsuno, Hidefumi; Haupt, Stephan Shuichi; Uchino, Keiro; Yokohari, Fumio; Nishioka, Takaaki; Kobayashi, Isao; Sezutsu, Hideki; Tamura, Toshiki; Kanzaki, Ryohei

2011-01-01

In insects and other animals, intraspecific communication between individuals of the opposite sex is mediated in part by chemical signals called sex pheromones. In most moth species, male moths rely heavily on species-specific sex pheromones emitted by female moths to identify and orient towards an appropriate mating partner among a large number of sympatric insect species. The silkmoth, Bombyx mori, utilizes the simplest possible pheromone system, in which a single pheromone component, (E, Z)-10,12-hexadecadienol (bombykol), is sufficient to elicit full sexual behavior. We have previously shown that the sex pheromone receptor BmOR1 mediates specific detection of bombykol in the antennae of male silkmoths. However, it is unclear whether the sex pheromone receptor is the minimally sufficient determination factor that triggers initiation of orientation behavior towards a potential mate. Using transgenic silkmoths expressing the sex pheromone receptor PxOR1 of the diamondback moth Plutella xylostella in BmOR1-expressing neurons, we show that the selectivity of the sex pheromone receptor determines the chemical response specificity of sexual behavior in the silkmoth. Bombykol receptor neurons expressing PxOR1 responded to its specific ligand, (Z)-11-hexadecenal (Z11-16:Ald), in a dose-dependent manner. Male moths expressing PxOR1 exhibited typical pheromone orientation behavior and copulation attempts in response to Z11-16:Ald and to females of P. xylostella. Transformation of the bombykol receptor neurons had no effect on their projections in the antennal lobe. These results indicate that activation of bombykol receptor neurons alone is sufficient to trigger full sexual behavior. Thus, a single gene defines behavioral selectivity in sex pheromone communication in the silkmoth. Our findings show that a single molecular determinant can not only function as a modulator of behavior but also as an all-or-nothing initiator of a complex species-specific behavioral sequence. PMID:21738481

A single sex pheromone receptor determines chemical response specificity of sexual behavior in the silkmoth Bombyx mori.

PubMed

Sakurai, Takeshi; Mitsuno, Hidefumi; Haupt, Stephan Shuichi; Uchino, Keiro; Yokohari, Fumio; Nishioka, Takaaki; Kobayashi, Isao; Sezutsu, Hideki; Tamura, Toshiki; Kanzaki, Ryohei

2011-06-01

In insects and other animals, intraspecific communication between individuals of the opposite sex is mediated in part by chemical signals called sex pheromones. In most moth species, male moths rely heavily on species-specific sex pheromones emitted by female moths to identify and orient towards an appropriate mating partner among a large number of sympatric insect species. The silkmoth, Bombyx mori, utilizes the simplest possible pheromone system, in which a single pheromone component, (E, Z)-10,12-hexadecadienol (bombykol), is sufficient to elicit full sexual behavior. We have previously shown that the sex pheromone receptor BmOR1 mediates specific detection of bombykol in the antennae of male silkmoths. However, it is unclear whether the sex pheromone receptor is the minimally sufficient determination factor that triggers initiation of orientation behavior towards a potential mate. Using transgenic silkmoths expressing the sex pheromone receptor PxOR1 of the diamondback moth Plutella xylostella in BmOR1-expressing neurons, we show that the selectivity of the sex pheromone receptor determines the chemical response specificity of sexual behavior in the silkmoth. Bombykol receptor neurons expressing PxOR1 responded to its specific ligand, (Z)-11-hexadecenal (Z11-16:Ald), in a dose-dependent manner. Male moths expressing PxOR1 exhibited typical pheromone orientation behavior and copulation attempts in response to Z11-16:Ald and to females of P. xylostella. Transformation of the bombykol receptor neurons had no effect on their projections in the antennal lobe. These results indicate that activation of bombykol receptor neurons alone is sufficient to trigger full sexual behavior. Thus, a single gene defines behavioral selectivity in sex pheromone communication in the silkmoth. Our findings show that a single molecular determinant can not only function as a modulator of behavior but also as an all-or-nothing initiator of a complex species-specific behavioral sequence.

Molecular elements of pheromone detection in the female moth, Heliothis virescens.

PubMed

Zielonka, Monika; Breer, Heinz; Krieger, Jürgen

2018-06-01

Pheromones play pivotal roles in the reproductive behavior of moths, most prominently for the mate finding of male moths. Accordingly, the molecular basis for the detection of female-released pheromones by male moths has been studied in great detail. In contrast, little is known about how females can detect pheromone components released by themselves or by conspecifics. In this study, we assessed the antenna of female Heliothis virescens for elements of pheromone detection. In accordance with previous findings that female antennae respond to the sex pheromone component (Z)-9-tetradecenal, we identified olfactory sensory neurons that express its cognate receptor, the receptor type HR6. All HR6 cells coexpressed the "sensory neuron membrane protein 1" (SNMP1) and were associated with supporting cells expressing the pheromone-binding proteins PBP1 and PBP2. These features are reminiscent to male antennae and point to congruent mechanisms for pheromone detection in the two sexes. Further analysis of the SNMP1-expressing cells revealed a higher number in females compared to males. Moreover, in females, the SNMP1 neurons were arranged in clusters, which project their dendrites into a common sensillum, whereas in males there were only solitary SNMP1-neurons and only 1 per sensillum. Not all SNMP1 positive cells in female antennae expressed HR6 but instead the putative pheromone receptors HR11 and HR18, respectively. Neurons expressing 1 of the 3 receptor types were assigned to different sensilla. Together the data indicate that on the antenna of females, sensory neurons in a subset of sensilla trichodea are equipped with molecular elements, which render them responsive to pheromones. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Chemical communication in termites: syn-4,6-dimethylundecan-1-ol as trail-following pheromone, syn-4,6-dimethylundecanal and (5E)-2,6,10-trimethylundeca-5,9-dienal as the respective male and female sex pheromones in Hodotermopsis sjoestedti (Isoptera, Archotermopsidae).

PubMed

Lacey, Michael J; Sémon, Etienne; Krasulová, Jana; Sillam-Dussès, David; Robert, Alain; Cornette, Richard; Hoskovec, Michal; Záček, Petr; Valterová, Irena; Bordereau, Christian

2011-12-01

The trail-following pheromone and sex pheromones were investigated in the Indomalayan termite Hodotermopsis sjoestedti belonging to the new family Archotermopsidae. Gas chromatography coupled to mass spectrometry (GC-MS) after solid phase microextraction (SPME) of the sternal gland secretion of pseudergates and trail-following bioassays demonstrated that the trail-following pheromone of H. sjoestedti was syn-4,6-dimethylundecan-1-ol, a new chemical structure for termite pheromones. GC-MS after SPME of the sternal gland secretion of alates also allowed the identification of sex-specific compounds. In female alates, the major sex-specific compound was identified as (5E)-2,6,10-trimethylundeca-5,9-dienal, a compound previously identified as the female sex pheromone of the termite Zootermopsis nevadensis. In male alates, the major sex-specific compound was identified as syn-4,6-dimethylundecanal, a homolog of syn-4,6-dimethyldodecanal, which has previously been confirmed as the male sex pheromone of Z. nevadensis. The presence of sex-specific compounds in alates of H. sjoestedti strongly suggests for this termite the presence of sex-specific pairing pheromones which were only known until now in Z. nevadensis. Our results showed therefore a close chemical relationship between the pheromones of the taxa Hodotermopsis and Zootermopsis and, in contrast, a clear difference with the taxa Stolotermes and Porotermes, which is in total agreement with the recent creation of the families Archotermopsidae and Stolotermitidae as a substitute for the former family Termopsidae. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization of Odorant Receptors from a Non-ditrysian Moth, Eriocrania semipurpurella Sheds Light on the Origin of Sex Pheromone Receptors in Lepidoptera

PubMed Central

Yuvaraj, Jothi Kumar; Corcoran, Jacob A.; Andersson, Martin N.; Newcomb, Richard D.; Anderbrant, Olle; Löfstedt, Christer

2017-01-01

Abstract Pheromone receptors (PRs) are essential in moths to detect sex pheromones for mate finding. However, it remains unknown from which ancestral proteins these specialized receptors arose. The oldest lineages of moths, so-called non-ditrysian moths, use short-chain pheromone components, secondary alcohols, or ketones, so called Type 0 pheromones that are similar to many common plant volatiles. It is, therefore, possible that receptors for these ancestral pheromones evolved from receptors detecting plant volatiles. Hence, we identified the odorant receptors (ORs) from a non-ditrysian moth, Eriocrania semipurpurella (Eriocraniidae, Lepidoptera), and performed functional characterization of ORs using HEK293 cells. We report the first receptors that respond to Type 0 pheromone compounds; EsemOR3 displayed highest sensitivity toward (2S, 6Z)-6-nonen-2-ol, whereas EsemOR5 was most sensitive to the behavioral antagonist (Z)-6-nonen-2-one. These receptors also respond to plant volatiles of similar chemical structures, but with lower sensitivity. Phylogenetically, EsemOR3 and EsemOR5 group with a plant volatile-responding receptor from the tortricid moth Epiphyas postvittana (EposOR3), which together reside outside the previously defined lepidopteran PR clade that contains the PRs from more derived lepidopteran families. In addition, one receptor (EsemOR1) that falls at the base of the lepidopteran PR clade, responded specifically to β-caryophyllene and not to any other additional plant or pheromone compounds. Our results suggest that PRs for Type 0 pheromones have evolved from ORs that detect structurally-related plant volatiles. They are unrelated to PRs detecting pheromones in more derived Lepidoptera, which, in turn, also independently may have evolved a novel function from ORs detecting plant volatiles. PMID:29126322

A honey bee odorant receptor for the queen substance 9-oxo-2-decenoic acid

PubMed Central

Wanner, Kevin W.; Nichols, Andrew S.; Walden, Kimberly K. O.; Brockmann, Axel; Luetje, Charles W.; Robertson, Hugh M.

2007-01-01

By using a functional genomics approach, we have identified a honey bee [Apis mellifera (Am)] odorant receptor (Or) for the queen substance 9-oxo-2-decenoic acid (9-ODA). Honey bees live in large eusocial colonies in which a single queen is responsible for reproduction, several thousand sterile female worker bees complete a myriad of tasks to maintain the colony, and several hundred male drones exist only to mate. The “queen substance” [also termed the queen retinue pheromone (QRP)] is an eight-component pheromone that maintains the queen's dominance in the colony. The main component, 9-ODA, acts as a releaser pheromone by attracting workers to the queen and as a primer pheromone by physiologically inhibiting worker ovary development; it also acts as a sex pheromone, attracting drones during mating flights. However, the extent to which social and sexual chemical messages are shared remains unresolved. By using a custom chemosensory-specific microarray and qPCR, we identified four candidate sex pheromone Ors (AmOr10, -11, -18, and -170) from the honey bee genome based on their biased expression in drone antennae. We assayed the pheromone responsiveness of these receptors by using Xenopus oocytes and electrophysiology. AmOr11 responded specifically to 9-ODA (EC50 = 280 ± 31 nM) and not to any of the other seven QRP components, other social pheromones, or floral odors. We did not observe any responses of the other three Ors to any of the eight QRP pheromone components, suggesting 9-ODA is the only QRP component that also acts as a long-distance sex pheromone. PMID:17761794

The Pheromone of the Cave Cricket, Hadenoecus cumberlandicus, Causes Cricket Aggregation but Does Not Attract the Co-Distributed Predatory Spider, Meta ovalis

PubMed Central

Yoder, Jay A.; Christensen, Brady S.; Croxall, Travis J.; Tank, Justin L.; Hobbs, Horton H.

2010-01-01

Food input by the cave cricket, Hadenoecus cumberlandicus Hubble & Norton (Orthoptera: Rhaphidophoridae), is vital to the cave community, making this cricket a true keystone species. Bioassays conducted on cave walls and in the laboratory show that clustering in H. cumberlandicus is guided by a pheromone, presumably excreta. This aggregation pheromone was demonstrated by using filter paper discs that had previous adult H. cumberlandicus exposure, resulting in > 70% response by either nymphs or adults, prompting attraction (thus, active component is a volatile), followed by reduced mobility (arrestment) on treated surfaces. Adults were similarly responsive to pheromone from nymphs, agreeing with mixed stage composition of clusters in the cave. Effects of [0.001M – 0.1M] uric acid (insect excreta's principle component) on H. cumberlandicus behavior were inconsistent. This pheromone is not a host cue (kairomone) and is not used as a repellent (allomone) as noted through lack of responses to natural H. cumberlandicus pheromone and uric acid concentrations by a co-occurring predatory cave orb weaver spider, Meta ovalis Gertsch (Araneae: Tetragnathidae). This pheromone is not serving as a sex pheromone because nymphs were affected by it and because this population of H. cumberlandicus is parthenogenic. The conclusion of this study is that the biological value of the aggregation pheromone is to concentrate H. cumberlandicus in sheltered sites in the cave conducive for minimizing water stress. Rather than signaling H. cumberlandicus presence and quality, the reduced mobility expressed as a result of contacting this pheromone conceivably may act as a defense tactic (antipredator behavior) against M. ovalis, which shares this favored habitat site. PMID:20572786

Interference of plant volatiles on pheromone receptor neurons of male Grapholita molesta (Lepidoptera: Tortricidae).

PubMed

Ammagarahalli, Byrappa; Gemeno, César

2015-10-01

In moths, sex pheromone components are detected by pheromone-specific olfactory receptor neurons (ph-ORNs) housed in sensilla trichodea in the male antennae. In Grapholita molesta, ph-ORNs are highly sensitive and specific to the individual sex pheromone components, and thus help in the detection and discrimination of the unique conspecific pheromone blend. Plant odors interspersed with a sub-optimal pheromone dose are reported to increase male moth attraction. To determine if the behavioral synergism of pheromone and plant odors starts at the ph-ORN level, single sensillum recordings were performed on Z8-12:Ac and E8-12:Ac ph-ORNs (Z-ORNs and E-ORNs, respectively) stimulated with pheromone-plant volatile mixtures. First, biologically meaningful plant-volatile doses were determined by recording the response of plant-specific ORNs housed in sensilla auricillica and trichodea to several plant odorants. This exploration provided a first glance at plant ORNs in this species. Then, using these plant volatile doses, we found that the spontaneous activity of ph-ORNs was not affected by the stimulation with plant volatiles, but that a binary mixture of sex pheromone and plant odorants resulted in a small (about 15%), dose-independent, but statistically significant, reduction in the spike frequency of Z-ORNs with respect to stimulation with Z8-12:Ac alone. The response of E-ORNs to a combination of E8-12:Ac and plant volatiles was not different from E8-12:Ac alone. We argue that the small inhibition of Z-ORNs caused by physiologically realistic plant volatile doses is probably not fully responsible for the observed behavioral synergism of pheromone and plant odors. Copyright © 2015 Elsevier Ltd. All rights reserved.

(2E,6Z,9Z)-2,6,9-Pentadecatrienal as a Male-Produced Aggregation-Sex Pheromone of the Cerambycid Beetle Elaphidion mucronatum.

PubMed

Millar, Jocelyn G; Mitchell, Robert F; Meier, Linnea R; Johnson, Todd D; Mongold-Diers, Judith A; Hanks, Lawrence M

2017-12-01

An increasing body of evidence suggests that the volatile pheromones of cerambycid beetles are much more diverse in structure than previously hypothesized. Here, we describe the identification, synthesis, and field testing of (2E,6Z,9Z)-2,6,9-pentadecatrienal as a male-produced aggregation-sex pheromone of the cerambycid Elaphidion mucronatum (Say) (subfamily Cerambycinae, tribe Elaphidiini). This novel structure is unlike any previously described cerambycid pheromone, and in field bioassays attracted only this species. Males produced about 9 μg of pheromone per 24 h period, and, in field trials, lures loaded with 10, 25, and 100 mg of synthetic pheromone attracted beetles of both sexes, whereas lures loaded with 1 mg of pheromone or less were not significantly attractive. Other typical cerambycine pheromones such as 3-hydroxy-2-hexanone, syn-2,3-hexanediol, and anti-2,3-hexanediol were not attractive to E. mucronatum, and when combined with (2E,6Z,9Z)-2,6,9-pentadecatrienal, the former two compounds appeared to inhibit attraction. Unexpectedly, adults of the cerambycine Xylotrechus colonus (F.) were attracted in significant numbers to a blend of 3-hydroxyhexan-2-one and (2E,6Z,9Z)-2,6,9-pentadecatrienal, even though there is no evidence that this species produces the latter compound. From timed pheromone trap catches, adults of E. mucronatum were determined to be active from dusk until shortly after midnight.

Proteinaceous Pheromone Homologs Identified from the Cloacal Gland Transcriptome of a Male Axolotl, Ambystoma mexicanum.

PubMed

Hall, Kevin W; Eisthen, Heather L; Williams, Barry L

2016-01-01

Pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. Courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. The first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male Cynops pyrrhogaster. Other proteinaceous pheromones in salamanders have been shown to elicit responses from females towards conspecific males. The presence and levels of expression of proteinaceous pheromones have not been identified in the family Ambystomatidae, which includes several important research models. The objective of this research was therefore to identify putative proteinaceous pheromones from male axolotls, Ambystoma mexicanum, as well as their relative expression levels. The results indicate that axolotls possess two different forms of sodefrin precursor-like factor (alpha and beta), as well as a putative ortholog of plethodontid modulating factor. The beta form of sodefrin precursor-like factor was amongst the most highly expressed transcripts within the cloacal gland. The ortholog of plethodontid modulating factor was expressed at a level equivalent to the beta sodefrin precursor-like factor. The results are from a single male axolotl; therefore, we are unable to assess how representative our results may be. Nevertheless, the presence of these highly expressed proteinaceous pheromones suggests that male axolotls use multiple chemical cues to attract female conspecifics. Behavioral assays would indicate whether the putative protein pheromones elicit courtship activity from female axolotls.

Proteinaceous Pheromone Homologs Identified from the Cloacal Gland Transcriptome of a Male Axolotl, Ambystoma mexicanum

PubMed Central

Hall, Kevin W.; Eisthen, Heather L.; Williams, Barry L.

2016-01-01

Pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. Courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. The first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male Cynops pyrrhogaster. Other proteinaceous pheromones in salamanders have been shown to elicit responses from females towards conspecific males. The presence and levels of expression of proteinaceous pheromones have not been identified in the family Ambystomatidae, which includes several important research models. The objective of this research was therefore to identify putative proteinaceous pheromones from male axolotls, Ambystoma mexicanum, as well as their relative expression levels. The results indicate that axolotls possess two different forms of sodefrin precursor-like factor (alpha and beta), as well as a putative ortholog of plethodontid modulating factor. The beta form of sodefrin precursor-like factor was amongst the most highly expressed transcripts within the cloacal gland. The ortholog of plethodontid modulating factor was expressed at a level equivalent to the beta sodefrin precursor-like factor. The results are from a single male axolotl; therefore, we are unable to assess how representative our results may be. Nevertheless, the presence of these highly expressed proteinaceous pheromones suggests that male axolotls use multiple chemical cues to attract female conspecifics. Behavioral assays would indicate whether the putative protein pheromones elicit courtship activity from female axolotls. PMID:26885665

Chemoreception to aggregation pheromones in the common bed bug, Cimex lectularius.

PubMed

Liu, Feng; Xiong, Caixing; Liu, Nannan

2017-03-01

The common bed bug, Cimex lectularius, is an obligate blood-feeding insect that is resurgent worldwide, posing a threat to human beings through its biting nuisance and disease transmission. Bed bug aggregation pheromone is considered a very promising attractant for use in the monitoring and management of bed bugs, but as yet little is known regarding the sensory physiology of bed bugs related to this pheromone. This study examined how the individual components of aggregation pheromone are perceived by the olfactory receptor neurons (ORNs) housed in different types of olfactory sensilla in bed bugs and the molecular basis for the ORNs' responses to the aggregation pheromone. We found that the ORNs in the D olfactory sensilla played a predominant role in detecting all the components of aggregation pheromone except for histamine, which was only recognized by the C sensilla. Bed bugs' E sensilla, which include four functionally distinct groups, showed only a very weak but variant sensitivity (both excitatory and inhibitory) to the components of aggregation pheromone. Functional tests of 15 odorant receptors (ORs) in response to the components of aggregation pheromone revealed that most of these components were encoded by multiple ORs with various tuning properties. This study provides a comprehensive understanding of how bed bug aggregation pheromone is perceived and recognized in the peripheral olfactory system and will contribute useful information to support the development of synthetic attractants for bed bug monitoring and control. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nonadecadienone, a new termite trail-following pheromone identified in Glossotermes oculatus (Serritermitidae).

PubMed

Hanus, Robert; Šobotník, Jan; Krasulová, Jana; Jiroš, Pavel; Žáček, Petr; Kalinová, Blanka; Dolejšová, Klára; Cvačka, Josef; Bourguignon, Thomas; Roisin, Yves; Lacey, Michael J; Sillam-Dussès, David

2012-01-01

Within the multitude of chemical signals used by termites, the trail marking by means of pheromones is ubiquitous. Chemistry and biology of the trail-following communication have been described in more than 60 species from all families except for the Neotropical Serritermitidae. The chemical ecology of Serritermitidae is of special interest not only as a missing piece of knowledge on the diversity and evolution of isopteran pheromones but also because it may contribute to the debate on the phylogenetic position of this family, which is still unresolved. Therefore, we aimed in this study to identify the trail-following pheromone of the serritermitid Glossotermes oculatus. Based on a combined approach of analytical chemistry, electrophysiology, and behavioral bioassays, we propose (10Z,13Z)-nonadeca-10,13-dien-2-one to be the trail-following pheromone of G. oculatus, secreted by the sternal gland of pseudergates. Thus, we report on a new termite trail-following pheromone of an unexpected chemical structure, a ketone with 19 carbons, contrasting with unsaturated alcohols containing 12 carbons as trail-following pheromones in other advanced termite families. In addition to this unique trail-following pheromone, we also describe the sternal gland in pseudergates as an organ of unusual shape, size, and structure when compared with other isopteran species. These results underline the peculiarity of the family Serritermitidae and prompt our interest in the chemistry of pheromones in the other genus of the family, Serritermes. © The Author 2011. Published by Oxford University Press. All rights reserved.

Helminthiasis, bystander diseases and vaccines: analysis of interaction.

PubMed

Markus, Miles B; Fincham, John E

2007-11-01

Helminthiasis has assumed a new medical and veterinary significance following the recognition of its immunomodulatory consequences for the severity of bystander conditions and the efficacy of immunization against non-helminthic diseases of humans and livestock. Recent papers by Jackson et al. and Turner et al. have an important bearing on research in these areas. One of the implications of their work is that the parasitological criterion of egg-positivity versus egg-negativity is too simplistic to use in co-infection and related studies unless accompanied by immunological analysis.

The trail pheromone of a stingless bee, Trigona corvina (Hymenoptera, Apidae, Meliponini), varies between populations.

PubMed

Jarau, Stefan; Dambacher, Jochen; Twele, Robert; Aguilar, Ingrid; Francke, Wittko; Ayasse, Manfred

2010-09-01

Stingless bees, like honeybees, live in highly organized, perennial colonies. Their eusocial way of life, which includes division of labor, implies that only a fraction of the workers leave the nest to forage for food. To ensure a sufficient food supply for all colony members, stingless bees have evolved different mechanisms to recruit workers to foraging or even to communicate the location of particular food sites. In some species, foragers deposit pheromone marks between food sources and their nest, which are used by recruited workers to locate the food. To date, pheromone compounds have only been described for 3 species. We have identified the trail pheromone of a further species by means of chemical and electrophysiological analyses and with bioassays testing natural gland extracts and synthetic compounds. The pheromone is a blend of wax type and terpene esters. The relative proportions of the single components showed significant differences in the pheromones of foragers form 3 different colonies. This is the first report on a trail pheromone comprised of esters of 2 different biogenetic origins proving variability of the system. Pheromone specificity may serve to avoid confusions between the trails deposited by foragers of different nests and, thus, to decrease competition at food sources.

Natural variation in dauer pheromone production and sensing supports intraspecific competition in nematodes.

PubMed

Bose, Neelanjan; Meyer, Jan M; Yim, Joshua J; Mayer, Melanie G; Markov, Gabriel V; Ogawa, Akira; Schroeder, Frank C; Sommer, Ralf J

2014-07-07

Dauer formation, a major nematode survival strategy, represents a model for small-molecule regulation of metazoan development [1-10]. Free-living nematodes excrete dauer-inducing pheromones that have been assumed to target conspecifics of the same genotype [9, 11]. However, recent studies in Pristionchus pacificus revealed that the dauer pheromone of some strains affects conspecifics of other genotypes more strongly than individuals of the same genotype [12]. To elucidate the mechanistic basis for this intriguing cross-preference, we compared six P. pacificus wild isolates to determine the chemical composition of their dauer-inducing metabolomes and responses to individual pheromone components. We found that these isolates produce dauer pheromone blends of different composition and respond differently to individual pheromone components. Strikingly, there is no correlation between production of and dauer response to a specific compound in individual strains. Specifically, pheromone components that are abundantly produced by one genotype induce dauer formation in other genotypes, but not necessarily in the abundant producer. Furthermore, some genotypes respond to pheromone components they do not produce themselves. These results support a model of intraspecific competition in nematode dauer formation. Indeed, we observed intraspecific competition among sympatric strains in a novel experimental assay, suggesting a new role of small molecules in nematode ecology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multi-functional roles of a soldier-specific volatile as a worker arrestant, primer pheromone and an antimicrobial agent in a termite.

PubMed

Mitaka, Yuki; Mori, Naoki; Matsuura, Kenji

2017-07-26

Division of labour in eusocial insects is characterized by efficient communication systems based on pheromones. Among such insects, termites have evolved specialized sterile defenders, called soldiers. Because they are incapable of feeding themselves, it has been suggested that soldiers are sustained by workers and emit the pheromone arresting workers. However, such a soldier pheromone has not been identified in any termite species, and the details of the soldier-worker interaction remain to be explored. Here, we identified a soldier-specific volatile sesquiterpene as a worker arrestant, which also acts as a primer pheromone regulating soldier differentiation and fungistatic agent in a termite Reticulitermes speratus Chemical analyses revealed that (-)- β -elemene is the major component of soldier extract, and its authentic standard exhibited arrestant activity to workers and inhibited the differentiation from workers to soldiers. This compound also showed fungistatic activity against entomopathogenic fungi. These suggest that (-)- β -elemene secreted by soldiers acts not only as a worker arrestant but also as one component of inhibitory primer pheromone and an anti-pathogenic agent. Our study provides novel evidence supporting the multi-functionality of termite soldier pheromone and provides new insights into the role of soldiers and the evolutionary mechanisms of pheromone compounds. © 2017 The Author(s).

Structural differences in the drone olfactory system of two phylogenetically distant Apis species, A. florea and A. mellifera

NASA Astrophysics Data System (ADS)

Brockmann, Axel; Brückner, Dorothea

2001-01-01

Male insects that are attracted by sex pheromones to find their female mates over long distances have specialized olfactory subsystems. Morphologically, these subsystems are characterized by a large number of receptor neurons sensitive to components of the female's pheromones and hypertrophied glomerular subunits ('macroglomeruli' or 'macroglomerular complexes') in the antennal lobes, in which the axons of the receptor neurons converge. The olfactory subsystems are adapted for an increased sensitivity to perceive minute amounts of pheromones. In Apis mellifera, drones have 18,600 olfactory poreplate sensilla per antenna, each equipped with receptor neurons sensitive to the queen's sex pheromone, and four voluminous macroglomeruli (MG1-MG4) in the antennal lobes. In contrast, we show that drones of the phylogenetically distant species, Apis florea, have only 1,200 poreplate sensilla per antenna and only two macroglomeruli in their antennal lobes. These macroglomeruli are homologous in anatomical position to the two most prominent macroglomeruli in A. mellifera, the MG1 and MG2, but they are much smaller in size. The morphological and anatomical differences described here suggest major modifications in the sex-pheromone processing subsystem of both species: (1) less pheromone sensitivity in A. florea and (2) a more complex sex-pheromone processing and thus a more complex sex-pheromone communication in A. mellifera.

Cloning and functional characterization of three new pheromone receptors from the diamondback moth, Plutella xylostella.

PubMed

Liu, Yipeng; Liu, Yang; Jiang, Xingchuan; Wang, Guirong

The highly specialized olfactory receptor neurons (ORNs) on the antennae of male moths can recognize blends of several pheromone components. In previous studies, a total of six candidate pheromone receptor (PR) genes were cloned and functionally characterized in the diamondback moth, Plutella xylostella. In the present work, we report on three novel candidate pheromone receptor genes: PxylOR8, PxylOR41, and PxylOR45 in the same species. Gene expression analysis revealed that PxylOR8 is specifically expressed in female adult antennae, while PxylOR41 and PxylOR45 are expressed in antennae in both sexes, but with a male bias. In situ hybridization revealed that PxylOR8, PxylOR41 and PxylOR45 are localized in long trichoid sensilla. Functional analyses on the three pheromone receptor genes were then performed using the heterologous expression system of Xenopus oocytes. PxylOR41 was tuned to two minor pheromone components Z9-14:Ac, Z9-14:OH, and their analog Z9-14:Ald. PxylOR8 and PxylOR45 did not respond to any tested pheromone components and analogs. These results may contribute to clarifying how pheromone detection works in P. xylostella. Copyright © 2018 Elsevier Ltd. All rights reserved.

Pheromone binding proteins enhance the sensitivity of olfactory receptors to sex pheromones in Chilo suppressalis

PubMed Central

Chang, Hetan; Liu, Yang; Yang, Ting; Pelosi, Paolo; Dong, Shuanglin; Wang, Guirong

2015-01-01

Sexual communication in moths offers a simplified scenario to model and investigate insect sensory perception. Both PBPs (pheromone-binding proteins) and PRs (pheromone receptors) are involved in the detection of sex pheromones, but the interplay between them still remains largely unknown. In this study, we have measured the binding affinities of the four recombinant PBPs of Chilo suppressalis (CsupPBPs) to pheromone components and analogs and characterized the six PRs using the Xenopus oocytes expression system. Interestingly, when the responses of PRs were recorded in the presence of PBPs, we measured in several combinations a dramatic increase in signals as well as in sensitivity of such combined systems. Furthermore, the discrimination ability of appropriate combinations of PRs and PBPs was improved compared with the performance of PBPs or PRs alone. Besides further supporting a role of PBPs in the pheromone detection and discrimination, our data shows for the first time that appropriate combinations of PRs and PBPs improved the discrimination ability of PBPs or PRs alone. The variety of responses measured with different pairing of PBPs and PRs indicates the complexity of the olfaction system, which, even for the relatively simple task of detecting sex pheromones, utilises a highly sophisticated combinatorial approach. PMID:26310773

Demonstration and Characterization of a Persistent Pheromone Lure for the Navel Orangeworm, Amyelois transitella (Lepidoptera: Pyralidae).

PubMed

Higbee, Bradley S; Burks, Charles S; Larsen, Thomas E

2014-07-22

The lack of an effective pheromone lure has made it difficult to monitor and manage the navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae), in the economically important crops in which it is the primary insect pest. A series of experiments was conducted to demonstrate and characterize a practical synthetic pheromone lure for capturing navel orangeworm males. Traps baited with lures prepared with 1 or 2 mg of a three- or four-component formulation captured similar numbers of males. The fluctuation over time in the number of males captured in traps baited with the pheromone lure correlated significantly with males captured in female-baited traps. Traps baited with the pheromone lure usually did not capture as many males as traps baited with unmated females, and the ratio of males trapped with pheromone to males trapped with females varied between crops and with abundance. The pheromone lure described improves the ability of pest managers to detect and monitor navel orangeworm efficiently and may improve management and decrease insecticide treatments applied as a precaution against damage. Awareness of differences between male interaction with the pheromone lure and calling females, as shown in these data, will be important as further studies and experience determine how best to use this lure for pest management.

Demonstration and Characterization of a Persistent Pheromone Lure for the Navel Orangeworm, Amyelois transitella (Lepidoptera: Pyralidae)

PubMed Central

Higbee, Bradley S.; Burks, Charles S.; Larsen, Thomas E.

2014-01-01

The lack of an effective pheromone lure has made it difficult to monitor and manage the navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae), in the economically important crops in which it is the primary insect pest. A series of experiments was conducted to demonstrate and characterize a practical synthetic pheromone lure for capturing navel orangeworm males. Traps baited with lures prepared with 1 or 2 mg of a three- or four-component formulation captured similar numbers of males. The fluctuation over time in the number of males captured in traps baited with the pheromone lure correlated significantly with males captured in female-baited traps. Traps baited with the pheromone lure usually did not capture as many males as traps baited with unmated females, and the ratio of males trapped with pheromone to males trapped with females varied between crops and with abundance. The pheromone lure described improves the ability of pest managers to detect and monitor navel orangeworm efficiently and may improve management and decrease insecticide treatments applied as a precaution against damage. Awareness of differences between male interaction with the pheromone lure and calling females, as shown in these data, will be important as further studies and experience determine how best to use this lure for pest management. PMID:26462827

Larval salivary glands are a source of primer and releaser pheromone in honey bee ( Apis mellifera L.)

NASA Astrophysics Data System (ADS)

Conte, Yves Le; Bécard, Jean-Marc; Costagliola, Guy; de Vaublanc, Gérard; Maâtaoui, Mohamed El; Crauser, Didier; Plettner, Erika; Slessor, Keith N.

2006-05-01

A brood pheromone identified in honeybee larvae has primer and releaser pheromone effects on adult bees. Using gas chromatography-mass spectrometry (GC-MS) to evaluate fatty acid esters—the pheromonal compounds—in different parts of the larvae, we have localized the source of the esters as the larval salivary glands. A histochemical study describes the glands and confirms the presence of lipids in the glands. Epithelial cells of the gland likely secrete the fatty acids into the lumen of the gland. These results demonstrate the salivary glands to be a reservoir of esters, components of brood pheromone, in honeybee larvae.

Do pheromones reveal male immunocompetence?

PubMed Central

Rantala, Markus J; Jokinen, Ilmari; Kortet, Raine; Vainikka, Anssi; Suhonen, Jukka

2002-01-01

Pheromones function not only as mate attractors, but they may also relay important information to prospective mates. It has been shown that vertebrates can distinguish, via olfactory mechanisms, major histocompatibility complex types in their prospective mates. However, whether pheromones can transmit information about immunocompetence is unknown. Here, we show that female mealworm beetles (Tenebrio molitor) prefer pheromones from males with better immunocompetence, indicated by a faster encapsulation rate against a novel antigen, and higher levels of phenoloxidase in haemolymph. Thus, the present study indicates that pheromones could transmit information about males' parasite resistance ability and may work as a reliable sexual ornament for female choice. PMID:12204128

Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies.

PubMed

Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y

2016-12-14

Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season.

Thigmotaxis Mediates Trail Odour Disruption.

PubMed

Stringer, Lloyd D; Corn, Joshua E; Sik Roh, Hyun; Jiménez-Pérez, Alfredo; Manning, Lee-Anne M; Harper, Aimee R; Suckling, David M

2017-05-10

Disruption of foraging using oversupply of ant trail pheromones is a novel pest management application under investigation. It presents an opportunity to investigate the interaction of sensory modalities by removal of one of the modes. Superficially similar to sex pheromone-based mating disruption in moths, ant trail pheromone disruption lacks an equivalent mechanistic understanding of how the ants respond to an oversupply of their trail pheromone. Since significant compromise of one sensory modality essential for trail following (chemotaxis) has been demonstrated, we hypothesised that other sensory modalities such as thigmotaxis could act to reduce the impact on olfactory disruption of foraging behaviour. To test this, we provided a physical stimulus of thread to aid trailing by Argentine ants otherwise under disruptive pheromone concentrations. Trail following success was higher using a physical cue. While trail integrity reduced under continuous over-supply of trail pheromone delivered directly on the thread, provision of a physical cue in the form of thread slightly improved trail following and mediated trail disruption from high concentrations upwind. Our results indicate that ants are able to use physical structures to reduce but not eliminate the effects of trail pheromone disruption.

The neuropeptide tachykinin is essential for pheromone detection in a gustatory neural circuit

PubMed Central

Shankar, Shruti; Chua, Jia Yi; Tan, Kah Junn; Calvert, Meredith EK; Weng, Ruifen; Ng, Wan Chin; Mori, Kenji; Yew, Joanne Y

2015-01-01

Gustatory pheromones play an essential role in shaping the behavior of many organisms. However, little is known about the processing of taste pheromones in higher order brain centers. Here, we describe a male-specific gustatory circuit in Drosophila that underlies the detection of the anti-aphrodisiac pheromone (3R,11Z,19Z)-3-acetoxy-11,19-octacosadien-1-ol (CH503). Using behavioral analysis, genetic manipulation, and live calcium imaging, we show that Gr68a-expressing neurons on the forelegs of male flies exhibit a sexually dimorphic physiological response to the pheromone and relay information to the central brain via peptidergic neurons. The release of tachykinin from 8 to 10 cells within the subesophageal zone is required for the pheromone-triggered courtship suppression. Taken together, this work describes a neuropeptide-modulated central brain circuit that underlies the programmed behavioral response to a gustatory sex pheromone. These results will allow further examination of the molecular basis by which innate behaviors are modulated by gustatory cues and physiological state. DOI: http://dx.doi.org/10.7554/eLife.06914.001 PMID:26083710

Cooperation, conflict, and the evolution of queen pheromones.

PubMed

Kocher, Sarah D; Grozinger, Christina M

2011-11-01

While chemical communication regulates individual behavior in a wide variety of species, these communication systems are most elaborated in insect societies. In these complex systems, pheromones produced by the reproductive individuals (queens) are critical in establishing and maintaining dominant reproductive status over hundreds to thousands of workers. The proximate and ultimate mechanisms by which these intricate pheromone communication systems evolved are largely unknown, though there has been much debate over whether queen pheromones function as a control mechanism or as an honest signal facilitating cooperation. Here, we summarize results from recent studies in honey bees, bumble bees, wasps, ants and termites. We further discuss evolutionary mechanisms by which queen pheromone communication systems may have evolved. Overall, these studies suggest that queen-worker pheromone communication is a multi-component, labile dialog between the castes, rather than a simple, fixed signal-response system. We also discuss future approaches that can shed light on the proximate and ultimate mechanisms that underlie these complex systems by focusing on the development of increasingly sophisticated genomic tools and their potential applications to examine the molecular mechanisms that regulate pheromone production and perception.

A conserved neuronal DAF-16/FoxO plays an important role in conveying pheromone signals to elicit repulsion behavior in Caenorhabditis elegans.

PubMed

Park, Donha; Hahm, Jeong-Hoon; Park, Saeram; Ha, Go; Chang, Gyeong-Eon; Jeong, Haelim; Kim, Heekyeong; Kim, Sunhee; Cheong, Eunji; Paik, Young-Ki

2017-08-03

Animals use pheromones as a conspecific chemical language to respond appropriately to environmental changes. The soil nematode Caenorhabditis elegans secretes ascaroside pheromones throughout the lifecycle, which influences entry into dauer phase in early larvae, in addition to sexual attraction and aggregation. In adult hermaphrodites, pheromone sensory signals perceived by worms usually elicit repulsion as an initial behavioral signature. However, the molecular mechanisms underlying neuronal pheromone sensory process from perception to repulsion in adult hermaphrodites remain poorly understood. Here, we show that pheromone signals perceived by GPA-3 is conveyed through glutamatergic neurotransmission in which neuronal DAF-16/FoxO plays an important modulatory role by controlling glutaminase gene expression. We further provide evidence that this modulatory role for DAF-16/FoxO seems to be conserved evolutionarily by electro-physiological study in mouse primary hippocampal neurons that are responsible for glutamatergic neurotransmission. These findings provide the basis for understanding the nematode pheromone signaling, which seems crucial for adaptation of adult hermaphrodites to changes in environmental condition for survival.

Inhibition of the Responses to Sex Pheromone of the Fall Armyworm, Spodoptera frugiperda

PubMed Central

Malo, Edi A.; Rojas, Julio C.; Gago, Rafael; Guerrero, Ángel

2013-01-01

Trifluoromethyl ketones reversibly inhibit pheromone-degrading esterases in insect olfactory tissues, affecting pheromone detection and behavior of moth males. In this work, (Z)-9-tetradecenyl trifluoromethyl ketone (Z9-14:TFMK), a closely-related analogue of the pheromone of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), was prepared and tested in electroantennogram and field tests as possible inhibitors of the pheromone action. The electroantennogram parameters, amplitude, and the repolarization time of the antennal responses of S. frugiperda males were affected by Z9-14:TFMK vapors. Exposure of male antennae to a stream of air passing through 100 ìg of the ketone produced a significant reduction of the amplitude and an increase of 2/3 repolarization time signals to the pheromone. The effect was reversible and dose-dependent. In the field, the analogue significantly decreased the number of males caught when mixed with the pheromone in 10:1 ratio. The results suggest that Z9-14:TFMK is a mating disruptant of S. frugiperda and may be a good candidate to consider in future strategies to control this pest. PMID:24766416

Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging

USGS Publications Warehouse

Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.

2010-01-01

Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

Propheromones that release pheromonal carbonyl compounds in light.

PubMed

Liu, X; Macaulay, E D; Pickett, J A

1984-05-01

Pheromonal carbonyl compounds; (Z)-11-hexadecanal, (E)-citral, and 2-heptanone were treated with six alcohols to give acetals or ketals, some of which acted as propheromones by releasing the pheromonal carbonyl compounds in ultraviolet or simulated sunlight. Highest yields of pheromone were obtained from adducts prepared witho-nitrobenzyl alcohol ando-nitrophenylethane-1,2-diol. Adducts from (Z)-11-hexadecenal and these two alcohols were employed in lures to catch diamondback moths,Plutella xylostella (L.).

Uncoupling primer and releaser responses to pheromone in honey bees

NASA Astrophysics Data System (ADS)

Grozinger, Christina M.; Fischer, Patrick; Hampton, Jacob E.

2007-05-01

Pheromones produce dramatic behavioral and physiological responses in a wide variety of species. Releaser pheromones elicit rapid responses within seconds or minutes, while primer pheromones produce long-term changes which may take days to manifest. Honeybee queen mandibular pheromone (QMP) elicits multiple distinct behavioral and physiological responses in worker bees, as both a releaser and primer, and thus produces responses on vastly different time scales. In this study, we demonstrate that releaser and primer responses to QMP can be uncoupled. First, treatment with the juvenile hormone analog methoprene leaves a releaser response (attraction to QMP) intact, but modulates QMP’s primer effects on sucrose responsiveness. Secondly, two components of QMP (9-ODA and 9-HDA) do not elicit a releaser response (attraction) but are as effective as QMP at modulating a primer response, downregulation of foraging-related brain gene expression. These results suggest that different responses to a single pheromone may be produced via distinct pathways.

Mating and male pheromone kill Caenorhabditis males through distinct mechanisms.

PubMed

Shi, Cheng; Runnels, Alexi M; Murphy, Coleen T

2017-03-14

Differences in longevity between sexes is a mysterious yet general phenomenon across great evolutionary distances. To test the roles of responses to environmental cues and sexual behaviors in longevity regulation, we examined Caenorhabditis male lifespan under solitary, grouped, and mated conditions. We find that neurons and the germline are required for male pheromone-dependent male death. Hermaphrodites with a masculinized nervous system secrete male pheromone and are susceptible to male pheromone killing. Male pheromone-mediated killing is unique to androdioecious Caenorhabditis , and may reduce the number of males in hermaphroditic populations; neither males nor females of gonochoristic species are susceptible to male pheromone killing. By contrast, mating-induced death, which is characterized by germline-dependent shrinking, glycogen loss, and ectopic vitellogenin expression, utilizes distinct molecular pathways and is shared between the sexes and across species. The study of sex- and species-specific regulation of aging reveals deeply conserved mechanisms of longevity and population structure regulation.

Efficient Management of Fruit Pests by Pheromone Nanogels

PubMed Central

Bhagat, Deepa; Samanta, Suman K.; Bhattacharya, Santanu

2013-01-01

Environment-friendly management of fruit flies involving pheromones is useful in reducing the undesirable pest populations responsible for decreasing the yield and the crop quality. A nanogel has been prepared from a pheromone, methyl eugenol (ME) using a low-molecular mass gelator. This was very stable at open ambient conditions and slowed down the evaporation of pheromone significantly. This enabled its easy handling and transportation without refrigeration, and reduction in the frequency of pheromone recharging in the orchard. Notably the involvement of the nano-gelled pheromone brought about an effective management of Bactrocera dorsalis, a prevalent harmful pest for a number of fruits including guava. Thus a simple, practical and low cost green chemical approach is developed that has a significant potential for crop protection, long lasting residual activity, excellent efficacy and favorable safety profiles. This makes the present invention well-suited for pest management in a variety of crops. PMID:23416455

Pheromone detection by mammalian vomeronasal neurons.

PubMed

Zufall, Frank; Kelliher, Kevin R; Leinders-Zufall, Trese

2002-08-01

The vomeronasal organ (VNO) of mammals plays an essential role in the perception of chemical stimuli of social nature including pheromone-like signals but direct evidence for the transduction of pheromones by vomeronasal sensory neurons has been lacking. The recent development of electrophysiological and optical imaging methods using confocal microscopy has enabled researchers to systematically analyze sensory responses in large populations of mouse vomeronasal neurons. These experiments revealed that vomeronasal neurons are surprisingly sensitive and highly discriminative detectors of volatile, urinary metabolites that have pheromonal activity in recipient mice. Functional mapping studies of pheromone receptor activation have uncovered the basic principles of sensory processing by vomeronasal neurons and revealed striking differences in the neural mechanisms by which chemosensory information is detected by receptor neurons in the VNO and the main olfactory epithelium. These advances offer the opportunity to decipher the logic of mammalian pheromonal communication. Copyright 2002 Wiley-Liss, Inc.

Listening in Pheromone Plumes: Disruption of Olfactory-Guided Mate Attraction in a Moth by a Bat-Like Ultrasound

PubMed Central

Svenssona, Glenn P.; Löfstedt, Christer; Skals, Niels

2007-01-01

Nocturnal moths often use sex pheromones to find mates and ultrasonic hearing to evade echolocating bat predators. Male moths, when confronted with both pheromones and sound, thus have to trade off reproduction and predator avoidance depending on the relative strengths of the perceived conflicting stimuli. The ultrasonic hearing of Plodia interpunctella was investigated. A threshold curve for evasive reaction to ultrasound of tethered moths was established, and the frequency of best hearing was found to be between 40 and 70 kHz. Flight tunnel experiments were performed where males orienting in a sex pheromone plume were stimulated with 50 kHz pulses of different intensities. Pheromone-stimulated males showed increased defensive response with increased intensity of the sound stimulus, and the acoustic cue had long-lasting effects on their pheromone-mediated flight, revealing a cost associated with vital evasive behaviours. PMID:20331396

Evidence that insect herbivores are deterred by ant pheromones.

PubMed Central

Offenberg, Joachim; Nielsen, Mogens Gissel; MacIntosh, Donald J; Havanon, Sopon; Aksornkoae, Sanit

2004-01-01

It is well documented that ants can protect plants against insect herbivores, but the underlying mechanisms remain almost undocumented. We propose and test the pheromone avoidance hypothesis--an indirect mechanism where insect herbivores are repelled not only by ants but also by ant pheromones. Herbivores subjected to ant predation will experience a selective advantage if they evolve mechanisms enabling them to avoid feeding within ant territories. Such a mechanism could be based on the ability to detect and evade ant pheromones. Field observations and data from the literature showed that the ant Oecophylla smaragdina distributes persistent pheromones throughout its territory. In addition, a laboratory test showed that the beetle Rhyparida wallacei, which this ant preys on, was reluctant to feed on leaves sampled within ant territories compared with leaves sampled outside territories. Thus, this study provides an example of an ant-herbivore system conforming to the pheromone avoidance hypothesis. PMID:15801596

Variation in sex pheromone emission does not reflect immunocompetence but affects attractiveness of male burying beetles—a combination of laboratory and field experiments

NASA Astrophysics Data System (ADS)

Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

2017-08-01

Life history theory predicts a trade-off between male sexual trait expression and immunocompetence. Using burying beetles, Nicrophorus vespilloides, as a model, we investigated the relationship between male immune function, sex pheromone emission, and attractiveness under field conditions. In the first experiment, we tested whether there is a positive correlation between immune capacity, sex pheromone characteristics (quantity, relative composition, and time invested in pheromone emission), and male attractiveness. As a measurement of immune capacity, we used an individual's encapsulation ability against a novel antigen. In the second experiment, we specifically examined whether a trade-off between chemical trait expression and immune function existed. To this end, we challenged the immune system and measured the subsequent investment in sex pheromone emission and the attractiveness of the male under field conditions. We found that a male's immunocompetence was neither related to the emission of the male's sex pheromone nor to its attractiveness in the field. Furthermore, none of the immune-challenge treatments affected the subsequent investment in pheromone emission or number of females attracted. However, we showed that the same males that emitted a high quantity of their sex pheromone in the laboratory were able to attract more females in the field. Our data suggest that the chemical signal is not a reliable predictor of a male's immunocompetence but rather is a general important fitness-related trait, with a higher emission of the sex pheromone measured in the laboratory directly affecting the attractiveness of a male under field conditions.

Trail-following pheromones in basal termites, with special reference to Mastotermes darwiniensis.

PubMed

Sillam-Dussès, David; Sémon, Etienne; Lacey, Michael J; Robert, Alain; Lenz, Michael; Bordereau, Christian

2007-10-01

In the framework of an evolutionary study, trail pheromones have been studied in the most basal extant termite, Mastotermes darwiniensis (Mastotermitidae), and two other basal termites, the Termopsidae Porotermes adamsoni (Porotermitinae) and Stolotermes victoriensis (Stolotermitinae). Although workers of M. darwiniensis do not walk in single file while exploring a new environment under experimental conditions and are unable to follow artificial trails in 'open field' experiments, they do secrete a trail-following pheromone from their sternal glands. This unique behavior might reflect a primitive function of communication of the sternal gland. The major component of the pheromone appears to be the same in the three basal species: the norsesquiterpene alcohol (E)-2,6,10-trimethyl-5,9-undecadien-1-ol. This represents a new chemical category of trail-following pheromones for termites. The quantity of pheromone was estimated as 20 pg/individual in M. darwiniensis, 700 pg/individual in P. adamsoni, and 4 pg/individual in S. victoriensis. The activity threshold was 1 ng/cm in M. darwiniensis and 10 pg/cm in P. adamsoni. In M. darwiniensis, the trail pheromone was secreted by sternal gland 4 and to a lesser degree by sternal gland 3, sternal gland 5 being almost inactive. This study highlighted phylogenetic relationships between the Mastotermitidae and two subfamilies of the Termopsidae, the Porotermitinae and the Stolotermitinae. Furthermore, it indicated a heterogeneity within the Termopsidae, with Porotermitinae and Stolotermitinae on one hand, and Termopsinae on the other. Finally, Mastotermitidae and Termopsidae, with C14 trail pheromones, are clearly separated from the Kalotermitidae, Rhinotermitidae, and Termitidae that secrete C12 or C20 trail pheromones.

Identification of Sex Pheromones and Sex Pheromone Mimics for Two North American Click Beetle Species (Coleoptera: Elateridae) in the Genus Cardiophorus Esch.

PubMed

Serrano, Jacqueline M; Collignon, R Maxwell; Zou, Yunfan; Millar, Jocelyn G

2018-04-01

To date, all known or suspected pheromones of click beetles (Coleoptera: Elateridae) have been identified solely from species native to Europe and Asia; reports of identifications from North American species dating from the 1970s have since proven to be incorrect. While conducting bioassays of pheromones of a longhorned beetle (Coleoptera: Cerambycidae), we serendipitously discovered that males of Cardiophorus tenebrosus L. and Cardiophorus edwardsi Horn were specifically attracted to the cerambycid pheromone fuscumol acetate, (E)-6,10-dimethylundeca-5,9-dien-2-yl acetate, suggesting that this compound might also be a sex pheromone for the two Cardiophorus species. Further field bioassays and electrophysiological assays with the enantiomers of fuscumol acetate determined that males were specifically attracted by the (R)-enantiomer. However, subsequent analyses of extracts of volatiles from female C. tenebrosus and C. edwardsi showed that the females actually produced a different compound, which was identified as (3R,6E)-3,7,11-trimethyl-6,10-dodecadienoic acid methyl ester (methyl (3R,6E)-2,3-dihydrofarnesoate). In field trials, both the racemate and the (R)-enantiomer of the pheromone attracted similar numbers of male beetles, suggesting that the (S)-enantiomer was not interfering with responses to the insect-produced (R)-enantiomer. This report constitutes the first conclusive identification of sex pheromones for any North American click beetle species. Possible reasons for the strong and specific attraction of males to fuscumol acetate, which is markedly different in structure to the actual pheromone, are discussed.

Synthetic Co-Attractants of the Aggregation Pheromone of the Date Palm Root Borer Oryctes agamemnon.

PubMed

Hasni, Narjes; Pinier, Centina; Imed, Cheraief; Ouhichi, Monêem; Couzi, Philippe; Chermiti, Brahim; Frérot, Brigitte; Saïd, Imen; Rochat, Didier

2017-07-01

Laboratory and field investigations to identify and evaluate plant co-attractants of the aggregation pheromone of the date palm pest Oryctes agamemnon are reported. Volatiles emitted by freshly cut palm core and palm core with feeding males, were collected, analyzed by gas chromatography coupled to mass spectrometry and evaluated in olfactometers alone or combined with synthetic pheromone. A collection of palm odor without male effluvia was attractive alone and enhanced attraction to synthetic pheromone in an olfactometer similar to that to a collection of palm odor emitted with feeding males and containing natural pheromone. Behavioral responses to collections of palm volatiles were correlated to the amount of volatiles material in them. Enhancement of the attractiveness of the pheromone was not correlated to chemicals specific to beetle feeding. The chemicals common to the active collections extracts were benzoate esters, mostly ethyl benzoate, anisole derivatives and sesquiterpenes. Blends of the most abundant components of the extracts were evaluated for enhancement of the attractiveness of pheromone (1 μg) in olfactometers at 1 or 10 μg doses. The mixtures were further evaluated by field trapping in Tunisia at 3-10 mg/day using reference (6 mg/day) or experimental pheromone formulations. A mixture of ethyl benzoate, 4-methylanisole and farnesol (1:1:1 w/w at 6.5 mg/day) enhanced captures in pheromone baited traps in 2014 and 2015 and this mixture was as active as the natural palm bait. The practical prospect of the result for the management for O. agamemnon, and other palm beetles is discussed.

Identification and Differential Expression of a Candidate Sex Pheromone Receptor in Natural Populations of Spodoptera litura

PubMed Central

Lin, Xinda; Zhang, Qinhui; Wu, Zhongnan; Du, Yongjun

2015-01-01

Olfaction is primarily mediated by highly specific olfactory receptors (ORs), a subfamily of which are the pheromone receptors that play a key role in sexual communication and can contribute to reproductive isolation. Here we cloned and identified an olfactory receptor, SlituOR3 (Genbank NO. JN835270), from Spodoptera litura, to be the candidate pheromone receptor. It exhibited male-biased expression in the antennae, where they were localized at the base of sensilla trichoidea. Conserved orthologues of these receptors were found amongst known pheromone receptors within the Lepidoptera, and SlituOR3 were placed amongst a clade of candidate pheromone receptors in a phylogeny tree of insect ORs. SlituOR3 is required for the EAG responses to both Z9E11-14:OAc and Z9E12-14:OAc SlituOR3 showed differential expression in S. litura populations attracted to traps baited with a series of sex pheromone blends composed of different ratios of (9Z,11E)-tetradecadienyl acetate (Z9E11-14:OAc) and (9Z,12E)-tetradecadienyl acetate (Z9E12-14:OAc). The changes in the expression level of SlitOR3 and antennal responses after SlitOR3 silencing suggested that SlitOR3 is required for the sex pheromone signaling. We infer that variation in transcription levels of olfactory receptors may modulate sex pheromone perception in male moths and could affect both of pest control and monitoring efficiency by pheromone application after long time mass trapping with one particular ratio of blend in the field. PMID:26126192

Variation in sex pheromone emission does not reflect immunocompetence but affects attractiveness of male burying beetles-a combination of laboratory and field experiments.

PubMed

Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

2017-08-01

Life history theory predicts a trade-off between male sexual trait expression and immunocompetence. Using burying beetles, Nicrophorus vespilloides, as a model, we investigated the relationship between male immune function, sex pheromone emission, and attractiveness under field conditions. In the first experiment, we tested whether there is a positive correlation between immune capacity, sex pheromone characteristics (quantity, relative composition, and time invested in pheromone emission), and male attractiveness. As a measurement of immune capacity, we used an individual's encapsulation ability against a novel antigen. In the second experiment, we specifically examined whether a trade-off between chemical trait expression and immune function existed. To this end, we challenged the immune system and measured the subsequent investment in sex pheromone emission and the attractiveness of the male under field conditions. We found that a male's immunocompetence was neither related to the emission of the male's sex pheromone nor to its attractiveness in the field. Furthermore, none of the immune-challenge treatments affected the subsequent investment in pheromone emission or number of females attracted. However, we showed that the same males that emitted a high quantity of their sex pheromone in the laboratory were able to attract more females in the field. Our data suggest that the chemical signal is not a reliable predictor of a male's immunocompetence but rather is a general important fitness-related trait, with a higher emission of the sex pheromone measured in the laboratory directly affecting the attractiveness of a male under field conditions.

77 FR 66836 - Notice of Receipt of Pesticide Products; Registration Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

... Pheromone Mimic (7,9,11-Dodecatrien-1-ol, formate at 90.8%. Product Type: Pheromone (Mating Disruptor... (Mating Disruptor) with Carob Moth Pheromone Mimic (7,9,11-Dodecatrien-1-ol, formate at 2%. Product Type...

Notch signalling mediates reproductive constraint in the adult worker honeybee

PubMed Central

Duncan, Elizabeth J.; Hyink, Otto; Dearden, Peter K.

2016-01-01

The hallmark of eusociality is the reproductive division of labour, in which one female caste reproduces, while reproduction is constrained in the subordinate caste. In adult worker honeybees (Apis mellifera) reproductive constraint is conditional: in the absence of the queen and brood, adult worker honeybees activate their ovaries and lay haploid male eggs. Here, we demonstrate that chemical inhibition of Notch signalling can overcome the repressive effect of queen pheromone and promote ovary activity in adult worker honeybees. We show that Notch signalling acts on the earliest stages of oogenesis and that the removal of the queen corresponds with a loss of Notch protein in the germarium. We conclude that the ancient and pleiotropic Notch signalling pathway has been co-opted into constraining reproduction in worker honeybees and we provide the first molecular mechanism directly linking ovary activity in adult worker bees with the presence of the queen. PMID:27485026

Modeling Honey Bee Populations.

PubMed

Torres, David J; Ricoy, Ulises M; Roybal, Shanae

2015-01-01

Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population.

Modeling Honey Bee Populations

PubMed Central

Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

2015-01-01

Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

Key biosynthetic gene subfamily recruited for pheromone production prior to the extensive radiation of Lepidoptera

PubMed Central

2008-01-01

Background Moths have evolved highly successful mating systems, relying on species-specific mixtures of sex pheromone components for long-distance mate communication. Acyl-CoA desaturases are key enzymes in the biosynthesis of these compounds and to a large extent they account for the great diversity of pheromone structures in Lepidoptera. A novel desaturase gene subfamily that displays Δ11 catalytic activities has been highlighted to account for most of the unique pheromone signatures of the taxonomically advanced ditrysian species. To assess the mechanisms driving pheromone evolution, information is needed about the signalling machinery of primitive moths. The currant shoot borer, Lampronia capitella, is the sole reported primitive non-ditrysian moth known to use unsaturated fatty-acid derivatives as sex-pheromone. By combining biochemical and molecular approaches we elucidated the biosynthesis paths of its main pheromone component, the (Z,Z)-9,11-tetradecadien-1-ol and bring new insights into the time point of the recruitment of the key Δ11-desaturase gene subfamily in moth pheromone biosynthesis. Results The reconstructed evolutionary tree of desaturases evidenced two ditrysian-specific lineages (the Δ11 and Δ9 (18C>16C)) to have orthologs in the primitive moth L. capitella despite being absent in Diptera and other insect genomes. Four acyl-CoA desaturase cDNAs were isolated from the pheromone gland, three of which are related to Δ9-desaturases whereas the fourth cDNA clusters with Δ11-desaturases. We demonstrated that this transcript (Lca-KPVQ) exclusively accounts for both steps of desaturation involved in pheromone biosynthesis. This enzyme possesses a Z11-desaturase activity that allows transforming the palmitate precursor (C16:0) into (Z)-11-hexadecenoic acid and the (Z)-9-tetradecenoic acid into the conjugated intermediate (Z,Z)-9,11-tetradecadienoic acid. Conclusion The involvement of a single Z11-desaturase in pheromone biosynthesis of a non-ditrysian moth species, supports that the duplication event leading to the origin of the Lepidoptera-specific Δ11-desaturase gene subfamily took place before radiation of ditrysian moths and their divergence from other heteroneuran lineages. Our findings uncover that this novel class of enzymes affords complex combinations of unique unsaturated fatty acyl-moieties of variable chain-lengths, regio- and stereo-specificities since early in moth history and contributes a notable innovation in the early evolution of moth-pheromones. PMID:18831750

Pheromone Static Routing Strategy for Complex Networks

NASA Astrophysics Data System (ADS)

Hu, Mao-Bin; Henry, Y. K. Lau; Ling, Xiang; Jiang, Rui

2012-12-01

We adopt the concept of using pheromones to generate a set of static paths that can reach the performance of global dynamic routing strategy [Phys. Rev. E 81 (2010) 016113]. The path generation method consists of two stages. In the first stage, a pheromone is dropped to the nodes by packets forwarded according to the global dynamic routing strategy. In the second stage, pheromone static paths are generated according to the pheromone density. The output paths can greatly improve traffic systems' overall capacity on different network structures, including scale-free networks, small-world networks and random graphs. Because the paths are static, the system needs much less computational resources than the global dynamic routing strategy.

Synthesis of syn-4,6-dimethyldodecanal, the male sex pheromone and trail-following pheromone of two species of the termite Zootermopsis.

PubMed

Ghostin, J; Bordereau, C; Braekman, J C

2011-03-01

Recently, we reported that syn-4,6-dimethyldodecanal is the male sex pheromone and the trail-following pheromone of the Termopsidae Zootermopsis nevadensis and Zootermopsis angusticollis. In this article, we describe the syntheses of the mixture of the four stereoisomers of 4,6-dimethyldodecanal using a synthetic pathway where the key step is a Wittig reaction between methyl 4-methyl-5-oxo-pentanoate and 1-methylheptyl-triphenylphosphonium iodide, and of (±)-syn-4,6-dimethyldodecanal starting from 3,5-dimethyl-2-cyclohexen-1-one. Direct GC-MS comparison of these synthetic samples with the natural pheromone allowed its unambiguous identification.

Identification by GC-EAD of the two-component trail-following pheromone of Prorhinotermes simplex (Isoptera, Rhinotermitidae, Prorhinotermitinae).

PubMed

Sillam-Dussès, David; Kalinová, Blanka; Jiros, Pavel; Brezinová, Anna; Cvacka, Josef; Hanus, Robert; Sobotník, Jan; Bordereau, Christian; Valterová, Irena

2009-08-01

GC/MS analysis confirmed that neocembrene is the major component of the trail pheromone in the three species of the termite genus Prorhinotermes (P. simplex, P. canalifrons, P. inopinatus). In addition, EAG and GC-EAD experiments with P. simplex strongly suggest that dodecatrienol is a quantitatively minor component but a qualitatively important component of this trail pheromone. Trail-following bioassays confirmed the two-component nature of the trail pheromone. This is the first report of the use of the GC-EAD for the identification of trail pheromone in termites. These original results underline once again the special phylogenetic status of the Prorhinotermitinae among Rhinotermitidae.

Evolving Self-Organized Behavior for Homogeneous and Heterogeneous UAV or UCAV Swarms

DTIC Science & Technology

2006-03-01

of sensed UAVs and a simple target associated pheromone . At its core, the sets of behaviors are built upon behavior rules describing formation...search randomly around the nest, dropping pheromones for communication. When an ant locates food and returns to the hive, it leaves a trail of... pheromones between the hive and the food-source. When other ants are exposed to the pheromone signal released by the first ant, they have a greater

The Iron-Dependent Regulator Fur Controls Pheromone Signaling Systems and Luminescence in the Squid Symbiont Vibrio fischeri ES114

PubMed Central

Septer, Alecia N.; Lyell, Noreen L.

2013-01-01

Bacteria often use pheromones to coordinate group behaviors in specific environments. While high cell density is required for pheromones to achieve stimulatory levels, environmental cues can also influence pheromone accumulation and signaling. For the squid symbiont Vibrio fischeri ES114, bioluminescence requires pheromone-mediated regulation, and this signaling is induced in the host to a greater extent than in culture, even at an equivalent cell density. Our goal is to better understand this environment-specific control over pheromone signaling and bioluminescence. Previous work with V. fischeri MJ1 showed that iron limitation induces luminescence, and we recently found that ES114 encounters a low-iron environment in its host. Here we show that ES114 induces luminescence at lower cell density and achieves brighter luminescence in low-iron media. This iron-dependent effect on luminescence required ferric uptake regulator (Fur), which we propose influences two pheromone signaling master regulators, LitR and LuxR. Genetic and bioinformatic analyses suggested that under low-iron conditions, Fur-mediated repression of litR is relieved, enabling more LitR to perform its established role as an activator of luxR. Interestingly, Fur may similarly control the LitR homolog SmcR of Vibrio vulnificus. These results reveal an intriguing regulatory link between low-iron conditions, which are often encountered in host tissues, and pheromone-dependent master regulators. PMID:23315731

Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency

PubMed Central

Eller, Fred J.; Palmquist, Debra E.

2014-01-01

Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about age 15 days old and then tapered off. Male pepper weevils produced the highest amount of pheromone between noon and 2 pm (i.e., 4 to 6 h after “lights on”) and were producing ca. 800 ng/h during this period. Thereafter, pheromone production decreased and was extremely low during the scotophase (i.e., ca. 12 ng/h). Male pepper weevil density had a significant effect on both release rate and pheromone composition. Pheromone production on a per male basis was highest for individual males and the percentage of geranic acid in the blend was lowest for individual males. Male pepper weevils produced only extremely low amounts of pheromone when feeding on artificial diet; however, they produced very high amounts when on fresh peppers. Together, this information will be useful in designing better attractant lures for pepper weevils. PMID:26462948

Endogenous fatty acids in olfactory hairs influence pheromone binding protein structure and function in Lymantria dispar.

PubMed

Nardella, Jason; Terrado, Mailyn; Honson, Nicolette S; Plettner, Erika

2015-08-01

The gypsy moth utilizes a pheromone, (7R,8S)-2-methyl-7,8-epoxyoctadecane, for mate location. The pheromone is detected by sensory hairs (sensilla) on the antennae of adult males. Sensilla contain the dendrites of olfactory neurons bathed in lymph, which contains pheromone binding proteins (PBPs). We have extracted and identified free fatty acids from lymph of sensory hairs, and we demonstrate that these function as endogenous ligands for gypsy moth PBP1 and PBP2. Homology modeling of both PBPs, and docking of fatty acids reveal multiple binding sites: one internal, the others external. Pheromone binding assays suggest that these fatty acids increase PBP-pheromone binding affinity. We show that fatty acid binding causes an increase in α-helix content in the N-terminal domain, but not in the C-terminal peptide of both proteins. The C-terminal peptide was shown to form a α-helix in a hydrophobic, homogeneous environment, but not in the presence of fatty acid micelles. Through partition assays we show that the fatty acids prevent adsorption of the pheromone on hydrophobic surfaces and facilitate pheromone partition into an aqueous phase. We propose that lymph is an emulsion of fatty acids and PBP that influence each other and thereby control the partition equilibria of hydrophobic odorants. Copyright © 2015 Elsevier Inc. All rights reserved.

Trail Communication Regulated by Two Trail Pheromone Components in the Fungus-Growing Termite Odontotermes formosanus (Shiraki)

PubMed Central

Wen, Ping; Ji, Bao-Zhong; Sillam-Dussès, David

2014-01-01

The eusocial termites are well accomplished in chemical communication, but how they achieve the communication using trace amount of no more than two pheromone components is mostly unknown. In this study, the foraging process and trail pheromones of the fungus-growing termite Odontotermes formosanus (Shiraki) were systematically studied and monitored in real-time using a combination of techniques, including video analysis, solid-phase microextraction, gas chromatography coupled with either mass spectrometry or an electroantennographic detector, and bioassays. The trail pheromone components in foraging workers were (3Z)-dodec-3-en-1-ol and (3Z,6Z)-dodeca-3,6-dien-1-ol secreted by their sternal glands. Interestingly, ratio of the two components changed according to the behaviors that the termites were displaying. This situation only occurs in termites whereas ratios of pheromone components are fixed and species-specific for other insect cuticular glands. Moreover, in bioassays, the active thresholds of the two components ranged from 1 fg/cm to 10 pg/cm according to the behavioral contexts or the pheromonal exposure of tested workers. The two components did not act in synergy. (3Z)-Dodec-3-en-1-ol induced orientation behavior of termites that explore their environment, whereas (3Z,6Z)-dodeca-3,6-dien-1-ol had both an orientation effect and a recruitment effect when food was discovered. The trail pheromone of O. formosanus was regulated both quantitatively by the increasing number of workers involved in the early phases of foraging process, and qualitatively by the change in ratio of the two pheromone components on sternal glandular cuticle in the food-collecting workers. In bioassays, the responses of workers to the pheromone were also affected by the variation in pheromone concentration and component ratio in the microenvironment. Thus, this termite could exchange more information with nestmates using the traces of the two trail pheromone components that can be easily regulated within a limited microenvironment formed by the tunnels or chambers. PMID:24670407

Plant odorants interfere with detection of sex pheromone signals by male Heliothis virescens

PubMed Central

Pregitzer, Pablo; Schubert, Marco; Breer, Heinz; Hansson, Bill S.; Sachse, Silke; Krieger, Jürgen

2012-01-01

In many insects, mate finding relies on female-released sex pheromones, which have to be deciphered by the male olfactory system within an odorous background of plant volatiles present in the environment of a calling female. With respect to pheromone-mediated mate localization, plant odorants may be neutral, favorable, or disturbing. Here we examined the impact of plant odorants on detection and coding of the major sex pheromone component, (Z)-11-hexadecenal (Z11-16:Ald) in the noctuid moth Heliothis virescens. By in vivo imaging the activity in the male antennal lobe (AL), we monitored the interference at the level of olfactory sensory neurons (OSN) to illuminate mixture interactions. The results show that stimulating the male antenna with Z11-16:Ald and distinct plant-related odorants simultaneously suppressed pheromone-evoked activity in the region of the macroglomerular complex (MGC), where Z11-16:Ald-specific OSNs terminate. Based on our previous findings that antennal detection of Z11-16:Ald involves an interplay of the pheromone binding protein (PBP) HvirPBP2 and the pheromone receptor (PR) HR13, we asked if the plant odorants may interfere with any of the elements involved in pheromone detection. Using a competitive fluorescence binding assay, we found that the plant odorants neither bind to HvirPBP2 nor affect the binding of Z11-16:Ald to the protein. However, imaging experiments analyzing a cell line that expressed the receptor HR13 revealed that plant odorants significantly inhibited the Z11-16:Ald-evoked calcium responses. Together the results indicate that plant odorants can interfere with the signaling process of the major sex pheromone component at the receptor level. Consequently, it can be assumed that plant odorants in the environment may reduce the firing activity of pheromone-specific OSNs in H. virescens and thus affect mate localization. PMID:23060749

Moths behaving like butterflies. Evolutionary loss of long range attractant pheromones in castniid moths: a Paysandisia archon model.

PubMed

Sarto i Monteys, Víctor; Acín, Patricia; Rosell, Glòria; Quero, Carmen; Jiménez, Miquel A; Guerrero, Angel

2012-01-01

In the course of evolution butterflies and moths developed two different reproductive behaviors. Whereas butterflies rely on visual stimuli for mate location, moths use the 'female calling plus male seduction' system, in which females release long-range sex pheromones to attract conspecific males. There are few exceptions from this pattern but in all cases known female moths possess sex pheromone glands which apparently have been lost in female butterflies. In the day-flying moth family Castniidae ("butterfly-moths"), which includes some important crop pests, no pheromones have been found so far. Using a multidisciplinary approach we described the steps involved in the courtship of P. archon, showing that visual cues are the only ones used for mate location; showed that the morphology and fine structure of the antennae of this moth are strikingly similar to those of butterflies, with male sensilla apparently not suited to detect female-released long range pheromones; showed that its females lack pheromone-producing glands, and identified three compounds as putative male sex pheromone (MSP) components of P. archon, released from the proximal halves of male forewings and hindwings. This study provides evidence for the first time in Lepidoptera that females of a moth do not produce any pheromone to attract males, and that mate location is achieved only visually by patrolling males, which may release a pheromone at short distance, putatively a mixture of Z,E-farnesal, E,E-farnesal, and (E,Z)-2,13-octadecadienol. The outlined behavior, long thought to be unique to butterflies, is likely to be widespread in Castniidae implying a novel, unparalleled butterfly-like reproductive behavior in moths. This will also have practical implications in applied entomology since it signifies that the monitoring/control of castniid pests should not be based on the use of female-produced pheromones, as it is usually done in many moths.

Sex-specific trail pheromone mediates complex mate finding behavior in Anoplophora glabripennis.

PubMed

Hoover, Kelli; Keena, Melody; Nehme, Maya; Wang, Shifa; Meng, Peter; Zhang, Aijun

2014-02-01

Anoplophora glabripennis (Motsch.) is a polyphagous member of the Cerambycidae, and is considered, worldwide, to be one of the most serious quarantine pests of deciduous trees. We isolated four chemicals from the trail of A. glabripennis virgin and mated females that were not present in trails of mature males. These compounds were identified as 2-methyldocosane and (Z)-9-tricosene (major components), as well as (Z)-9-pentacosene and (Z)-7-pentacosene (minor components); every trail wash sample contained all four chemical components, although the amounts and ratios changed with age of the female. Males responded to the full pheromone blend, regardless of mating status, but virgin females chose the control over the pheromone, suggesting that they may use it as a spacing pheromone to avoid intraspecific competition and maximize resources. Virgin, but not mated, males also chose the major pheromone components in the absence of the minor components, over the control. Taken together, these results indicate that all four chemicals are components of the trail pheromone. The timing of production of the ratios of the pheromone blend components that produced positive responses from males coincided with the timing of sexual maturation of the female.

Male sex pheromone components in Heliconius butterflies released by the androconia affect female choice

PubMed Central

Morrison, Colin R.; Salazar, Camilo; Pardo-Diaz, Carolina; Merrill, Richard M.; McMillan, W. Owen; Schulz, Stefan

2017-01-01

Sex-specific pheromones are known to play an important role in butterfly courtship, and may influence both individual reproductive success and reproductive isolation between species. Extensive ecological, behavioural and genetic studies of Heliconius butterflies have made a substantial contribution to our understanding of speciation. Male pheromones, although long suspected to play an important role, have received relatively little attention in this genus. Here, we combine morphological, chemical and behavioural analyses of male pheromones in the Neotropical butterfly Heliconius melpomene. First, we identify putative androconia that are specialized brush-like scales that lie within the shiny grey region of the male hindwing. We then describe putative male sex pheromone compounds, which are largely confined to the androconial region of the hindwing of mature males, but are absent in immature males and females. Finally, behavioural choice experiments reveal that females of H. melpomene, H. erato and H. timareta strongly discriminate against conspecific males which have their androconial region experimentally blocked. As well as demonstrating the importance of chemical signalling for female mate choice in Heliconius butterflies, the results describe structures involved in release of the pheromone and a list of potential male sex pheromone compounds. PMID:29134139

Unusual pheromone chemistry in the navel orangeworm: novel sex attractants and a behavioral antagonist

NASA Astrophysics Data System (ADS)

Leal, W. S.; Parra-Pedrazzoli, A. L.; Kaissling, K.-E.; Morgan, T. I.; Zalom, F. G.; Pesak, D. J.; Dundulis, E. A.; Burks, C. S.; Higbee, B. S.

2005-03-01

Using molecular- and sensory physiology-based approaches, three novel natural products, a simple ester, and a behavioral antagonist have been identified from the pheromone gland of the navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae). In addition to the previously identified (Z,Z)-11,13-hexadecadienal, the pheromone blend is composed of (Z,Z,Z,Z,Z)-3,6,9,12,15-tricosapentaene, (Z,Z,Z,Z,Z)-3,6,9,12,15-pentacosapentaene, ethyl palmitate, ethyl-(Z,Z)-11,13-hexadecadienoate, and (Z,Z)-11,13-hexadecadien-1-yl acetate. The C23 and C25 pentaenes are not only novel sex pheromones, but also new natural products. In field tests, catches of A. transitella males in traps baited with the full mixture of pheromones were as high as those in traps with virgin females, whereas control and traps baited only with the previously known constituent did not capture any moths at all. The navel orangeworm sex pheromone is also an attractant for the meal moth, Pyralis farinalis L. (Pyralidae), but (Z,Z)-11,13-hexadecadien-1-yl acetate is a behavioral antagonist. The new pheromone blend may be highly effective in mating disruption and monitoring programs.

A novel screen for genes associated with pheromone-induced sterility

PubMed Central

Camiletti, Alison L.; Percival-Smith, Anthony; Croft, Justin R.; Thompson, Graham J.

2016-01-01

For honey bee and other social insect colonies the ‘queen substance’ regulates colony reproduction rendering workers functionally sterile. The evolution of worker reproductive altruism is explained by inclusive fitness theory, but little is known of the genes involved or how they regulate the phenotypic expression of altruism. We previously showed that application of honeybee queen pheromone to virgin fruit flies suppresses fecundity. Here we exploit this finding to identify genes associated with the perception of an ovary-inhibiting social pheromone. Mutational and RNAi approaches in Drosophila reveal that the olfactory co-factor Orco together with receptors Or49b, Or56a and Or98a are potentially involved in the perception of queen pheromone and the suppression of fecundity. One of these, Or98a, is known to mediate female fly mating behaviour, and its predicted ligand is structurally similar to a methyl component of the queen pheromone. Our novel approach to finding genes associated with pheromone-induced sterility implies conserved reproductive regulation between social and pre-social orders, and further helps to identify candidate orthologues from the pheromone-responsive pathway that may regulate honeybee worker sterility. PMID:27786267

Assessment of commercially available pheromone lures for monitoring diamondback moth (Lepidoptera: Plutellidae) in canola.

PubMed

Evenden, M L; Gries, R

2010-06-01

Sex pheromone monitoring lures from five different commercial sources were compared for their attractiveness to male diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae) in canola, Brassica napus L., fields in western Canada. Lures that had the highest pheromone release rate, as determined by aeration analyses in the laboratory, were the least attractive in field tests. Lures from all the commercial sources tested released more (Z)-11-hexadecenal than (Z)-11-hexadecenyl acetate and the most attractive lures released a significantly higher aldehyde to acetate ratio than less attractive lures. Traps baited with sex pheromone lures from APTIV Inc. (Portland, OR) and ConTech Enterprises Inc. (Delta, BC, Canada) consistently captured more male diamondback moths than traps baited with lures from the other sources tested. In two different lure longevity field trapping experiments, older lures were more attractive to male diamondback moths than fresh lures. Pheromone release from aged lures was constant at very low release rates. The most attractive commercially available sex pheromone lures tested attracted fewer diamondback moth males than calling virgin female moths suggesting that research on the development of a more attractive synthetic sex pheromone lure is warranted.

Identification of novel inhibitors of calling and in vitro [14C]acetate incorporation by pheromone glands of Plodia interpunctella.

PubMed

Hirashima, A; Eiraku, T; Watanabe, Y; Kuwano, E; Taniguchi, E; Eto, M

2001-08-01

Some octopamine agonists were found to suppress in vitro biosynthesis of the calling pheromone of the Indian meal moth, Plodia interpunctella. Isolated pheromone-gland preparations incorporated sodium [14C]acetate at a linear rate for 3 h when incubated with the pheromone biosynthesis activating neuropeptide (PBAN). This incorporation was dependent on the dose of PBAN (up to 0.5 microM). Thin-layer chromatography of a pheromone-gland extract revealed quantitative incorporation of radioactivity into a product exhibiting the same mobility as (Z,E)-9,12-tetradecadienyl acetate, the main component of the calling pheromone of P interpunctella. Twenty-seven octopamine agonists were initially screened using a calling behaviour bioassay of female P interpunctella. Four derivatives with activity in the nanomolar range were identified which were, in order of decreasing pheromonostatic activity: 2-(2,6-diethylphenylimino)thiazolidine > 2-(2,6-diethylphenylimino)oxazolidine > 2-(2,6-dimethylphenylimino)thiazolidine > 2-(2-ethylphenylimino)oxazolidine. These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis. The results of the present study indicate that these derivatives could provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.

Understanding the Logics of Pheromone Processing in the Honeybee Brain: From Labeled-Lines to Across-Fiber Patterns

PubMed Central

Sandoz, Jean-Christophe; Deisig, Nina; de Brito Sanchez, Maria Gabriela; Giurfa, Martin

2007-01-01

Honeybees employ a very rich repertoire of pheromones to ensure intraspecific communication in a wide range of behavioral contexts. This communication can be complex, since the same compounds can have a variety of physiological and behavioral effects depending on the receiver. Honeybees constitute an ideal model to study the neurobiological basis of pheromonal processing, as they are already one of the most influential animal models for the study of general odor processing and learning at behavioral, cellular and molecular levels. Accordingly, the anatomy of the bee brain is well characterized and electro- and opto-physiological recording techniques at different stages of the olfactory circuit are possible in the laboratory. Here we review pheromone communication in honeybees and analyze the different stages of olfactory processing in the honeybee brain, focusing on available data on pheromone detection, processing and representation at these different stages. In particular, we argue that the traditional distinction between labeled-line and across-fiber pattern processing, attributed to pheromone and general odors respectively, may not be so clear in the case of honeybees, especially for social-pheromones. We propose new research avenues for stimulating future work in this area. PMID:18958187

Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies

PubMed Central

Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y.

2016-01-01

Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season. PMID:27966579

A volatile trail Pheromone of the Leaf-Cutting Ant, Atta Texana

Treesearch

J. H. Tumlinson; John C. Moser; R. M. Silverstein; R. G. Brownlee; J. M. Ruth

1972-01-01

The major volatile trail-marking pheromone of the Texas leaf-cutting Ant, Atta texana, was isolated, identified as methyl 4-methylpyrrole-2-carboxylate, and synthesized. The synthesized pheromone elicited strong trail-following response from workers in the laboratory and field.

Lifespan extending activity of substances secreted by the nematode Caenorhabditis elegans that include the dauer-inducing pheromone.

PubMed

Kawano, Tsuyoshi; Kataoka, Naoya; Abe, Sunao; Ohtani, Mari; Honda, Yoko; Honda, Shuji; Kimura, Yasuo

2005-12-01

The nematode Caenorhabditis elegans yields a substance(s) inducing the larval diapause, called dauer-inducing pheromone. We discovered that the crude pheromone extract extends the adult lifespan in the animal. This extension does not occur in the mutant animal, in which expansion of the lifespan caused by other mutations reducing insulin signaling is suppressed. This is the first description concerning the relevancy of the pheromone to the longevity in the animal.

Enhanced Detection of Orthogonal Radar Waveforms Using Time-Frequency and Bi-Frequency Signal Processing Techniques

DTIC Science & Technology

2008-09-01

using the principle of pheromones . The termite senses the pheromone , which tells him to gather up dirt in its mouth and deposit it where the scent of...the pheromone is the strongest. The termite gathers dirt and moves to the location of the strongest scent and deposits the mud there. As this...process is repeated by a number of termites all leaving their own contribution of pheromone at the scene, the autocatalytic effect takes over. This

Allelic exchange of pheromones and their receptors reprograms sexual identity in Cryptococcus neoformans.

PubMed

Stanton, Brynne C; Giles, Steven S; Staudt, Mark W; Kruzel, Emilia K; Hull, Christina M

2010-02-26

Cell type specification is a fundamental process that all cells must carry out to ensure appropriate behaviors in response to environmental stimuli. In fungi, cell identity is critical for defining "sexes" known as mating types and is controlled by components of mating type (MAT) loci. MAT-encoded genes function to define sexes via two distinct paradigms: 1) by controlling transcription of components common to both sexes, or 2) by expressing specially encoded factors (pheromones and their receptors) that differ between mating types. The human fungal pathogen Cryptococcus neoformans has two mating types (a and alpha) that are specified by an extremely unusual MAT locus. The complex architecture of this locus makes it impossible to predict which paradigm governs mating type. To identify the mechanism by which the C. neoformans sexes are determined, we created strains in which the pheromone and pheromone receptor from one mating type (a) replaced the pheromone and pheromone receptor of the other (alpha). We discovered that these "alpha(a)" cells effectively adopt a new mating type (that of a cells); they sense and respond to alpha factor, they elicit a mating response from alpha cells, and they fuse with alpha cells. In addition, alpha(a) cells lose the alpha cell type-specific response to pheromone and do not form germ tubes, instead remaining spherical like a cells. Finally, we discovered that exogenous expression of the diploid/dikaryon-specific transcription factor Sxi2a could then promote complete sexual development in crosses between alpha and alpha(a) strains. These data reveal that cell identity in C. neoformans is controlled fully by three kinds of MAT-encoded proteins: pheromones, pheromone receptors, and homeodomain proteins. Our findings establish the mechanisms for maintenance of distinct cell types and subsequent developmental behaviors in this unusual human fungal pathogen.

Breaking the cipher: ant eavesdropping on the variational trail pheromone of its termite prey

PubMed Central

Wen, Xiao-Lan

2017-01-01

Predators may eavesdrop on their prey using innate signals of varying nature. In regards to social prey, most of the prey signals are derived from social communication and may therefore be highly complex. The most efficient predators select signals that provide the highest benefits. Here, we showed the use of eusocial prey signals by the termite-raiding ant Odontoponera transversa. O. transversa selected the trail pheromone of termites as kairomone in several species of fungus-growing termites (Termitidae: Macrotermitinae: Odontotermes yunnanensis, Macrotermes yunnanensis, Ancistrotermes dimorphus). The most commonly predated termite, O. yunnanensis, was able to regulate the trail pheromone component ratios during its foraging activity. The ratio of the two trail pheromone compounds was correlated with the number of termites in the foraging party. (3Z)-Dodec-3-en-1-ol (DOE) was the dominant trail pheromone component in the initial foraging stages when fewer termites were present. Once a trail was established, (3Z,6Z)-dodeca-3,6-dien-1-ol (DDE) became the major recruitment component in the trail pheromone and enabled mass recruitment of nest-mates to the food source. Although the ants could perceive both components, they revealed stronger behavioural responses to the recruitment component, DDE, than to the common major component, DOE. In other words, the ants use the trail pheromone information as an indication of suitable prey abundance, and regulate their behavioural responses based on the changing trail pheromone component. The eavesdropping behaviour in ants therefore leads to an arms race between predator and prey where the species specific production of trail pheromones in termites is targeted by predatory ant species. PMID:28446695

Breaking the cipher: ant eavesdropping on the variational trail pheromone of its termite prey.

PubMed

Wen, Xiao-Lan; Wen, Ping; Dahlsjö, Cecilia A L; Sillam-Dussès, David; Šobotník, Jan

2017-04-26

Predators may eavesdrop on their prey using innate signals of varying nature. In regards to social prey, most of the prey signals are derived from social communication and may therefore be highly complex. The most efficient predators select signals that provide the highest benefits. Here, we showed the use of eusocial prey signals by the termite-raiding ant Odontoponera transversa O. transversa selected the trail pheromone of termites as kairomone in several species of fungus-growing termites (Termitidae: Macrotermitinae: Odontotermes yunnanensis , Macrotermes yunnanensis , Ancistrotermes dimorphus ). The most commonly predated termite, O. yunnanensis, was able to regulate the trail pheromone component ratios during its foraging activity. The ratio of the two trail pheromone compounds was correlated with the number of termites in the foraging party. (3 Z )-Dodec-3-en-1-ol (DOE) was the dominant trail pheromone component in the initial foraging stages when fewer termites were present. Once a trail was established, (3 Z,6Z )-dodeca-3,6-dien-1-ol (DDE) became the major recruitment component in the trail pheromone and enabled mass recruitment of nest-mates to the food source. Although the ants could perceive both components, they revealed stronger behavioural responses to the recruitment component, DDE, than to the common major component, DOE. In other words, the ants use the trail pheromone information as an indication of suitable prey abundance, and regulate their behavioural responses based on the changing trail pheromone component. The eavesdropping behaviour in ants therefore leads to an arms race between predator and prey where the species specific production of trail pheromones in termites is targeted by predatory ant species. © 2017 The Author(s).

Moth Sex Pheromone Receptors and Deceitful Parapheromones

PubMed Central

Xu, Pingxi; Garczynski, Stephen F.; Atungulu, Elizabeth; Syed, Zainulabeuddin; Choo, Young-Moo; Vidal, Diogo M.; Zitelli, Caio H. L.; Leal, Walter S.

2012-01-01

The insect's olfactory system is so selective that male moths, for example, can discriminate female-produced sex pheromones from compounds with minimal structural modifications. Yet, there is an exception for this “lock-and-key” tight selectivity. Formate analogs can be used as replacement for less chemically stable, long-chain aldehyde pheromones, because male moths respond physiologically and behaviorally to these parapheromones. However, it remained hitherto unknown how formate analogs interact with aldehyde-sensitive odorant receptors (ORs). Neuronal responses to semiochemicals were investigated with single sensillum recordings. Odorant receptors (ORs) were cloned using degenerate primers, and tested with the Xenopus oocyte expression system. Quality, relative quantity, and purity of samples were evaluated by gas chromatography and gas chromatography-mass spectrometry. We identified olfactory receptor neurons (ORNs) housed in trichoid sensilla on the antennae of male navel orangeworm that responded equally to the main constituent of the sex pheromone, (11Z,13Z)-hexadecadienal (Z11Z13-16Ald), and its formate analog, (9Z,11Z)-tetradecen-1-yl formate (Z9Z11-14OFor). We cloned an odorant receptor co-receptor (Orco) and aldehyde-sensitive ORs from the navel orangeworm, one of which (AtraOR1) was expressed specifically in male antennae. AtraOR1•AtraOrco-expressing oocytes responded mainly to Z11Z13-16Ald, with moderate sensitivity to another component of the sex pheromone, (11Z,13Z)-hexadecadien-1-ol. Surprisingly, this receptor was more sensitive to the related formate than to the natural sex pheromone. A pheromone receptor from Heliothis virescens, HR13 ( = HvirOR13) showed a similar profile, with stronger responses elicited by a formate analog than to the natural sex pheromone, (11Z)-hexadecenal thus suggesting this might be a common feature of moth pheromone receptors. PMID:22911835

Phylogenetic distribution of a male pheromone that may exploit a nonsexual preference in lampreys

USGS Publications Warehouse

Buchinger, Tyler J.; Bussy, Ugo; Li, Ke; Wang, Huiyong; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas

2017-01-01

Pheromones are among the most important sexual signals used by organisms throughout the animal kingdom. However, few are identified in vertebrates, leaving the evolutionary mechanisms underlying vertebrate pheromones poorly understood. Pre-existing biases in receivers’ perceptual systems shape visual and auditory signaling systems, but studies on how receiver biases influence the evolution of pheromone communication remain sparse. The lamprey Petromyzon marinus uses a relatively well-understood suite of pheromones and offers a unique opportunity to study the evolution of vertebrate pheromone communication. Previous studies indicate that male signaling with the mating pheromone 3-keto petromyzonol sulfate (3kPZS) may exploit a nonsexual attraction to juvenile-released 3kPZS that guides migration into productive rearing habitat. Here, we infer the distribution of male signaling with 3kPZS using a phylogenetic comparison comprising six of ten genera and two of three families. Our results indicate that only P. marinus and Ichthyomyzon castaneus release 3kPZS at high rates. Olfactory and behavioral assays with P. marinus, I. castaneus and a subset of three other species that do not use 3kPZS as a sexual signal indicate that male signaling might drive the evolution of female adaptations to detect 3kPZS with specific olfactory mechanisms and respond to 3kPZS with targeted attraction relevant during mate search. We postulate that 3kPZS communication evolved independently in I. castaneus and P. marinus, but cannot eliminate the alternative that other species lost 3kPZS communication. Regardless, our results represent a rare macroevolutionary investigation of a vertebrate pheromone and insight into the evolutionary mechanisms underlying pheromone communication.

An anti-steroidogenic inhibitory primer pheromone in male sea lamprey (Petromyzon marinus)

USGS Publications Warehouse

Chung-Davidson, Yu-Wen; Wang, Huiyong; Bryan, Mara B.; Wu, Hong; Johnson, Nicholas S.; Li, Weiming

2013-01-01

Reproductive functions can be modulated by both stimulatory and inhibitory primer pheromones released by conspecifics. Many stimulatory primer pheromones have been documented, but relatively few inhibitory primer pheromones have been reported in vertebrates. The sea lamprey male sex pheromone system presents an advantageous model to explore the stimulatory and inhibitory primer pheromone functions in vertebrates since several pheromone components have been identified. We hypothesized that a candidate sex pheromone component, 7α, 12α-dihydroxy-5α-cholan-3-one-24-oic acid (3 keto-allocholic acid or 3kACA), exerts priming effects through the hypothalamic-pituitary-gonadal (HPG) axis. To test this hypothesis, we measured the peptide concentrations and gene expressions of lamprey gonadotropin releasing hormones (lGnRH) and the HPG output in immature male sea lamprey exposed to waterborne 3kACA. Exposure to waterborne 3kACA altered neuronal activation markers such as jun and jun N-terminal kinase (JNK), and lGnRH mRNA levels in the brain. Waterborne 3kACA also increased lGnRH-III, but not lGnRH-I or -II, in the forebrain. In the plasma, 3kACA exposure decreased all three lGnRH peptide concentrations after 1 h exposure. After 2 h exposure, 3kACA increased lGnRHI and -III, but decreased lGnRH-II peptide concentrations in the plasma. Plasma lGnRH peptide concentrations showed differential phasic patterns. Group housing condition appeared to increase the averaged plasma lGnRH levels in male sea lamprey compared to isolated males. Interestingly, 15α-hydroxyprogesterone (15α-P) concentrations decreased after prolonged 3kACA exposure (at least 24 h). To our knowledge, this is the only known synthetic vertebrate pheromone component that inhibits steroidogenesis in males.

Evidence for a pheromone in the locust borer

Treesearch

Jimmy R. Galford

1977-01-01

Laboratory studies have suggested the existence of a pheromone in the locust borer. Male beetles spent more time on bolts of wood exposed to virgin females than on control bolts. The females apparently deposited the pheromone on the bolts of wood and filter paper.

Evolved differences in larval social behavior mediated by novel pheromones

USDA-ARS?s Scientific Manuscript database

Pheromones, chemical signals that convey social information, mediate many insect social behaviors in both adult and immature stages. Multiple pheromones and neural pathways that underlie adult social behavior have been described in the genetic model organism, Drosophila melanogaster, but there is no...

Midgut tissue of male pine engraver , Ips pini, synthesizes monoterpenoid pheromone component ipsdienol de novo

NASA Astrophysics Data System (ADS)

Hall, Gregory M.; Tittiger, Claus; Andrews, Gracie L.; Mastick, Grant S.; Kuenzli, Marilyn; Luo, Xin; Seybold, Steven J.; Blomquist, Gary J.

2002-02-01

For over three decades the site and pathways of bark beetle aggregation pheromone production have remained elusive. Studies on pheromone production in Ips spp. bark beetles have recently shown de novo biosynthesis of pheromone components via the mevalonate pathway. The gene encoding a key regulated enzyme in this pathway, 3-hydroxy-3-methylglutaryl-CoA reductase ( HMG-R), showed high transcript levels in the anterior midgut of male pine engravers, Ips pini (Say) (Coleoptera:Scolytidae). HMG-R expression in the midgut was sex, juvenile hormone, and feeding dependent, providing strong evidence that this is the site of acyclic monoterpenoid (ipsdienol) pheromone production in male beetles. Additionally, isolated midgut tissue from fed or juvenile hormone III (JH III)-treated males converted radiolabeled acetate to ipsdienol, as assayed by radio-HPLC. These data support the de novo production of this frass-associated aggregation pheromone component by the mevalonate pathway. The induction of a metazoan HMG-R in this process does not support the postulated role of microorganisms in ipsdienol production.

Mating and male pheromone kill Caenorhabditis males through distinct mechanisms

PubMed Central

Shi, Cheng; Runnels, Alexi M; Murphy, Coleen T

2017-01-01

Differences in longevity between sexes is a mysterious yet general phenomenon across great evolutionary distances. To test the roles of responses to environmental cues and sexual behaviors in longevity regulation, we examined Caenorhabditis male lifespan under solitary, grouped, and mated conditions. We find that neurons and the germline are required for male pheromone-dependent male death. Hermaphrodites with a masculinized nervous system secrete male pheromone and are susceptible to male pheromone killing. Male pheromone-mediated killing is unique to androdioecious Caenorhabditis, and may reduce the number of males in hermaphroditic populations; neither males nor females of gonochoristic species are susceptible to male pheromone killing. By contrast, mating-induced death, which is characterized by germline-dependent shrinking, glycogen loss, and ectopic vitellogenin expression, utilizes distinct molecular pathways and is shared between the sexes and across species. The study of sex- and species-specific regulation of aging reveals deeply conserved mechanisms of longevity and population structure regulation. DOI: http://dx.doi.org/10.7554/eLife.23493.001 PMID:28290982

Integrated action of pheromone signals in promoting courtship behavior in male mice

PubMed Central

Haga-Yamanaka, Sachiko; Ma, Limei; He, Jie; Qiu, Qiang; Lavis, Luke D; Looger, Loren L; Yu, C Ron

2014-01-01

The mammalian vomeronasal organ encodes pheromone information about gender, reproductive status, genetic background and individual differences. It remains unknown how pheromone information interacts to trigger innate behaviors. In this study, we identify vomeronasal receptors responsible for detecting female pheromones. A sub-group of V1re clade members recognizes gender-identifying cues in female urine. Multiple members of the V1rj clade are cognate receptors for urinary estrus signals, as well as for sulfated estrogen (SE) compounds. In both cases, the same cue activates multiple homologous receptors, suggesting redundancy in encoding female pheromone cues. Neither gender-specific cues nor SEs alone are sufficient to promote courtship behavior in male mice, whereas robust courtship behavior can be induced when the two cues are applied together. Thus, integrated action of different female cues is required in pheromone-triggered mating behavior. These results suggest a gating mechanism in the vomeronasal circuit in promoting specific innate behavior. DOI: http://dx.doi.org/10.7554/eLife.03025.001 PMID:25073926

Non-Host Plant Volatiles Disrupt Sex Pheromone Communication in a Specialist Herbivore.

PubMed

Wang, Fumin; Deng, Jianyu; Schal, Coby; Lou, Yonggen; Zhou, Guoxin; Ye, Bingbing; Yin, Xiaohui; Xu, Zhihong; Shen, Lize

2016-09-02

The ecological effects of plant volatiles on herbivores are manifold. Little is known, however, about the impacts of non-host plant volatiles on intersexual pheromonal communication in specialist herbivores. We tested the effects of several prominent constitutive terpenoids released by conifers and Eucalyptus trees on electrophysiological and behavioral responses of an oligophagous species, Plutella xylostella, which feeds on Brassicaceae. The non-host plant volatile terpenoids adversely affected the calling behavior (pheromone emission) of adult females, and the orientation responses of adult males to sex pheromone were also significantly inhibited by these terpenoids in a wind tunnel and in the field. We suggest that disruption of both pheromone emission and orientation to sex pheromone may explain, at least in part, an observed reduction in herbivore attack in polyculture compared with monoculture plantings. We also propose that mating disruption of both male and female moths with non-host plant volatiles may be a promising alternative pest management strategy.

Non-Host Plant Volatiles Disrupt Sex Pheromone Communication in a Specialist Herbivore

PubMed Central

Wang, Fumin; Deng, Jianyu; Schal, Coby; Lou, Yonggen; Zhou, Guoxin; Ye, Bingbing; Yin, Xiaohui; Xu, Zhihong; Shen, Lize

2016-01-01

The ecological effects of plant volatiles on herbivores are manifold. Little is known, however, about the impacts of non-host plant volatiles on intersexual pheromonal communication in specialist herbivores. We tested the effects of several prominent constitutive terpenoids released by conifers and Eucalyptus trees on electrophysiological and behavioral responses of an oligophagous species, Plutella xylostella, which feeds on Brassicaceae. The non-host plant volatile terpenoids adversely affected the calling behavior (pheromone emission) of adult females, and the orientation responses of adult males to sex pheromone were also significantly inhibited by these terpenoids in a wind tunnel and in the field. We suggest that disruption of both pheromone emission and orientation to sex pheromone may explain, at least in part, an observed reduction in herbivore attack in polyculture compared with monoculture plantings. We also propose that mating disruption of both male and female moths with non-host plant volatiles may be a promising alternative pest management strategy. PMID:27585907

A sex-inducing pheromone triggers cell cycle arrest and mate attraction in the diatom Seminavis robusta

PubMed Central

Moeys, Sara; Frenkel, Johannes; Lembke, Christine; Gillard, Jeroen T. F.; Devos, Valerie; Van den Berge, Koen; Bouillon, Barbara; Huysman, Marie J. J.; De Decker, Sam; Scharf, Julia; Bones, Atle; Brembu, Tore; Winge, Per; Sabbe, Koen; Vuylsteke, Marnik; Clement, Lieven; De Veylder, Lieven; Pohnert, Georg; Vyverman, Wim

2016-01-01

Although sexual reproduction is believed to play a major role in the high diversification rates and species richness of diatoms, a mechanistic understanding of diatom life cycle control is virtually lacking. Diatom sexual signalling is controlled by a complex, yet largely unknown, pheromone system. Here, a sex-inducing pheromone (SIP+) of the benthic pennate diatom Seminavis robusta was identified by comparative metabolomics, subsequently purified, and physicochemically characterized. Transcriptome analysis revealed that SIP+ triggers the switch from mitosis-to-meiosis in the opposing mating type, coupled with the transcriptional induction of proline biosynthesis genes, and the release of the proline-derived attraction pheromone. The induction of cell cycle arrest by a pheromone, chemically distinct from the one used to attract the opposite mating type, highlights the existence of a sophisticated mechanism to increase chances of mate finding, while keeping the metabolic losses associated with the release of an attraction pheromone to a minimum. PMID:26786712

Cerambycid Beetle Species with Similar Pheromones are Segregated by Phenology and Minor Pheromone Components.

PubMed

Mitchell, Robert F; Reagel, Peter F; Wong, Joseph C H; Meier, Linnea R; Silva, Weliton Dias; Mongold-Diers, Judith; Millar, Jocelyn G; Hanks, Lawrence M

2015-05-01

Recent research has shown that volatile sex and aggregation-sex pheromones of many species of cerambycid beetles are highly conserved, with sympatric and synchronic species that are closely related (i.e., congeners), and even more distantly related (different subfamilies), using the same or similar pheromones. Here, we investigated mechanisms by which cross attraction is averted among seven cerambycid species that are native to eastern North America and active as adults in spring: Anelaphus pumilus (Newman), Cyrtophorus verrucosus (Olivier), Euderces pini (Olivier), Neoclytus caprea (Say), and the congeners Phymatodes aereus (Newman), P. amoenus (Say), and P. varius (F.). Males of these species produce (R)-3-hydroxyhexan-2-one as their dominant or sole pheromone component. Our field bioassays support the hypothesis that cross attraction between species is averted or at least minimized by differences among species in seasonal phenology and circadian flight periods of adults, and/or by minor pheromone components that act as synergists for conspecifics and antagonists for heterospecifics.

The Chemical Basis of Species, Sex, and Individual Recognition Using Feces in the Domestic Cat.

PubMed

Miyazaki, Masao; Miyazaki, Tamako; Nishimura, Takashi; Hojo, Wataru; Yamashita, Tetsuro

2018-04-01

Scents emitted from excretions provide important information about the owner. Volatile compounds with higher levels in a species and/or sex, or that vary among individuals could be odor cues for species and/or sex, or individual recognition. However, such compounds have been identified in only a few vertebrate species. In domestic cats (Felis silvestris catus), it is known that unburied cat feces are territorial markers asserting the border of their home range, but little was known which fecal compounds are scent cues for species, sex, and individual recognition in cats. In the present study, we demonstrated the chemical basis for species, sex, and individual recognition using feces of cats. For males, major contents were fatty acids and 3-mercapto-3-methyl-1-butanol (MMB), a derivative of the unusual amino acid, felinine. MMB emission levels from feces had sex-based differences (male > female) and dynamic temporal changes during aging. Cats distinguished fecal odors with and without MMB, and different fatty acid compositions among individuals. No cat-specific compound, such as MMB, was detectable from their anal odor emitting fatty acids. We concluded that fecal MMB is a male sex recognition pheromone in cats and also provides a temporal trace of the owner. After sensing MMB, they may distinguish individual differences of conspecific feces with variable subsets of fatty acids. In contrast to scent marks, since cats can obtain species information from visual cues before sniffing conspecific anal odors, they may use their efforts to distinguish individual differences of anal odors during sniffing.

A new C12 alcohol identified as a sex pheromone and a trail-following pheromone in termites: the diene (Z,Z)-dodeca-3,6-dien-1-ol.

PubMed

Robert, Alain; Peppuy, Alexis; Sémon, Etienne; Boyer, François D; Lacey, Michael J; Bordereau, Christian

2004-01-01

The diunsaturated C12 alcohol (Z,Z)-dodeca-3,6-dien-1-ol (dodecadienol) has been characterized by GC-MS and FTIR as a novel releaser pheromone in termites. This alcohol identified in Ancistrotermes pakistanicus (Termitidae, Macrotermitinae) possesses a double pheromonal function which again illustrates the chemical parsimony of termites compared with other social insects. In workers, dodecadienol elicits trail-following at a very low concentration (activity threshold at 0.1 pg/cm of trail); in male alates it induces trail-following at a low concentration (1-10 pg/cm) and sexual attraction at a higher concentration (about 1 ng). Traces of the monounsaturated C12 alcohol (Z)-dodec-3-en-1-ol (dodecenol), known as a trail pheromone of several Macrotermitinae, were also found in the sternal gland extracts of A. pakistanicus, although only dodecadienol was present at the surface of the sternal gland. Workers of A. pakistanicus are not sensitive to dodecenol, but they are as sensitive to dodecatrienol as to dodecadienol. However, in the study area (Vietnam), A. pakistanicus is living in sympatry only with those Macrotermitinae using dodecenol as a trail pheromone, the foraging populations therefore being well isolated through their respective trail pheromones. The presence of three types of unsaturated C12 alcohols as releaser pheromones in the only Macrotermitinae subfamily is discussed, and a possible biosynthetic pathway from linoleic acid is proposed for dodecadienol.

Insectivorous birds eavesdrop on the pheromones of their prey.

PubMed

Saavedra, Irene; Amo, Luisa

2018-01-01

Chemical cues play a fundamental role in mate attraction and mate choice. Lepidopteran females, such as the winter moth (Operophtera brumata), emit pheromones to attract males in the reproductive period. However, these chemical cues could also be eavesdropped by predators. To our knowledge, no studies have examined whether birds can detect pheromones of their prey. O. brumata adults are part of the winter diet of some insectivorous tit species, such as the great tit (Parus major) and blue tit (Cyanistes caeruleus). We performed a field experiment aimed to disentangle whether insectivorous birds can exploit the pheromones emitted by their prey for prey location. We placed artificial larvae and a dispenser on branches of Pyrenean oak trees (Quercus pyrenaica). In half of the trees we placed an O. brumata pheromone dispenser and in the other half we placed a control dispenser. We measured the predation rate of birds on artificial larvae. Our results show that more trees had larvae with signs of avian predation when they contained an O. brumata pheromone than when they contained a control dispenser. Furthermore, the proportion of artificial larvae with signs of avian predation was greater in trees that contained the pheromone than in control trees. Our results indicate that insectivorous birds can exploit the pheromones emitted by moth females to attract males, as a method of prey detection. These results highlight the potential use of insectivorous birds in the biological control of insect pests.

Effect of Male House Mouse Pheromone Components on Behavioral Responses of Mice in Laboratory and Field Experiments.

PubMed

Musso, Antonia E; Gries, Regine; Zhai, Huimin; Takács, Stephen; Gries, Gerhard

2017-03-01

Urine of male house mice, Mus musculus, is known to have primer pheromone effects on the reproductive physiology of female mice. Urine-mediated releaser pheromone effects that trigger certain behavioral responses are much less understood, and no field studies have investigated whether urine deposits by male or female mice, or synthetic mouse pheromone, increase trap captures of mice. In field experiments, we baited traps with bedding soiled with urine and feces of caged female or male mice, and recorded captures of mice in these and in control traps containing clean bedding. Traps baited with female bedding preferentially captured adult males, whereas traps baited with male bedding preferentially captured juvenile and adult females, indicating the presence of male- and female-specific sex pheromones in soiled bedding. Analyses of headspace volatiles emanating from soiled bedding by gas chromatography/mass spectrometry revealed that 3,4-dehydro-exo-brevicomin (DEB) was seven times more prevalent in male bedding and that 2-sec-butyl-4,5-dihydrothiazole (DHT) was male-specific. In a follow-up field experiment, traps baited with DEB and DHT captured 4 times more female mice than corresponding control traps, thus indicating that DEB and DHT are sex attractant pheromone components of house mouse males. Our study provides impetus to identify the sex attractant pheromone of female mice, and to develop synthetic mouse pheromone as a lure to enhance the efficacy of trapping programs for mouse control.

Olfactory Proteins Mediating Chemical Communication in the Navel Orangeworm Moth, Amyelois transitella

PubMed Central

Leal, Walter S.; Ishida, Yuko; Pelletier, Julien; Xu, Wei; Rayo, Josep; Xu, Xianzhong; Ames, James B.

2009-01-01

Background The navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae), is the most serious insect pest of almonds and pistachios in California for which environmentally friendly alternative methods of control — like pheromone-based approaches — are highly desirable. Some constituents of the sex pheromone are unstable and could be replaced with parapheromones, which may be designed on the basis of molecular interaction of pheromones and pheromone-detecting olfactory proteins. Methodology By analyzing extracts from olfactory and non-olfactory tissues, we identified putative olfactory proteins, obtained their N-terminal amino acid sequences by Edman degradation, and used degenerate primers to clone the corresponding cDNAs by SMART RACE. Additionally, we used degenerate primers based on conserved sequences of known proteins to fish out other candidate olfactory genes. We expressed the gene encoding a newly identified pheromone-binding protein, which was analyzed by circular dichroism, fluorescence, and nuclear magnetic resonance, and used in a binding assay to assess affinity to pheromone components. Conclusion We have cloned nine cDNAs encoding olfactory proteins from the navel orangeworm, including two pheromone-binding proteins, two general odorant-binding proteins, one chemosensory protein, one glutathione S-transferase, one antennal binding protein X, one sensory neuron membrane protein, and one odorant receptor. Of these, AtraPBP1 is highly enriched in male antennae. Fluorescence, CD and NMR studies suggest a dramatic pH-dependent conformational change, with high affinity to pheromone constituents at neutral pH and no binding at low pH. PMID:19789654

Synergism between Enantiomers Creates Species-Specific Pheromone Blends and Minimizes Cross-Attraction for Two Species of Cerambycid Beetles.

PubMed

Meier, Linnea R; Zou, Yunfan; Millar, Jocelyn G; Mongold-Diers, Judith A; Hanks, Lawrence M

2016-11-01

Research over the last decade has revealed extensive parsimony among pheromones within the large insect family Cerambycidae, with males of many species producing the same, or very similar aggregation pheromones. Among some species in the subfamily Cerambycinae, interspecific attraction is minimized by temporal segregation, and/or by minor pheromone components that synergize attraction of conspecifics or inhibit attraction of heterospecifics. Less is known about pheromone-based mechanisms of reproductive isolation among species in the largest subfamily, the Lamiinae. Here, we present evidence that the pheromone systems of two sympatric lamiine species consist of synergistic blends of enantiomers of (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol) and the structurally related (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate), as a mechanism by which species-specific blends of pheromone components can minimize interspecific attraction. Male Astylidius parvus (LeConte) were found to produce (R)- and (S)-fuscumol + (R)-fuscumol acetate + geranylacetone, whereas males of Lepturges angulatus (LeConte) produced (R)- and (S)-fuscumol acetate + geranylacetone. Field experiments confirmed that adult beetles were attracted only by their species-specific blend of the enantiomers of fuscumol and fuscumol acetate, respectively, and not to the individual enantiomers. Because other lamiine species are known to produce single enantiomers or blends of enantiomers of fuscumol and/or fuscumol acetate, synergism between enantiomers, or inhibition by enantiomers, may be a widespread mechanism for forming species-specific pheromone blends in this subfamily.

Cloning of the Lentinula edodes B mating-type locus and identification of the genetic structure controlling B mating.

PubMed

Wu, Lin; van Peer, Arend; Song, Wenhua; Wang, Hong; Chen, Mingjie; Tan, Qi; Song, Chunyan; Zhang, Meiyan; Bao, Dapeng

2013-12-01

During the life cycle of heterothallic tetrapolar Agaricomycetes such as Lentinula edodes (Berk.) Pegler, the mating type system, composed of unlinked A and B loci, plays a vital role in controlling sexual development and resulting formation of the fruit body. L. edodes is produced worldwide for consumption and medicinal purposes, and understanding its sexual development is therefore of great importance. A considerable amount of mating type factors has been indicated over the past decades but few genes have actually been identified, and no complete genetic structures of L. edodes B mating-type loci are available. In this study, we cloned the matB regions from two mating compatible L. edodes strains, 939P26 and 939P42. Four pheromone receptors were identified on each new matB region, together with three and four pheromone precursor genes in the respective strains. Gene polymorphism, phylogenetic analysis and distribution of pheromone receptors and pheromone precursors clearly indicate a bipartite matB locus, each sublocus containing a pheromone receptor and one or two pheromone precursors. Detailed sequence comparisons of genetic structures between the matB regions of strains 939P42, 939P26 and a previously reported strain SUP2 further supported this model and allowed identification of the B mating type subloci borders. Mating studies confirmed the control of B mating by the identified pheromone receptors and pheromones in L. edodes. © 2013 Elsevier B.V. All rights reserved.

Functional characterization of sex pheromone receptors in the purple stem borer, Sesamia inferens (Walker).

PubMed

Zhang, Y-N; Zhang, J; Yan, S-W; Chang, H-T; Liu, Y; Wang, G-R; Dong, S-L

2014-10-01

The sex pheromone communication system in moths is highly species-specific and extremely sensitive, and pheromone receptors (PRs) are thought to be the most important factors in males. In the present study, three full-length cDNAs encoding PRs were characterized from Sesamia inferens antennae. These three PRs were all male-specific in expression, but their relative expression levels were very different; SinfOR29 was 17- to 23-fold higher than the other two PRs. Phylogenetic and motif pattern analyses showed that these three PRs were allocated to different PR subfamilies with different motif patterns. Functional analysis using the heterologous expression system of Xenopus oocytes demonstrated that SinfOR29 specifically and sensitively responded to the major pheromone component, Z11-16:OAc [concentration for 50% of maximal effect (EC50 ) = 3.431 × 10(-7) M], while SinfOR21 responded robustly to a minor pheromone component Z11-16:OH (EC50  = 1.087 × 10(-6) M). SinfOR27, however, displayed no response to any of the three pheromone components, but, interestingly, it was sensitive to a non-sex pheromone component Z9,E12-14:OAc (EC50  = 1.522 × 10(-6) M). Our results provide insight into the molecular mechanisms of specificity and sensitivity of the sex pheromone communication system in moths. © 2014 The Royal Entomological Society.

Using pheromones in the management of bark beetle outbreaks

Treesearch

Alf Bakke

1991-01-01

Identification of aggregation pheromones and field experiments using synthetic components have given scientists a better understanding of the behavior of many bark beetles. They have also yielded more effective weapons with which to control outbreaks of aggressive pest species. Synthetic pheromone components are commercially available for control of many species (...

Evolutionary ecology of pheromone signaling in Dendroctonus frontalis

Treesearch

Deepa S. Pureswaran; Brian T. Sullivan; Matthew P. Ayres

2007-01-01

Although studies of pheromone production in the southern pine beetle (Dendroctonus frontalis) extend back to the dawn of chemical ecology, it is only recently that instrumentation has become sufficiently sensitive to measure pheromone production of individual beetles. Now, recent studies have revealed surprisingly high variation among individuals in...

Pheromone-based mating disruption to control the historical top three insect pests of Wisconsin cranberries

USDA-ARS?s Scientific Manuscript database

In 2012, the first 3-species pheromone mating disruption program was tested in Wisconsin cranberries. Preliminary data suggest that there was substantial disruption of blackheaded fireworm and Sparganothis fruitworm mating. The pheromone of cranberry fruitworm only contained a single component, and ...

The volatilization of SPLAT® for use in pheromone mating disruption of cranberry pests

USDA-ARS?s Scientific Manuscript database

The paraffin-based pheromone carrier, SPLAT, was tested for its volatilization rate. A multi-factorial study was initiated to examine the interactive effects of point-source size, shape, and duration. The study showed that tremendous amounts of the pheromone were released early, followed by a gradua...

40 CFR 180.1080 - Plant volatiles and pheromone; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Plant volatiles and pheromone... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1080 Plant volatiles and pheromone; exemptions from the...

40 CFR 180.1080 - Plant volatiles and pheromone; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Plant volatiles and pheromone... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1080 Plant volatiles and pheromone; exemptions from the...

40 CFR 180.1080 - Plant volatiles and pheromone; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Plant volatiles and pheromone... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1080 Plant volatiles and pheromone; exemptions from the...

40 CFR 180.1080 - Plant volatiles and pheromone; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Plant volatiles and pheromone... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1080 Plant volatiles and pheromone; exemptions from the...

Sex pheromones of the southern armyworm moth: isolation, identification, and synthesis.

PubMed

Jacobson, M; Redfern, R E; Jones, W A; Aldridge, M H

1970-10-30

Two sex pheromones have been isolated from the female southern armyworm moth, Prodenia eridania (Cramer), and identified as cis-9-tetradecen-1-ol acetate, identical with the sex pheromone of the fall armyworm moth, Spodoptera frugiperda (J. E. Smith), and cis-9,trans-12-tetradecadien-1-ol acetate.

Just follow your nose: homing by olfactory cues in ants.

PubMed

Steck, Kathrin

2012-04-01

How is an ant-equipped with a brain that barely exceeds the size of a pinhead-capable of achieving navigational marvels? Even though evidences suggest that navigation is a multimodal process, ants heavily depend on olfactory cues-of pheromonal and non-pheromonal nature-for foraging and orientation. Recent studies have directed their attention to the efficiency of pheromone trail networks. Advances in neurophysiological techniques make it possible to investigate trail pheromone processing in the ant's brain. In addition to relying on pheromone odours, ants also make use of volatiles emanating from the nest surroundings. Deposited in the vicinity of the nest, these home-range markings help the ants to home after a foraging run. Furthermore, olfactory landmarks associated with the nest enhance ants' homing abilities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pheromone trailing behavior of the brown tree snake, Boiga irregularis.

PubMed

Greene, M J; Stark, S L; Mason, R T

2001-11-01

The ability of snakes to follow pheromone trails has significant consequences for survival and reproduction. Of particular importance is the ability of snakes to locate conspecifics during the breeding season via the detection of pheromone trails. In this study, the ability of male brown tree snakes (Boiga irregularis), a tropical, rear-fanged colubrid, to follow pheromone trails produced by reproductively active conspecifics was tested in the laboratory by using a Y maze. Males displayed a trailing response to both female and male pheromone trails over blank controls. As males of this species display ritualized combat behavior, these responses likely represent both direct and indirect mechanisms, respectively, for the location of potential mates in the wild. Males did not, however, discriminate between male and female trails when given a choice on the Y maze.

Small-molecule pheromones that control dauer development in Caenorhabditis elegans.

PubMed

Butcher, Rebecca A; Fujita, Masaki; Schroeder, Frank C; Clardy, Jon

2007-07-01

In response to high population density or low food supply, the nematode Caenorhabditis elegans enters an alternative larval stage, known as the dauer, that can withstand adverse conditions for prolonged periods. C. elegans senses its population density through a small-molecule signal, traditionally called the dauer pheromone, that it secretes into its surroundings. Here we show that the dauer pheromone consists of several structurally related ascarosides-derivatives of the dideoxysugar ascarylose-and that two of these ascarosides (1 and 2) are roughly two orders of magnitude more potent at inducing dauer formation than a previously reported dauer pheromone component (3) and constitute a physiologically relevant signal. The identification of dauer pheromone components 1 and 2 will facilitate the identification of target receptors and downstream signaling proteins.

Aggressive reproductive competition among hopelessly queenless honeybee workers triggered by pheromone signaling

NASA Astrophysics Data System (ADS)

Malka, O.; Shnieor, S.; Katzav-Gozansky, T.; Hefetz, A.

2008-06-01

In the honeybee, Apis mellifera, the queen monopolizes reproduction, while the sterile workers cooperate harmoniously in nest maintenance. However, under queenless (QL) conditions, cooperation collapses and reproductive competition among workers ensues. This is mediated through aggression and worker oviposition, as well as shifts in pheromones, from worker to queen-like composition. Many studies suggest a dichotomy between conflict resolution through aggression or through pheromonal signaling. In this paper, we demonstrate that both phenomena comprise essential components of reproductive competition and that pheromone signaling actually triggers the onset of aggression. We kept workers as QL groups until first aggression was observed and subsequently determined the contestants’ reproductive status and content of the mandibular (MG) and Dufour’s glands (DG). In groups in which aggression occurred early, the attacked bee had consistently more queen-like pheromone in both the MG and DG, although both contestants had undeveloped ovaries. In groups with late aggression, the attacked bee had consistently larger oocytes and more queen-like pheromone in the DG, but not the MG. We suggest that at early stages of competition, the MG secretion is utilized to establish dominance and that the DG provides an honest fertility signal. We further argue that it is the higher amount of DG pheromone that triggers aggression.

Social Modulation of Stress Reactivity and Learning in Young Worker Honey Bees

PubMed Central

Mercer, Alison R.

2014-01-01

Alarm pheromone and its major component isopentylacetate induce stress-like responses in forager honey bees, impairing their ability to associate odors with a food reward. We investigated whether isopentylacetate exposure decreases appetitive learning also in young worker bees. While isopentylacetate-induced learning deficits were observed in guards and foragers collected from a queen-right colony, learning impairments resulting from exposure to this pheromone could not be detected in bees cleaning cells. As cell cleaners are generally among the youngest workers in the colony, effects of isopentylacetate on learning behavior were examined further using bees of known age. Adult workers were maintained under laboratory conditions from the time of adult emergence. Fifty percent of the bees were exposed to queen mandibular pheromone during this period, whereas control bees were not exposed to this pheromone. Isopentylacetate-induced learning impairments were apparent in young (less than one week old) controls, but not in bees of the same age exposed to queen mandibular pheromone. This study reveals young worker bees can exhibit a stress-like response to alarm pheromone, but isopentylacetate-induced learning impairments in young bees are suppressed by queen mandibular pheromone. While isopentylacetate exposure reduced responses during associative learning (acquisition), it did not affect one-hour memory retrieval. PMID:25470128

Behavioural evidence of male volatile pheromones in the sex-role reversed wolf spiders Allocosa brasiliensis and Allocosa alticeps

NASA Astrophysics Data System (ADS)

Aisenberg, Anita; Baruffaldi, Luciana; González, Macarena

2010-01-01

The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders.

Two fatty acyl reductases involved in moth pheromone biosynthesis

PubMed Central

Antony, Binu; Ding, Bao-Jian; Moto, Ken’Ichi; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

2016-01-01

Fatty acyl reductases (FARs) constitute an evolutionarily conserved gene family found in all kingdoms of life. Members of the FAR gene family play diverse roles, including seed oil synthesis, insect pheromone biosynthesis, and mammalian wax biosynthesis. In insects, FAR genes dedicated to sex pheromone biosynthesis (pheromone-gland-specific fatty acyl reductase, pgFAR) form a unique clade that exhibits substantial modifications in gene structure and possesses unique specificity and selectivity for fatty acyl substrates. Highly selective and semi-selective ‘single pgFARs’ produce single and multicomponent pheromone signals in bombycid, pyralid, yponomeutid and noctuid moths. An intriguing question is how a ‘single reductase’ can direct the synthesis of several fatty alcohols of various chain lengths and isomeric forms. Here, we report two active pgFARs in the pheromone gland of Spodoptera, namely a semi-selective, C14:acyl-specific pgFAR and a highly selective, C16:acyl-specific pgFAR, and demonstrate that these pgFARs play a pivotal role in the formation of species-specific signals, a finding that is strongly supported by functional gene expression data. The study envisages a new area of research for disclosing evolutionary changes associated with C14- and C16-specific FARs in moth pheromone biosynthesis. PMID:27427355

Host plant volatiles serve to increase the response of male European grape berry moths, Eupoecilia ambiguella, to their sex pheromone.

PubMed

Schmidt-Büsser, Daniela; von Arx, Martin; Guerin, Patrick M

2009-09-01

The European grape berry moth is an important pest in vineyards. Males respond to the female-produced sex pheromone released from a piezo nebulizer in a dose-dependent manner in a wind tunnel: <50% arrive at the source at 5-50 pg/min (underdosed), 80% arrive at 100 pg/min to 10 ng/min (optimal) and <20% arrive at 100 ng/min (overdosed). Males responding to overdosed pheromone show in flight arrestment at 80 cm from the source. Host plant chemostimuli for Eupoecilia ambiguella increase the responses of males to underdosed and overdosed pheromone. (Z)-3-hexen-1-ol, (+)-terpinen-4-ol, (E)-beta-caryophyllene and methyl salicylate released with the underdosed pheromone cause a significant increase in male E. ambiguella flying to the source. Time-event analysis indicates a positive correlation between faster activation and probability of source contact by the responding males. The four host plant compounds added to the overdosed pheromone permitted males to take off faster and with a higher probability of flying to the source. This suggests that perception of host plant products with the sex pheromone facilitates male E. ambiguella to locate females on host plants, lending credence to the hypothesis that plant products can signal rendezvous sites suitable for mating.

The Dynamics of Pheromone Gland Synthesis and Release: a Paradigm Shift for Understanding Sex Pheromone Quantity in Female Moths.

PubMed

Foster, Stephen P; Anderson, Karin G; Casas, Jérôme

2018-05-10

Moths are exemplars of chemical communication, especially with regard to specificity and the minute amounts they use. Yet, little is known about how females manage synthesis and storage of pheromone to maintain release rates attractive to conspecific males and why such small amounts are used. We developed, for the first time, a quantitative model, based on an extensive empirical data set, describing the dynamical relationship among synthesis, storage (titer) and release of pheromone over time in a moth (Heliothis virescens). The model is compartmental, with one major state variable (titer), one time-varying (synthesis), and two constant (catabolism and release) rates. The model was a good fit, suggesting it accounted for the major processes. Overall, we found the relatively small amounts of pheromone stored and released were largely a function of high catabolism rather than a low rate of synthesis. A paradigm shift may be necessary to understand the low amounts released by female moths, away from the small quantities synthesized to the (relatively) large amounts catabolized. Future research on pheromone quantity should focus on structural and physicochemical processes that limit storage and release rate quantities. To our knowledge, this is the first time that pheromone gland function has been modeled for any animal.

ELECTROSPUN MESOFIBERS, A NOVEL BIODEGRADABLE PHEROMONE DISPENSER TECHNOLOGY, ARE COMBINED WITH MECHANICAL DEPLOYMENT FOR EFFICIENT IPM OF LOBESIA BOTRANA IN VINEYARDS.

PubMed

Hummel, Hans E; Langner, S S; Breuer, M

2015-01-01

Behaviour modifying pheromones are well known agents for disrupting mating communication of pest insects. For optimal activity, they must be dispensed in time and space at a quantitatively measurable, predetermined release rate covering the flight period of the target species. Pheromones appeal to environmentally conscientious entomologists for their biodegradability, non-toxicity and ecological compatibility. In attempts of combining the virtues of pheromones, suitable slow release dispensers, and their mechanical deployment, an ecologically sensible, reasonably priced and patented procedure was developed and tested with the vineyard pest Lobesia botrana (Lep.: Tortricidae). It is characterized by (1) Electrospun mesofibers with diameters ranging from 0.6 to 3.5 micrometres, containing disruptants and dispensing it by slow release diffusion into the crop, (2) simultaneous application of the fully biodegradable combination of pheromone with Ecoflex polyester mesofiber, (3) combination of mechanical deployment by multi-purpose cultivators of the prefabricated pheromone dispensers with other simultaneous cultivation measures, and thus further reducing labour time and treatment costs. The dispensers are biodegradable within half a year without leaving any objectionable residues. In the standard eco-toxicology tests pheromone dispensers are harmless to non-target organisms. The disruptive effect of one treatment lasts for seven weeks which covers well one of several flight periods of L. botrana.

Attraction Pheromone of The Benthic Diatom Seminavis robusta: Studies on Structure-Activity Relationships.

PubMed

Lembke, Christine; Stettin, Daniel; Speck, Franziska; Ueberschaar, Nico; De Decker, Sam; Vyverman, Wim; Pohnert, Georg

2018-04-01

Recently the first pheromone of a marine diatom was identified to be the diketopiperazine (S,S)-diproline. This compound facilitates attraction between mating partners in the benthic diatom Seminavis robusta. Interestingly, sexualized S. robusta cells are attracted to both the natural pheromone (S,S)-diproline as well as to its enantiomer (R,R)-diproline. Usually stereospecificity is a prerequisite for successful substrate-receptor interactions, and especially pheromone perception is often highly enantioselective. Here we introduce a structure-activity relationship study, to learn more about the principles of pheromone reception in diatoms. We analyzed the activity of nine different diketopiperazines in attraction and interference assays. The pheromone diproline itself, as well as a pipecolic acid derived diketopiperazine with two expanded aliphatic ring systems, showed the highest attractivity. Hydroxylatoin of the aliphatic rings abolished any bioactivity. Diketopiperazines derived from acyclic amino acids were not attrative as well. All stereoisomers of both the diproline and the pipecolic acid derived diketopiperazine were purified by enantioselective high-performance liquid chromatography, and application in bioactivity tests confirmed that attraction pheromone perception in this diatom is indeed not stereospecific. However, the lack of activity of diketopiperazines derived from acyclic amino acids suggests a specificity that prevents misguidance to sources of other naturally occurring diketopiperazines.

The search for human pheromones: the lost decades and the necessity of returning to first principles

PubMed Central

Wyatt, Tristram D.

2015-01-01

As humans are mammals, it is possible, perhaps even probable, that we have pheromones. However, there is no robust bioassay-led evidence for the widely published claims that four steroid molecules are human pheromones: androstenone, androstenol, androstadienone and estratetraenol. In the absence of sound reasons to test the molecules, positive results in studies need to be treated with scepticism as these are highly likely to be false positives. Common problems include small sample sizes, an overestimate of effect size (as no effect can be expected), positive publication bias and lack of replication. Instead, if we are to find human pheromones, we need to treat ourselves as if we were a newly discovered mammal, and use the rigorous methods already proven successful in pheromone research on other species. Establishing a pheromone relies on demonstration of an odour-mediated behavioural or physiological response, identification and synthesis of the bioactive molecule(s), followed by bioassay confirmation of activity. Likely sources include our sebaceous glands. Comparison of secretions from adult and pre-pubertal humans may highlight potential molecules involved in sexual behaviour. One of the most promising human pheromone leads is a nipple secretion from the areola glands produced by all lactating mothers, which stimulates suckling by any baby not just their own. PMID:25740891

A study of the female produced sex pheromone of Tenebrio molitor (Coleoptera: Tenebrionidae)

NASA Astrophysics Data System (ADS)

Mangat, Jaswinder

Mating behaviour in the yellow mealworm beetle, Tenebrio molitor , is mediated by several pheromones, including the female-produced 4-methylnonanol (4-MNol). Mating causes a decline in the titre of 4-MNol. The overall goal of this study was to determine the biochemical mechanism(s) responsible for this decline: i.e., whether the decline was due to an inhibition of pheromone biosynthesis and/or a stimulation of pheromone degradation; whether the decline was caused by the physical effect of mating or was due to the transfer of a factor from the male; and to conduct a preliminary investigation of the regulatory and signal transduction mechanisms involved in the regulation of 4-MNol production. In vitro radioassays for 4-MNol biosynthesis and degradation were developed and used to compare the levels of 4-MNol biosynthesis and degradation in virgin and mated females. Mating caused an inhibition of 4-MNol biosynthesis within 2 hours, but did not affect the rate of pheromone degradation. Decapitation of virgin females caused an inhibition of pheromone biosynthesis and did not prevent the inhibitory effect of mating. The inhibitory effect of mating was mimicked in females that were artificially inseminated with male reproductive tract homogenates (MRTH), but not in females similarly "inseminated" with water, saline, or air. Furthermore, 4-MNol biosynthesis could be inhibited in vitro by the addition of MRTH. These findings indicate that the male transferred one or more pheromonostatic factor(s) to the female during copulation that acted directly on the pheromone-producing tissue (the ovaries). In order to investigate the biochemical basis for the inhibition of pheromone biosynthesis after mating, the role of calcium was determined by modulating the level of calcium (using a calcium chelator, an ionophore, and calcium). However, due to the precipitation of calcium with the phosphate present in the buffer solution, we were unable to determine the role of calcium in the regulation of pheromone biosynthesis in mature mated and virgin beetles. Further work is required to elucidate the biochemical basis for the inhibition of pheromone biosynthesis. Understanding the regulation of sex pheromone biosynthesis in this model organism will enhance our understanding of the process in beetles in general, and may (in the long term) lead to new pest control strategies.

Outcomes of Brood Parasite–Host Interactions Mediated by Egg Matching: Common Cuckoos Cuculus canorus versus Fringilla Finches

PubMed Central

Vikan, Johan Reinert; Fossøy, Frode; Huhta, Esa; Moksnes, Arne; Røskaft, Eivin; Stokke, Bård Gunnar

2011-01-01

Background Antagonistic species often interact via matching of phenotypes, and interactions between brood parasitic common cuckoos (Cuculus canorus) and their hosts constitute classic examples. The outcome of a parasitic event is often determined by the match between host and cuckoo eggs, giving rise to potentially strong associations between fitness and egg phenotype. Yet, empirical efforts aiming to document and understand the resulting evolutionary outcomes are in short supply. Methods/Principal Findings We used avian color space models to analyze patterns of egg color variation within and between the cuckoo and two closely related hosts, the nomadic brambling (Fringilla montifringilla) and the site fidelic chaffinch (F. coelebs). We found that there is pronounced opportunity for disruptive selection on brambling egg coloration. The corresponding cuckoo host race has evolved egg colors that maximize fitness in both sympatric and allopatric brambling populations. By contrast, the chaffinch has a more bimodal egg color distribution consistent with the evolutionary direction predicted for the brambling. Whereas the brambling and its cuckoo host race show little geographical variation in their egg color distributions, the chaffinch's distribution becomes increasingly dissimilar to the brambling's distribution towards the core area of the brambling cuckoo host race. Conclusion High rates of brambling gene flow is likely to cool down coevolutionary hot spots by cancelling out the selection imposed by a patchily distributed cuckoo host race, thereby promoting a matching equilibrium. By contrast, the site fidelic chaffinch is more likely to respond to selection from adapting cuckoos, resulting in a markedly more bimodal egg color distribution. The geographic variation in the chaffinch's egg color distribution could reflect a historical gradient in parasitism pressure. Finally, marked cuckoo egg polymorphisms are unlikely to evolve in these systems unless the hosts evolve even more exquisite egg recognition capabilities than currently possessed. PMID:21559400

Sex Pheromone Receptor Specificity in the European Corn Borer Moth, Ostrinia nubilalis

PubMed Central

Wanner, Kevin W.; Nichols, Andrew S.; Allen, Jean E.; Bunger, Peggy L.; Garczynski, Stephen F.; Linn, Charles E.; Robertson, Hugh M.; Luetje, Charles W.

2010-01-01

Background The European corn borer (ECB), Ostrinia nubilalis (Hubner), exists as two separate sex pheromone races. ECB(Z) females produce a 97∶3 blend of Z11- and E11-tetradecenyl acetate whereas ECB(E) females produce an opposite 1∶99 ratio of the Z and E isomers. Males of each race respond specifically to their conspecific female's blend. A closely related species, the Asian corn borer (ACB), O. furnacalis, uses a 3∶2 blend of Z12- and E12-tetradecenyl acetate, and is believed to have evolved from an ECB-like ancestor. To further knowledge of the molecular mechanisms of pheromone detection and its evolution among closely related species we identified and characterized sex pheromone receptors from ECB(Z). Methodology Homology-dependent (degenerate PCR primers designed to conserved amino acid motifs) and homology-independent (pyrophosphate sequencing of antennal cDNA) approaches were used to identify candidate sex pheromone transcripts. Expression in male and female antennae was assayed by quantitative real-time PCR. Two-electrode voltage clamp electrophysiology was used to functionally characterize candidate receptors expressed in Xenopus oocytes. Conclusion We characterized five sex pheromone receptors, OnOrs1 and 3–6. Their transcripts were 14–100 times more abundant in male compared to female antennae. OnOr6 was highly selective for Z11-tetradecenyl acetate (EC50 = 0.86±0.27 µM) and was at least three orders of magnitude less responsive to E11-tetradecenyl acetate. Surprisingly, OnOr1, 3 and 5 responded to all four pheromones tested (Z11- and E11-tetradecenyl acetate, and Z12- and E12-tetradecenyl acetate) and to Z9-tetradecenyl acetate, a behavioral antagonist. OnOr1 was selective for E12-tetradecenyl acetate based on an efficacy that was at least 5-fold greater compared to the other four components. This combination of specifically- and broadly-responsive pheromone receptors corresponds to published results of sensory neuron activity in vivo. Receptors broadly-responsive to a class of pheromone components may provide a mechanism for variation in the male moth response that enables population level shifts in pheromone blend use. PMID:20084285

Temperature limits trail following behaviour through pheromone decay in ants

NASA Astrophysics Data System (ADS)

van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

2011-12-01

In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures.

Disposable Polydimethylsiloxane (PDMS)-Coated Fused Silica Optical Fibers for Sampling Pheromones of Moths.

PubMed

Lievers, Rik; Groot, Astrid T

2016-01-01

In the past decades, the sex pheromone composition in female moths has been analyzed by different methods, ranging from volatile collections to gland extractions, which all have some disadvantage: volatile collections can generally only be conducted on (small) groups of females to detect the minor pheromone compounds, whereas gland extractions are destructive. Direct-contact SPME overcomes some of these disadvantages, but is expensive, the SPME fiber coating can be damaged due to repeated usage, and samples need to be analyzed relatively quickly after sampling. In this study, we assessed the suitability of cheap and disposable fused silica optical fibers coated with 100 μm polydimethylsiloxane (PDMS) by sampling the pheromone of two noctuid moths, Heliothis virescens and Heliothis subflexa. By rubbing the disposable PDMS fibers over the pheromone glands of females that had called for at least 15 minutes and subsequently extracting the PDMS fibers in hexane, we collected all known pheromone compounds, and we found a strong positive correlation for most pheromone compounds between the disposable PDMS fiber rubs and the corresponding gland extracts of the same females. When comparing this method to volatile collections and the corresponding gland extracts, we generally found comparable percentages between the three techniques, with some differences that likely stem from the chemical properties of the individual pheromone compounds. Hexane extraction of cheap, disposable, PDMS coated fused silica optical fibers allows for sampling large quantities of individual females in a short time, eliminates the need for immediate sample analysis, and enables to use the same sample for multiple chemical analyses.

Disposable Polydimethylsiloxane (PDMS)-Coated Fused Silica Optical Fibers for Sampling Pheromones of Moths

PubMed Central

Lievers, Rik; Groot, Astrid T.

2016-01-01

In the past decades, the sex pheromone composition in female moths has been analyzed by different methods, ranging from volatile collections to gland extractions, which all have some disadvantage: volatile collections can generally only be conducted on (small) groups of females to detect the minor pheromone compounds, whereas gland extractions are destructive. Direct-contact SPME overcomes some of these disadvantages, but is expensive, the SPME fiber coating can be damaged due to repeated usage, and samples need to be analyzed relatively quickly after sampling. In this study, we assessed the suitability of cheap and disposable fused silica optical fibers coated with 100 μm polydimethylsiloxane (PDMS) by sampling the pheromone of two noctuid moths, Heliothis virescens and Heliothis subflexa. By rubbing the disposable PDMS fibers over the pheromone glands of females that had called for at least 15 minutes and subsequently extracting the PDMS fibers in hexane, we collected all known pheromone compounds, and we found a strong positive correlation for most pheromone compounds between the disposable PDMS fiber rubs and the corresponding gland extracts of the same females. When comparing this method to volatile collections and the corresponding gland extracts, we generally found comparable percentages between the three techniques, with some differences that likely stem from the chemical properties of the individual pheromone compounds. Hexane extraction of cheap, disposable, PDMS coated fused silica optical fibers allows for sampling large quantities of individual females in a short time, eliminates the need for immediate sample analysis, and enables to use the same sample for multiple chemical analyses. PMID:27533064

Reactive Searching and Infotaxis in Odor Source Localization

PubMed Central

Voges, Nicole; Chaffiol, Antoine; Lucas, Philippe; Martinez, Dominique

2014-01-01

Male moths aiming to locate pheromone-releasing females rely on stimulus-adapted search maneuvers complicated by a discontinuous distribution of pheromone patches. They alternate sequences of upwind surge when perceiving the pheromone and cross- or downwind casting when the odor is lost. We compare four search strategies: three reactive versus one cognitive. The former consist of pre-programmed movement sequences triggered by pheromone detections while the latter uses Bayesian inference to build spatial probability maps. Based on the analysis of triphasic responses of antennal lobe neurons (On, inhibition, Off), we propose three reactive strategies. One combines upwind surge (representing the On response to a pheromone detection) and spiral casting, only. The other two additionally include crosswind (zigzag) casting representing the Off phase. As cognitive strategy we use the infotaxis algorithm which was developed for searching in a turbulent medium. Detection events in the electroantennogram of a moth attached to a robot indirectly control this cyborg, depending on the strategy in use. The recorded trajectories are analyzed with regard to success rates, efficiency, and other features. In addition, we qualitatively compare our robotic trajectories to behavioral search paths. Reactive searching is more efficient (yielding shorter trajectories) for higher pheromone doses whereas cognitive searching works better for lower doses. With respect to our experimental conditions (2 m from starting position to pheromone source), reactive searching with crosswind zigzag yields the shortest trajectories (for comparable success rates). Assuming that the neuronal Off response represents a short-term memory, zigzagging is an efficient movement to relocate a recently lost pheromone plume. Accordingly, such reactive strategies offer an interesting alternative to complex cognitive searching. PMID:25330317

Reactive searching and infotaxis in odor source localization.

PubMed

Voges, Nicole; Chaffiol, Antoine; Lucas, Philippe; Martinez, Dominique

2014-10-01

Male moths aiming to locate pheromone-releasing females rely on stimulus-adapted search maneuvers complicated by a discontinuous distribution of pheromone patches. They alternate sequences of upwind surge when perceiving the pheromone and cross- or downwind casting when the odor is lost. We compare four search strategies: three reactive versus one cognitive. The former consist of pre-programmed movement sequences triggered by pheromone detections while the latter uses Bayesian inference to build spatial probability maps. Based on the analysis of triphasic responses of antennal lobe neurons (On, inhibition, Off), we propose three reactive strategies. One combines upwind surge (representing the On response to a pheromone detection) and spiral casting, only. The other two additionally include crosswind (zigzag) casting representing the Off phase. As cognitive strategy we use the infotaxis algorithm which was developed for searching in a turbulent medium. Detection events in the electroantennogram of a moth attached to a robot indirectly control this cyborg, depending on the strategy in use. The recorded trajectories are analyzed with regard to success rates, efficiency, and other features. In addition, we qualitatively compare our robotic trajectories to behavioral search paths. Reactive searching is more efficient (yielding shorter trajectories) for higher pheromone doses whereas cognitive searching works better for lower doses. With respect to our experimental conditions (2 m from starting position to pheromone source), reactive searching with crosswind zigzag yields the shortest trajectories (for comparable success rates). Assuming that the neuronal Off response represents a short-term memory, zigzagging is an efficient movement to relocate a recently lost pheromone plume. Accordingly, such reactive strategies offer an interesting alternative to complex cognitive searching.

Evolution of multicomponent pheromone signals in small ermine moths involves a single fatty-acyl reductase gene

PubMed Central

Liénard, Marjorie A.; Hagström, Åsa K.; Lassance, Jean-Marc; Löfstedt, Christer

2010-01-01

Fatty-acyl CoA reductases (FAR) convert fatty acids into fatty alcohols in pro- and eukaryotic organisms. In the Lepidoptera, members of the FAR gene family serve in the biosynthesis of sex pheromones involved in mate communication. We used a group of closely related species, the small ermine moths (Lepidoptera: Yponomeutidae) as a model to investigate the role of FARs in the biosynthesis of complex pheromone blends. Homology-based molecular cloning in three Yponomeuta species led to the identification of multiple putative FAR transcripts homologous to FAR genes from the Bombyx mori genome. The expression of one transcript was restricted to the female pheromone-gland tissue, suggesting a role in pheromone biosynthesis, and the encoded protein belonged to a recently identified Lepidoptera-specific pgFAR gene subfamily. The Yponomeuta evonymellus pgFAR mRNA was up-regulated in sexually mature females and exhibited a 24-h cyclic fluctuation pattern peaking in the pheromone production period. Heterologous expression confirmed that the Yponomeuta pgFAR orthologs in all three species investigated [Y. evonymellus (L.), Yponomeuta padellus (L.), and Yponomeuta rorellus (Hübner)] encode a functional FAR with a broad substrate range that efficiently promoted accumulation of primary alcohols in recombinant yeast supplied with a series of biologically relevant C14- or C16-acyl precursors. Taken together, our data evidence that a single alcohol-producing pgFAR played a critical function in the production of the multicomponent pheromones of yponomeutids and support the hypothesis of moth pheromone-biosynthetic FARs belonging to a FAR gene subfamily unique to Lepidoptera. PMID:20534481

Individual Rules for Trail Pattern Formation in Argentine Ants (Linepithema humile)

PubMed Central

Perna, Andrea; Granovskiy, Boris; Garnier, Simon; Nicolis, Stamatios C.; Labédan, Marjorie; Theraulaz, Guy; Fourcassié, Vincent; Sumpter, David J. T.

2012-01-01

We studied the formation of trail patterns by Argentine ants exploring an empty arena. Using a novel imaging and analysis technique we estimated pheromone concentrations at all spatial positions in the experimental arena and at different times. Then we derived the response function of individual ants to pheromone concentrations by looking at correlations between concentrations and changes in speed or direction of the ants. Ants were found to turn in response to local pheromone concentrations, while their speed was largely unaffected by these concentrations. Ants did not integrate pheromone concentrations over time, with the concentration of pheromone in a 1 cm radius in front of the ant determining the turning angle. The response to pheromone was found to follow a Weber's Law, such that the difference between quantities of pheromone on the two sides of the ant divided by their sum determines the magnitude of the turning angle. This proportional response is in apparent contradiction with the well-established non-linear choice function used in the literature to model the results of binary bridge experiments in ant colonies (Deneubourg et al. 1990). However, agent based simulations implementing the Weber's Law response function led to the formation of trails and reproduced results reported in the literature. We show analytically that a sigmoidal response, analogous to that in the classical Deneubourg model for collective decision making, can be derived from the individual Weber-type response to pheromone concentrations that we have established in our experiments when directional noise around the preferred direction of movement of the ants is assumed. PMID:22829756

Sexual dimorphism of bed bug (Cimex lectularis) attraction and aggregation responses to cuticular extracts from nymph exuviae

USDA-ARS?s Scientific Manuscript database

A large variety of releaser pheromones are used by insects to attract or disperse conspecifics, while group cohesion is often influenced by primer pheromones that induce behavioral or physiological changes. Differentiating the roles of such pheromones in insect taxa displaying intermediate levels of...

Interspecific Responses of Termites to Synthetic Trail-Following Pheromones.

DTIC Science & Technology

Various synthetic analogs of the trail-following pheromone were tested against several subterranean and dry- and damp-wood termites . The synthetic... pheromones were found to be generally active against subterranean termites , both under laboratory and semi-field conditions. One of the most active compounds, 4-phenyl-cis-3-butanol, can be synthesized easily. (Author)

Spatial displacement of release point can enhance activity of an attractant pheromone synergist of a bark beetle.

Treesearch

Brian Sullivan; Kenji Mori

2009-01-01

Flight responses of the southern pine beetle, Dendroctonus frontalis Zimmermann, to widely-spaced (>130 m) traps baited with pine volatiles (in turpentine) and the female-produced pheromone component frontalin were enhanced when a bait containing the male pheromone component (+)-endo-brevicomin was attached...

Molecular markers for identification of Hessian fly males caught on pheromone traps

USDA-ARS?s Scientific Manuscript database

Pheromone traps have been widely used to monitor insect populations in nature. However, pheromone traps for the Hessian fly (Mayetiola destructor), one of the most destructive insect pests of wheat, have been used only in recent years. Because Hessian fly male adults are small and fragile, it is d...

Synthetic analogs of the trail pheromone of the leaf-cutting ant, Atta texana (Buckley)

Treesearch

Philip E. Sonnet; John C. Moser

1972-01-01

The preparation and bioassay of a number of analogs of the trail-following pheromone of the town ant, Atta texana (Buckley), are described. Although several compounds were quite active, isomers of the pheromone were not. The results are discussed wit ha vew to the probable conformations of these molecules.

Gqalpha-linked PLCbeta and PLCgamma are essential components of the pheromone biosynthesis activating neuropeptide (PBAN) signal transduction cascade

USDA-ARS?s Scientific Manuscript database

Sex pheromone production for most moths is regulated by pheromone biosynthesis activating neuropeptide (PBAN). In Bombyx mori, PBAN binding triggers the opening of store-operated Ca2+ channels, suggesting the involvement of a receptor-activated phospholipase C (PLC). In this study, we found that P...

Field Comparison of Spruce Budworm Pheromone Lures

Treesearch

David G. Grimble

1987-01-01

Four types of spruce budworm pheromone lures were tested to compare field longevity and efficiency. Biolures with three different pheromone release rates and Silk-PVC lures all caught male budworm moths throughout the moth flight period in proportion to the different release rates. Fumigant strips in traps to kill trapped moths were necessary.

40 CFR 158.2000 - Biochemical pesticides definition and applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... history; and (iii) Has a non-toxic mode of action to the target pest(s). (2) A Pheromone is a compound... compounds, modifies the behavior of other individuals of the same species. (i) An Arthropod Pheromone is a... to: (1) Semiochemicals (insect pheromones and kairomones), (2) Natural plant and insect regulators...

40 CFR 158.2000 - Biochemical pesticides definition and applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... history; and (iii) Has a non-toxic mode of action to the target pest(s). (2) A Pheromone is a compound... compounds, modifies the behavior of other individuals of the same species. (i) An Arthropod Pheromone is a... to: (1) Semiochemicals (insect pheromones and kairomones), (2) Natural plant and insect regulators...

40 CFR 158.2000 - Biochemical pesticides definition and applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... history; and (iii) Has a non-toxic mode of action to the target pest(s). (2) A Pheromone is a compound... compounds, modifies the behavior of other individuals of the same species. (i) An Arthropod Pheromone is a... to: (1) Semiochemicals (insect pheromones and kairomones), (2) Natural plant and insect regulators...

Mixtures of Two Bile Alcohol Sulfates Function as a Proximity Pheromone in Sea Lamprey.

PubMed

Brant, Cory O; Huertas, Mar; Li, Ke; Li, Weiming

2016-01-01

Unique mixtures of pheromone components are commonly identified in insects, and have been shown to increase attractiveness towards conspecifics when reconstructed at the natural ratio released by the signaler. In previous field studies of pheromones that attract female sea lamprey (Petromyzon marinus, L.), putative components of the male-released mating pheromone included the newly described bile alcohol 3,12-diketo-4,6-petromyzonene-24-sulfate (DkPES) and the well characterized 3-keto petromyzonol sulfate (3kPZS). Here, we show chemical evidence that unequivocally confirms the elucidated structure of DkPES, electrophysiological evidence that each component is independently detected by the olfactory epithelium, and behavioral evidence that mature female sea lamprey prefer artificial nests activated with a mixture that reconstructs the male-released component ratio of 30:1 (3kPZS:DkPES, molar:molar). In addition, we characterize search behavior (sinuosity of swim paths) of females approaching ratio treatment sources. These results suggest unique pheromone ratios may underlie reproductive isolating mechanisms in vertebrates, as well as provide utility in pheromone-integrated control of invasive sea lamprey in the Great Lakes.

Identification of the sex pheromone of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) from Asunción, Paraguay.

PubMed

Brazil, Reginaldo P; Caballero, Norath Natalia; Hamilton, James Gordon C

2009-11-02

The sand fly Lutzomyia longipalpis is the main vector of Leishmania (L.) infantum (Nicolle), the causative agent of American visceral leishmaniasis (AVL) in the New World. Male Lu. longipalpis have secretory glands which produce sex pheromones in either abdominal tergites 4 or 3 and 4. These glands are sites of sex pheromone production and each pheromone type may represent true sibling species. In Latin America, apart from Lu. pseudolongipalpis Arrivillaga and Feliciangeli from Venezuela, populations of Lu. longipalpis s.l. can be identified by their male-produced sex pheromones: (S)-9-methylgermacrene-B, 3-methyl-alpha-himachalene and the two cembrenes, 1 and 2.In this study, we present the results of a coupled gas chromatography - mass spectrometry analysis of the pheromones of males Lu. longipalpis captured in an endemic area of visceral leishmaniasis in Asunción, Paraguay. Our results show that Lu. longipalpis from this site produce (S)-9-methylgermacrene-B which has also been found in Lu. longipalpis from different areas of Brazil, Colombia and Central America.

Pheromonal Communication in the European House Dust Mite, Dermatophagoides pteronyssinus

PubMed Central

Steidle, Johannes L.M.; Barcari, Elena; Hradecky, Marc; Trefz, Simone; Tolasch, Till; Gantert, Cornelia; Schulz, Stefan

2014-01-01

Despite the sanitary importance of the European house dust mite Dermatophagoides pteronyssinus (Trouessart, 1897), the pheromonal communication in this species has not been sufficiently studied. Headspace analysis using solid phase micro extraction (SPME) revealed that nerol, neryl formate, pentadecane, (6Z,9Z)-6,9-heptadecadiene, and (Z)-8-heptadecene are released by both sexes whereas neryl propionate was released by males only. Tritonymphs did not produce any detectable volatiles. In olfactometer experiments, pentadecane and neryl propionate were attractive to both sexes as well as to tritonymphs. (Z)-8-heptadecene was only attractive to male mites. Therefore it is discussed that pentadecane and neryl propionate are aggregation pheromones and (Z)-8-heptadecene is a sexual pheromone of the European house dust mite D. pteronyssinus. To study the potential use of pheromones in dust mite control, long-range olfactometer experiments were conducted showing that mites can be attracted to neryl propionate over distances of at least 50 cm. This indicates that mite pheromones might be useable to monitor the presence or absence of mites in the context of control strategies. PMID:26462831

Effects of a Caenorhabditis elegans dauer pheromone ascaroside on physiology and signal transduction pathways.

PubMed

Gallo, Marco; Riddle, Donald L

2009-02-01

Daumone is one of the three purified and artificially synthesized components of the Caenorhabditis elegans dauer pheromone. It affects the major signal transduction pathways known to discriminate between developmental arrest at the dauer stage and growth to the adult [the transforming growth factor beta (TGF-beta) and daf-2/IGF1R pathways], just as natural pheromone extracts do. Transcription of daf-7/TGF-beta is reduced in pre-dauer larvae, and nuclear localization of the DAF-16/FOXO transcription factor is increased in embryos and L1 larvae exposed to synthetic daumone. However, daumone does not require the cilia in the amphidial neurons to produce these effects nor does it require the Galpha protein GPA-3 to induce dauer entry, although GPA-3 is required for dauer induction by natural dauer pheromone extracts. Synthetic daumone has physiological effects that have not been observed with natural pheromone. It is toxic at the concentrations required for bioassay and is lethal to mutants with defective cuticles. The molecular and physiological effects of daumone and natural dauer pheromone are only partially overlapping.

Identification of the sex pheromone of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) from Asunción, Paraguay

PubMed Central

Brazil, Reginaldo P; Caballero, Norath Natalia; Hamilton, James Gordon C

2009-01-01

The sand fly Lutzomyia longipalpis is the main vector of Leishmania (L.) infantum (Nicolle), the causative agent of American visceral leishmaniasis (AVL) in the New World. Male Lu. longipalpis have secretory glands which produce sex pheromones in either abdominal tergites 4 or 3 and 4. These glands are sites of sex pheromone production and each pheromone type may represent true sibling species. In Latin America, apart from Lu. pseudolongipalpis Arrivillaga and Feliciangeli from Venezuela, populations of Lu. longipalpis s.l. can be identified by their male-produced sex pheromones: (S)-9-methylgermacrene-B, 3-methyl-α-himachalene and the two cembrenes, 1 and 2. In this study, we present the results of a coupled gas chromatography - mass spectrometry analysis of the pheromones of males Lu. longipalpis captured in an endemic area of visceral leishmaniasis in Asunción, Paraguay. Our results show that Lu. longipalpis from this site produce (S)-9-methylgermacrene-B which has also been found in Lu. longipalpis from different areas of Brazil, Colombia and Central America. PMID:19883505

Disulfide connectivity and reduction in pheromone-binding proteins of the gypsy moth, Lymantria dispar

NASA Astrophysics Data System (ADS)

Honson, Nicolette S.; Plettner, Erika

2006-06-01

Males of the gypsy moth, Lymantria dispar, are attracted by a pheromone released by females. Pheromones are detected by olfactory neurons housed in specialized sensory hairs located on the antennae of the male moth. Once pheromone molecules enter the sensilla lymph, a highly abundant pheromone-binding protein (PBP) transports the molecule to the sensory neuron. The PBPs are members of the insect odorant-binding protein family, with six conserved cysteine residues. In this study, the disulfide bond connectivities of the pheromone-binding proteins PBP1 and PBP2 from the gypsy moth were found to be cysteines 19-54, 50-109, and 97-118 for PBP1, and cysteines 19-54, 50-110, and 97-119 for PBP2, as determined by cyanylation reactions and cyanogen bromide chemical cleavage. We have discovered that the second disulfide linkage is the most easily reduced of the three, and this same linkage is missing among four cysteine-containing insect odorant-binding proteins (OBPs). We are the first to identify the unique steric and electronic properties of this second disulfide linkage.

Multiphasic On/Off Pheromone Signalling in Moths as Neural Correlates of a Search Strategy

PubMed Central

Martinez, Dominique; Chaffiol, Antoine; Voges, Nicole; Gu, Yuqiao; Anton, Sylvia; Rospars, Jean-Pierre; Lucas, Philippe

2013-01-01

Insects and robots searching for odour sources in turbulent plumes face the same problem: the random nature of mixing causes fluctuations and intermittency in perception. Pheromone-tracking male moths appear to deal with discontinuous flows of information by surging upwind, upon sensing a pheromone patch, and casting crosswind, upon losing the plume. Using a combination of neurophysiological recordings, computational modelling and experiments with a cyborg, we propose a neuronal mechanism that promotes a behavioural switch between surge and casting. We show how multiphasic On/Off pheromone-sensitive neurons may guide action selection based on signalling presence or loss of the pheromone. A Hodgkin-Huxley-type neuron model with a small-conductance calcium-activated potassium (SK) channel reproduces physiological On/Off responses. Using this model as a command neuron and the antennae of tethered moths as pheromone sensors, we demonstrate the efficiency of multiphasic patterning in driving a robotic searcher toward the source. Taken together, our results suggest that multiphasic On/Off responses may mediate olfactory navigation and that SK channels may account for these responses. PMID:23613816

Multiphasic on/off pheromone signalling in moths as neural correlates of a search strategy.

PubMed

Martinez, Dominique; Chaffiol, Antoine; Voges, Nicole; Gu, Yuqiao; Anton, Sylvia; Rospars, Jean-Pierre; Lucas, Philippe

2013-01-01

Insects and robots searching for odour sources in turbulent plumes face the same problem: the random nature of mixing causes fluctuations and intermittency in perception. Pheromone-tracking male moths appear to deal with discontinuous flows of information by surging upwind, upon sensing a pheromone patch, and casting crosswind, upon losing the plume. Using a combination of neurophysiological recordings, computational modelling and experiments with a cyborg, we propose a neuronal mechanism that promotes a behavioural switch between surge and casting. We show how multiphasic On/Off pheromone-sensitive neurons may guide action selection based on signalling presence or loss of the pheromone. A Hodgkin-Huxley-type neuron model with a small-conductance calcium-activated potassium (SK) channel reproduces physiological On/Off responses. Using this model as a command neuron and the antennae of tethered moths as pheromone sensors, we demonstrate the efficiency of multiphasic patterning in driving a robotic searcher toward the source. Taken together, our results suggest that multiphasic On/Off responses may mediate olfactory navigation and that SK channels may account for these responses.

The Egg Man and the Empress

ERIC Educational Resources Information Center

Smith, Dennis R.

2005-01-01

In this article, the author compares the legacies of two remarkable educators--John Dewey and Maria Montessori. These include changes in education now so commonplace that is accepted as traditional. Both Montessori and Dewey lived long enough to see their ideas receive worldwide recognition and acceptance, along with a share of misunderstanding…

An integrative approach to unravel the Ceratitis FAR (Diptera, Tephritidae) cryptic species complex: a review

PubMed Central

De Meyer, Marc; Delatte, Hélène; Ekesi, Sunday; Jordaens, Kurt; Kalinová, Blanka; Manrakhan, Aruna; Mwatawala, Maulid; Steck, Gary; Van Cann, Joannes; Vaníčková, Lucie; Břízová, Radka; Virgilio, Massimiliano

2015-01-01

Abstract This paper reviews all information gathered from different disciplines and studies to resolve the species status within the Ceratitis FAR (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa) complex, a group of polyphagous fruit fly pest species (Diptera, Tephritidae) from Africa. It includes information on larval and adult morphology, wing morphometrics, cuticular hydrocarbons, pheromones, microsatellites, developmental physiology and geographic distribution. The general consensus is that the FAR complex comprises Ceratitis anonae, two species within Ceratitis rosa (so-called R1 and R2) and two putatitve species under Ceratitis fasciventris. The information regarding the latter is, however, too limited to draw final conclusions on specific status. Evidence for this recognition is discussed with reference to publications providing further details. PMID:26798270

Structure of Peptide Sex Pheromone Receptor PrgX and PrgX/Pheromone Complexes and Regulation of Conjugation in Enterococcus faecalis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi,K.; Brown, C.; Gu, Z.

2005-01-01

Many bacterial activities, including expression of virulence factors, horizontal genetic transfer, and production of antibiotics, are controlled by intercellular signaling using small molecules. To date, understanding of the molecular mechanisms of peptide-mediated cell-cell signaling has been limited by a dearth of published information about the molecular structures of the signaling components. Here, we present the molecular structure of PrgX, a DNA- and peptide-binding protein that regulates expression of the conjugative transfer genes of the Enterococcus faecalis plasmid pCF10 in response to an intercellular peptide pheromone signal. Comparison of the structures of PrgX and the PrgX/pheromone complex suggests that pheromone bindingmore » destabilizes PrgX tetramers, opening a 70-bp pCF10 DNA loop required for conjugation repression.« less

The joy of sex pheromones

PubMed Central

Gomez-Diaz, Carolina; Benton, Richard

2013-01-01

Sex pheromones provide an important means of communication to unite individuals for successful reproduction. Although sex pheromones are highly diverse across animals, these signals fulfil common fundamental roles in enabling identification of a mating partner of the opposite sex, the appropriate species and of optimal fecundity. In this review, we synthesize both classic and recent investigations on sex pheromones in a range of species, spanning nematode worms, insects and mammals. These studies reveal comparable strategies in how these chemical signals are produced, detected and processed in the brain to regulate sexual behaviours. Elucidation of sex pheromone communication mechanisms both defines outstanding models to understand the molecular and neuronal basis of chemosensory behaviours, and reveals how similar evolutionary selection pressures yield convergent solutions in distinct animal nervous systems. EMBO reports advance online publication 13 September 2013; doi:10.1038/embor.2013.140 PMID:24030282

Site of pheromone biosynthesis and isolation of HMG-CoA reductase cDNA in the cotton boll weevil, Anthonomus grandis.

PubMed

Taban, A Huma; Fu, Jessica; Blake, Jacob; Awano, Ami; Tittiger, Claus; Blomquist, Gary J

2006-08-01

Isolated gut tissue from male cotton boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), incorporated radiolabeled acetate into components that co-eluted with monoterpenoid pheromone components on HPLC. This demonstrates that pheromone components of male A. grandis are produced de novo and strongly suggests that pheromone biosynthesis occurs in gut tissue. A central enzyme in isoprenoid biosynthesis is 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-R), and a full-length HMG-R cDNA was isolated from A. grandis. The predicted translation product was 54 and 45% identical to HMG-R from Ips paraconfusus and Drosophila melanogaster, respectively. HMG-R gene expression gradually increased with age in male A. grandis, which correlates with pheromone production. However, topical application of JH III did not significantly increase HMG-R mRNA levels.

Finite grade pheromone ant colony optimization for image segmentation

NASA Astrophysics Data System (ADS)

Yuanjing, F.; Li, Y.; Liangjun, K.

2008-06-01

By combining the decision process of ant colony optimization (ACO) with the multistage decision process of image segmentation based on active contour model (ACM), an algorithm called finite grade ACO (FACO) for image segmentation is proposed. This algorithm classifies pheromone into finite grades and updating of the pheromone is achieved by changing the grades and the updated quantity of pheromone is independent from the objective function. The algorithm that provides a new approach to obtain precise contour is proved to converge to the global optimal solutions linearly by means of finite Markov chains. The segmentation experiments with ultrasound heart image show the effectiveness of the algorithm. Comparing the results for segmentation of left ventricle images shows that the ACO for image segmentation is more effective than the GA approach and the new pheromone updating strategy appears good time performance in optimization process.

Sex-pairing pheromone in the Asian termite pest species Odontotermes formosanus.

PubMed

Wen, Ping; Ji, Bao-Zhong; Liu, Shu-Wen; Liu, Cong; Sillam-Dussès, David

2012-05-01

The sex-pairing pheromone of the black winged subterranean termite, Odontotermes formosanus (Shiraki) (Isoptera, Termitidae), was investigated using headspace-SPME, GC-MS, GC-EAD, and attraction bioassays. Females secrete the pheromone from their sternal gland to attract males. The sex-pairing pheromone is composed of (Z,Z)-dodeca-3,6-dien-1-ol and (Z)-dodec-3-en-1-ol, estimated at 9 to 16.64 ng and 0.2 to 0.54 ng, respectively. Both short- and long-distance sex attraction bioassays were employed to show that these compounds act in synergy at long distance, but only (Z,Z)-dodeca-3,6-dien-1-ol is active at short distance. The pheromone may be useful in efforts to control this pest, which is considered one of the most harmful termite species in Southeast Asia.

In Search for Pheromone Receptors: Certain Members of the Odorant Receptor Family in the Desert Locust Schistocerca gregaria (Orthoptera: Acrididae) Are Co-expressed with SNMP1.

PubMed

Pregitzer, Pablo; Jiang, Xingcong; Grosse-Wilde, Ewald; Breer, Heinz; Krieger, Jürgen; Fleischer, Joerg

2017-01-01

Under given environmental conditions, the desert locust ( Schistocera gregaria ) forms destructive migratory swarms of billions of animals, leading to enormous crop losses in invaded regions. Swarm formation requires massive reproduction as well as aggregation of the animals. Pheromones that are detected via the olfactory system have been reported to control both reproductive and aggregation behavior. However, the molecular basis of pheromone detection in the antennae of Schistocerca gregaria is unknown. As an initial step to disclose pheromone receptors, we sequenced the antennal transcriptome of the desert locust. By subsequent bioinformatical approaches, 119 distinct nucleotide sequences encoding candidate odorant receptors (ORs) were identified. Phylogenetic analyses employing the identified ORs from Schistocerca gregaria (SgreORs) and OR sequences from the related species Locusta migratoria revealed a group of locust ORs positioned close to the root, i.e. at a basal site in a phylogenetic tree. Within this particular OR group (termed basal or b-OR group), the locust OR sequences were strictly orthologous, a trait reminiscent of pheromone receptors from lepidopteran species. In situ hybridization experiments with antennal tissue demonstrated expression of b-OR types from Schistocerca gregaria in olfactory sensory neurons (OSNs) of either sensilla trichodea or sensilla basiconica, both of which have been reported to respond to pheromonal substances. More importantly, two-color fluorescent in situ hybridization experiments showed that most b-OR types were expressed in cells co-expressing the "sensory neuron membrane protein 1" (SNMP1), a marker indicative of pheromone-sensitive OSNs in insects. Analyzing the expression of a larger number of SgreOR types outside the b-OR group revealed that only a few of them were co-expressed with SNMP1. In summary, we have identified several candidate pheromone receptors from Schistocerca gregaria that could mediate responses to pheromones implicated in controlling reproduction and aggregation behavior.

A sea lamprey (Petromyzon marinus) sex pheromone mixture increases trap catch relative to a single synthesized component in specific environments

USGS Publications Warehouse

Johnson, Nicholas S.; Tix, John A.; Hlina, Benjamin L.; Wagner, C. Michael; Siefkes, Michael J.; Wang, Huiyong; Li, Weiming

2015-01-01

Spermiating male sea lamprey (Petromyzon marinus) release a sex pheromone, of which a component, 7α, 12α, 24-trihydoxy-3-one-5α-cholan-24-sulfate (3kPZS), has been identified and shown to induce long distance preference responses in ovulated females. However, other pheromone components exist, and when 3kPZS alone was used to control invasive sea lamprey populations in the Laurentian Great Lakes, trap catch increase was significant, but gains were generally marginal. We hypothesized that free-ranging sea lamprey populations discriminate between a partial and complete pheromone while migrating to spawning grounds and searching for mates at spawning grounds. As a means to test our hypothesis, and to test two possible uses of sex pheromones for sea lamprey control, we asked whether the full sex pheromone mixture released by males (spermiating male washings; SMW) is more effective than 3kPZS in capturing animals in traditional traps (1) en route to spawning grounds and (2) at spawning grounds. At locations where traps target sea lampreys en route to spawning grounds, SMW-baited traps captured significantly more sea lampreys than paired 3kPZS-baited traps (~10 % increase). At spawning grounds, no difference in trap catch was observed between 3kPZS and SMW-baited traps. The lack of an observed difference at spawning grounds may be attributed to increased pheromone competition and possible involvement of other sensory modalities to locate mates. Because fishes often rely on multiple and sometimes redundant sensory modalities for critical life history events, the addition of sex pheromones to traditionally used traps is not likely to work in all circumstances. In the case of the sea lamprey, sex pheromone application may increase catch when applied to specifically designed traps deployed in streams with low adult density and limited spawning habitat.

Communication disruption of guava moth (Coscinoptycha improbana) using a pheromone analog based on chain length.

PubMed

Suckling, D M; Dymock, J J; Park, K C; Wakelin, R H; Jamieson, L E

2013-09-01

The guava moth, Coscinoptycha improbana, an Australian species that infests fruit crops in commercial and home orchards, was first detected in New Zealand in 1997. A four-component pheromone blend was identified but is not yet commercially available. Using single sensillum recordings from male antennae, we established that the same olfactory receptor neurons responded to two guava moth sex pheromone components, (Z)-11-octadecen-8-one and (Z)-12-nonadecen-9-one, and to a chain length analog, (Z)-13-eicosen-10-one, the sex pheromone of the related peach fruit moth, Carposina sasakii. We then field tested whether this non-specificity of the olfactory neurons might enable disruption of sexual communication by the commercially available analog, using male catch to synthetic lures in traps in single-tree, nine-tree and 2-ha plots. A disruptive pheromone analog, based on chain length, is reported for the first time. Trap catches for guava moth were disrupted by three polyethylene tubing dispensers releasing the analog in single-tree plots (86% disruption of control catches) and in a plots of nine trees (99% disruption). Where peach fruit moth pheromone dispensers were deployed at a density of 1000/ha in two 2-ha areas, pheromone traps for guava moth were completely disrupted for an extended period (up to 470 days in peri-urban gardens in Mangonui and 422 days in macadamia nut orchards in Kerikeri). In contrast, traps in untreated areas over 100 m away caught 302.8 ± 128.1 moths/trap in Mangonui and 327.5 ± 78.5 moths/ trap in Kerikeri. The longer chain length in the pheromone analog has greater longevity than the natural pheromone due to its lower volatility. Chain length analogs may warrant further investigation for mating disruption in Lepidoptera, and screening using single-sensillum recording is recommended.

Addition of Alarm Pheromone Components Improves the Effectiveness of Desiccant Dusts Against Cimex lectularius

PubMed Central

BENOIT, JOSHUA B.; PHILLIPS, SETH A.; CROXALL, TRAVIS J.; CHRISTENSEN, BRADY S.; YODER, JAY A.; DENLINGER, DAVID L.

2009-01-01

We demonstrate that the addition of bed bug, Cimex lectularius, alarm pheromone to desiccant formulations greatly enhances their effectiveness during short-term exposure. Two desiccant formulations, diatomaceous earth (DE) and Dri-die (silica gel), were applied at the label rate with and without bed bug alarm pheromone components, (E)-2-hexenal, (E)-2-octenal, and a (E)-2-hexenal:(E)-2-octenal blend. First-instar nymphs and adult females were subjected to 10-min exposures, and water loss rates were used to evaluate the response. Optimal effectiveness was achieved with a pheromone concentration of 0.01 M. With Dri-die alone, the water loss was 21% higher than in untreated controls, and water loss increased nearly two times with (E)-2-hexenal and (E)-2-octenal and three times with the (E)-2-hexenal: (E)-2-octenal blend. This shortened survival of first-instar nymphs from 4 to 1 d, with a similar reduction noted in adult females. DE was effective only if supplemented with pheromone, resulting in a 50% increase in water loss over controls with the (E)-2-hexenal:(E)-2-octenal blend, and a survival decrease from 4 to 2 d in first-instar nymphs. Consistently, the addition of the pheromone blend to desiccant dust was more effective than adding either component by itself or by using Dri-die or DE alone. Based on observations in a small microhabitat, the addition of alarm pheromone components prompted bed bugs to leave their protective harborages and to move through the desiccant, improving the use of desiccants for control. We concluded that short exposure to Dri-die is a more effective treatment against bed bugs than DE and that the effectiveness of the desiccants can be further enhanced by incorporation of alarm pheromone. Presumably, the addition of alarm pheromone elevates excited crawling activity, thereby promoting cuticular changes that increase water loss. PMID:19496429

Identification of trail pheromone of larva of eastern tent caterpillarMalacosoma americanum (Lepidoptera: Lasiocampidae).

PubMed

Crump, D; Silverstein, R M; Williams, H J; Fitzgerald, T D

1987-03-01

Previous studies have shown that larvae of the eastern tent caterpillar (Malacosoma americanum F.) mark trails, leading from their tent to feeding sites on host trees, with a pheromone secreted from the posterior tip of the abdominal sternum. 5β-Cholestane-3,24-dione (1) has been identified as an active component of the trail. The larvae have a threshold sensitivity to the pheromone of 10(-11) g/mm of trail. Several related compounds elicit the trail-following response. Two other species of tent caterpillars also responded positively to the pheromone in preliminary laboratory tests.

Worker honey bee pheromone regulation of foraging ontogeny

NASA Astrophysics Data System (ADS)

Pankiw, Tanya

The evolution of sociality has configured communication chemicals, called primer pheromones, which play key roles in regulating the organization of social life. Primer pheromones exert relatively slow effects that fundamentally alter developmental, physiological, and neural systems. Here, I demonstrate how substances extracted from the surface of foraging and young pre-foraging worker bees regulated age at onset of foraging, a developmental process. Hexane-extractable compounds washed from foraging workers increased foraging age compared with controls, whereas extracts of young pre-foraging workers decreased foraging age. This represents the first known direct demonstration of primer pheromone activity derived from adult worker bees.

The Use of Double Translocation Heterozygotes To Control Populations of the German Cockroach and the Use of Genetic Mechanisms and Behavioral Characteristics To Control Natural Populations of the German Cockroach.

DTIC Science & Technology

1986-05-30

insecticide resistance, pheromones 3 A 817 R4A(1 (,CctinL’e on reverse if nece’ssary and idenity by block number) !’,--arch supported by this Contract .as...reproductive state. The results left 1 !7e doubt that females play a leading role in regulating population behavior. Subsequent research on pheromones showed...aggregation pheromone and a less well known dispersal pheromone revealed differences in response with age/sex class Ta the aggregation experiments

Pheromone communication and the mushroom body of the ant, Camponotus obscuripes (Hymenoptera: Formicidae)

NASA Astrophysics Data System (ADS)

Yamagata, Nobuhiro; Fujiwara-Tsujii, Nao; Yamaoka, Ryohei; Mizunami, Makoto

2005-11-01

Communication by means of pheromones plays predominant roles in colony integration by social insects. However, almost nothing is known about pheromone processing in the brains of social insects. In this study, we successfully applied intracellular recording and staining techniques to anatomically and physiologically characterize brain neurons of the ant Camponotus obscuripes. We identified 42 protocerebral neurons that responded to undecane and/or formic acid, components of alarm pheromones that evoke attraction or evasive behavior, respectively. Notably, 30 (71%) of these neurons were efferent (output) or feedback neurons of the mushroom body, and many of these exhibited different responses to formic acid and undecane. Eight of the remaining 12 neurons had arborizations in the lateral and/or medial protocerebrum, which receive terminations of efferent neurons of the mushroom body and from which premotor descending neurons originate. The remaining four neurons were bilateral neurons that connect lateral accessory lobes or dorsal protocerebrums of both hemispheres. We suggest that the mushroom body of the ant participates in the processing of alarm pheromones. Seventeen (40%) of 42 neurons exhibited responses to nonpheromonal odors, indicating that the pheromonal and nonpheromonal signals are not fully segregated when they are processed in the protocerebrum. This may be related to modulatory functions of alarm pheromones, i.e., they change alertness of the ant and change responses to a variety of sensory stimuli.

Argentine ant trail pheromone disruption is mediated by trail concentration.

PubMed

Suckling, David Maxwell; Stringer, Lloyd D; Corn, Joshua E

2011-10-01

Argentine ant trail pheromone disruption, using continuous release of the trail pheromone compound (Z)-9-hexadecanal, reduces the incidence of trails and foraging rates of field populations. However, little is known about the concentrations of pheromone required for successful disruption. We hypothesized that higher pheromone quantities would be necessary to disrupt larger ant populations. To test this, we laid a 30-cm long base trail of (Z)-9-hexadecanal on a glass surface at low and high rates (1 and 100 pg/cm) (Trail 1), and laid a second, shorter trail (Trail 2, 10 cm long, located 1.5 cm upwind) near the middle of Trail 1 at six rates (1, 10, 100, 1,000, 10,000, and 100,000 pg/cm). We then recorded and digitized movements of individual ants following Trail 1, and derived a regression statistic, r (2), as an index of trail integrity, and also recorded arrival success at the other end of the trail (30 cm) near a food supply. Disruption of trails required 100 fold more pheromone upwind, independent of base-trail concentration. This implies that in the field, trail disruption is likely to be less successful against high ant-trail densities (greater concentration of trail pheromone), and more successful against newly formed or weak trails, as could be expected along invasion fronts.

Attraction of Cerambycid Beetles to Their Aggregation-Sex Pheromones Is Influenced by Volatiles From Host Plants of Their Larvae.

PubMed

Wong, J C H; Zou, Y; Millar, J G; Hanks, L M

2017-06-01

Here, we describe a field experiment that tested for attraction of cerambycid beetles to odors from angiosperm hosts, and whether plant volatiles also serve to enhance attraction of beetles to their aggregation-sex pheromones. Traps were baited with a blend of synthesized chemicals that are common pheromone components of species in the subfamilies Cerambycinae and Lamiinae. The source of plant volatiles was chipped wood from trees of three angiosperm species, as well as from one nonhost, gymnosperm species. Bioassays were conducted in wooded areas of east-central Illinois. Traps were baited with the pheromone blend alone, the blend + wood chips from one tree species, wood chips alone, or a solvent control lure. Seven species of cerambycids were significantly attracted to the pheromone blend, with or without wood chips. In two cases, wood chips from angiosperms appeared to enhance attraction to pheromones, whereas they inhibited attraction in another three cases. Pine chips did not strongly influence attraction of any species. Overall, our results suggest that host plant volatiles from wood chips may improve trap catch with synthesized pheromones for some cerambycid species, but the effect is not general, necessitating case-by-case testing to determine how individual target species are affected. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A pheromone analogue affects the evaporation rate of (+)-disparlure in Lymantria dispar.

PubMed

Sollai, Giorgia; Murgia, Sergio; Secci, Francesco; Frongia, Angelo; Cerboneschi, Anna; Masala, Carla; Liscia, Anna; Crnjar, Roberto; Solari, Paolo

2014-04-01

The gypsy moth Lymantria dispar L. is a widespread pest that causes economic damage to cork oak forests. Females produce the sex pheromone (+)-(7R,8S)-epoxy-2-methyloctadecane, known as (+)-disparlure [(+)D], for long-distance attraction of conspecific males. A (+)D analogue, 2-decyl-1-oxaspiro[2.2]pentane (OXP-01), neither stimulating nor attractive by itself, causes short-time inhibition of male response in a 1:1 blend with (+)D. The authors investigated whether and how the biological activity of the natural pheromone is affected by OXP-01 on a long-time basis (up to 16 days), also by looking at possible physicochemical reciprocal interactions. Blending of (+)D with OXP-01 decreased, under low evaporation rate, the pheromone effectiveness, as assessed by electroantennogram recordings. In male trappings, within the first 24 h, OXP-01 decreased and later enhanced the blend attractiveness, but only under high evaporation rate. Gas chromatography-mass spectroscopy indicates that quantitative retrieval of (+)D from blend cartridges is higher than for pure pheromone, and nuclear magnetic resonance measurements show that OXP-01 produces, possibly by Van der Waals interactions, a bimolecular entity with pheromone causing retention and lengthening of its attractiveness over time. The biological and physicochemical interactions between (+)D and OXP-01 may provide valuable information for the optimisation of pheromone-based control strategies for gypsy moths. © 2013 Society of Chemical Industry.

Sexual response of male Drosophila to honey bee queen mandibular pheromone: implications for genetic studies of social insects.

PubMed

Croft, Justin R; Liu, Tom; Camiletti, Alison L; Simon, Anne F; Thompson, Graham J

2017-02-01

Honey bees secrete a queen mandibular pheromone that renders workers reproductively altruistic and drones sexually attentive. This sex-specific function of QMP may have evolved from a sexually dimorphic signaling mechanism derived from pre-social ancestors. If so, there is potential for pre-social insects to respond to QMP, and in a manner that is comparable to its normal effect on workers and drones. Remarkably, QMP applied to female Drosophila does induce worker-like qualities [Camiletti et al. (Entomol Exp Appl 147:262, 2013)], and we here extend this comparison to examine the effects of bee pheromone on male fruit flies. We find that male Drosophila melanogaster consistently orient towards a source of queen pheromone in a T-maze, suggesting a recruitment response comparable to the pheromone's normal effect on drones. Moreover, exposure to QMP renders male flies more sexually attentive; they display intensified pre-copulatory behavior towards conspecific females. We can inhibit this sexual effect through a loss-of-olfactory-function mutation, which suggests that the pheromone-responsive behavioral mechanism is olfactory-driven. These pheromone-induced changes to male Drosophila behavior suggest that aspects of sexual signaling are conserved between these two distantly related taxa. Our results highlight a role for Drosophila as a genetically tractable pre-social model for studies of social insect biology.

Structure-Activity Relationship of α Mating Pheromone from the Fungal Pathogen Fusarium oxysporum.

PubMed

Vitale, Stefania; Partida-Hanon, Angélica; Serrano, Soraya; Martínez-Del-Pozo, Álvaro; Di Pietro, Antonio; Turrà, David; Bruix, Marta

2017-03-03

During sexual development ascomycete fungi produce two types of peptide pheromones termed a and α. The α pheromone from the budding yeast Saccharomyces cerevisiae , a 13-residue peptide that elicits cell cycle arrest and chemotropic growth, has served as paradigm for the interaction of small peptides with their cognate G protein-coupled receptors. However, no structural information is currently available for α pheromones from filamentous ascomycetes, which are significantly shorter and share almost no sequence similarity with the S. cerevisiae homolog. High resolution structure of synthetic α-pheromone from the plant pathogenic ascomycete Fusarium oxysporum revealed the presence of a central β-turn resembling that of its yeast counterpart. Disruption of the-fold by d-alanine substitution of the conserved central Gly 6 -Gln 7 residues or by random sequence scrambling demonstrated a crucial role for this structural determinant in chemoattractant activity. Unexpectedly, the growth inhibitory effect of F. oxysporum α-pheromone was independent of the cognate G protein-coupled receptors Ste2 and of the central β-turn but instead required two conserved Trp 1 -Cys 2 residues at the N terminus. These results indicate that, despite their reduced size, fungal α-pheromones contain discrete functional regions with a defined secondary structure that regulate diverse biological processes such as polarity reorientation and cell division. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Pheromone biosynthetic pathways in the moths Heliothis subflexa and Heliothis virescens.

PubMed

Choi, Man-Yeon; Groot, Astrid; Jurenka, Russell A

2005-06-01

Sex pheromones of many moth species have relatively simple structures consisting of a hydrocarbon chain with a functional group and one to several double bonds. These sex pheromones are derived from fatty acids through specific biosynthetic pathways. We investigated the incorporation of deuterium-labeled tetradecanoic, hexadecanoic, and octadecanoic acid precursors into pheromone components of Heliothis subflexa and Heliothis virescens. The two species utilize (Z)11-hexadecenal as the major pheromone component, which is produced by Delta11 desaturation of hexadecanoic acid. H. subflexa also produced (Z)11-hexadecanol and (Z)-11-hexadecenyl acetate via Delta11 desaturation. In H. subflexa, octadecanoic acid was used to biosynthesize the minor pheromone components (Z)9-hexadecenal, (Z)9-hexadecenol, and (Z)9-hexadecenyl acetate. These minor components are produced by Delta11 desaturation of octadecanoic acid followed by one round of chain-shortening. In contrast, H. virescens used hexadecanoic acid as a substrate to form (Z)11-hexadecenal and (Z)11-hexadecenol and hexadecenal. H. virescens also produced (Z)9-tetradecenal by Delta11 desaturation of the hexadecanoic acid followed by one round of chain-shortening and reduction. Tetradecanoic acid was not utilized as a precursor to form Z9-14:Ald in H. virescens. This labeling pattern indicates that the Delta11 desaturase is the only active desaturase present in the pheromone gland cells of both species.

Beetle fauna captured in traps baited with Tomicus piniperda pheromone blends in a pine stand in Central Croatia

Treesearch

Milan Pernek; Boris Hrasovec; Miljenko Zupanic

2003-01-01

During field evaluations of pheromone blends used for monitoring Tomicus piniperda beetles, many non-target beetles were captured and identified. Five pheromone blends, plus commercially available TOMODOR were used in two different traps: the IPM Tech Intercept PTBB and the THEYSOHN intercept barrier trap. In addition to Tomicus...

Geometric isomers of sex pheromone components do not affect attractancy of Conopomorpha cramerella in cocoa plantations

USDA-ARS?s Scientific Manuscript database

Sex pheromone of cocoa pod borer (CPB), Conopomorpha cramerella, has previously been identified as a blend of (E,Z,Z)- and (E,E,Z)-4,6,10-hexadecatrienyl acetates and the corresponding alcohols. These pheromone components have been synthesized with modification of the existing method and relative at...

Irradiated boll weevils: pheromone production determined by GLC analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGovern, W.L.; McKibben, G.H.; Gueldner, R.C.

1975-08-15

The production of pheromone by Anthonomus grandis Boheman when treated with 10,000 rad of $sup 60$Co gamma irradiation compared favorably with that of control weevils for 5 days; however, feeding (determined by frass collection) was reduced from day one. No direct correlation was found between production of pheromone and elimination of frass. (auth)

Intra-annual variation in responses by flying southern pine beetles (Coleoptera: Curculionidae: Scolytinae) to pheromone component endo-brevicomin

Treesearch

Brian T. Sullivan; Cavell Brownie; JoAnne P. Barrett

2016-01-01

The southern pine beetle Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae) is attracted to an aggregation pheromone that includes the multifunctional pheromone component endobrevicomin. The effect of endo-brevicomin on attractive lures varies from strong enhancement to reduction of beetle attraction depending upon release rate, lure component...

Sex Pheromone of the Almond Moth and the Indian Meal Moth: cis-9, trans-12-Tetradecadienyl Acetate.

PubMed

Kuwahara, Y; Kitamura, C; Takashi, S; Hara, H; Ishii, S; Fukami, H

1971-02-26

Female moths of different species but belonging to the same subfamily produce an identical compound as their sex pheromone. The sex pheromone of the almond moth, Cadra cautella (Walker), and the Indian meal moth, Plodia interpunctella (Hübner), has been isolated and identified as cis-9, trans-12-tetradecadienyl acetate.

Range of Attraction of Pheromone Lures and Dispersal Behavior of Cerambycid Beetles

Treesearch

E. Dunn; J. Hough-Goldstein; L. M. Hanks; J. G. Millar; V. D' Amico

2016-01-01

Cerambycid beetles (Coleoptera: Cerambycidae) can locate suitable hosts and mates by sensing pheromones and plant volatiles. Many cerambycid pheromone components have been identified and are now produced synthetically for trap lures. The range over which these lures attract cerambycids within a forest, and the tendency for cerambycids to move out of a forest in...

Identification of functionally important residues in the silkmoth pheromone biosynthesis-activating neuropeptide receptor, an insect ortholog of the vertebrate Neuromedin U Receptor

USDA-ARS?s Scientific Manuscript database

The biosynthesis of sex pheromone components in many lepidopteran insects is regulated by interactions between pheromone biosynthesis-activating neuropeptide (PBAN) and the PBAN receptor (PBANR), a class-A G-protein-coupled receptor (GPCR). To identify functionally important amino acid residues in t...

Blends of Pheromones, With and Without Host Plant Volatiles, Can Attract Multiple Species of Cerambycid Beetles Simultaneously

Treesearch

L.M. Hanks; J.A. Mongold-Diers; T.H. Atkinson; M.K. Fierke; M.D. Ginzel; E.E. Graham; T.M. Poland; A.B. Richards; M.L. Richardson; J.G. Millar

2018-01-01

Pheromone components of cerambycid beetles are often conserved, with a given compound serving as a pheromone component for multiple related species, including species native to different continents. Consequently, a single synthesized compound may attract multiple species to a trap simultaneously. Furthermore, our previous research in east-central Illinois had...

Identification and quantification of pathogenic helminth eggs using a digital image system.

PubMed

Jiménez, B; Maya, C; Velásquez, G; Torner, F; Arambula, F; Barrios, J A; Velasco, M

2016-07-01

A system was developed to identify and quantify up to seven species of helminth eggs (Ascaris lumbricoides -fertile and unfertile eggs-, Trichuris trichiura, Toxocara canis, Taenia saginata, Hymenolepis nana, Hymenolepis diminuta, and Schistosoma mansoni) in wastewater using different image processing tools and pattern recognition algorithms. The system was developed in three stages. Version one was used to explore the viability of the concept of identifying helminth eggs through an image processing system, while versions 2 and 3 were used to improve its efficiency. The system development was based on the analysis of different properties of helminth eggs in order to discriminate them from other objects in samples processed using the conventional United States Environmental Protection Agency (US EPA) technique to quantify helminth eggs. The system was tested, in its three stages, considering two parameters: specificity (capacity to discriminate between species of helminth eggs and other objects) and sensitivity (capacity to correctly classify and identify the different species of helminth eggs). The final version showed a specificity of 99% while the sensitivity varied between 80 and 90%, depending on the total suspended solids content of the wastewater samples. To achieve such values in samples with total suspended solids (TSS) above 150 mg/L, it is recommended to dilute the concentrated sediment just before taking the images under the microscope. The system allows the helminth eggs most commonly found in wastewater to be reliably and uniformly detected and quantified. In addition, it provides the total number of eggs as well as the individual number by species, and for Ascaris lumbricoides it differentiates whether or not the egg is fertile. The system only requires basically trained technicians to prepare the samples, as for visual identification there is no need for highly trained personnel. The time required to analyze each image is less than a minute. This system could be used in central analytical laboratories providing a remote analysis service. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Fatty acyl pheromone analogue-containing lipids and their roles in sex pheromone biosynthesis in the lightbrown apple moth, Epipyhas postvittana (Walker).

PubMed

Foster, S P

2001-04-01

The pheromone gland of the moth Epiphyas postvittana was analysed for lipids containing the fatty acyl pheromone analogue (FAPA) of the component, (E)-11-tetradecenyl acetate. The FAPA was found predominantly in the triglycerides (TGs), and to a lesser extent in the choline phosphatides. The FAPA was found to be exclusively on the sn-1 or sn-3 position (probably the latter) of the TGs. When pheromone gland lipid extracts were eluted through silica solid phase extraction, a significant proportion of the FAPA was not recovered. Changes in titre of this non-recoverable FAPA paralleled changes in pheromone titre in females. In contrast, changes in recoverable FAPA (mostly in the TGs) titre showed a gradual increase with time after eclosion. The properties of this non-recoverable FAPA were consistent with it being the CoA ester of the FAPA. Thus, it appears that the FAPA-CoA ester is the immediate lipid precursor of the pheromone, and that the FAPA-containing TGs are formed by reaction of the FAPA-CoA with 1,2-DGs, as a consequence of the rate-limiting reduction of the FAPA-CoA. Finally, injection of PBAN into females decapitated for 3 days resulted in a decrease in recoverable FAPA and an increase in non-recoverable FAPA, suggesting that PBAN influences the lipolysis of TGs. Overall these data suggest that there are two routes for biosynthesis of the pheromone component E11-14:OAc in E. postvittana: a de novo route, directly via the CoA esters of the various fatty acid intermediates, and a less direct route via the lipolysis of FAPA-containing TGs.

A Drosophila protein family implicated in pheromone perception is related to Tay-Sachs GM2-activator protein.

PubMed

Starostina, Elena; Xu, Aiguo; Lin, Heping; Pikielny, Claudio W

2009-01-02

Low volatility, lipid-like cuticular hydrocarbon pheromones produced by Drosophila melanogaster females play an essential role in triggering and modulating mating behavior, but the chemosensory mechanisms involved remain poorly understood. Recently, we showed that the CheB42a protein, which is expressed in only 10 pheromone-sensing taste hairs on the front legs of males, modulates progression to late stages of male courtship behavior in response to female-specific cuticular hydrocarbons. Here we report that expression of all 12 genes in the CheB gene family is predominantly or exclusively gustatory-specific, and occurs in many different, often non-overlapping patterns. Only the Gr family of gustatory receptor genes displays a comparable variety of gustatory-specific expression patterns. Unlike Grs, however, expression of all but one CheB gene is sexually dimorphic. Like CheB42a, other CheBs may therefore function specifically in gustatory perception of pheromones. We also show that CheBs belong to the ML superfamily of lipid-binding proteins, and are most similar to human GM2-activator protein (GM2-AP). In particular, GM2-AP residues involved in ligand binding are conserved in CheBs but not in other ML proteins. Finally, CheB42a is specifically secreted into the inner lumen of pheromone-sensing taste hairs, where pheromones interact with membrane-bound receptors. We propose that CheB proteins interact directly with lipid-like Drosophila pheromones and modulate their detection by the gustatory signal transduction machinery. Furthermore, as loss of GM2-AP in Tay-Sachs disease prevents degradation of GM2 gangliosides and results in neurodegeneration, the function of CheBs in pheromone response may involve biochemical mechanisms critical for lipid metabolism in human neurons.

Fire ant alarm pheromone and venom alkaloids act in concert to attract parasitic phorid flies, Pseudacteon spp.

PubMed

Sharma, Kavita R; Fadamiro, Henry Y

2013-11-01

Pseudacteon tricuspis, Pseudacteon obtusus and Pseudacteon curvatus are three species of parasitic phorid flies (Diptera: Phoridae), which have been introduced as classical biological control agents of imported, Solenopsis fire ants (Hymenoptera: Formicidae) in the southern USA. Previous studies demonstrated the behavioral response of P. tricuspis to the venom alkaloids and alarm pheromone of the fire ant, S. invicta. In the present study, we compared the responses of P. tricuspis, P. obtusus and P. curvatus to Solenopsis invicta alarm pheromone, venom alkaloids, or a mixture of both chemicals in four-choice olfactometer bioassays. The main hypothesis tested was that the fire ant alarm pheromone and venom alkaloids act in concert to attract Pseudacteon phorid flies. Both sexes of all three Pseudacteon species were attracted to low doses of the fire ant alarm pheromone or venom alkaloids (i.e. 1 ant worker equivalent) alone. However, the flies were significantly more attracted to a mixture of both chemicals (i.e., 1:1 mixture of alarm pheromone+alkaloids) than to either chemical. The results suggest an additive rather than a synergistic effect of combining both chemicals. Comparing the fly species, P. tricuspis showed relatively greater attraction to cis alkaloids, whereas the alkaloid mixture (cis+trans) was preferred by P. obtusus and P. curvatus. In general, no key sexual differences were recorded, although females of P. tricuspis and P. obtusus showed slightly higher response than conspecific males to lower doses of the alarm pheromone. The ecological significance of these findings is discussed, and a host location model is proposed for parasitic phorid flies involving the use of fire ant alarm pheromone and venom alkaloids as long range and short range attractants, respectively. Published by Elsevier Ltd.

Aggregation pheromone of the cereal leaf beetle: field evaluation and emission from males in the laboratory.

PubMed

Rao, Sujaya; Cossé, Allard A; Zilkowski, Bruce W; Bartelt, Robert J

2003-09-01

The previously identified, male-specific compound of the cereal leaf beetle (CLB, Chrysomelidae; Oulema melanopus), (E)-8-hydroxy-6-methyl-6-octen-3-one, was studied further with respect to field activity and emission rate from male beetles. In a 5-week field experiment in Oregon, the compound was shown to function as an aggregation pheromone in attracting male and female CLBs migrating from overwintering sites in spring. Traps baited with the synthetic compound (500 microg per rubber septum) caught 3.3 times more CLBs than control traps. Lower doses of the pheromone (50 and 150 microg) were less attractive than the 500 microg dose. One relatively abundant, volatile compound from the host plant (oats), (Z)-3-hexenyl acetate, that elicited responses from beetle antennae was not attractive, either by itself or as a synergist of the pheromone. Both sexes were captured about equally for all treatments. We also measured daily pheromone emission by male beetles in the laboratory. Individual males feeding on oat seedlings under greenhouse conditions emitted as much as 6 microg per day, which is about 500 times higher than had been previously observed under incubator conditions. The pheromone emission rate was at least five times higher during the day than at night, and in one male, emission spanned a period of 28 d. The release rate of synthetic pheromone from the 500 microg septa was very similar to the maximum from single males; thus, future experiments should evaluate even higher doses. The field results indicate that the pheromone has potential as a monitoring tool for early detection of CLBs as they move from their overwintering sites into newly planted cereal crops in spring.

Factors influencing capture of invasive sea lamprey in traps baited with a synthesized sex pheromone component

USGS Publications Warehouse

Johnson, Nicholas; Siefkes, Michael J.; Wagner, C. Michael; Bravener, Gale; Steeves, Todd; Twohey, Michael; Li, Weiming

2015-01-01

The sea lamprey, Petromyzon marinus, is emerging as a model organism for understanding how pheromones can be used for manipulating vertebrate behavior in an integrated pest management program. In a previous study, a synthetic sex pheromone component 7α,12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) was applied to sea lamprey traps in eight streams at a final in-stream concentration of 10−12 M. Application of 3kPZS increased sea lamprey catch, but where and when 3kPZS had the greatest impact was not determined. Here, by applying 3kPZS to additional streams, we determined that overall increases in yearly exploitation rate (proportion of sea lampreys that were marked, released, and subsequently recaptured) were highest (20–40 %) in wide streams (~40 m) with low adult sea lamprey abundance (<1000). Wide streams with low adult abundance may be representative of low-attraction systems for adult sea lamprey and, in the absence of other attractants (larval odor, sex pheromone), sea lamprey may have been more responsive to a partial sex pheromone blend emitted from traps. Furthermore, we found that the largest and most consistent responses to 3kPZS were during nights early in the trapping season, when water temperatures were increasing. This may have occurred because, during periods of increasing water temperatures, sea lamprey become more active and males at large may not have begun to release sex pheromone. In general, our results are consistent with those for pheromones of invertebrates, which are most effective when pest density is low and when pheromone competition is low.

Pheromone-Regulated Expression of Sex Pheromone Plasmid pAD1-Encoded Aggregation Substance Depends on at Least Six Upstream Genes and a cis-Acting, Orientation-Dependent Factor

PubMed Central

Muscholl-Silberhorn, Albrecht B.

2000-01-01

Conjugative transfer of Enterococcus faecalis-specific sex pheromone plasmids relies on an adhesin, called aggregation substance, to confer a tight cell-to-cell contact between the mating partners. To analyze the dependence of pAD1-encoded aggregation substance, Asa1, on pheromone induction, a variety of upstream fragments were fused to an α-amylase reporter gene, amyL, by use of a novel promoter probe vector, pAMY-em1. For pheromone-regulated α-amylase activity, a total of at least six genes, traB, traC, traA, traE1, orfY, and orf1, are required: TraB efficiently represses asa1 (by a mechanism unrelated to its presumptive function in pheromone shutdown, since a complete shutdown is observed exclusively in the presence of traC); only traC can relieve traB-mediated repression in a pheromone-dependent manner. In addition to traB, traA is required but not sufficient for negative control. Mutational inactivation of traE1, orfY, or orf1, respectively, results in a total loss of α-amylase activity for constructs normally mediating constitutive expression. Inversion of a fragment covering traA, P0, and traE1 without disrupting any gene or control element switches off amyL or asa1 expression, indicating the involvement of a cis-acting, orientation-dependent factor (as had been shown for plasmid pCF10). Unexpectedly, pAD1 represses all pAMY-em1 derivatives in trans, while its own pheromone-dependent functions are unaffected. The discrepancy between the new data and those of former studies defining TraE1 as a trans-acting positive regulator is discussed. PMID:10850999

Bed bug aggregation pheromone finally identified.

PubMed

Gries, Regine; Britton, Robert; Holmes, Michael; Zhai, Huimin; Draper, Jason; Gries, Gerhard

2015-01-19

Bed bugs have become a global epidemic and current detection tools are poorly suited for routine surveillance. Despite intense research on bed bug aggregation behavior and the aggregation pheromone, which could be used as a chemical lure, the complete composition of this pheromone has thus far proven elusive. Here, we report that the bed bug aggregation pheromone comprises five volatile components (dimethyl disulfide, dimethyl trisulfide, (E)-2-hexenal, (E)-2-octenal, 2-hexanone), which attract bed bugs to safe shelters, and one less-volatile component (histamine), which causes their arrestment upon contact. In infested premises, a blend of all six components is highly effective at luring bed bugs into traps. The trapping of juvenile and adult bed bugs, with or without recent blood meals, provides strong evidence that this unique pheromone bait could become an effective and inexpensive tool for bed bug detection and potentially their control. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Contact sex pheromone components of the cowpea weevil, Callosobruchus maculatus.

PubMed

Nojima, Satoshi; Shimomura, Kenji; Honda, Hiroshi; Yamamoto, Izuru; Ohsawa, Kanju

2007-05-01

The cowpea weevil, Callosobruchus maculatus, is a major pest of stored pulses. Females of this species produce a contact sex pheromone that elicits copulation behavior in males. Pheromone was extracted from filter-paper shelters taken from cages that housed females. Crude ether extract stimulated copulation in male C. maculatus. Initial fractionation showed behavioral activity in acidic and neutral fractions. Furthermore, bioassay-guided fractionation and gas chromatography-mass spectroscopy (GC-MS) analysis of active fractions revealed that the active components of the acidic fraction were 2,6-dimethyloctane-1,8-dioic acid and nonanedioic acid. These components along with the hydrocarbon fraction, a mixture of C(27)-C(35) straight chain and methyl branched hydrocarbons, had a synergistic effect on the behavior of males. Glass dummies treated with an authentic pheromone blend induced copulation behavior in males. The potential roles of the contact sex pheromone of C. maculatus are discussed.

Role of solid-phase microextraction in the identification of highly volatile pheromones of two Rhinoceros beetles Scapanes australis and Strategus aloeus (Coleoptera, Scarabaeidae, Dynastinae).

PubMed

Rochat, D; Ramirez-Lucas, P; Malosse, C; Aldana, R; Kakul, T; Morin, J P

2000-07-14

Solid-phase microextraction (SPME) samplings from live insects or natural secretion allowed one to identify the aggregation pheromones of the pest beetles Scapanes australis and Strategus aloeus by efficient and rapid isolation of their highly volatile (72 < M(r) < 116) components. S. australis male pheromone was identified as a 84:12:4 (w/w) mixture of 2-butanol [67:33 (R)-(-):(S)-(+) ratio], 3-hydroxy-2-butanone and 2,3-butanediol [43:17:40 (R,R)-(-):(S,S)-(+):meso ratio], and S. aloeus pheromone as a 95.5:4.0:0.5 (w/w) mixture of 2-butanone, 3-pentanone and sec.-butyl acetate by GC-MS using conventional and chiral capillary columns. This is the first report of Scarabaeidae pheromones based on such small and common molecules.

Directional Bias and Pheromone for Discovery and Coverage on Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fink, Glenn A.; Berenhaut, Kenneth S.; Oehmen, Christopher S.

2012-09-11

Natural multi-agent systems often rely on “correlated random walks” (random walks that are biased toward a current heading) to distribute their agents over a space (e.g., for foraging, search, etc.). Our contribution involves creation of a new movement and pheromone model that applies the concept of heading bias in random walks to a multi-agent, digital-ants system designed for cyber-security monitoring. We examine the relative performance effects of both pheromone and heading bias on speed of discovery of a target and search-area coverage in a two-dimensional network layout. We found that heading bias was unexpectedly helpful in reducing search time andmore » that it was more influential than pheromone for improving coverage. We conclude that while pheromone is very important for rapid discovery, heading bias can also greatly improve both performance metrics.« less

A quantitative trait locus for recognition of foreign eggs in the host of a brood parasite.

PubMed

Martín-Gálvez, D; Soler, J J; Martínez, J G; Krupa, A P; Richard, M; Soler, M; Møller, A P; Burke, T

2006-03-01

Avian brood parasites reduce the reproductive output of their hosts and thereby select for defence mechanisms such as ejection of parasitic eggs. Such defence mechanisms simultaneously select for counter-defences in brood parasites, causing a coevolutionary arms race. Although coevolutionary models assume that defences and counter-defences are genetically influenced, this has never been demonstrated for brood parasites. Here, we give strong evidence for genetic differences between ejector and nonejectors, which could allow the study of such host defence at the genetic level, as well as studies of maintenance of genetic variation in defences. Briefly, we found that magpies, that are the main host of the great spotted cuckoo in Europe, have alleles of one microsatellite locus (Ase64) that segregate between accepters and rejecters of experimental parasitic eggs. Furthermore, differences in ejection rate among host populations exploited by the brood parasite covaried significantly with the genetic distance for this locus.

Atlantic salmon eggs favour sperm in competition that have similar major histocompatibility alleles.

PubMed

Yeates, Sarah E; Einum, Sigurd; Fleming, Ian A; Megens, Hendrik-Jan; Stet, René J M; Hindar, Kjetil; Holt, William V; Van Look, Katrien J W; Gage, Matthew J G

2009-02-07

Polyandry and post-copulatory sexual selection provide opportunities for the evolution of female differential sperm selection. Here, we examined the influence of variation in major histocompatibility (MH) class I allelic composition upon sperm competition dynamics in Atlantic salmon. We ran in vitro fertilization competitions that mimicked the gametic microenvironment, and replicated a paired-male experimental design that allowed us to compare differences in sperm competition success among males when their sperm compete for eggs from females that were genetically either similar or dissimilar at the MH class I locus. Concurrently, we measured variation in spermatozoal traits that are known to influence relative fertilization success under these conditions. Contrary to the findings demonstrating mechanisms that promote MH complex heterozygosity, our results showed that males won significantly greater relative fertilization success when competing for eggs from genetically similar females at the MH class I. This result also showed covariation with the known influences of sperm velocity on relative fertilization success. We discuss these unexpected findings in relation to sperm-egg recognition and hybridization avoidance mechanisms based upon immunogenetic variation.

Predicting infestation levels of the nantucket pine tip moth (Lepidoptera: Tortricidae) using pheromone traps

Treesearch

Christopher Asaro; C. Wayne Berisford

2001-01-01

There is considerable interest in using pheromone trap catches of the Nantucket pine tip moth, Rhyacionia frustrana (Conistock), to estimate or predict population density and damage. At six sites in the Georgia Piedmont, adult tip moths were monitored through one or more years using pheromone traps while population density and damage for each tip...

Investigating Ground Swarm Robotics Using Agent Based Simulation

DTIC Science & Technology

2006-12-01

Incorporation of virtual pheromones as a shared memory map is modeled as an additional capability that is found to enhance the robustness and reliability of the...virtual pheromones as a shared memory map is modeled as an additional capability that is found to enhance the robustness and reliability of the swarm... PHEROMONES .......................................... 42 1. Repel Friends under Inorganic SA.................................................. 45 2. Max

Hormonal Interference with Pheromone Systems in Parasitic Acarines, Especially Ixodid Ticks.

DTIC Science & Technology

1983-05-01

Genital Pheromone(s); Precocene-2; Hyalomma dromedarii; Dermacentor variabilis; Radioimmunoassay; juvenile hormone; Dermanyssus gallinae 19. KEY...dromedarii; Dermacentor variabilis; Radioimmunoassay; juvenile hormone; Dermanyssus gallinae . 20. A STRACT (Continue on reverse side I nfecessry and...allatotropin Precocene-2 and the juvenile hormone, JH3, on reporduction in the chicken mite, Dermanyssus gallinae is described. These studies are part of

Attraction of spathius agrili yang (Hymenoptera: eulophidae) to male-produced "aggregation-sex pheromone:" differences between the sexes and mating status

USDA-ARS?s Scientific Manuscript database

Male and female Spathius agrili Yang were tested for attraction to the synthetic male pheromone. Lures consisting of a 3-component pheromone blend were placed in the center of a white filter paper target used to activate upwind flight in the wind tunnel. When virgin males and females were tested for...

Deciphering the selectivity of Bombyx mori pheromone binding protein for bombykol over bombykal: a theoretical approach.

PubMed

Charlier, Landry; Antonczak, Serge; Jacquin-Joly, Emmanuelle; Cabrol-Bass, Daniel; Golebiowski, Jérôme

2008-12-22

In this article we report calculations dedicated to estimate the selectivity of the Bombyx mori pheromone binding protein towards the two closely related pheromonal components Bombykol and Bombykal. The selectivity is quantified by the binding free-energy difference, obtained either by the thermodynamic integration or by the MM-GBSA approach. In the latter, the selectivity is decomposed on a per-residue basis, which identifies the residues considered crucial for the selectivity of the protein for Bombykol over Bombykal. A discussion on the role of Bombyx mori pheromone binding protein is provided on the basis of these results.

Pheromone communication in amphibians and reptiles.

PubMed

Houck, Lynne D

2009-01-01

This selective review considers herpetological papers that feature the use of chemical cues, particularly pheromones involved in reproductive interactions between potential mates. Primary examples include garter snake females that attract males, lacertid lizards and the effects of their femoral gland secretions, aquatic male newts that chemically attract females, and terrestrial salamander males that chemically persuade a female to mate. Each case study spans a number of research approaches (molecular, biochemical, behavioral) and is related to sensory processing and the physiological effects of pheromone delivery. These and related studies show that natural pheromones can be identified, validated with behavioral tests, and incorporated in research on vomeronasal functional response.

Ejaculate of sneaker males is pheromonally inconspicuous in the black goby, Gobius niger (Teleostei, Gobiidae).

PubMed

Locatello, L; Mazzoldi, C; Rasotto, M B

2002-11-01

The black goby, Gobius niger, shows alternative male mating tactics, i.e., parental and sneaker males. Males release a sexual pheromone that attracts females and stimulates aggressive displays in males. This pheromone is produced by the mesorchial gland, a structure well developed in parental males but markedly undeveloped in sneakers. We measured the behavioral response of parental males to the ejaculates of males performing different reproductive tactics. Parental males reacted to the ejaculate of other parental males, with stereotypic aggressive behaviors, but not to the ejaculate of sneakers; consequently sneaker male ejaculate appears to be pheromonally inconspicuous. Copyright 2002 Wiley-Liss, Inc.

Courtship Pheromone Use in a Model Urodele, the Mexican Axolotl (Ambystoma mexicanum)

PubMed Central

Maex, Margo; Van Bocxlaer, Ines; Mortier, Anneleen; Proost, Paul; Bossuyt, Franky

2016-01-01

Sex pheromones have been shown to constitute a crucial aspect of salamander reproduction. Until now, courtship pheromones of Salamandridae and Plethodontidae have been intensively studied, but information on chemical communication in other urodelan families is essentially lacking. The axolotl (Ambystoma mexicanum, Ambystomatidae) has a courtship display that suggests a key role for chemical communication in the orchestration of its sexual behavior, but no sex pheromones have yet been characterized from this species. Here we combined whole transcriptome analyses of the male cloaca with proteomic analyses of water in which axolotls were allowed to court to show that male axolotls secrete multiple ca. 20 kDa glycosylated sodefrin precursor-like factor (SPF) proteins during courtship. In combination with phylogenetic analyses, our data show that the male cloaca essentially secretes a courtship-specific clade of SPF proteins that is orthologous to salamandrid courtship pheromones. In addition, we identified an SPF protein for which no orthologs have been described from other salamanders so far. Overall, our study advocates a central role for SPF proteins during the courtship display of axolotls and adds knowledge on pheromone use in a previously unexplored deep evolutionary branch of salamander evolution. PMID:26842386

Courtship Pheromone Use in a Model Urodele, the Mexican Axolotl (Ambystoma mexicanum).

PubMed

Maex, Margo; Van Bocxlaer, Ines; Mortier, Anneleen; Proost, Paul; Bossuyt, Franky

2016-02-04

Sex pheromones have been shown to constitute a crucial aspect of salamander reproduction. Until now, courtship pheromones of Salamandridae and Plethodontidae have been intensively studied, but information on chemical communication in other urodelan families is essentially lacking. The axolotl (Ambystoma mexicanum, Ambystomatidae) has a courtship display that suggests a key role for chemical communication in the orchestration of its sexual behavior, but no sex pheromones have yet been characterized from this species. Here we combined whole transcriptome analyses of the male cloaca with proteomic analyses of water in which axolotls were allowed to court to show that male axolotls secrete multiple ca. 20 kDa glycosylated sodefrin precursor-like factor (SPF) proteins during courtship. In combination with phylogenetic analyses, our data show that the male cloaca essentially secretes a courtship-specific clade of SPF proteins that is orthologous to salamandrid courtship pheromones. In addition, we identified an SPF protein for which no orthologs have been described from other salamanders so far. Overall, our study advocates a central role for SPF proteins during the courtship display of axolotls and adds knowledge on pheromone use in a previously unexplored deep evolutionary branch of salamander evolution.

The effects of mating status and time since mating on female sex pheromone levels in the rice leaf bug, Trigonotylus caelestialium

NASA Astrophysics Data System (ADS)

Yamane, Takashi; Yasuda, Tetsuya

2014-02-01

Although mating status affects future mating opportunities, the biochemical changes that occur in response to mating are not well understood. This study investigated the effects of mating status on the quantities of sex pheromone components found in whole-body extracts and volatile emissions of females of the rice leaf bug, Trigonotylus caelestialium. When sampled at one of four time points within a 4-day postmating period, females that had copulated with a male had greater whole-body quantities of sex pheromone components than those of virgin females sampled at the same times. The quantities of sex pheromone components emitted by virgin females over a 24-h period were initially high but then steadily decreased, whereas 24-h emissions were persistently low among mated females when measured at three time points within the 4 days after mating. As a result, soon after mating, the mated females emitted less sex pheromones than virgin females, but there were no significant differences between mated and virgin females at the end of the experiment. Thus, postmating reduction in the rate of emission of sex pheromones could explain previously observed changes in female attractiveness to male T. caelestialium.

Identification of an aggression-promoting pheromone and its receptor neurons in Drosophila.

PubMed

Wang, Liming; Anderson, David J

2010-01-14

Aggression is regulated by pheromones in many animal species. However, in no system have aggression pheromones, their cognate receptors and corresponding sensory neurons been identified. Here we show that 11-cis-vaccenyl acetate (cVA), a male-specific volatile pheromone, robustly promotes male-male aggression in the vinegar fly Drosophila melanogaster. The aggression-promoting effect of synthetic cVA requires olfactory sensory neurons (OSNs) expressing the receptor Or67d, as well as the receptor itself. Activation of Or67d-expressing OSNs, either by genetic manipulation of their excitability or by exposure to male pheromones in the absence of other classes of OSNs, is sufficient to promote aggression. High densities of male flies can promote aggression by the release of volatile cVA. In turn, cVA-promoted aggression can promote male fly dispersal from a food resource, in a manner dependent on Or67d-expressing OSNs. These data indicate that cVA may mediate negative-feedback control of male population density, through its effect on aggression. Identification of a pheromone-OSN pair controlling aggression in a genetic organism opens the way to unravelling the neurobiology of this evolutionarily conserved behaviour.

Management strategy evaluation of pheromone-baited trapping techniques to improve management of invasive sea lamprey

USGS Publications Warehouse

Dawson, Heather; Jones, Michael L.; Irwin, Brian J.; Johnson, Nicholas; Wagner, Michael C.; Szymanski, Melissa

2016-01-01

We applied a management strategy evaluation (MSE) model to examine the potential cost-effectiveness of using pheromone-baited trapping along with conventional lampricide treatment to manage invasive sea lamprey. Four pheromone-baited trapping strategies were modeled: (1) stream activation wherein pheromone was applied to existing traps to achieve 10−12 mol/L in-stream concentration, (2) stream activation plus two additional traps downstream with pheromone applied at 2.5 mg/hr (reverse-intercept approach), (3) trap activation wherein pheromone was applied at 10 mg/hr to existing traps, and (4) trap activation and reverse-intercept approach. Each new strategy was applied, with remaining funds applied to conventional lampricide control. Simulating deployment of these hybrid strategies on fourteen Lake Michigan streams resulted in increases of 17 and 11% (strategies 1 and 2) and decreases of 4 and 7% (strategies 3 and 4) of the lakewide mean abundance of adult sea lamprey relative to status quo. MSE revealed performance targets for trap efficacy to guide additional research because results indicate that combining lampricides and high efficacy trapping technologies can reduce sea lamprey abundance on average without increasing control costs.

A novel bio-engineering approach to generate an eminent surface-functionalized template for selective detection of female sex pheromone of Helicoverpa armigera.

PubMed

Moitra, Parikshit; Bhagat, Deepa; Pratap, Rudra; Bhattacharya, Santanu

2016-11-28

Plant pests exert serious effects on food production due to which the global crop yields are reduced by ~20-40 percent per year. Hence to meet the world's food needs, loses of food due to crop pests must be reduced. Herein the silicon dioxide based MEMS devices are covalently functionalized for robust and efficient optical sensing of the female sex pheromones of the pests like Helicoverpa armigera for the first time in literature. The functionalized devices are also capable of selectively measuring the concentration of this pheromone at femtogram level which is much below the concentration of pheromone at the time of pest infestation in an agricultural field. Experiments are also performed in a confined region in the presence of male and female pests and tomato plants which directly mimics the real environmental conditions. Again the reversible use and absolutely trouble free transportation of these pheromone nanosensors heightens their potentials for commercial use. Overall, a novel and unique approach for the selective and reversible sensing of female sex pheromones of certain hazardous pests is reported herein which may be efficiently and economically carried forward from the research laboratory to the agricultural field.

Odor Landscapes in Turbulent Environments

NASA Astrophysics Data System (ADS)

Celani, Antonio; Villermaux, Emmanuel; Vergassola, Massimo

2014-10-01

The olfactory system of male moths is exquisitely sensitive to pheromones emitted by females and transported in the environment by atmospheric turbulence. Moths respond to minute amounts of pheromones, and their behavior is sensitive to the fine-scale structure of turbulent plumes where pheromone concentration is detectible. The signal of pheromone whiffs is qualitatively known to be intermittent, yet quantitative characterization of its statistical properties is lacking. This challenging fluid dynamics problem is also relevant for entomology, neurobiology, and the technological design of olfactory stimulators aimed at reproducing physiological odor signals in well-controlled laboratory conditions. Here, we develop a Lagrangian approach to the transport of pheromones by turbulent flows and exploit it to predict the statistics of odor detection during olfactory searches. The theory yields explicit probability distributions for the intensity and the duration of pheromone detections, as well as their spacing in time. Predictions are favorably tested by using numerical simulations, laboratory experiments, and field data for the atmospheric surface layer. The resulting signal of odor detections lends itself to implementation with state-of-the-art technologies and quantifies the amount and the type of information that male moths can exploit during olfactory searches.

A novel bio-engineering approach to generate an eminent surface-functionalized template for selective detection of female sex pheromone of Helicoverpa armigera

NASA Astrophysics Data System (ADS)

Moitra, Parikshit; Bhagat, Deepa; Pratap, Rudra; Bhattacharya, Santanu

2016-11-01

Plant pests exert serious effects on food production due to which the global crop yields are reduced by ~20-40 percent per year. Hence to meet the world’s food needs, loses of food due to crop pests must be reduced. Herein the silicon dioxide based MEMS devices are covalently functionalized for robust and efficient optical sensing of the female sex pheromones of the pests like Helicoverpa armigera for the first time in literature. The functionalized devices are also capable of selectively measuring the concentration of this pheromone at femtogram level which is much below the concentration of pheromone at the time of pest infestation in an agricultural field. Experiments are also performed in a confined region in the presence of male and female pests and tomato plants which directly mimics the real environmental conditions. Again the reversible use and absolutely trouble free transportation of these pheromone nanosensors heightens their potentials for commercial use. Overall, a novel and unique approach for the selective and reversible sensing of female sex pheromones of certain hazardous pests is reported herein which may be efficiently and economically carried forward from the research laboratory to the agricultural field.

(R)-3-hydroxyhexan-2-one is a major pheromone component of Anelaphus inflaticollis (Coleoptera: Cerambycidae).

PubMed

Ray, A M; Swift, I P; Moreira, J A; Millar, J G; Hanks, L M

2009-10-01

We report the identification and field bioassays of a major component of the male-produced aggregation pheromone of Anelaphus inflaticollis Chemsak, an uncommon desert cerambycine beetle. Male A. inflaticollis produced a sex-specific blend of components that included (R)-3-hydroxyhexan-2-one, (S)-2-hydroxyhexan-3-one, 2,3-hexanedione, and (2R,3R)- and (2R,3S)-2,3-hexanediols. Field trials with baited bucket traps determined that the reconstructed synthetic pheromone blend and (R)-3-hydroxyhexan-2-one alone attracted adult A. inflaticollis of both sexes, with significantly more beetles being attracted to the blend. We conclude that (R)-3-hydroxyhexan-2-one is a major pheromone component of A. inflaticollis, and our results suggest that one or more of the minor components may further increase attraction of conspecifics. Scanning electron microscopy showed that male A. inflaticollis have pores on the prothorax that are consistent in structure with sex-specific pheromone gland pores in related species. Males also displayed stereotyped calling behavior similar to that observed in other cerambycine species. This study represents the first report of volatile pheromones for a cerambycine species in the tribe Elaphidiini.

Ants adjust their pheromone deposition to a changing environment and their probability of making errors

PubMed Central

Czaczkes, Tomer J.; Heinze, Jürgen

2015-01-01

Animals must contend with an ever-changing environment. Social animals, especially eusocial insects such as ants and bees, rely heavily on communication for their success. However, in a changing environment, communicated information can become rapidly outdated. This is a particular problem for pheromone trail using ants, as once deposited pheromones cannot be removed. Here, we study the response of ant foragers to an environmental change. Ants were trained to one feeder location, and the feeder was then moved to a different location. We found that ants responded to an environmental change by strongly upregulating pheromone deposition immediately after experiencing the change. This may help maintain the colony's foraging flexibility, and allow multiple food locations to be exploited simultaneously. Our treatment also caused uncertainty in the foragers, by making their memories less reliable. Ants which had made an error but eventually found the food source upregulated pheromone deposition when returning to the nest. Intriguingly, ants on their way towards the food source downregulated pheromone deposition if they were going to make an error. This may suggest that individual ants can measure the reliability of their own memories and respond appropriately. PMID:26063845

Mobile Diagnostics Based on Motion? A Close Look at Motility Patterns in the Schistosome Life Cycle

PubMed Central

Linder, Ewert; Varjo, Sami; Thors, Cecilia

2016-01-01

Imaging at high resolution and subsequent image analysis with modified mobile phones have the potential to solve problems related to microscopy-based diagnostics of parasitic infections in many endemic regions. Diagnostics using the computing power of “smartphones” is not restricted by limited expertise or limitations set by visual perception of a microscopist. Thus diagnostics currently almost exclusively dependent on recognition of morphological features of pathogenic organisms could be based on additional properties, such as motility characteristics recognizable by computer vision. Of special interest are infectious larval stages and “micro swimmers” of e.g., the schistosome life cycle, which infect the intermediate and definitive hosts, respectively. The ciliated miracidium, emerges from the excreted egg upon its contact with water. This means that for diagnostics, recognition of a swimming miracidium is equivalent to recognition of an egg. The motility pattern of miracidia could be defined by computer vision and used as a diagnostic criterion. To develop motility pattern-based diagnostics of schistosomiasis using simple imaging devices, we analyzed Paramecium as a model for the schistosome miracidium. As a model for invasive nematodes, such as strongyloids and filaria, we examined a different type of motility in the apathogenic nematode Turbatrix, the “vinegar eel.” The results of motion time and frequency analysis suggest that target motility may be expressed as specific spectrograms serving as “diagnostic fingerprints.” PMID:27322330

Chemical similarity between historical and novel host plants promotes range and host expansion of the mountain pine beetle in a naïve host ecosystem.

PubMed

Erbilgin, Nadir; Ma, Cary; Whitehouse, Caroline; Shan, Bin; Najar, Ahmed; Evenden, Maya

2014-02-01

Host plant secondary chemistry can have cascading impacts on host and range expansion of herbivorous insect populations. We investigated the role of host secondary compounds on pheromone production by the mountain pine beetle (Dendroctonus ponderosae) (MPB) and beetle attraction in response to a historical (lodgepole pine, Pinus contorta var. latifolia) and a novel (jack pine, Pinus banksiana) hosts, as pheromones regulate the host colonization process. Beetles emit the same pheromones from both hosts, but more trans-verbenol, the primary aggregation pheromone, was emitted by female beetles on the novel host. The phloem of the novel host contains more α-pinene, a secondary compound that is the precursor for trans-verbenol production in beetle, than the historical host. Beetle-induced emission of 3-carene, another secondary compound found in both hosts, was also higher from the novel host. Field tests showed that the addition of 3-carene to the pheromone mixture mimicking the aggregation pheromones produced from the two host species increased beetle capture. We conclude that chemical similarity between historical and novel hosts has facilitated host expansion of MPB in jack pine forests through the exploitation of common host secondary compounds for pheromone production and aggregation on the hosts. Furthermore, broods emerging from the novel host were larger in terms of body size. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Effects of sex pheromones and sexual maturation on locomotor activity in female sea lamprey (Petromyzon marinus)

USGS Publications Warehouse

Walaszczyk, Erin J.; Johnson, Nicholas S.; Steibel, Juan Pedro; Li, Weiming

2013-01-01

Synchronization of male and female locomotor rhythmicity can play a vital role in ensuring reproductive success. Several physiological and environmental factors alter these locomotor rhythms. As sea lamprey, Petromyzon marinus, progress through their life cycle, their locomotor activity rhythm changes multiple times. The goal of this study was to elucidate the activity patterns of adult female sea lamprey during the sexual maturation process and discern the interactions of these patterns with exposure to male pheromones. During these stages, preovulated and ovulated adult females are exposed to sex pheromone compounds, which are released by spermiated males and attract ovulated females to the nest for spawning. The locomotor behavior of adult females was monitored in a natural stream with a passive integrated tag responder system as they matured, and they were exposed to a sex pheromone treatment (spermiated male washings) or a control (prespermiated male washings). Results showed that, dependent on the hour of day, male sex pheromone compounds reduce total activity (p < 0.05) and cause increases in activity during several daytime hours in preovulated and ovulated females. These results are one of the first examples of how sex pheromones modulate a locomotor rhythm in a vertebrate, and they suggest that the interaction between maturity stage and sex pheromone exposure contributes to the differential locomotor rhythms found in adult female sea lamprey. This phenomenon may contribute to the reproductive synchrony of mature adults, thus increasing reproductive success in this species.

Synthetic Sex Pheromone Attracts the Leishmaniasis Vector Lutzomyia longipalpis (Diptera: Psychodidae) to Traps in the Field

PubMed Central

Bray, D. P.; Bandi, K. K.; Brazil, R. P.; Oliveira, A. G.; Hamilton, J.G.C.

2011-01-01

Improving vector control remains a key goal in reducing the world’s burden of infectious diseases. More cost-effective approaches to vector control are urgently needed, particularly as vaccines are unavailable and treatment is prohibitively expensive. The causative agent of AVL, Leishmania chagasi, Cunha and Chagas (Kinetoplastida: Trypanosomatidae) is transmitted between animal and human hosts by blood-feeding female sand flies, attracted to mating aggregations formed on or above host animals by male-produced sex pheromones. Our results demonstrate the potential of using synthetic pheromones to control populations of Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae), the sand fly vector of one of the world’s most important neglected diseases, American visceral leishmaniasis (AVL). We showed that a synthetic pheromone, (±)-9-methylgermacrene-B, produced from a low-cost plant intermediate, attracted females in the laboratory. Then by formulating dispensers that released this pheromone at a rate similar to that released by aggregating males, we were able to attract flies of both sexes to traps in the field. These dispensers worked equally well when deployed with mechanical light traps and inexpensive sticky traps. If deployed effectively, pheromone-based traps could be used to decrease AVL transmission rates through specific targeting and reduction of L. longipalpis populations. This is the first study to show attraction of a human disease-transmitting insect to a synthetic pheromone in the field, demonstrating the general applicability of this novel approach for developing new tools for use in vector control. PMID:19496409

Synthetic sex pheromone attracts the leishmaniasis vector Lutzomyia longipalpis (Diptera: Psychodidae) to traps in the field.

PubMed

Bray, D P; Bandi, K K; Brazil, R P; Oliveira, A G; Hamilton, J G C

2009-05-01

Improving vector control remains a key goal in reducing the world's burden of infectious diseases. More cost-effective approaches to vector control are urgently needed, particularly because vaccines are unavailable and treatment is prohibitively expensive. The causative agent of American visceral leishmaniasis (AVL), Leishmania chagasi, Cunha and Chagas (Kinetoplastida: Trypanosomatidae), is transmitted between animal and human hosts by blood-feeding female sand flies attracted to mating aggregations formed on or above host animals by male-produced sex pheromones. Our results show the potential of using synthetic pheromones to control populations of Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae), the sand fly vector of one of the world's most important neglected diseases, AVL. We showed that a synthetic pheromone, (+/-)-9-methylgermacrene-B, produced from a low-cost plant intermediate, attracted females in the laboratory. By formulating dispensers that released this pheromone at a rate similar to that released by aggregating males, we were able to attract flies of both sexes to traps in the field. These dispensers worked equally well when deployed with mechanical light traps and inexpensive sticky traps. If deployed effectively, pheromone-based traps could be used to decrease AVL transmission rates through specific targeting and reduction of L. longipalpis populations. This is the first study to show attraction of a human disease-transmitting insect to a synthetic pheromone in the field, showing the general applicability of this novel approach for developing new tools for use in vector control.

Pheromone Production by an Invasive Bark Beetle Varies with Monoterpene Composition of its Naïve Host.

PubMed

Taft, Spencer; Najar, Ahmed; Erbilgin, Nadir

2015-06-01

The secondary chemistry of host plants can have cascading impacts on the establishment of new insect herbivore populations, their long-term population dynamics, and their invasion potential in novel habitats. Mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) has recently expanded its range into forests of jack pine, Pinus banksiana Lamb., in western Canada. We investigated whether variations in jack pine monoterpenes affect beetle pheromone production, as the primary components of the beetle's aggregation pheromone, (-)-trans-verbenol and anti-aggregation pheromone (-)-verbenone, are biosynthesized from the host monoterpene α-pinene. Jack pine bolts were collected from five Canadian provinces east of the beetle's current range, live D. ponderosae were introduced into them, and their monoterpene compositions were characterized. Production of (-)-trans-verbenol and (-)-verbenone emitted by beetles was measured to determine whether pheromone production varies with monoterpene composition of jack pines. Depending on particular ratios of major monoterpenes in host phloem, jack pine could be classified into three monoterpenoid groups characterized by high amounts of (+)-α-pinene, 3-carene, or a more moderate blend of monoterpenes, and beetle pheromone production varied among these groups. Specifically, beetles reared in trees characterized by high (+)-α-pinene produced the most (-)-trans-verbenol and (-)-verbenone, while beetles in trees characterized by high 3-carene produced the least. Our results indicate that pheromone production by D. ponderosae will remain a significant aspect and important predictor of its survival and persistence in the boreal forest.

It's All in the Mix: Blend-Specific Behavioral Response to a Sexual Pheromone in a Butterfly

PubMed Central

Larsdotter-Mellström, Helena; Eriksson, Kerstin; Liblikas I, Ilme; Wiklund, Christer; Borg-Karlson, Anna K.; Nylin, Sören; Janz, Niklas; Carlsson, Mikael A.

2016-01-01

Among insects, sexual pheromones are typically mixtures of two to several components, all of which are generally required to elicit a behavioral response. Here we show for the first time that a complete blend of sexual pheromone components is needed to elicit a response also in a butterfly. Males of the Green-veined White, Pieris napi, emit an aphrodisiac pheromone, citral, from wing glands. This pheromone is requisite for females to accept mating with a courting male. Citral is a mixture of the two geometric isomers geranial (E-isomer) and neral (Z-isomer) in an approximate 1:1 ratio. We found that both these compounds are required to elicit acceptance behavior, which indicates synergistic interaction between processing of the isomers. Using functional Ca2+ imaging we found that geranial and neral evoke significantly different but overlapping glomerular activity patterns in the antennal lobe, which suggests receptors with different affinity for the two isomers. However, these glomeruli were intermingled with glomeruli responding to, for example, plant-related compounds, i.e., no distinct subpopulation of pheromone-responding glomeruli as in moths and other insects. In addition, these glomeruli showed lower specificity than pheromone-activated glomeruli in moths. We could, however, not detect any mixture interactions among four identified glomeruli, indicating that the synergistic effect may be generated at a higher processing level. Furthermore, correlations between glomerular activity patterns evoked by the single isomers and the blend did not change over time. PMID:26973536

Expression of a desaturase gene, desat1, in neural and nonneural tissues separately affects perception and emission of sex pheromones in Drosophila

PubMed Central

Bousquet, François; Nojima, Tetsuya; Houot, Benjamin; Chauvel, Isabelle; Chaudy, Sylvie; Dupas, Stéphane; Yamamoto, Daisuke; Ferveur, Jean-François

2012-01-01

Animals often use sex pheromones for mate choice and reproduction. As for other signals, the genetic control of the emission and perception of sex pheromones must be tightly coadapted, and yet we still have no worked-out example of how these two aspects interact. Most models suggest that emission and perception rely on separate genetic control. We have identified a Drosophila melanogaster gene, desat1, that is involved in both the emission and the perception of sex pheromones. To explore the mechanism whereby these two aspects of communication interact, we investigated the relationship between the molecular structure, tissue-specific expression, and pheromonal phenotypes of desat1. We characterized the five desat1 transcripts—all of which yielded the same desaturase protein—and constructed transgenes with the different desat1 putative regulatory regions. Each region was used to target reporter transgenes with either (i) the fluorescent GFP marker to reveal desat1 tissue expression, or (ii) the desat1 RNAi sequence to determine the effects of genetic down-regulation on pheromonal phenotypes. We found that desat1 is expressed in a variety of neural and nonneural tissues, most of which are involved in reproductive functions. Our results suggest that distinct desat1 putative regulatory regions independently drive the expression in nonneural and in neural cells, such that the emission and perception of sex pheromones are precisely coordinated in this species. PMID:22114190

Synthetic Sex Pheromone in a Long-Lasting Lure Attracts the Visceral Leishmaniasis Vector, Lutzomyia longipalpis, for up to 12 Weeks in Brazil

PubMed Central

Bray, Daniel P.; Carter, Vicky; Alves, Graziella B.; Brazil, Reginaldo P.; Bandi, Krishna K.; Hamilton, James G. C.

2014-01-01

Current control methodologies have not prevented the spread of visceral leishmaniasis (VL) across Brazil. Here, we describe the development of a new tool for controlling the sand fly vector of the disease: a long-lasting lure, which releases a synthetic male sex pheromone, attractive to both sexes of Lutzomyia longipalpis. This device could be used to improve the effectiveness of residual insecticide spraying as a means of sand fly control, attracting L. longipalpis to insecticide-treated animal houses, where they could be killed in potentially large numbers over a number of weeks. Different lure designs releasing the synthetic pheromone (±)-9-methylgermacrene-B (CAS 183158-38-5) were field-tested in Araçatuba, São Paulo (SP). Experiments compared numbers of sand flies caught overnight in experimental chicken sheds with pheromone lures, to numbers caught in control sheds without pheromone. Prototype lures, designed to last one night, were first used to confirm the attractiveness of the pheromone in SP, and shown to attract significantly more flies to test sheds than controls. Longer-lasting lures were tested when new, and at fortnightly intervals. Lures loaded with 1 mg of pheromone did not attract sand flies for more than two weeks. However, lures loaded with 10 mg of pheromone, with a releasing surface of 15 cm2 or 7.5 cm2, attracted female L. longipalpis for up to ten weeks, and males for up to twelve weeks. Approximately five times more sand flies were caught with 7.5 cm2 10 mg lures when first used than occurred naturally in non-experimental chicken resting sites. These results demonstrate that these lures are suitably long-lasting and attractive for use in sand fly control programmes in SP. To our knowledge, this is the first sex pheromone-based technology targeting an insect vector of a neglected human disease. Further studies should explore the general applicability of this approach for combating other insect-borne diseases. PMID:24651528

Phorid fly, Pseudacteon tricuspis, response to alkylpyrazine analogs of a fire ant, Solenopsis invicta, alarm pheromone.

PubMed

Sharma, Kavita; Vander Meer, Robert K; Fadamiro, Henry Y

2011-07-01

The phorid fly, Pseudacteon tricuspis Borgmeier, is a parasitoid of the red imported fire ant, Solenopsis invicta Buren. This fly has been reported to use fire ant chemicals, specifically venom alkaloids and possibly alarm pheromone to locate its host. A recent study identified 2-ethyl-3,6-dimethyl pyrazine as a component of the alarm pheromone of S. invicta. To determine the possible involvement of this fire ant alarm pheromone component in mediating fire ant-phorid fly interactions, we tested electroantennogram (EAG) and behavioral responses of P. tricuspis females to the commercially available mixture of 2-ethyl-3,6-dimethyl pyrazine and its 3,5-dimethyl isomer, as well as six structurally related alkylpyrazine analogs at varying doses. Pseudacteon tricuspis females showed significant EAG response to 2-ethyl-3,6(or 5)-dimethyl pyrazine (herein referred to as pheromone-isomer) at all doses, 0.001-10 μg. Among the tested alkylpyrazine analogs, 2,3-diethyl-5-methyl pyrazine showed significant EAG activity at 0.1 and 1 μg. 2,3-dimethyl pyrazine also showed significant EAG activity at 0.1 μg. Results of four-choice olfactometer bioassays demonstrated significant attraction of P. tricuspis females to the pheromone-isomer (2-ethyl-3,6(or 5)-dimethyl pyrazine) at all tested doses (0.01, 0.1, 1 and 10 μg). The analogs, 2,3-diethyl-5-methyl pyrazine and 2,3-dimethyl pyrazine were significantly better than the control at the higher doses (0.1, 1 and 10 μg). The pheromone-isomer was significantly better than both analogs at two doses, 0.1 and 1 μg. These results confirm that the reported fire ant alarm pheromone component plays a role in mediating attraction of phorid flies to host workers. Venom alkaloids were previously shown to attract P. tricuspis; therefore, we propose that fire ant alarm pheromones may act in tandem or synergistically with venom alkaloids to attract phorid fly parasitoids to fire ant workers. Published by Elsevier Ltd.

Synthetic sex pheromone in a long-lasting lure attracts the visceral leishmaniasis vector, Lutzomyia longipalpis, for up to 12 weeks in Brazil.

PubMed

Bray, Daniel P; Carter, Vicky; Alves, Graziella B; Brazil, Reginaldo P; Bandi, Krishna K; Hamilton, James G C

2014-03-01

Current control methodologies have not prevented the spread of visceral leishmaniasis (VL) across Brazil. Here, we describe the development of a new tool for controlling the sand fly vector of the disease: a long-lasting lure, which releases a synthetic male sex pheromone, attractive to both sexes of Lutzomyia longipalpis. This device could be used to improve the effectiveness of residual insecticide spraying as a means of sand fly control, attracting L. longipalpis to insecticide-treated animal houses, where they could be killed in potentially large numbers over a number of weeks. Different lure designs releasing the synthetic pheromone (±)-9-methylgermacrene-B (CAS 183158-38-5) were field-tested in Araçatuba, São Paulo (SP). Experiments compared numbers of sand flies caught overnight in experimental chicken sheds with pheromone lures, to numbers caught in control sheds without pheromone. Prototype lures, designed to last one night, were first used to confirm the attractiveness of the pheromone in SP, and shown to attract significantly more flies to test sheds than controls. Longer-lasting lures were tested when new, and at fortnightly intervals. Lures loaded with 1 mg of pheromone did not attract sand flies for more than two weeks. However, lures loaded with 10 mg of pheromone, with a releasing surface of 15 cm2 or 7.5 cm2, attracted female L. longipalpis for up to ten weeks, and males for up to twelve weeks. Approximately five times more sand flies were caught with 7.5 cm2 10 mg lures when first used than occurred naturally in non-experimental chicken resting sites. These results demonstrate that these lures are suitably long-lasting and attractive for use in sand fly control programmes in SP. To our knowledge, this is the first sex pheromone-based technology targeting an insect vector of a neglected human disease. Further studies should explore the general applicability of this approach for combating other insect-borne diseases.

The Odour of Sex: Sex-Related Differences in Volatile Compound Composition among Barn Swallow Eggs Carrying Embryos of Either Sex

PubMed Central

Costanzo, Alessandra; Panseri, Sara; Giorgi, Annamaria; Romano, Andrea; Caprioli, Manuela; Saino, Nicola

2016-01-01

Avian communication has been traditionally believed to be mainly mediated by visual and auditory channels. However, an increasing number of studies are disclosing the role of olfaction in the interaction of birds with their social environment and with other species, as well as in other behaviors such as nest recognition, food location and navigation. Olfaction has also been suggested to play a role in parent-offspring communication not only in the post- but also in the pre-hatching period. Volatile compounds produced during embryogenesis and passively released through the eggshell pores may indeed represent the only cue at parents’ disposal to assess offspring quality, including the sex composition of their clutch before hatching. In turn, sex identification before hatching may mediate adaptive strategies of allocation to either sex. In the present study, we analyzed odour composition of barn swallow eggs incubated in their nest in order to identify any sex-related differences in volatile compounds emitted. For the first time in any bird species, we also investigated whether odour composition is associated with relatedness. The evidence of differences in odour composition among eggs containing embryos of either sex indicates that parents have a cue to identify their brood sex composition even before hatching which can be used to modulate their behavior accordingly. Moreover, odour similarity within nests may represent the prerequisite for kin recognition in this species. PMID:27851741

Endocrine disruption of sexual selection by an estrogenic herbicide in the mealworm beetle (Tenebrio molitor).

PubMed

McCallum, Malcolm L; Matlock, Makensey; Treas, Justin; Safi, Barroq; Sanson, Wendy; McCallum, Jamie L

2013-12-01

The role that endocrine disruption could play in sexual selection remains relatively untested, and although estrogens occur in insects, little information exists about their biological role in insect reproduction. Atrazine is a commonly applied herbicide that mimics estrogen in vertebrates. Tenebrio molitor were raised from egg to adult under a gradation of environmentally relevant atrazine exposures and a non-treated control. Atrazine was delivered in the drinking water ad libitum. Female T. molitor were provided with a choice between unrelated males raised under three levels of atrazine exposures. Female preference for males demonstrated a non-monotonic inverted U-shaped response to atrazine exposure. There was no significant difference between the control and the high exposure to atrazine. Excluding the control, female preference increased as exposure concentration increased. These results have important repercussions for nonlethal effects of endocrine disruption on populations, their capacity to interfere with sexual selection, and the role of estrogen in pheromone communication among insects.

In-vitro trials to ascertain sustained release efficacy of assembly pheromone micro particles for the control of brown dog tick, Rhipicephalus sanguineus.

PubMed

Bhoopathy, Dhivya; Bhaskaran Ravi, Latha

2017-12-01

Sustained release micro particles were prepared incorporating assembly pheromone and deltamethrin. Two natural polymers, namely, chitosan and calcium alginate and a synthetic polymer, poly-ε-caprolactone were used for encapsulating the assembly pheromone-acaricide combination. The micro particles were subjected to in vitro evaluation freshly after preparation and then at monthly intervals to assess their sustained release efficacy. The response of the unfed stages of dog tick, Rhipicephalus sanguineus to fresh and aged micro particles was assessed and results were recorded. The micro particles were found to release assembly pheromone in a sustained manner up to 2 months of study period.

Quantitative assessment of pheromone-induced Dauer formation in Caenorhabditis elegans.

PubMed

Neal, Scott J; Kim, Kyuhyung; Sengupta, Piali

2013-01-01

Environmental conditions experienced during early larval stages dictate the developmental trajectory of the nematode C. elegans. Favorable conditions such as low population density, abundant food, and lower temperatures allow reproductive growth, while stressful conditions promote entry of second-stage (L2) larvae into the alternate dauer developmental stage. Population density is signaled by the concentration and composition of a complex mixture of small molecules that is produced by all stages of animals, and is collectively referred to as dauer pheromone; pheromone concentration is a major trigger for dauer formation. Here, we describe a quantitative dauer formation assay that provides a measure of the potency of single or mixtures of pheromone components in regulating this critical developmental decision.

Spatial focalization of pheromone/MAPK signaling triggers commitment to cell–cell fusion

PubMed Central

Merlini, Laura

2016-01-01

Cell fusion is universal in eukaryotes for fertilization and development, but what signals this process is unknown. Here, we show in Schizosaccharomyces pombe that fusion does not require a dedicated signal but is triggered by spatial focalization of the same pheromone–GPCR (G-protein-coupled receptor)–MAPK signaling cascade that drives earlier mating events. Autocrine cells expressing the receptor for their own pheromone trigger fusion attempts independently of cell–cell contact by concentrating pheromone release at the fusion focus, a dynamic actin aster underlying the secretion of cell wall hydrolases. Pheromone receptor and MAPK cascade are similarly enriched at the fusion focus, concomitant with fusion commitment in wild-type mating pairs. This focalization promotes cell fusion by immobilizing the fusion focus, thus driving local cell wall dissolution. We propose that fusion commitment is imposed by a local increase in MAPK concentration at the fusion focus, driven by a positive feedback between fusion focus formation and focalization of pheromone release and perception. PMID:27798845

Disruption by conophthorin of the kairomonal response of sawyer beetles to bark beetle pheromones.

PubMed

Morewood, W D; Simmonds, K E; Gries, R; Allison, J D; Borden, J H

2003-09-01

Antennally active nonhost angiosperm bark volatiles were tested for their ability to reduce the response of three common species of coniferophagous wood-boring Cerambycidae to attractant-baited multiple funnel traps in the southern interior of British Columbia. Of the nonhost volatiles tested, only conophthorin was behaviorally active, disrupting the attraction of sawyer beetles, Monochamus spp., to traps baited with the host volatiles alpha-pinene and ethanol and the bark beetle pheromones ipsenol and ipsdienol. Conophthorin did not affect the attraction of sawyer beetles to the host kairomones alpha-pinene and ethanol in the absence of bark beetle pheromones, nor did it have any behavioral effect on adults of Xylotrechus longitarsis, which were not attracted to bark beetle pheromones. These results indicate that conophthorin does not act as a general repellent for coniferophagous Cerambycidae, as it seems to do for many species of Scolytidae, but has the specific activity of disrupting the kairomonal response of sawyer beetles to bark beetle pheromones.

Concordant preferences for opposite-sex signals? Human pheromones and facial characteristics.

PubMed Central

Cornwell, R. Elisabeth; Boothroyd, Lynda; Burt, D. Michael; Feinberg, David R.; Jones, Ben C.; Little, Anthony C.; Pitman, Robert; Whiten, Susie; Perrett, David I.

2004-01-01

We have investigated whether preferences for masculine and feminine characteristics are correlated across two modalities, olfaction and vision. In study 1, subjects rated the pleasantness of putative male (4,16-androstadien-3-one; 5alpha-androst-16-en-3-one) and female (1,3,5 (10),16-estratetraen-3-ol) pheromones, and chose the most attractive face shape from a masculine-feminine continuum for a long- and a short-term relationship. Study 2 replicated study 1 and further explored the effects of relationship context on pheromone ratings. For long-term relationships, women's preferences for masculine face shapes correlated with ratings of 4,16-androstadien-3-one and men's preferences for feminine face shapes correlated with ratings of 1,3,5(10),16-estratetraen-3-ol. These studies link sex-specific preferences for putative human sex pheromones and sexually dimorphic facial characteristics. Our findings suggest that putative sex pheromones and sexually dimorphic facial characteristics convey common information about the quality of potential mates. PMID:15156922

Pheromone-Based Pest Management in China: Past, Present, and Future Prospects.

PubMed

Cui, Gen Zhong; Zhu, Junwei Jerry

2016-07-01

Semiochemical-based pest management technology has been widely used to monitor and control insect pests in agricultural, forestry, and public health sectors in the western world. It became a popular tool in the early 1970s with tremendous efforts in developing environment-friendly control technologies for the integrated pest management. However, in China, similar research lagged 15 to 20 years and was not initiated until the late 1980s. In this review, we present the early history of pheromone research that has led to the current practical applications in China, particularly in the development of pheromone-based pest management products. We also provide information regarding the current status of pheromone-based product manufacturing, marketing, and regulatory issues related to local semiochemical industries, which may be useful to other international companies interested in pursuing business in China. In addition, we share some research topics that represent new directions of the present pheromone research to explore novel tools for advancing semiochemical-based pest management in China.

Mammalian pheromones VIII Chemical characterization of preorbital gland secretion of grey duiker,Sylvicapra grimmia (Artiodactyla: Bovidae).

PubMed

Burger, B V; Pretorius, P J; Spies, H S; Bigalke, R C; Grierson, G R

1990-02-01

Using gas chromatography-mass spectrometry 33 constituents of the preorbital gland of the grey duiker,Sylvicapra grimmia, were identified as unbranched alkanes, 2-alkanones, alkanals, alkanoic acids, alkan-4-olides, as well as 3-methyl-3-buten-1-ol, (Z)-9-octadecenoic acid, benzyl cyanide, diethyl sulfoxide, 2-isobutyl-1,3-thiazole, 2-isobutyl-4,5-dihydro-1,3-thiazole, and 3,4-epoxy-2-dodecanone. Determination of the relative concentrations of these components in a limited number of secretion samples taken from males and females revealed that in these samples the two thiazole derivatives and the epoxy ketone were present in consistently and significantly higher concentrations in male than in female secretions. This suggests that they could act as sex recognition cues.

Control and monitoring of codling moth (Lepidoptera: Tortricidae) in walnut orchards treated with novel high-load, low-density “meso” dispensers of sex pheromone and pear ester

USDA-ARS?s Scientific Manuscript database

Novel low-density per ha “meso” dispensers loaded with both pear ester, ethyl (E,Z)-2,4-decadienoate, kairomone and codlemone, (E,E)-8,10-dodecadien-1-ol, the sex pheromone of codling moth, Cydia pomonella (L)., were evaluated versus meso dispensers loaded with pheromone-alone for their mating disru...

Foundations of Swarm Intelligence: From Principles to Practice

DTIC Science & Technology

2003-01-01

through the use of chemical substances known as pheromones which have a scent that decays over time through the process of evaporation [6, p. 26...These pheromones form the basis of what amounts to a clever, and apparently simple, communications and information storage and retrieval system. Since... pheromone strength or intensity decays over time, it also provides a very simple information processing mechanism that can implement forms of positive