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Sample records for queen fire ant

  1. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Wang, Lei; Zeng, Ling; Chen, Jian

    2015-12-08

    Neonicotinoid insecticides are commonly used in managing pest insects, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicotinoids on S. invicta has never been investigated. In this study, the newly mated queens were fed with water containing 0.01 or 0.25 μg/ml imidacloprid. Imidacloprid at both concentrations did not cause any increase in queen mortality during the founding stage; however, it significantly reduced queens' brood tending ability. In the 0.25 μg/ml imidacloprid treatment, the time to larval emergence was significantly delayed and no pupae or adult workers were produced. This study provides clear evidence that imidacloprid at sublethal concentrations has a significant detrimental impact on S. invicta queens and the development of incipient colonies.

  2. Effect of irradiation on queen survivorship and reproduction in the invasive fire ant Solenopsis invicta,(Hymenoptera: Formicidae) and a generic phytosanitary irradiation dose for ants

    USDA-ARS?s Scientific Manuscript database

    Ants are common hitchhiker pests on traded agricultural commodities that could be controlled by postharvest irradiation treatment. We studied radiation tolerance in queens of the red imported fire ant Solenopsis invicta Buren to determine the dose sufficient for its control. Virgin or fertile queens...

  3. Queen regulates biogenic amine level and nestmate recognition in workers of the fire ant, Solenopsis invicta

    NASA Astrophysics Data System (ADS)

    Vander Meer, Robert K.; Preston, Catherine A.; Hefetz, Abraham

    2008-12-01

    Nestmate recognition is a critical element in social insect organization, providing a means to maintain territoriality and close the colony to parasites and predators. Ants detect the colony chemical label via their antennae and respond to the label mismatch of an intruder with aggressive behavior. In the fire ant, Solenopsis invicta, worker ability to recognize conspecific nonnestmates decreases if the colony queen is removed, such that they do not recognize conspecific nonnestmates as different. Here, we tested the hypothesis that the presence of the colony queen influences the concentration of octopamine, a neuromodulator, in worker ants, which in turn has an effect on nestmate recognition acuity in workers. We demonstrate that queenless workers exhibit reduced brain octopamine levels and reduced discriminatory acuteness; however, feeding queenless workers octopamine restored both. Dopamine levels are influenced by honeybee queen pheromones; however, levels of this biogenic amine were unchanged in our experiments. This is the first demonstration of a link between the presence of the colony queen, a worker biogenic amine, and conspecific nestmate recognition, a powerful expression of colony cohesion and territoriality.

  4. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    PubMed Central

    Wang, Lei; Zeng, Ling; Chen, Jian

    2015-01-01

    Neonicotinoid insecticides are commonly used in managing pest insects, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicotinoids on S. invicta has never been investigated. In this study, the newly mated queens were fed with water containing 0.01 or 0.25 μg/ml imidacloprid. Imidacloprid at both concentrations did not cause any increase in queen mortality during the founding stage; however, it significantly reduced queens’ brood tending ability. In the 0.25 μg/ml imidacloprid treatment, the time to larval emergence was significantly delayed and no pupae or adult workers were produced. This study provides clear evidence that imidacloprid at sublethal concentrations has a significant detrimental impact on S. invicta queens and the development of incipient colonies. PMID:26643971

  5. Oocyte membrane localization of vitellogenin receptor coincides with queen flying age, and receptor silencing by RNAi disrupts egg formation in fire ant virgin queens.

    PubMed

    Lu, Hsiao-Ling; Vinson, S B; Pietrantonio, Patricia V

    2009-06-01

    In ant species in which mating flights are a strategic life-history trait for dispersal and reproduction, maturation of virgin queens occurs. However, the specific molecular mechanisms that mark this transition and the effectors that control premating ovarian growth are unknown. The vitellogenin receptor (VgR) is responsible for vitellogenin uptake during egg formation in insects. In the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), virgin queens have more abundant VgR transcripts than newly mated queens, but limited egg formation. To elucidate whether the transition to egg production involved changes in VgR expression, we investigated both virgin and mated queens. In both queens, western blot analysis showed an ovary-specific VgR band (approximately 202 kDa), and immunofluorescence analysis of ovaries detected differential VgR localization in early- and late-stage oocytes. However, the VgR signal was much lower in virgin queens ready to fly than in mated queens 8 h post mating flight. In virgin queens, the receptor signal was first observed at the oocyte membrane beginning at day 12 post emergence, coinciding with the 2 weeks of maturation required before a mating flight. Thus, the membrane localization of VgR appears to be a potential marker for queen mating readiness. Silencing of the receptor in virgin queens through RNA interference abolished egg formation, demonstrating that VgR is involved in fire ant ovary development pre mating. To our knowledge, this is the first report of RNA interference in any ant species and the first report of silencing of a hymenopteran VgR.

  6. Venom Alkaloid and Cuticular Hydrocarbon Profiles Are Associated with Social Organization, Queen Fertility Status, and Queen Genotype in the Fire Ant Solenopsis invicta

    PubMed Central

    Eliyahu, Dorit; Ross, Kenneth G.; Haight, Kevin L.; Keller, Laurent

    2013-01-01

    Queens in social insect colonies advertise their presence in the colony to: a) attract workers’ attention and care; b) gain acceptance by workers as replacement or supplemental reproductives; c) prevent reproductive development in nestmates. We analyzed the chemical content of whole body surface extracts of adult queens of different developmental and reproductive stages, and of adult workers from monogyne (single colony queen) and polygyne (multiple colony queens) forms of the fire ant Solenopsis invicta. We found that the composition of the most abundant components, venom alkaloids, differed between queens and workers, as well as between reproductive and non-reproductive queens. Additionally, workers of the two forms could be distinguished by alkaloid composition. Finally, sexually mature, non-reproductive queens from polygyne colonies differed in their proportions of cis-piperidine alkaloids, depending on their Gp-9 genotype, although the difference disappeared once they became functional reproductives. Among the unsaturated cuticular hydrocarbons characteristic of queens, there were differences in amounts of alkenes/alkadienes between non-reproductive polygyne queens of different Gp-9 genotypes, between non-reproductive and reproductive queens, and between polygyne and monogyne reproductive queens, with the amounts increasing at a relatively higher rate through reproductive ontogeny in queens bearing the Gp-9 b allele. Given that the genotype-specific piperidine differences reflect differences in rates of reproductive maturation between queens, we speculate that these abundant and unique compounds have been co-opted to serve in fertility signaling, while the cuticular hydrocarbons now play a complementary role in regulation of social organization by signaling queen Gp-9 genotype. PMID:22095515

  7. Effect of Irradiation on Queen Survivorship and Reproduction in the Invasive Fire Ant Solenopsis invicta (Hymenoptera: Formicidae) and a Proposed Phytosanitary Irradiation Treatment for Ants.

    PubMed

    Follett, Peter A; Porcel, Sol; Calcaterra, Luis A

    2016-12-01

    We studied radiation tolerance in queens of the red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) to identify a dose that prevents reproduction. Virgin or fertile queens were collected from Santa Fe and Formosa provinces in Argentina and reared in the laboratory in microcolonies. Virgin queens were irradiated at 0 (control), 70, 90, 120, or 150 Gy, and fertile queens were irradiated at 0, 60, 125, and 190 Gy, and then followed for 11 wk in the microcolonies to evaluate survival and reproduction. Virgin queens lay trophic eggs that do not hatch, whereas fertile queens lay eggs that hatch and develop into brood. In general, queen oviposition and survival decreased with increasing irradiation dose. For virgin queens, no eggs were laid by irradiated queens after the third week, whereas the control queens continued laying eggs throughout the 11-wk experiment. For fertile queens, only one larva and no pupae was observed in the 60 Gy treatment and no larvae or pupae were observed in the 125 and 190 Gy treatments, whereas a total of 431 larvae and 83 pupae were produced by untreated control queens during 11 wks. Survivorship of virgin and fertile queens was similarly reduced by irradiation treatment. These results with S. invicta are consistent with previous findings for three other invasive ants, Wasmannia auropunctata (Roger), Pheidole megacephala (F.), and Linephithema humile (Mayr), that are hitchhiker pests on fresh horticultural commodities. A radiation dose of 150 Gy is proposed as a phytosanitary treatment to prevent reproduction in ants. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  8. A queen pheromone induces workers to kill sexual larvae in colonies of the red imported fire ant (Solenopsis invicta)

    NASA Astrophysics Data System (ADS)

    Klobuchar, Emily; Deslippe, Richard

    2002-05-01

    We conducted five bioassays to study how queens control the execution of sexual larvae by workers in colonies of the red imported fire ant, Solenopsis invicta. In each assay, subset colonies were made from many large polygyne colonies, and the 20 sexual larvae they contained were monitored over time. Sexual larvae mostly survived in queenless colonies, but were mostly killed in colonies with a single dealated queen, regardless of whether or not the queen was fertilized. The larvae were also killed when fresh corpses of queens were added to queenless colonies. Whereas acetone extracts of queens did not produce a significant increase in killings, extracts in buffered saline induced workers to execute most sexual larvae, indicating successful extraction of an execution pheromone. We identified the probable storage location of the chemical as the poison sac, and found both fresh (1 day) and old (21 day) extracts of poison sacs to be equally effective in inducing executions. The pheromone is stable at room temperature, perhaps because venom alkaloids also present in the extracts keep the pheromone from degrading. It is apparently either proteinaceous or associated with a proteinaceous molecule, a novel finding, as no queen pheromone of a proteinaceous nature has been previously demonstrated in ants.

  9. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Neonicotinoid insecticides are commonly used in managing pest ants, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicot...

  10. Social chromosome variants differentially affect queen determination and the survival of workers in the fire ant Solenopsis invicta.

    PubMed

    Buechel, Séverine D; Wurm, Yanick; Keller, Laurent

    2014-10-01

    Intraspecific variation in social organization is common, yet the underlying causes are rarely known. An exception is the fire ant Solenopsis invicta in which the existence of two distinct forms of social colony organization is under the control of the two variants of a pair of social chromosomes, SB and Sb. Colonies containing exclusively SB/SB workers accept only one single queen and she must be SB/SB. By contrast, when colonies contain more than 10% of SB/Sb workers, they accept several queens but only SB/Sb queens. The variants of the social chromosome are associated with several additional important phenotypic differences, including the size, fecundity and dispersal strategies of queens, aggressiveness of workers, and sperm count in males. However, little is known about whether social chromosome variants affect fitness in other life stages. Here, we perform experiments to determine whether differential selection occurs during development and in adult workers. We find evidence that the Sb variant of the social chromosome increases the likelihood of female brood to develop into queens and that adult SB/Sb workers, the workers that cull SB/SB queens, are overrepresented in comparison to SB/SB workers. This demonstrates that supergenes such as the social chromosome can have complex effects on phenotypes at various stages of development.

  11. Males are here to stay: fertilization enhances viable egg production by clonal queens of the little fire ant ( Wasmannia auropunctata)

    NASA Astrophysics Data System (ADS)

    Miyakawa, Misato O.; Mikheyev, Alexander S.

    2015-04-01

    Evolution of reproduction strategies is affected by both phylogenetic and physiological constraints. Although clonality may benefit females, it may not be selected if a male contribution is necessary to start egg laying and embryo development. In little fire ant, Wasmannia auropunctata, sexual populations employ a typical Hymenopteran system of reproduction. In clonal populations, however, queens and males are produced with only maternal and paternal genomes, respectively, whereas sterile workers are produced sexually. Although this system requires both sexes for worker production, previous work has shown that workers may also be produced clonally by the queens. If so, why are males maintained in this species? Our data suggest that fertilization is necessary to increase the hatching rate of eggs. Although clonal queens can indeed produce both workers and queens without mating, the hatching rate is far below the level necessary to maintain functional colonies. On the other hand, virgin queens from populations exhibiting the original Hymenopteran reproduction system also show low hatching rates, but produce only haploid male eggs. Reasons for the existence of W. auropunctata males have been disputed. However, our data suggest that physiological constraints, such as the requirement for insemination, must be considered in regard to evolution of reproduction systems, in addition to ecological data and theoretical considerations of fitness.

  12. Single-queen introductions characterize regional and local invasions by the facultatively clonal little fire ant Wasmannia auropunctata.

    PubMed

    Mikheyev, A S; Bresson, S; Conant, P

    2009-07-01

    Clonal reproduction may facilitate the spread of invasive species by reducing the minimum population size necessary for successful establishment. We used microsatellite markers to reconstruct the composition of founding populations in two regional (Central Africa and Hawaii) and 23 local (near a Gabonese oilfield) invasions of the facultatively parthenogenetic little fire ant. Central Africa had a single dominant queen clone, which appears to have initiated the regional infestation, and then produced numerous other clones by rare sexual reproduction. This interpretation of the data was also supported by the genotype of a worker from the first collection in Africa (Gabon 1913). We found only a single queen clone in Hawaii, likewise indicating a single-clone introduction, most likely from an earlier infestation in Florida. Single-clone introductions also gave rise to the vast majority (92%) of local infestations at our oilfield study site. These results suggest the unusual, largely clonal, reproductive strategy of the little fire ant may enhance its success as an invasive species. However, the occasional sexual production of novel genotypes after the initial introduction may provide genetic flexibility that overcomes shortcomings of pure clonality.

  13. Dynamic changes in host-virus interactions associated with colony founding and social environment in fire ant queens (Solenopsis invicta).

    PubMed

    Manfredini, Fabio; Shoemaker, DeWayne; Grozinger, Christina M

    2016-01-01

    The dynamics of host-parasite interactions can change dramatically over the course of a chronic infection as the internal (physiological) and external (environmental) conditions of the host change. When queens of social insects found a colony, they experience changes in both their physiological state (they develop their ovaries and begin laying eggs) and the social environment (they suddenly stop interacting with the other members of the mother colony), making this an excellent model system for examining how these factors interact with chronic infections. We investigated the dynamics of host-viral interactions in queens of Solenopsis invicta (fire ant) as they transition from mating to colony founding/brood rearing to the emergence of the first workers. We examined these dynamics in naturally infected queens in two different social environments, where queens either founded colonies as individuals or as pairs. We hypothesized that stress associated with colony founding plays an important role in the dynamics of host-parasite interactions. We also hypothesized that different viruses have different modalities of interaction with the host that can be quantified by physiological measures and genomic analysis of gene expression in the host. We found that the two most prevalent viruses, SINV-1 and SINV-2, are associated with different fitness costs that are mirrored by different patterns of gene expression in the host. In fact SINV-2, the virus that imposes the significant reduction of a queen's reproductive output is also associated with larger changes of global gene expression in the host. These results show the complexity of interactions between S. invicta and two viral parasites. Our findings also show that chronic infections by viral parasites in insects are dynamic processes that may pose different challenges in the host, laying the groundwork for interesting ecological and evolutionary considerations.

  14. Identification, expression, and immuno-reactivity of Sol i 2 & Sol i 4 venom proteins of queen red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae).

    PubMed

    Lockwood, Stephanie A; Haghipour-Peasley, Jilla; Hoffman, Donald R; Deslippe, Richard J

    2012-10-01

    We report on two low-molecular weight proteins that are stored in the venom of queen red imported fire ants (Solenopsis invicta). Translated amino acid sequences identified one protein to have 74.8% identity with the Sol i 2w worker allergen, and the other protein was found to have 96/97% identity with Sol i 4.01w/4.02w worker allergens. Both Sol i 2 and Sol i 4 queen and worker proteins were expressed using pEXP1-DEST vector in SHuffle™ T7 Express lysY Escherichia coli. Proteins were expressed at significant concentrations, as opposed to the μg/ml amounts by our previous expression methods, enabling further study of these proteins. Sol i 2q protein bound weakly to human IgE, sera pooled from allergic patients, whereas Sol i 2w, Sol i 4.01w, and Sol i 4q proteins bound strongly. Despite Sol i 2w and Sol i 2q proteins having 74.8% identity, the queen protein is less immuno-reactive than the worker allergen. This finding is consistent with allergic individuals being less sensitive to queen than worker venom. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. A histochemical and X-ray microanalysis study of calcium changes in insect flight muscle degeneration in Solenopsis, the queen fire ant

    SciTech Connect

    Jones, R.G.; Davis, W.L.; Vinson, S.B.

    1982-04-01

    Potassium pyroantimonate histochemistry, coupled with ethyleneglycoltetraacetic acid (EGTA)-chelation and X-ray microprobe analysis, was employed to localize intracellular calcium binding sites in the normal and degenerating flight musculature in queens of Solenopsis, the fire ant. In normal animals, calcium distribution was light to moderate within myofibrils and mitochondria. In the early contracture stages of the insemination-induced degeneration, both myofilament and mitochondrial calcium loading was markedly increased. In the terminal stages of myofibril breakdown, only Z-lines (isolated or in clusters) with an associated filamentous residue persisted. These complexes were also intensely calcium positive. This study further documents the presence of increased sarcoplasmic calcium during muscle necrosis. Surface membrane defects, mitochondrial calcium overload, and calcium-activated proteases may all be involved in this ''normal'' breakdown process.

  16. Male reproductive fitness and queen polyandry are linked to variation in the supergene Gp-9 in the fire ant Solenopsis invicta

    PubMed Central

    Lawson, Lucinda P.; Vander Meer, Robert K.; Shoemaker, DeWayne

    2012-01-01

    Supergenes are clusters of tightly linked loci maintained in specific allelic combinations to facilitate co-segregation of genes governing adaptive phenotypes. In species where strong selection potentially operates at different levels (e.g. eusocial Hymenoptera), positive selection acting within a population to maintain specific allelic combinations in supergenes may have unexpected consequences for some individuals, including the preservation of disadvantageous traits. The nuclear gene Gp-9 in the invasive fire ant Solenopsis invicta is part of a non-recombining, polymorphic supergene region associated with polymorphism in social organization as well as traits affecting physiology, fecundity and behaviour. We show that both male reproductive success and facultative polyandry in queens have a simple genetic basis and are dependent on male Gp-9 genotype. Gp-9b males are unable to maintain exclusive reproductive control over their mates such that queens mated to Gp-9b males remain highly receptive to remating. Queens mated to multiple Gp-9B males are rare. This difference appears to be independent of mating plug production in fertile males of each Gp-9 genotype. However, Gp-9b males have significantly lower sperm counts than Gp-9B males, which could be a cue to females to seek additional mates. Despite the reduced fitness of Gp-9b males, polygyne worker-induced selective mortality of sexuals lacking b-like alleles coupled with the overall success of the polygyne social form act to maintain the Gp-9b allele within nature. Our findings highlight how strong worker-induced selection acting to maintain the Gp-9b allele in the polygyne social form may simultaneously result in reduced reproductive fitness for individual sexual offspring. PMID:22535783

  17. Male reproductive fitness and queen polyandry are linked to variation in the supergene Gp-9 in the fire ant Solenopsis invicta.

    PubMed

    Lawson, Lucinda P; Vander Meer, Robert K; Shoemaker, Dewayne

    2012-08-22

    Supergenes are clusters of tightly linked loci maintained in specific allelic combinations to facilitate co-segregation of genes governing adaptive phenotypes. In species where strong selection potentially operates at different levels (e.g. eusocial Hymenoptera), positive selection acting within a population to maintain specific allelic combinations in supergenes may have unexpected consequences for some individuals, including the preservation of disadvantageous traits. The nuclear gene Gp-9 in the invasive fire ant Solenopsis invicta is part of a non-recombining, polymorphic supergene region associated with polymorphism in social organization as well as traits affecting physiology, fecundity and behaviour. We show that both male reproductive success and facultative polyandry in queens have a simple genetic basis and are dependent on male Gp-9 genotype. Gp-9(b) males are unable to maintain exclusive reproductive control over their mates such that queens mated to Gp-9(b) males remain highly receptive to remating. Queens mated to multiple Gp-9(B) males are rare. This difference appears to be independent of mating plug production in fertile males of each Gp-9 genotype. However, Gp-9(b) males have significantly lower sperm counts than Gp-9(B) males, which could be a cue to females to seek additional mates. Despite the reduced fitness of Gp-9(b) males, polygyne worker-induced selective mortality of sexuals lacking b-like alleles coupled with the overall success of the polygyne social form act to maintain the Gp-9(b) allele within nature. Our findings highlight how strong worker-induced selection acting to maintain the Gp-9(b) allele in the polygyne social form may simultaneously result in reduced reproductive fitness for individual sexual offspring.

  18. Fire Ant Allergy

    MedlinePlus

    ... Serious Reaction For people with fire ant allergy, stings may cause a life-threatening reaction called anaphylaxis ( ... Fire ants bite with their jaws while they sting. This allows them to pull the stinger out, ...

  19. Dispersal Polymorphisms in Invasive Fire Ants.

    PubMed

    Helms, Jackson A; Godfrey, Aaron

    2016-01-01

    In the Found or Fly (FoF) hypothesis ant queens experience reproduction-dispersal tradeoffs such that queens with heavier abdomens are better at founding colonies but are worse flyers. We tested predictions of FoF in two globally invasive fire ants, Solenopsis geminata (Fabricius, 1804) and S. invicta (Buren, 1972). Colonies of these species may produce two different monogyne queen types-claustral queens with heavy abdomens that found colonies independently, and parasitic queens with small abdomens that enter conspecific nests. Claustral and parasitic queens were similarly sized, but the abdomens of claustral queens weighed twice as much as those of their parasitic counterparts. Their heavier abdomens adversely impacted morphological predictors of flight ability, resulting in 32-38% lower flight muscle ratios, 55-63% higher wing loading, and 32-33% higher abdomen drag. In lab experiments maximum flight durations in claustral S. invicta queens decreased by about 18 minutes for every milligram of abdomen mass. Combining our results into a simple fitness tradeoff model, we calculated that an average parasitic S. invicta queen could produce only 1/3 as many worker offspring as a claustral queen, but could fly 4 times as long and have a 17- to 36-fold larger potential colonization area. Investigations of dispersal polymorphisms and their associated tradeoffs promises to shed light on range expansions in invasive species, the evolution of alternative reproductive strategies, and the selective forces driving the recurrent evolution of parasitism in ants.

  20. Dispersal Polymorphisms in Invasive Fire Ants

    PubMed Central

    Helms, Jackson A.; Godfrey, Aaron

    2016-01-01

    In the Found or Fly (FoF) hypothesis ant queens experience reproduction-dispersal tradeoffs such that queens with heavier abdomens are better at founding colonies but are worse flyers. We tested predictions of FoF in two globally invasive fire ants, Solenopsis geminata (Fabricius, 1804) and S. invicta (Buren, 1972). Colonies of these species may produce two different monogyne queen types—claustral queens with heavy abdomens that found colonies independently, and parasitic queens with small abdomens that enter conspecific nests. Claustral and parasitic queens were similarly sized, but the abdomens of claustral queens weighed twice as much as those of their parasitic counterparts. Their heavier abdomens adversely impacted morphological predictors of flight ability, resulting in 32–38% lower flight muscle ratios, 55–63% higher wing loading, and 32–33% higher abdomen drag. In lab experiments maximum flight durations in claustral S. invicta queens decreased by about 18 minutes for every milligram of abdomen mass. Combining our results into a simple fitness tradeoff model, we calculated that an average parasitic S. invicta queen could produce only 1/3 as many worker offspring as a claustral queen, but could fly 4 times as long and have a 17- to 36-fold larger potential colonization area. Investigations of dispersal polymorphisms and their associated tradeoffs promises to shed light on range expansions in invasive species, the evolution of alternative reproductive strategies, and the selective forces driving the recurrent evolution of parasitism in ants. PMID:27082115

  1. Immune priming and pathogen resistance in ant queens

    PubMed Central

    Gálvez, Dumas; Chapuisat, Michel

    2014-01-01

    Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring. PMID:24963375

  2. Behavioral Plasticity in Ant Queens: Environmental Manipulation Induces Aggression among Normally Peaceful Queens in the Socially Polymorphic Ant Leptothorax acervorum

    PubMed Central

    Trettin, Jürgen; Seyferth, Thomas; Heinze, Jürgen

    2014-01-01

    The behavioral traits that shape the structure of animal societies vary considerably among species but appear to be less flexible within species or at least within populations. Populations of the ant Leptothorax acervorum differ in how queens interact with other queens. Nestmate queens from extended, homogeneous habitats tolerate each other and contribute quite equally to the offspring of the colony (polygyny: low reproductive skew). In contrast, nestmate queens from patchy habitats establish social hierarchies by biting and antennal boxing, and eventually only the top-ranking queen of the colony lays eggs (functional monogyny: high reproductive skew). Here we investigate whether queen-queen behavior is fixed within populations or whether aggression and high skew can be elicited by manipulation of socio-environmental factors in colonies from low skew populations. An increase of queen/worker ratio and to a lesser extent food limitation elicited queen-queen antagonism in polygynous colonies from Nürnberger Reichswald similar to that underlying social and reproductive hierarchies in high-skew populations from Spain, Japan, and Alaska. In manipulated colonies, queens differed more in ovarian status than in control colonies. This indicates that queens are in principle capable of adapting the magnitude of reproductive skew to environmental changes in behavioral rather than evolutionary time. PMID:24743352

  3. Bioturbation by Fire Ants in the Coastal Prairie of Texas

    NASA Astrophysics Data System (ADS)

    Cameron, G.; Williams, L.

    2001-12-01

    Fire ants (Solenopsis invicta) were introduced to the US in the early part of the last century. They have spread throughout the southeastern US in the absence of native competitors and predators with a range limited by abiotic factors. Each fire ant mound contains thousands of individuals, can be large, and can be numerous enough to comprise a dominant feature of the landscape. Studies of this species have focused upon its spread, formation of single- and multiple-queen colonies, genetic structure, and impact on native fauna and human health. Some studies have analyzed native fire ant-soil interactions, but few studies have examined the process of bioturbation by introduced fire ants in native ecosystems. Fire ants on the coastal prairie of Texas primarily are of the multiple-queen type that exhibit a much higher density of mounds than the single-queen type. Consequently, mound-building activities by fire ants can have a marked effect upon soil structure and nutrient content and may affect soil organisms and plants. Fire ant activity, mound density, mound dispersion, soil texture, soil permeability, soil moisture content, and soil nutrients were measured. Fire ants mounds are visible aboveground from April-November. Density of mounds was 117-738/ha, and average mound lifespan was 3.6 months with only 9% of the mounds remaining active throughout the entire season. Mounds were dispersed randomly. Foraging activity by fire ants was from June through October with a peak in July. Annual soil turnover was estimated by collecting and weighing mounds. There was no effect of ant mounds on soil texture, but water infiltration was higher in areas with ant mounds. Early-season samples showed no nutrient differences, but late-season samples showed that ant mounds contained higher amounts of micronutrients than random samples of soil. These data are compared to similar data on effects of mounds from native ants and from native and introduced ants in different habitats.

  4. Alternative mating behaviors of the queen polymorphic ant Temnothorax longispinosus

    NASA Astrophysics Data System (ADS)

    Howard, Kenneth J.; Kennedy, David

    2007-11-01

    Mating behaviors of ants fall into two categories: female calling, in which a female alate releases pheromones that attract males, and male swarming, in which large male aggregations attract females. Female calling is common in species with queens that return to their natal nest to found colonies dependently after mating, while male swarming is common in species with queens that disperse to found independently. In some species that display both founding strategies, a queen-size polymorphism has evolved in which dependent-founding queens are smaller than independent-founding queens. Dependent founding is likely difficult if gynes (virgin queens) are mating in distant swarms. Therefore, a queen may adopt one or the other mating strategy based on its size and founding behavior. We investigated mating behaviors in the queen-polymorphic ant, Temnothorax longispinosus. Observations in laboratory mating arenas indicated that small gynes exhibited significantly lower flight activity than large gynes. Both forms mated in male swarms, and neither form exhibited female calling. The reduced flight activity of the small morph may facilitate returning to the natal nest after mating, provided the mating swarm is located nearby. Therefore, alternative colony-founding behaviors may be possible without the evolution of female-calling behavior; however, the reduced flight activity of small morphs may require that mating swarms are not distant from the natal nest.

  5. Prudent sperm use by leaf-cutter ant queens

    PubMed Central

    den Boer, Susanne P. A.; Baer, Boris; Dreier, Stephanie; Aron, Serge; Nash, David R.; Boomsma, Jacobus J.

    2009-01-01

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants. PMID:19710057

  6. Prudent sperm use by leaf-cutter ant queens.

    PubMed

    den Boer, Susanne P A; Baer, Boris; Dreier, Stephanie; Aron, Serge; Nash, David R; Boomsma, Jacobus J

    2009-11-22

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants.

  7. 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

  8. Queen reproductive tract secretions enhance sperm motility in ants

    PubMed Central

    Baer, Boris; Boomsma, Jacobus J.

    2016-01-01

    Queens of Acromyrmex leaf-cutting ants store sperm of multiple males after a single mating flight, and never remate even though they may live for decades and lay tens of thousands of eggs. Sperm of different males are initially transferred to the bursa copulatrix and compete for access to the long-term storage organ of queens, but the factors determining storage success or failure have never been studied. We used in vitro experiments to show that reproductive tract secretions of Acromyrmex echinatior queens increase sperm swimming performance by at least 50% without discriminating between sperm of brothers and unrelated males. Indiscriminate female-induced sperm chemokinesis makes the likelihood of storage directly dependent on initial sperm viability and thus provides a simple mechanism to secure maximal possible reproductive success of queens, provided that initial sperm motility is an accurate predictor of viability during later egg fertilization. PMID:27807252

  9. Onset of fights and mutual assessment in ant founding queens.

    PubMed

    Berthelot, Kévin; Portugal, Felipe Ramon; Jeanson, Raphaël

    2017-03-01

    In animals, the progress and outcome of contests can be influenced by an individual's own condition, their opponent's condition or a combination of the two. The use of chemical information to assess the quality of rivals has been underestimated despite its central role in the regulation of social interactions in many taxa. Here, we studied pairwise contests between founding queens of the ant Lasius niger to investigate whether the decision to engage in agonistic interactions relies on self-assessment or mutual assessment. Queens modulated their aggressive behaviours depending on both their own status and their opponent's status. We found no influence of lipid stores or size on the onset of fights. However, differences in cuticular chemical signatures linked to fertility status accurately predicted the probability of behaving aggressively in pairs. Our study thus suggests that ant queens could rely on mutual assessment via chemical cues to make informed decisions about fight initiation.

  10. Identification of an ant queen pheromone regulating worker sterility

    PubMed Central

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

    2010-01-01

    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. PMID:20591861

  11. Fire ant microsporidia acquired by parasitoid flies of fire ants

    USDA-ARS?s Scientific Manuscript database

    The microsporidium Kneallhazia (formerly Thelohania) solenopsae and parasitoid flies in the genus Pseudacteon are natural enemies of the invasive fire ant, Solenopsis invicta. Pseudacteon flies oviposit into adult fire ants, where maggots that eclose from eggs migrate to the ants’ head, pupate, and...

  12. Surface lipids of queen-laid eggs do not regulate queen production in a fission-performing ant.

    PubMed

    Ruel, Camille; Lenoir, Alain; Cerdá, Xim; Boulay, Raphaël

    2013-01-01

    In animal societies, most collective and individual decision making depends on the presence of reproductive individuals. The efficient transmission of information among reproductive and non-reproductive individuals is therefore a determinant of colony organization. In social insects, the presence of a queen modulates multiple colonial activities. In many species, it negatively affects worker reproduction and the development of diploid larvae into future queens. The queen mostly signals her presence through pheromone emission, but the means by which these chemicals are distributed in the colony are still unclear. In several ant species, queen-laid eggs are the vehicle of the queen signal. The aim of this study was to investigate whether queen-laid eggs of the ant Aphaenogaster senilis possess queen-specific cuticular hydrocarbons and/or Dufour or poison gland compounds, and whether the presence of eggs inhibited larval development into queens. Our results show that the queen- and worker-laid eggs shared cuticular and Dufour hydrocarbons with the adults; however, their poison gland compounds were not similar. Queen-laid eggs had more dimethylalkanes and possessed a queen-specific mixture of cuticular hydrocarbons composed of 3,11 + 3,9 + 3,7-dimethylnonacosane, in higher proportions than did worker-laid eggs. Even though the queen-laid eggs were biochemically similar to the queen, their addition to experimentally queenless groups did not prevent the development of new queens. More studies are needed on the means by which queen ant pheromones are transmitted in the colony, and how these mechanisms correlates with life history traits.

  13. Surface lipids of queen-laid eggs do not regulate queen production in a fission-performing ant

    NASA Astrophysics Data System (ADS)

    Ruel, Camille; Lenoir, Alain; Cerdá, Xim; Boulay, Raphaël

    2013-01-01

    In animal societies, most collective and individual decision making depends on the presence of reproductive individuals. The efficient transmission of information among reproductive and non-reproductive individuals is therefore a determinant of colony organization. In social insects, the presence of a queen modulates multiple colonial activities. In many species, it negatively affects worker reproduction and the development of diploid larvae into future queens. The queen mostly signals her presence through pheromone emission, but the means by which these chemicals are distributed in the colony are still unclear. In several ant species, queen-laid eggs are the vehicle of the queen signal. The aim of this study was to investigate whether queen-laid eggs of the ant Aphaenogaster senilis possess queen-specific cuticular hydrocarbons and/or Dufour or poison gland compounds, and whether the presence of eggs inhibited larval development into queens. Our results show that the queen- and worker-laid eggs shared cuticular and Dufour hydrocarbons with the adults; however, their poison gland compounds were not similar. Queen-laid eggs had more dimethylalkanes and possessed a queen-specific mixture of cuticular hydrocarbons composed of 3,11 + 3,9 + 3,7-dimethylnonacosane, in higher proportions than did worker-laid eggs. Even though the queen-laid eggs were biochemically similar to the queen, their addition to experimentally queenless groups did not prevent the development of new queens. More studies are needed on the means by which queen ant pheromones are transmitted in the colony, and how these mechanisms correlates with life history traits.

  14. The evolution of queen pheromones in the ant genus Lasius.

    PubMed

    Holman, L; Lanfear, R; d'Ettorre, P

    2013-07-01

    Queen pheromones are among the most important chemical messages regulating insect societies yet they remain largely undiscovered, hindering research into interesting proximate and ultimate questions. Identifying queen pheromones in multiple species would give new insight into the selective pressures and evolutionary constraints acting on these ubiquitous signals. Here, we present experimental and comparative evidence that 3-methylalkanes, hydrocarbons present on the queen's cuticle, are a queen pheromone throughout the ant genus Lasius. Interspecific variation in the chemical profile is consistent with 3-methylalkanes evolving more slowly than other types of hydrocarbons, perhaps due to differential selection or evolutionary constraints. We argue that the sensory ecology of the worker response imposes strong stabilizing selection on queen pheromones relative to other hydrocarbons. 3-Methylalkanes are also strongly physiologically and genetically coupled with fecundity in at least one Lasius species, which may translate into evolutionary constraints. Our results highlight how honest signalling could minimize evolutionary conflict over reproduction, promoting the evolution and maintenance of eusociality. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  15. Release and establishment of the little decapitating fly Pseudacteon cultellatus on imported fire ants in Florida

    USDA-ARS?s Scientific Manuscript database

    The little decapitating fly Pseudacteon cultellatus from Argentina was released as a self-sustaining biological control agent against the red imported fire ant, Solenopsis invicta, in Florida to parasitize small fire ant workers associated with multiple-queen colonies. This fly appears to be establi...

  16. Non-transferable signals on ant queen eggs

    NASA Astrophysics Data System (ADS)

    D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen; Ratnieks, Francis L. W.

    2006-03-01

    How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such “cue scrambling” does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker-laid eggs. Chemical analyses also showed that the surface hydrocarbon profile of these eggs was unchanged. Policing, therefore, is stable against this potential cheating mechanism probably because queen-laid eggs are made chemically distinct using chemicals, that are not easily transferred by physical contact.

  17. Imported fire ants in the southeast

    Treesearch

    David F. Williams

    1998-01-01

    Two species of imported fire ants were introduced into the U.S. at Mobile, Alabama. The black imported fire ant, Solenopsis richteri Forel, was introduced around the early 1900's while the red imported fire ant, Solenopsis invicta Buren entered in the late 1930' or early 1940's. The red imported fire ant is the most...

  18. When invasive ants meet: effects of outbreeding on queen performance in the tramp ant Cardiocondyla itsukii.

    PubMed

    Heinze, Jürgen; Frohschammer, Sabine; Bernadou, Abel

    2017-08-18

    Most disturbed habitats in the tropics and subtropics harbor numerous species of invasive ants, and occasionally the same species has been introduced repeatedly from multiple geographical sources. We examined how experimental crossbreeding between sexuals from different populations affects the fitness of queens of the tramp ant Cardiocondyla itsukii, which is widely distributed in Asia and the Pacific Islands. Eggs laid by queens that mated with nestmate males had a higher hatching rate than eggs laid by queens mated to males from neighboring (Hawaii x Kauai) or distant introduced populations (Hawaii / Kauai x Okinawa). Furthermore, inbreeding queens had a longer lifespan and produced a less female-biased offspring sex ratio than queens from allopatric mating. This suggests that the genetic divergence between different source populations may already be so large that in case of multiple invasions eventual crossbreeding might negatively affect the fitness of tramp ants. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. Are invasive fire ants kept in check by native aerial insectivores?

    PubMed

    Helms, Jackson A; Godfrey, Aaron P; Ames, Tayna; Bridge, Eli S

    2016-05-01

    Aerial predator-prey interactions may impact populations of many terrestrial species. Here, we use altitude loggers to study aerial foraging in a native insectivore, the purple martin (Progne subis), in the southern USA. Purple martins fed primarily on mating queens and males of the invasive red imported fire ant (Solenopsis invicta), and doubled their foraging efficiency by doing so. Across the USA, purple martins likely eat billions of fire ant queens each year, potentially impacting the spread of this species. Alternatively, predation on fire ants may help sustain populations of purple martins and other aerial insectivores.

  20. Asymmetric Dispersal and Colonization Success of Amazonian Plant-Ants Queens

    PubMed Central

    Bruna, Emilio M.; Izzo, Thiago J.; Inouye, Brian D.; Uriarte, Maria; Vasconcelos, Heraldo L.

    2011-01-01

    Background The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. Methodology/Principal Findings We used empirical data and inverse modeling—a technique developed by plant ecologists to model seed dispersal—to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis) having a greater modal distance than two specialists (Pheidole minutula, Azteca sp.) that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. Conclusions/Significance We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the

  1. Tyramides in male alates of black imported fire ants, Solenopsis richetri

    USDA-ARS?s Scientific Manuscript database

    Tyramides were recently reported to exist in males of many ant species in the subfamily Myrmicinae. N-(4-hydroxyphenethyl)ethanamide and N-(4-hydroxyphenethyl)hexanamide were found in S. invicta . Transfer of tyramides from male to newly mated queen was demonstrated in the red imported fire ants. ...

  2. Queen Specific Exocrine Glands in Legionary Ants and Their Possible Function in Sexual Selection

    PubMed Central

    Hölldobler, Bert

    2016-01-01

    The colonies of army ants and some other legionary ant species have single, permanently wingless queens with massive post petioles and large gasters. Such highly modified queens are called dichthadiigynes. This paper presents the unusually rich exocrine gland endowment of dichthadiigynes, which is not found in queens of other ant species. It has been suggested these kinds of glands produce secretions that attract and maintain worker retinues around queens, especially during migration. However, large worker retinues also occur in non-legionary species whose queens do not have such an exuberance of exocrine glands. We argue and present evidence in support of our previously proposed hypothesis that the enormous outfit of exocrine glands found in dichthadiigynes is due to sexual selection mediated by workers as the main selecting agents. PMID:26986740

  3. Selection against aerial dispersal in ants: two non-flying queen phenotypes in Pogonomyrmex laticeps.

    PubMed

    Peeters, Christian; Keller, Roberto A; Johnson, Robert A

    2012-01-01

    The South American seed-harvester ant Pogonomyrmex laticeps has dimorphic queens: ergatoid (permanently wingless) and brachypterous (short, non-functional wings). Surveys in western Argentina indicated that colonies near Chilecito, La Rioja Province, produced only ergatoid queens, while those near Punta Balasto, Catamarca Province (263 km away), produced only brachypterous queens. Brachypterous queens were significantly larger than ergatoid queens for 10 of 11 external characters, but both phenotypes had comparable reproductive potential, i.e., a spermatheca and a similar number of ovarioles. Using normal winged queens of the closely related P. uruguayensis for comparison, we determined that both queen phenotypes in P. laticeps had a full set of dorsal thoracic sclerites, albeit each sclerite was much reduced, whereas workers had a thorax without distinct dorsal sclerites. Sclerites were fused and immobile in ergatoid queens, while they were separable and fully articulated in brachypterous queens. Both phenotypes lacked the big indirect flight muscles, but brachypterous queens retained the tiny direct flight muscles. Overall, this dimorphism across populations indicates that there are alternative solutions to selective pressures against flying queens. We lack field data about colony founding strategy (independent or dependent) for either queen phenotype, but colonies at both sites produced numerous gynes, and we infer that all foundresses initiate colonies independently and are obligate foragers.

  4. Cuticular hydrocarbons as queen adoption cues in the invasive Argentine ant.

    PubMed

    Vásquez, Gissella M; Schal, Coby; Silverman, Jules

    2008-04-01

    In social insects, individuals typically recognize and behave aggressively towards alien conspecifics, thereby maintaining colony integrity. This is presumably achieved via a nestmate recognition system in which cuticular compounds, usually cuticular hydrocarbons (CHC), of genetic and/or environmental origin serve as recognition cues. Most invasive populations of the Argentine ant, Linepithema humile (Mayr), display minimal nestmate-non-nestmate discrimination, resulting in low levels of intraspecific aggression allowing free movement of workers and queens among nests. However, invasive L. humile in the southeastern United States show relatively high levels of intraspecific aggression, and selectively adopt non-nestmate queens. Using behavioral assays and gas chromatography, we found an association between non-nestmate queen adoption and similarity of the CHC profiles of adopted and host colony queens. Also, nestmate and non-nestmate queen CHC profiles became more similar after adoption by queenless colonies. Furthermore, queens treated with non-nestmate queen CHC had distinct CHC profiles and were generally attacked by nestmate workers. We suggest that in L. humile, CHC are used as queen recognition cues, and that queen recognition errors are more likely to occur when the CHC profiles of non-nestmate and host colony queens are similar. Our findings provide further evidence for the complex and dynamic nature of L. humile nestmate discrimination, which may in part underlie the success of introduced populations of this invasive ant.

  5. Thelytokous parthenogenesis by queens in the dacetine ant Pyramica membranifera (Hymenoptera: Formicidae)

    NASA Astrophysics Data System (ADS)

    Ito, Fuminori; Touyama, Yoshifumi; Gotoh, Ayako; Kitahiro, Shungo; Billen, Johan

    2010-08-01

    Thelytokous parthenogenesis in which diploid females are produced from unfertilized eggs, was recently reported for some ant species. Here, we document thelytokous reproduction by queens in the polygynous species Pyramica membranifera. Queens that emerged in the laboratory were kept with or without workers under laboratory conditions. Independent colony founding was successful for a few queens if prey was provided. All artificial colonies, which started with a newly emerged queen and workers produced new workers and some of the colonies also produced female sexuals. Some of the female sexuals shed their wings in the laboratory and started formation of new polygynous colonies. Workers had no ovaries and thus, were obligatorily sterile.

  6. Thelytokous parthenogenesis by queens in the dacetine ant Pyramica membranifera (Hymenoptera: Formicidae).

    PubMed

    Ito, Fuminori; Touyama, Yoshifumi; Gotoh, Ayako; Kitahiro, Shungo; Billen, Johan

    2010-08-01

    Thelytokous parthenogenesis in which diploid females are produced from unfertilized eggs, was recently reported for some ant species. Here, we document thelytokous reproduction by queens in the polygynous species Pyramica membranifera. Queens that emerged in the laboratory were kept with or without workers under laboratory conditions. Independent colony founding was successful for a few queens if prey was provided. All artificial colonies, which started with a newly emerged queen and workers produced new workers and some of the colonies also produced female sexuals. Some of the female sexuals shed their wings in the laboratory and started formation of new polygynous colonies. Workers had no ovaries and thus, were obligatorily sterile.

  7. Octopamine and cooperation: octopamine regulates the disappearance of cooperative behaviours between genetically unrelated founding queens in the ant.

    PubMed

    Koyama, Satoshi; Matsui, Shingo; Satoh, Toshiyuki; Sasaki, Ken

    2015-06-01

    We investigated whether octopamine (OA) is associated with the disappearance of cooperation in Polyrhachis moesta ant queens. Queens of P. moesta facultatively found the colony with genetically unrelated queens. The founding queens perform frequent food exchange with these non-related queens and partake in cooperative brood rearing, whereas single colony queens exclude non-related queens via aggressive behaviour. Thus, aggression is a factor that reduces cooperation. Given that aggression is generally associated with brain OA in insects, we hypothesized that OA controls the behavioural change in cooperation in the ant queen, via an increase in aggression. To test this hypothesis, we compared the amounts of OA and related substances in the brain between founding and colony queens, and observed the interaction of founding queens following oral OA administration. The brain OA levels in colony queens were significantly higher than those in founding queens. Oral administration of OA to founding queens caused significantly less trophallaxis and allogrooming behaviour than in the control founding queens, but with no significant increase in aggression. These results suggest that OA promotes the disappearance of cooperation in founding queens of P. moesta. This is the first study to reveal the neuroendocrine mechanism of cooperation in ant queens.

  8. Experimental manipulation of queen number affects colony sex ratio investment in the highly polygynous ant Formica exsecta

    PubMed Central

    Kümmerli, Rolf; Helms, Ken R; Keller, Laurent

    2005-01-01

    In polygynous (multiple queens per nest) ants, queen dispersal is often limited with young queens being recruited within the parental colony. This mode of dispersal leads to local resource competition between nestmate queens and is frequently associated with extremely male-biased sex ratios at the population level. The queen-replenishment hypothesis has been recently proposed to explain colony sex ratio investment under such conditions. It predicts that colonies containing many queens (subject to high local resource competition) should only produce males, whereas colonies hosting few queens (reduced or no local resource competition) should produce new queens in addition to males. We experimentally tested this hypothesis in the ant Formica exsecta by manipulating queen number over three consecutive years in 120 colonies of a highly polygynous population. Queens were transferred from 40 colonies into another 40 colonies while queen number was not manipulated in 40 control colonies. Genetic analyses of worker offspring revealed that our treatment significantly changed the number of reproductive queens. The sex ratio of colonies was significantly different between treatments in the third breeding season following the experiment initiation. We found that, as predicted by the queen-replenishment hypothesis, queen removal resulted in a significant increase in the proportion of colonies that produced new queens. These results provide the first experimental evidence for the queen-replenishment hypothesis, which might account for sex ratio specialization in many highly polygynous ant species. PMID:16096090

  9. Trail pheromone disruption of red imported fire ant.

    PubMed

    Suckling, David M; Stringer, Lloyd D; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K

    2010-07-01

    The fire ant, Solenopsis invicta (Hymenoptera: Formicidae), is considered one of the most aggressive and invasive species in the world. Toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. The fire ant uses recruitment pheromones to organize the retrieval of large food resources back to the colony, with Z,E-alpha-farnesene responsible for the orientation of workers along trails. We prepared Z,E-alpha-farnesene, (91% purity) from extracted E,E-alpha-farnesene and demonstrated disruption of worker trail orientation after presentation of an oversupply of this compound from filter paper point sources (30 microg). Trails were established between queen-right colony cells and food sources in plastic tubs. Trail-following behavior was recorded by overhead webcam, and ants were digitized before and after presentation of the treatment, using two software approaches. The linear regression statistic, r(2) was calculated. Ants initially showed high linear trail integrity (r(2) = 0.75). Within seconds of presentation of the Z,E-alpha-farnesene treatment, the trailing ants showed little or no further evidence of trail following behavior in the vicinity of the pheromone source. These results show that trailing fire ants become disorientated in the presence of large amounts of Z,E-alpha-farnesene. Disrupting fire ant recruitment to resources may have a negative effect on colony size or other effects yet to be determined. This phenomenon was demonstrated recently for the Argentine ant, where trails were disrupted for two weeks by using their formulated trail pheromone, Z-9-hexadecenal. Further research is needed to establish the long term effects and control potential for trail disruption in S. invicta.

  10. Chemical recognition of partner plant species by foundress ant queens in Macaranga-Crematogaster myrmecophytism.

    PubMed

    Inui, Y; Itioka, T; Murase, K; Yamaoka, R; Itino, T

    2001-10-01

    The partnership in the Crematogaster-Macaranga ant-plant interaction is highly species-specific. Because a mutualistic relationship on a Macaranga plant starts with colonization by a foundress queen of a partner Crematogaster species, we hypothesized that the foundress queens select their partner plant species by chemical recognition. We tested this hypothesis with four sympatric Macaranga species and their Crematogaster plant-ant species. We demonstrated that foundress Crematogaster queens can recognize their partner Macaranga species by contact with the surface of the seedlings, that they can recognize compounds from the stem surface of seedlings of their partner plant species, and that the gas chromatographic profiles are characteristic of the plant species. These findings support the hypothesis that foundress queens of the Crematogaster plant-ant species select their partner Macaranga species by recognizing nonvolatile chemical characteristics of the stem surfaces of seedlings.

  11. The genome of the fire ant Solenopsis invicta

    PubMed Central

    Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana; Corona, Miguel; Nygaard, Sanne; Hunt, Brendan G.; Ingram, Krista K.; Falquet, Laurent; Nipitwattanaphon, Mingkwan; Gotzek, Dietrich; Dijkstra, Michiel B.; Oettler, Jan; Comtesse, Fabien; Shih, Cheng-Jen; Wu, Wen-Jer; Yang, Chin-Cheng; Thomas, Jerome; Beaudoing, Emmanuel; Pradervand, Sylvain; Flegel, Volker; Cook, Erin D.; Fabbretti, Roberto; Stockinger, Heinz; Long, Li; Farmerie, William G.; Oakey, Jane; Boomsma, Jacobus J.; Pamilo, Pekka; Yi, Soojin V.; Heinze, Jürgen; Goodisman, Michael A. D.; Farinelli, Laurent; Harshman, Keith; Hulo, Nicolas; Cerutti, Lorenzo; Xenarios, Ioannis; Shoemaker, DeWayne; Keller, Laurent

    2011-01-01

    Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species. PMID:21282665

  12. The genome of the fire ant Solenopsis invicta.

    PubMed

    Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana; Corona, Miguel; Nygaard, Sanne; Hunt, Brendan G; Ingram, Krista K; Falquet, Laurent; Nipitwattanaphon, Mingkwan; Gotzek, Dietrich; Dijkstra, Michiel B; Oettler, Jan; Comtesse, Fabien; Shih, Cheng-Jen; Wu, Wen-Jer; Yang, Chin-Cheng; Thomas, Jerome; Beaudoing, Emmanuel; Pradervand, Sylvain; Flegel, Volker; Cook, Erin D; Fabbretti, Roberto; Stockinger, Heinz; Long, Li; Farmerie, William G; Oakey, Jane; Boomsma, Jacobus J; Pamilo, Pekka; Yi, Soojin V; Heinze, Jürgen; Goodisman, Michael A D; Farinelli, Laurent; Harshman, Keith; Hulo, Nicolas; Cerutti, Lorenzo; Xenarios, Ioannis; Shoemaker, Dewayne; Keller, Laurent

    2011-04-05

    Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species.

  13. Plasticity in queen number and social structure in the invasive Argentine ant (Linepithema humile).

    PubMed

    Ingram, Krista K

    2002-10-01

    In many polygynous social insect societies, ecological factors such as habitat saturation promote high queen numbers by increasing the cost of solitary breeding. If polygyny is associated with constrained environments, queen number in colonies of invasive social insects should increase as saturation of their new habitat increases. Here I describe the variation in queen number, nestmate relatedness, and nest size along a gradient of time since colonization in an invading population of Argentine ants (Linepithema humile) in Haleakala, Hawaii. Nest densities in this population increase with distance from the leading edge of the invasion, reaching a stable density plateau approximately 80 m from the edge (> 2 years after colonization). Although the number of queens per nest in Haleakala is generally lower than previously reported for Argentine ants, there is significant variation in queen number across this population. Both the observed and effective queen numbers increase across the density gradient, and nests in the center of the population contain queen numbers three to nine times higher than those on the edge of the invasion. The number of workers per nest is correlated with queen number, and nests in the center are six times larger than nests at the edge. Microsatellite analysis of relatedness among nestmates reveals that all nests in the Haleakala population are characterized by low relatedness and have evidence of multiple reproducing queens. Relatedness values are significantly lower in nests in the center of the population, indicating that the number of reproducing queens is greater in areas of high nest density. The variation in queen number and nestmate relatedness in this study is consistent with expectations based on changes in ecological constraints during the invasion of a new habitat, suggesting that the social structure of Argentine ant populations is strongly influenced by ecological factors. Flexibility in social structure may facilitate persistence

  14. Fire ant-detecting canines: a complementary method in detecting red imported fire ants.

    PubMed

    Lin, Hui-Min; Chi, Wei-Lien; Lin, Chung-Chi; Tseng, Yu-Ching; Chen, Wang-Ting; Kung, Yu-Ling; Lien, Yi-Yang; Chen, Yang-Yuan

    2011-02-01

    In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment.

  15. No evidence of volatile chemicals regulating reproduction in a multiple queen ant

    NASA Astrophysics Data System (ADS)

    Coston, Duncan J.; Gill, Richard J.; Hammond, Robert L.

    2011-07-01

    Efficient cooperation in eusocial insect colonies requires effective communication, and there is abundant evidence of non-volatile chemicals playing a role in regulating reproduction within colonies. In contrast, there have been fewer studies investigating the role of volatile chemicals. This study investigated the potential role of volatile chemicals in regulating queen reproduction either by directly inhibiting queen reproduction or by honestly signalling queen fecundity to workers. We tested this using multiple queen colonies of the ant ( Leptothorax acervorum) from a functionally monogynous population where one queen monopolizes all reproduction. Nine colonies, each with an established laying queen, were split to produce two colony fragments—one containing the reproducing queen (group 1) and one containing only previously non-reproducing queens (group 2). Each group was separated by a fine wire mesh preventing physical contact, but allowing volatile chemical contact. In each group 2 fragment, we found that a single formerly non-reproductive queen commenced reproduction and that the rate of egg laying and maximum number of eggs recorded did not significantly differ between groups 1 and 2, results that do not support volatile chemicals as playing a role in regulating queen reproduction. Instead, our findings suggest that physical contact is necessary to maintain functional monogyny.

  16. Queen execution increases relatedness among workers of the invasive Argentine ant, Linepithema humile.

    PubMed

    Inoue, Maki N; Ito, Fuminori; Goka, Koichi

    2015-09-01

    Polygyny in social insects can greatly reduce within-nest genetic relatedness. In polygynous ant species, potential rival queens in colonies with multiple queens are often executed by other queens, workers, or both. The Argentine ant, Linepithema humile, native to South America, forms a "supercolony" that is composed of a large number of nests and is considered to contribute to the ant's invasion success. Currently, four mutually antagonistic supercolonies are contiguously distributed within a small area of Japan. Here, we analyzed the genetic structure and relatedness within and among the four supercolonies using microsatellite markers to clarify how L. humile maintains its supercoloniality. The results of AMOVA and BASP, the F ST values, and the existence of several private alleles indicated that the L. humile population in the Kobe area had a characteristic genetic structure. Within a given supercolony, there was significant genetic differentiation (F ST) among workers collected in May and those collected in September. The significant deviation from Hardy-Weinberg equilibrium increased, and the relatedness among workers significantly increased from May to September in all supercolonies. This result suggested that the supercolonies replaced old queens with new ones during the reproductive season, thus supporting the plausibility of queen execution. From the perspective of kin selection, workers collectively eliminate queens, thereby increasing their own inclusive fitness. Restricted gene flow among supercolonies, together with mating with sib and queen execution, could help to maintain the unique social structure of L. humile, the distribution of which is expanding worldwide.

  17. Young fire ant workers feign death and survive aggressive neighbors

    NASA Astrophysics Data System (ADS)

    Cassill, Deby L.; Vo, Kim; Becker, Brandie

    2008-07-01

    Feigning death is a method of self-defense employed among a wide range of prey species when threatened by predator species. This paper reports on death-feigning behavior by the fire ant, Solenopsis invicta, during intraspecific aggression among neighboring fire ant workers. Days-old workers responded to aggression by death feigning, weeks-old workers responded by fleeing and months-old workers responded by fighting back. By feigning death, days-old workers were four times more likely to survive aggression than older workers. From a proximate perspective, retaliation by young workers against aggressive older workers is certain to fail. With their relatively soft exoskeleton, young workers would be prone to injury and death and unable to execute an effective attack of biting or stinging older workers with harder exoskeletons. From an ultimate perspective, death feigning allows young workers to survive and contribute to brood care and colony growth, both of which are essential to queen survival and fitness.

  18. Young fire ant workers feign death and survive aggressive neighbors.

    PubMed

    Cassill, Deby L; Vo, Kim; Becker, Brandie

    2008-07-01

    Feigning death is a method of self-defense employed among a wide range of prey species when threatened by predator species. This paper reports on death-feigning behavior by the fire ant, Solenopsis invicta, during intraspecific aggression among neighboring fire ant workers. Days-old workers responded to aggression by death feigning, weeks-old workers responded by fleeing and months-old workers responded by fighting back. By feigning death, days-old workers were four times more likely to survive aggression than older workers. From a proximate perspective, retaliation by young workers against aggressive older workers is certain to fail. With their relatively soft exoskeleton, young workers would be prone to injury and death and unable to execute an effective attack of biting or stinging older workers with harder exoskeletons. From an ultimate perspective, death feigning allows young workers to survive and contribute to brood care and colony growth, both of which are essential to queen survival and fitness.

  19. Ant queens adjust egg fertilization to benefit from both sexual and asexual reproduction.

    PubMed

    Aron, S; Timmermans, I; Pearcy, M

    2011-08-23

    An enduring problem in evolutionary biology is the near ubiquity of sexual reproduction despite the inherent cost of transmitting only half the parent's genes to progeny. Queens of some ant species circumvent this cost by using selectively both sexual reproduction and parthenogenesis: workers arise from fertilized eggs, while new queens are produced by parthenogenesis. We show that queens of the ant Cataglyphis cursor maximize the transmission rate of their genes by regulating the proportion of fertilized and parthenogenetic eggs laid over time. Parthenogenetic offspring are produced in early spring, when workers raise the brood into sexuals. After the mating period, queens lay mostly fertilized eggs that will be reared as the non-reproductive caste. This journal is © 2011 The Royal Society

  20. Ant queens adjust egg fertilization to benefit from both sexual and asexual reproduction

    PubMed Central

    Aron, S.; Timmermans, I.; Pearcy, M.

    2011-01-01

    An enduring problem in evolutionary biology is the near ubiquity of sexual reproduction despite the inherent cost of transmitting only half the parent's genes to progeny. Queens of some ant species circumvent this cost by using selectively both sexual reproduction and parthenogenesis: workers arise from fertilized eggs, while new queens are produced by parthenogenesis. We show that queens of the ant Cataglyphis cursor maximize the transmission rate of their genes by regulating the proportion of fertilized and parthenogenetic eggs laid over time. Parthenogenetic offspring are produced in early spring, when workers raise the brood into sexuals. After the mating period, queens lay mostly fertilized eggs that will be reared as the non-reproductive caste. PMID:21307046

  1. Hey! A Fire Ant Stung Me!

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? Hey! A Fire Ant Stung Me! KidsHealth > For Kids > Hey! A Fire Ant Stung Me! Print A A ... For Kids For Parents MORE ON THIS TOPIC Hey! A Bee Stung Me! Hey! A Scorpion Stung ...

  2. Higher expression of somatic repair genes in long-lived ant queens than workers

    PubMed Central

    Lucas, Eric R.; Privman, Eyal; Keller, Laurent

    2016-01-01

    Understanding why organisms senesce is a fundamental question in biology. One common explanation is that senescence results from an increase in macromolecular damage with age. The tremendous variation in lifespan between genetically identical queen and worker ants, ranging over an order of magnitude, provides a unique system to study how investment into processes of somatic maintenance and macromolecular repair influence lifespan. Here we use RNAseq to compare patterns of expression of genes involved in DNA and protein repair of age-matched queens and workers. There was no difference between queens and workers in 1-day-old individuals, but the level of expression of these genes increased with age and this up-regulation was greater in queens than in workers, resulting in significantly queen-biased expression in 2-month-old individuals in both legs and brains. Overall, these differences are consistent with the hypothesis that higher longevity is associated with increased investment into somatic repair. PMID:27617474

  3. Transcriptomic Signatures Mirror the Lack of the Fecundity/Longevity Trade-Off in Ant Queens

    PubMed Central

    von Wyschetzki, Katharina; Rueppell, Olav; Oettler, Jan; Heinze, Jürgen

    2015-01-01

    Life-history theory predicts a trade-off between reproductive investment and self-maintenance. The negative association between fertility and longevity found throughout multicellular organisms supports this prediction. As an important exception, the reproductives of many eusocial insects (ants, bees, and termites) are simultaneously very long-lived and highly fertile. Here, we examine the proximate basis for this exceptional relationship by comparing whole-body transcriptomes of differently aged queens of the ant Cardiocondyla obscurior. We show that the sets of genes differentially expressed with age significantly overlap with age-related expression changes previously found in female Drosophila melanogaster. We identified several developmental processes, such as the generation of neurons, as common signatures of aging. More generally, however, gene expression in ant queens and flies changes with age mainly in opposite directions. In contrast to flies, reproduction-associated genes were upregulated and genes associated with metabolic processes and muscle contraction were downregulated in old relative to young ant queens. Furthermore, we searched for putative C. obscurior longevity candidates associated with the previously reported lifespan-prolonging effect of mating by comparing the transcriptomes of queens that differed in mating and reproductive status. We found 21 genes, including the putative aging candidate NLaz (an insect homolog of APOD), which were consistently more highly expressed in short-lived, unmated queens than in long-lived, mated queens. Our study provides clear evidence that the alternative regulation of conserved molecular pathways that mediate the interplay among mating, egg laying, and aging underlies the lack of the fecundity/longevity trade-off in ant queens. PMID:26341296

  4. Sampling High-Altitude and Stratified Mating Flights of Red Imported Fire Ant

    USDA-ARS?s Scientific Manuscript database

    With the exception of an airplane equipped with nets, no method has been developed that successfully samples red imported fire ant, Solenopsis invicta Buren, sexuals in mating/dispersal flights throughout their potential altitudinal trajectories. We developed and tested a method for sampling queens ...

  5. Queen pheromones modulate DNA methyltransferase activity in bee and ant workers

    PubMed Central

    Holman, Luke; Trontti, Kalevi; Helanterä, Heikki

    2016-01-01

    DNA methylation is emerging as an important regulator of polyphenism in the social insects. Research has concentrated on differences in methylation between queens and workers, though we hypothesized that methylation is involved in mediating other flexible phenotypes, including pheromone-dependent changes in worker behaviour and physiology. Here, we find that exposure to queen pheromone affects the expression of two DNA methyltransferase genes in Apis mellifera honeybees and in two species of Lasius ants, but not in Bombus terrestris bumblebees. These results suggest that queen pheromones influence the worker methylome, pointing to a novel proximate mechanism for these key social signals. PMID:26814223

  6. Queen pheromones modulate DNA methyltransferase activity in bee and ant workers.

    PubMed

    Holman, Luke; Trontti, Kalevi; Helanterä, Heikki

    2016-01-01

    DNA methylation is emerging as an important regulator of polyphenism in the social insects. Research has concentrated on differences in methylation between queens and workers, though we hypothesized that methylation is involved in mediating other flexible phenotypes, including pheromone-dependent changes in worker behaviour and physiology. Here, we find that exposure to queen pheromone affects the expression of two DNA methyltransferase genes in Apis mellifera honeybees and in two species of Lasius ants, but not in Bombus terrestris bumblebees. These results suggest that queen pheromones influence the worker methylome, pointing to a novel proximate mechanism for these key social signals. © 2016 The Author(s).

  7. Small queens and big-headed workers in a monomorphic ponerine ant

    NASA Astrophysics Data System (ADS)

    Kikuchi, Tomonori; Miyazaki, Satoshi; Ohnishi, Hitoshi; Takahashi, Junichi; Nakajima, Yumiko; Tsuji, Kazuki

    2008-10-01

    Evolution of caste is a central issue in the biology of social insects. Comparative studies on their morphology so far suggest the following three patterns: (1) a positive correlation between queen worker size dimorphism and the divergence in reproductive ability between castes, (2) a negative correlation among workers between morphological diversity and reproductive ability, and (3) a positive correlation between queen worker body shape difference and the diversity in worker morphology. We conducted morphological comparisons between castes in Pachycondyla luteipes, workers of which are monomorphic and lack their reproductive ability. Although the size distribution broadly overlapped, mean head width, head length, and scape length were significantly different between queens and workers. Conversely, in eye length, petiole width, and Weber’s length, the size differences were reversed. The allometries (head length/head width, scape length/head width, and Weber’s length/head width) were also significantly different between queens and workers. Morphological examinations showed that the body shape was different between queens and workers, and the head part of workers was disproportionately larger than that of queens. This pattern of queen worker dimorphism is novel in ants with monomorphic workers and a clear exception to the last pattern. This study suggests that it is possible that the loss of individual-level selection, the lack of reproductive ability, influences morphological modification in ants.

  8. Measuring inotocin receptor gene expression in chronological order in ant queens.

    PubMed

    Chérasse, Sarah; Aron, Serge

    2017-09-24

    In vertebrates and invertebrates, oxytocin/vasopressin-like peptides modulate a variety of behaviors. The recent discovery of the gene and receptor sequences of inotocin, the insect ortholog of oxytocin/vasopressin, opens new opportunities for understanding the role of this peptide family in regulating behaviors in the most populated class of living animals. Ants live in highly organized colonies. Once a year, they produce future queens that soon leave the nest to mate and found new colonies. During the first months of their lives, ant queens display a sequence of behaviors ranging from copulation and social interactions to violent fighting. In order to investigate the potential roles of inotocin in shaping queen behavior, we measured gene expression of the inotocin receptor in the heads of Lasius niger ant queens at different points in time. The highest levels of expression occurred early in queen life when they experience crowded conditions in their mother nests and soon thereafter set out to mate. Inotocin could thus be involved in regulating social and reproductive behaviors as reported in other animals. While oxytocin and vasopressin are also involved in aggression in mammals, we found no direct link between these behaviors and inotocin receptor expression in L. niger. Our study provides a first glimpse into the roles the inotocin receptor might play in regulating important processes in ant physiology and behavior. Further studies are needed to understand the molecular function of this complex signaling system in more detail. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Queens defense by workers in the highly polygynous ant Crematogaster pygmaea (Hymenoptera: Myrmicinae).

    PubMed

    Martins Segundo, Glauco Bezerra; de Biseau, Jean-Christophe; Quinet, Yves

    2012-11-01

    Some aspects of the biology of Crematogaster pygmaea, a highly polydomous and polygynous ant, are more commonly found in monogynous species. One such characteristic is the high attractiveness of its queens. In this study, this attractiveness was assessed under varying experimental conditions to investigate the factors responsible for its expression and variation, and to identify the nature of queen attractiveness. It was shown (1) that C. pygmaea queens are highly attractive to the workers that cluster on and around them (retinue), (2) that the attractiveness of C. pygmaea queens is context-dependent, i.e., it increases with increasing degree of potential danger to the queen, (3) that the attractiveness signal of C. pygmaea queens is chemically based, and (4) that this signal is persistent and apparently not colony-specific. The proposed hypothesis is that the C. pygmaea queens constantly release an attractiveness signal that is "read" by the workers, in a dependent way linked to the context, and that the main function of this attractiveness is to protect queens. This protection would have a high adaptive value in the context of the social structure and the reproductive strategies in C. pygmaea.

  10. Facultative use of thelytokous parthenogenesis for queen production in the polyandrous ant Cataglyphis cursor.

    PubMed

    Doums, C; Cronin, A L; Ruel, C; Fédérici, P; Haussy, C; Tirard, C; Monnin, T

    2013-07-01

    The evolutionary paradox of sex remains one of the major debates in evolutionary biology. The study of species capable of both sexual and asexual reproduction can elucidate factors important in the evolution of sex. One such species is the ant Cataglyphis cursor, where the queen maximizes the transmission of her genes by producing new queens (gynes) asexually while simultaneously maintaining a genetically diverse workforce via the sexual production of workers. We show that the queen can also produce gynes sexually and may do so to offset the costs of asexual reproduction. We genotyped 235 gynes from 18 colonies and found that half were sexually produced. A few colonies contained both sexually and asexually produced gynes. Although workers in this species can also use thelytoky, we found no evidence of worker production of gynes based on genotypes of 471 workers from the six colonies producing sexual gynes. Gynes are thus mainly, and potentially exclusively, produced by the queen. Simulations of gynes inbreeding level following one to ten generations of automictic thelytoky suggest that the queen switches between or combines thelytoky and sex, which may reduce the costs of inbreeding. This is supported by the relatively small size of inbred gynes in one colony, although we found no relationship between the level of inbreeding and immune parameters. Such facultative use of sex and thelytoky by individual queens contrasts with other known forms of parthenogenesis in ants, which are typically characterized by distinct lineages specializing in one strategy or the other.

  11. Usefulness of fire ant genetics in insecticide efficacy trials

    USDA-ARS?s Scientific Manuscript database

    Mature fire ant colonies contain an average of 80,000 worker ants. For this study, eight fire ant workers were randomly sampled from each colony. DNA fingerprints for each individual ant were generated using 21 simple sequence repeats (SSR) markers that were developed from fire ant DNA by other lab...

  12. Virgin ant queens mate with their own sons to avoid failure at colony foundation

    NASA Astrophysics Data System (ADS)

    Schmidt, Christine Vanessa; Frohschammer, Sabine; Schrempf, Alexandra; Heinze, Jürgen

    2014-01-01

    Mother-son mating (oedipal mating) is practically non-existent in social Hymenoptera, as queens typically avoid inbreeding, mate only early in life and do not mate again after having begun to lay eggs. In the ant genus Cardiocondyla mating occurs among sib in the natal nests. Sex ratios are extremely female-biased and young queens face the risk of remaining without mating partners. Here, we show that virgin queens of Cardiocondyla argyrotricha produce sons from their own unfertilized eggs and later mate with them to produce female offspring from fertilized eggs. Oedipal mating may allow C. argyrotricha queens to found new colonies when no mating partners are available and thus maintains their unusual life history combining monogyny, mating in the nest, and low male production. Our result indicates that a trait that sporadically occurs in solitary haplodiploid animals may evolve also in social Hymenoptera under appropriate ecological and social conditions.

  13. Chemical profiles of mated and virgin queens, egg-laying intermorphs and workers of the ant Crematogaster smithi.

    PubMed

    Oettler, Jan; Schmitt, Thomas; Herzner, Gudrun; Heinze, Jürgen

    2008-04-01

    Many colonies of the North American ant Crematogaster smithi contain a "third female caste" in addition to queens and workers. These "intermorphs" are morphological intermediate of queens and workers and have well-developed ovaries but lack a spermatheca for the storage of sperm. They are specialised for laying large numbers of unfertilised, viable eggs, most of which serve as food for larvae and adults, though a few may eventually develop into males. Based on the assumption that cuticular hydrocarbons (CHCs) in social insects honestly signal the reproductive status of an individual we investigated the CHC of mated mature queens, virgin queens, intermorphs and workers. We expected intermorphs to show chemical profiles intermediate between those of mated queens and non-reproductive workers. A discriminant analysis of the chemical profiles reliably separated queens, virgin queens, and workers, but failed to distinguish between queens and intermorphs even though workers were apparently capable of doing so.

  14. Opposable spines facilitate fine and gross object manipulation in fire ants.

    PubMed

    Cassill, Deby; Greco, Anthony; Silwal, Rajesh; Wang, Xuefeng

    2007-04-01

    Ants inhabit diverse terrestrial biomes from the Sahara Desert to the Arctic tundra. One factor contributing to the ants' successful colonization of diverse geographical regions is their ability to manipulate objects when excavating nests, capturing, transporting and rendering prey or grooming, feeding and transporting helpless brood. This paper is the first to report the form and function of opposable spines on the foretarsi of queens and workers used during fine motor and gross motor object manipulation in the fire ant, Solenopsis invicta. In conjunction with their mandibles, queens and workers used their foretarsi to grasp and rotate eggs, push or pull thread-like objects out of their way or push excavated soil pellets behind them for disposal by other workers. Opposable spines were found on the foretarsi of workers from seven of eight other ant species suggesting that they might be a common feature in the Formicidae.

  15. Winged queens replaced by reproductives smaller than workers in Mystrium ants

    NASA Astrophysics Data System (ADS)

    Molet, Mathieu; Peeters, Christian; Fisher, Brian L.

    2007-04-01

    In ants, winged queens that are specialized for independent colony foundation can be replaced by wingless reproductives better adapted for colony fission. We studied this shift in reproductive strategy by comparing two Mystrium species from Madagascar using morphometry, allometry and dissections. Mystrium rogeri has a single dealate queen in each colony with a larger thorax than workers and similar mandibles that allow these queens to hunt during non-claustral foundation. In contrast, Mystrium ‘red’ lacks winged queens and half of the female adults belong to a wingless ‘intermorph’ caste smaller and allometrically distinct from the workers. Intermorphs have functional ovaries and spermatheca while those of workers are degenerate. Intermorphs care for brood and a few mate and reproduce making them an all-purpose caste that takes charge of both work and reproduction. However, their mandibles are reduced and inappropriate for hunting centipedes, unlike the workers’ mandibles. This together with their small thorax disallow them to perform independent colony foundation, and colonies reproduce by fission. M. rogeri workers have mandibles polymorphic in size and shape, which allow for all tasks from brood care to hunting. In M. ‘red’, colonial investment in reproduction has shifted from producing expensive winged queens to more numerous helpers. M. ‘red’ intermorphs are the first case of reproductives smaller than workers in ants and illustrate their potential to diversify their caste system for better colonial economy.

  16. Colony fusion in Argentine ants is guided by worker and queen cuticular hydrocarbon profile similarity.

    PubMed

    Vásquez, Gissella M; Schal, Coby; Silverman, Jules

    2009-08-01

    Introduced populations of the Argentine ant, Linepithema humile, have experienced moderate to severe losses of genetic diversity, which may have affected nestmate recognition to various degrees. We hypothesized that cuticular hydrocarbons (CHC) serve as nestmate recognition cues, and facilitate colony fusion of unrelated L. humile colonies that share similar CHC profiles. In this study, we paired six southeastern U.S. L. humile colonies in a 6-month laboratory fusion assay, and determined if worker and queen CHC profile similarity between colonies was associated with colony fusion and intercolony genetic similarity. We also compared worker and queen CHC profiles between fused colony pairs and unpaired controls to determine if worker and queen chemical profiles changed after fusion. We found that colony fusion correlated with the CHC similarity of workers and queens, with the frequency of fusion increasing with greater CHC profile similarity between colonies. Worker and queen CHC profile similarity between colonies also was associated with genetic similarity between colonies. Queen CHC profiles in fused colonies appeared to be a mix of the two colony phenotypes. In contrast, when only one of the paired colonies survived, the CHC profile of the surviving queens did not diverge from that of the colony of origin. Similarly, workers in non-fused colonies maintained their colony-specific CHC, whereas in fused colonies the worker CHC profiles were intermediate between those of the two colonies. These results suggest a role for CHC in regulating interactions among mutually aggressive L. humile colonies, and demonstrate that colony fusion correlates with both genetic and CHC similarities. Further, changes in worker and queen chemical profiles in fused colonies suggest that CHC plasticity may sustain the cohesion of unrelated L. humile colonies that had fused.

  17. Impact of red imported fire ant infestation on northern bobwhite quail abundance trends in southeastern United States

    USGS Publications Warehouse

    Allen, C.R.; Willey, R.D.; Myers, P.E.; Horton, P.M.; Buffa, J.

    2000-01-01

    Northern bobwhite quail (Colinus virginianus L.) populations are declining throughout their range. One factor contributing to the decline in the southeastern United States may be the red imported fire ant (Solenopsis invicta Buren). Recent research in Texas has documented that red imported fire ants can have a significant impact on northern bobwhite quail. That research was conducted in areas where fire ants are predominately polygynous (multiple queen). Polygynous infestations have much higher mound densities than the monogynous (single queen) form. In most of the southeastern United States, fire ants are predominately monogynous. We determined if there was a relationship between the invasion of monogynous red imported fire ants and abundance trends in northern bobwhite quail in the southeastern United States. For Florida, Georgia, and South Carolina we compared average northern bobwhite quail abundance based on Christmas Bird Count data for each county before and after fire ant invasion, and conducted regression analyses on bobwhite quail abundance and year preinvasion, and abundance and year postinvasion. Regionally, northern bobwhite quail were more abundant before (0.067 ??0.018 bobwhite quail per observer hour) than after fire ants invaded (0.019 ?? 0.006; Z = -3.746, df = 18, P 30-yr variation in invasion dates.

  18. An oral bioassay for the toxicity of hydramethylnon to individual workers and queens of Argentine ants, Linepithema humile.

    PubMed

    Hooper-Bùi, L M; Rust, M K

    2001-11-01

    We have developed an oral bioassay to determine the toxicity of hydramethylnon to individual workers and queens of the Argentine ant, Linepithema humile. We fed seven concentrations of hydramethylnon in suspension to individual workers or queens, determined the amount of hydramethylnon ingested and evaluated the individual ants for mortality 14 days later. At concentrations > or = 0.37 g liter-1, the amount of liquid the queens ingested decreased dramatically, indicating that Argentine ant queens may detect hydramethylnon. Significantly larger volumes of the two highest concentrations of the hydramethylnon suspension were ingested by the workers, compared to the lower concentrations, suggesting that hydramethylnon may act as a feeding stimulant for the workers. Worker mortality was higher than queen mortality at the highest concentrations tested. The highest worker mortality resulted when the ants ingested 1.03 micrograms of hydramethylnon per mg of ant tissue. At the highest concentration (1.0 g liter-1) tested, workers ingested almost 12 times as much active ingredient per mg of body weight as did queens, suggesting that, in order to increase mortality of queens, multiple feedings must occur.

  19. Colony fusion and worker reproduction after queen loss in army ants

    PubMed Central

    Kronauer, Daniel J. C.; Schöning, Caspar; d'Ettorre, Patrizia; Boomsma, Jacobus J.

    2010-01-01

    Theory predicts that altruism is only evolutionarily stable if it is preferentially directed towards relatives, so that any such behaviour towards seemingly unrelated individuals requires scrutiny. Queenless army ant colonies, which have anecdotally been reported to fuse with queenright foreign colonies, are such an enigmatic case. Here we combine experimental queen removal with population genetics and cuticular chemistry analyses to show that colonies of the African army ant Dorylus molestus frequently merge with neighbouring colonies after queen loss. Merging colonies often have no direct co-ancestry, but are on average probably distantly related because of overall population viscosity. The alternative of male production by orphaned workers appears to be so inefficient that residual inclusive fitness of orphaned workers might be maximized by indiscriminately merging with neighbouring colonies to increase their reproductive success. We show that worker chemical recognition profiles remain similar after queen loss, but rapidly change into a mixed colony Gestalt odour after fusion, consistent with indiscriminate acceptance of alien workers that are no longer aggressive. We hypothesize that colony fusion after queen loss might be more widespread, especially in spatially structured populations of social insects where worker reproduction is not profitable. PMID:19889701

  20. Opposable spines facilitate fine and gross object manipulation in fire ants

    NASA Astrophysics Data System (ADS)

    Cassill, Deby; Greco, Anthony; Silwal, Rajesh; Wang, Xuefeng

    2007-04-01

    Ants inhabit diverse terrestrial biomes from the Sahara Desert to the Arctic tundra. One factor contributing to the ants’ successful colonization of diverse geographical regions is their ability to manipulate objects when excavating nests, capturing, transporting and rendering prey or grooming, feeding and transporting helpless brood. This paper is the first to report the form and function of opposable spines on the foretarsi of queens and workers used during fine motor and gross motor object manipulation in the fire ant, Solenopsis invicta. In conjunction with their mandibles, queens and workers used their foretarsi to grasp and rotate eggs, push or pull thread-like objects out of their way or push excavated soil pellets behind them for disposal by other workers. Opposable spines were found on the foretarsi of workers from seven of eight other ant species suggesting that they might be a common feature in the Formicidae.

  1. [The queen technic for ant control. I. The effect of tepa on laboratory colonies of the pharaoh ant].

    PubMed

    Berndt, K P; Nitschmann, J

    1977-02-01

    The present paper discussed at the example of Tepa [Tris (1-aziridinyl) phosphine oxide] in which manner the control of pharaoh's ant in the sense of the "queen technique" with chemosterilants is possible; which points of view must be considered and which condition an acceptable substance should be fulfilled. The application of Tepa is ralized according to various techniques (e.g. dipping, baiting, tarsal contact), in the course of which the baiting technique is preferred. The influence of different concentrations in various baits on the brood, workers and queens are described. In baits with 1% of the substance a permanent sterilization could be achieved. In combination with other population depressing factors (larval and worker mortality) resulted in eradication of the colonies. The action extended also to the larvae of the sexuals, so that the queenless colonies failed in the production of new queens and males. Histological investigations showed in the females at higher concentrations distinct pathological alterations (pycnosis, vacuolizations, proliferation in the follicles epithelium); whereas the spermatogenesis in the males is decreased but not entirely suppressed. At lower concentrations only the fertility but not the fecundity was influenced. A handing-over of recessive lethal mutations to the progeny does not take place. The practical points of view for the use of chemosterilants in the control of pharaoh's ant are discussed. Whereas the low biological stability of Tepa does not exclude an introduction in the practice, the high mutagenic activity prevents an application in the field.

  2. Fatty Amines from Little Black Ants, Monomorium minimum, and Their Biological Activities Against Red Imported Fire Ants, Solenopsis invicta.

    PubMed

    Wang, Lei; Chen, Jian

    2015-08-01

    Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum.

  3. Alternative genetic foundations for a key social polymorphism in fire ants.

    PubMed

    Ross, Kenneth G; Krieger, Michael J B; Shoemaker, D DeWayne

    2003-12-01

    Little is known about the genetic foundations of colony social organization. One rare example in which a single major gene is implicated in the expression of alternative social organizations involves the presumed odorant-binding protein gene Gp-9 in fire ants. Specific amino acid substitutions in this gene invariably are associated with the expression of monogyny (single queen per colony) or polygyny (multiple queens per colony) in fire ant species of the Solenopsis richteri clade. These substitutions are hypothesized to alter the abilities of workers to recognize queens and thereby regulate their numbers in a colony. We examined whether these same substitutions underlie the monogyny/polygyny social polymorphism in the distantly related fire ant S. geminata. We found that Gp-9 coding region sequences are identical in the polygyne and monogyne forms of this species, disproving our hypothesis that one or a few specific amino acid replacements in the protein are necessary to induce transitions in social organization in fire ants. On the other hand, polygyne S. geminata differs genetically from the monogyne form in ways not mirrored in the two forms of S. invicta, a well-studied member of the S. richteri clade, supporting the conclusion that polygyny did not evolve via analogous routes in the two lineages. Specifically, polygyne S. geminata has lower genetic diversity and different gene frequencies than the monogyne form, suggesting that the polygyne form originated via a founder event from a local monogyne population. These comparative data suggest an alternative route to polygyny in S. geminata in which loss of allelic variation at genes encoding recognition cues has led to a breakdown in discrimination abilities and the consequent acceptance of multiple queens in colonies.

  4. Alternative genetic foundations for a key social polymorphism in fire ants.

    PubMed Central

    Ross, Kenneth G; Krieger, Michael J B; Shoemaker, D DeWayne

    2003-01-01

    Little is known about the genetic foundations of colony social organization. One rare example in which a single major gene is implicated in the expression of alternative social organizations involves the presumed odorant-binding protein gene Gp-9 in fire ants. Specific amino acid substitutions in this gene invariably are associated with the expression of monogyny (single queen per colony) or polygyny (multiple queens per colony) in fire ant species of the Solenopsis richteri clade. These substitutions are hypothesized to alter the abilities of workers to recognize queens and thereby regulate their numbers in a colony. We examined whether these same substitutions underlie the monogyny/polygyny social polymorphism in the distantly related fire ant S. geminata. We found that Gp-9 coding region sequences are identical in the polygyne and monogyne forms of this species, disproving our hypothesis that one or a few specific amino acid replacements in the protein are necessary to induce transitions in social organization in fire ants. On the other hand, polygyne S. geminata differs genetically from the monogyne form in ways not mirrored in the two forms of S. invicta, a well-studied member of the S. richteri clade, supporting the conclusion that polygyny did not evolve via analogous routes in the two lineages. Specifically, polygyne S. geminata has lower genetic diversity and different gene frequencies than the monogyne form, suggesting that the polygyne form originated via a founder event from a local monogyne population. These comparative data suggest an alternative route to polygyny in S. geminata in which loss of allelic variation at genes encoding recognition cues has led to a breakdown in discrimination abilities and the consequent acceptance of multiple queens in colonies. PMID:14704171

  5. Hey! A Fire Ant Stung Me!

    MedlinePlus

    ... nest in the ground, and then create a mound of dirt over the nest. These mounds can grow up to 18 inches high and ... burning. Someone who steps on a fire ant mound will get a lot of stings at once ...

  6. Strength in numbers: large and permanent colonies have higher queen oviposition rates in the invasive Argentine ant (Linepithema humile, Mayr).

    PubMed

    Abril, Sílvia; Gómez, Crisanto

    2014-03-01

    Polydomy associated with unicoloniality is a common trait of invasive species. In the invasive Argentine ant, colonies are seasonally polydomous. Most follow a seasonal fission-fussion pattern: they disperse in the spring and summer and aggregate in the fall and winter. However, a small proportion of colonies do not migrate; instead, they inhabit permanent nesting sites. These colonies are large and highly polydomous. The aim of this study was to (1) search for differences in the fecundity of queens between mother colonies (large and permanent) and satellite colonies (small and temporal), (2) determine if queens in mother and satellite colonies have different diets to clarify if colony size influences social organization and queen feeding, and (3) examine if colony location relative to the invasion front results in differences in the queen's diet. Our results indicate that queens from mother nests are more fertile than queens from satellite nests and that colony location does not affect queen oviposition rate. Ovarian dissections suggest that differences in ovarian morphology are not responsible for the higher queen oviposition rate in mother vs. satellite nests, since there were no differences in the number and length of ovarioles in queens from the two types of colonies. In contrast, the higher δ(15)N values of queens from mother nests imply that greater carnivorous source intake accounts for the higher oviposition rates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Transcriptomic response to injury sheds light on the physiological costs of reproduction in ant queens.

    PubMed

    von Wyschetzki, Katharina; Lowack, Helena; Heinze, Jürgen

    2016-05-01

    The trade-off between reproduction and longevity is widespread among multicellular organisms. As an important exception, the reproductive females of perennial social insects (ants, honeybees, termites) are simultaneously highly fertile and very long-lived relative to their nonreproductive nestmates. The observation that increased fecundity is not coupled with decreased lifespan suggests that social insect queens do not have to reallocate resources between reproduction and self-maintenance. If queens have to compensate for the costs of reproduction on the level of the individual, the activation of other energy-demanding physiological processes might force them to reduce the production of eggs. To test this hypothesis in ant queens, we increased immunity costs by injury and measured the effect of this treatment on egg-laying rates and genomewide gene expression. Amputation of both middle legs led to a temporary decrease in egg-laying rates and affected the expression of 947 genes corresponding to 9% of the transcriptome. The changes comprised the upregulation of the immune and wound healing response on the one hand, and the downregulation of germ cell development, central nervous system development and learning ability on the other hand. Injury strongly influenced metabolism by inducing catabolism and repressing amino acid and nitrogen compound metabolism. By comparing our results to similar transcriptomic studies in insects, we found a highly consistent upregulation of immune genes due to sterile and septic wounding. The gene expression changes, complemented by the temporary decline of egg-laying rates, clearly reveal a trade-off between reproduction and the immune response in social insect queens. © 2016 John Wiley & Sons Ltd.

  8. Tolerating an infection: an indirect benefit of co-founding queen associations in the ant Lasius niger

    NASA Astrophysics Data System (ADS)

    Pull, Christopher D.; Hughes, William O. H.; Brown, Mark J. F.

    2013-12-01

    Pathogens exert a strong selection pressure on organisms to evolve effective immune defences. In addition to individual immunity, social organisms can act cooperatively to produce collective defences. In many ant species, queens have the option to found a colony alone or in groups with other, often unrelated, conspecifics. These associations are transient, usually lasting only as long as each queen benefits from the presence of others. In fact, once the first workers emerge, queens fight to the death for dominance. One potential advantage of co-founding may be that queens benefit from collective disease defences, such as mutual grooming, that act against common soil pathogens. We test this hypothesis by exposing single and co-founding queens to a fungal parasite, in order to assess whether queens in co-founding associations have improved survival. Surprisingly, co-foundresses exposed to the entomopathogenic fungus Metarhizium did not engage in cooperative disease defences, and consequently, we find no direct benefit of multiple queens on survival. However, an indirect benefit was observed, with parasite-exposed queens producing more brood when they co-founded, than when they were alone. We suggest this is due to a trade-off between reproduction and immunity. Additionally, we report an extraordinary ability of the queens to tolerate an infection for long periods after parasite exposure. Our study suggests that there are no social immunity benefits for co-founding ant queens, but that in parasite-rich environments, the presence of additional queens may nevertheless improve the chances of colony founding success.

  9. Sociogenomics of cooperation and conflict during colony founding in the fire ant Solenopsis invicta.

    PubMed

    Manfredini, Fabio; Riba-Grognuz, Oksana; Wurm, Yannick; Keller, Laurent; Shoemaker, DeWayne; Grozinger, Christina M

    2013-01-01

    One of the fundamental questions in biology is how cooperative and altruistic behaviors evolved. The majority of studies seeking to identify the genes regulating these behaviors have been performed in systems where behavioral and physiological differences are relatively fixed, such as in the honey bee. During colony founding in the monogyne (one queen per colony) social form of the fire ant Solenopsis invicta, newly-mated queens may start new colonies either individually (haplometrosis) or in groups (pleometrosis). However, only one queen (the "winner") in pleometrotic associations survives and takes the lead of the young colony while the others (the "losers") are executed. Thus, colony founding in fire ants provides an excellent system in which to examine the genes underpinning cooperative behavior and how the social environment shapes the expression of these genes. We developed a new whole genome microarray platform for S. invicta to characterize the gene expression patterns associated with colony founding behavior. First, we compared haplometrotic queens, pleometrotic winners and pleometrotic losers. Second, we manipulated pleometrotic couples in order to switch or maintain the social ranks of the two cofoundresses. Haplometrotic and pleometrotic queens differed in the expression of genes involved in stress response, aging, immunity, reproduction and lipid biosynthesis. Smaller sets of genes were differentially expressed between winners and losers. In the second experiment, switching social rank had a much greater impact on gene expression patterns than the initial/final rank. Expression differences for several candidate genes involved in key biological processes were confirmed using qRT-PCR. Our findings indicate that, in S. invicta, social environment plays a major role in the determination of the patterns of gene expression, while the queen's physiological state is secondary. These results highlight the powerful influence of social environment on regulation

  10. Sociogenomics of Cooperation and Conflict during Colony Founding in the Fire Ant Solenopsis invicta

    PubMed Central

    Manfredini, Fabio; Riba-Grognuz, Oksana; Wurm, Yannick; Keller, Laurent; Shoemaker, DeWayne; Grozinger, Christina M.

    2013-01-01

    One of the fundamental questions in biology is how cooperative and altruistic behaviors evolved. The majority of studies seeking to identify the genes regulating these behaviors have been performed in systems where behavioral and physiological differences are relatively fixed, such as in the honey bee. During colony founding in the monogyne (one queen per colony) social form of the fire ant Solenopsis invicta, newly-mated queens may start new colonies either individually (haplometrosis) or in groups (pleometrosis). However, only one queen (the “winner”) in pleometrotic associations survives and takes the lead of the young colony while the others (the “losers”) are executed. Thus, colony founding in fire ants provides an excellent system in which to examine the genes underpinning cooperative behavior and how the social environment shapes the expression of these genes. We developed a new whole genome microarray platform for S. invicta to characterize the gene expression patterns associated with colony founding behavior. First, we compared haplometrotic queens, pleometrotic winners and pleometrotic losers. Second, we manipulated pleometrotic couples in order to switch or maintain the social ranks of the two cofoundresses. Haplometrotic and pleometrotic queens differed in the expression of genes involved in stress response, aging, immunity, reproduction and lipid biosynthesis. Smaller sets of genes were differentially expressed between winners and losers. In the second experiment, switching social rank had a much greater impact on gene expression patterns than the initial/final rank. Expression differences for several candidate genes involved in key biological processes were confirmed using qRT-PCR. Our findings indicate that, in S. invicta, social environment plays a major role in the determination of the patterns of gene expression, while the queen's physiological state is secondary. These results highlight the powerful influence of social environment on

  11. Modeling temperature-mediated fluctuation in colony size in the fire ant, Solenopsis invicta.

    PubMed

    Asano, Erika; Cassill, Deby L

    2012-07-21

    In the social insects, colony size is central to the survival of the queen. Two endogenous factors, worker longevity and queen's daily egg production, are known to determine maximum colony size. A third endogenous factor, duration of worker development from egg to adult, regulates the rate of colony growth. In this paper, we report findings from a simulation quantifying the effects of temperature on colony size in the fire ant, Solenopsis invicta. The monthly average temperature over a six year period for the panhandle of north Florida was interpolated to determine the effects of daily temperature on a queen's egg production, worker developmental time and worker longevity. Additional daily temperatures were simulated: 7°C higher and 7°C lower than daily temperatures for north Florida. As expected, colony size was the largest when annual temperatures were the highest across seasons, ranging from 57,000 to 187,000. Colony size at intermediate daily temperatures ranged from 14,000 to 103,000; small colonies recovered rapidly as temperatures warmed. Colony size at lower daily temperatures ranged from 14,000 to 21,000. Extended worker longevity at lower temperatures compensated for low egg production and longer developmental time. And vice versa, the queen's high rate of egg production and the shorter developmental time compensated for shorter worker longevity at high temperatures. Because the fire ant nest consists of a heat-collecting dome in which to incubate brood during cold weather, and deep chambers in which to cool workers during hot weather, colony size is likely to be higher and more stable than our simulation showed. The extended longevity of workers and queens at low temperatures, and perhaps their ability to hibernate below the permafrost, might explain the ability of ants to colonize habitats worldwide. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Fire ants perpetually rebuild sinking towers

    NASA Astrophysics Data System (ADS)

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig

    2017-07-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  13. Fire ants perpetually rebuild sinking towers

    PubMed Central

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Tovey, Craig

    2017-01-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers. PMID:28791170

  14. Fire ants perpetually rebuild sinking towers.

    PubMed

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L; Tovey, Craig

    2017-07-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  15. Fighting for a harem of queens: physiology of reproduction in Cardiocondyla male ants.

    PubMed

    Heinze, J; Hölldobler, B

    1993-09-15

    Several species of the ant genus Cardiocondyla produce dimorphic males, which exhibit sharply different mating strategies. Winged males typically disperse to mate outside the nest, whereas wingless, ergatoid males stay in the nest and aggressively employ their mandibles against competing ergatoid males to monopolize the virgin queens eclosing in the nest. Such aggressive mating strategy would only be adaptive if the males had unlimited sperm supply. Histological studies showed that, contrary to the rule in the Hymenoptera order, the ergatoid Cardiocondyla males are indeed able to produce sperm during their entire adult life. Winged males, on the other hand, have only a limited sperm supply since spermatogenesis ceases in the late pupal stage.

  16. Effect of temperature on the oviposition rate of Argentine ant queens (Linepithema humile Mayr) under monogynous and polygynous experimental conditions.

    PubMed

    Abril, Sílvia; Oliveras, Jordi; Gómez, Crisanto

    2008-01-01

    Data concerning the influence of temperature on a species' physiological parameters can be a useful tool for predicting its potential distribution range, but in the case of the Argentine ant, data based on its physiological needs are too scarce and incomplete to make accurate predictions of this type. In the present study, we offer new and complete data concerning the Argentine ant queen's oviposition rate under a wide range of temperatures in the laboratory. We analyzed the oviposition rate of the Argentine ant (Linepithema humile) at 12 experimental temperatures: 10, 12, 14, 16, 18, 21, 24, 26, 28, 30, 32 and 34 degrees C under monogynous conditions (one queen per nest) and three different polygynous conditions (two, four and eight queens per nest). We found that temperature affected their oviposition rate and that the effect was similar regardless of the number of queens in the nest. Egg laying was at its maximum at 28 degrees C, with variation in the upper and lower temperature limits at which oviposition took place depending on the degree of polygyny. Oviposition rates were negatively correlated with the number of queens in the nest. We also observed a marked variation in the oviposition rate of queens subjected to the same experimental conditions.

  17. Fire ant control with Entomopathogens in the USA

    USDA-ARS?s Scientific Manuscript database

    Fire ants, Solenopsis richteri and Solenopsis invicta, are stinging invasive ants from South America that infest over 129.5 million hectares in the southern United States. In the southern U.S., eradication is no longer considered possible and toxicant-based fire ant baiting is currently the primary...

  18. Extreme genetic differences between queens and workers in hybridizing Pogonomyrmex harvester ants.

    PubMed Central

    Helms Cahan, Sara; Parker, Joel D; Rissing, Steven W; Johnson, Robert A; Polony, Tatjana S; Weiser, Michael D; Smith, Deborah R

    2002-01-01

    The process of reproductive caste determination in eusocial insect colonies is generally understood to be mediated by environmental, rather than genetic factors. We present data demonstrating unexpected genetic differences between reproductive castes in a variant of the rough harvester ant, Pogonomyrmex rugosus var. fuscatus. Across multiple loci, queens were consistently more homozygous than expected, while workers were more heterozygous. Adult colony queens were divided into two highly divergent genetic groups, indicating the presence of two cryptic species, rather than a single population. The observed genetic differences between castes reflect differential representation of heterospecific and conspecific patrilines in these offspring groups. All workers were hybrids; by contrast, winged queens were nearly all pure-species. The complete lack of pure-species workers indicates a loss of worker potential in pure-species female offspring. Hybrids appear to be bipotential, but do not normally develop into reproductives because they are displaced by pure-species females in the reproductive pool. Genetic differences between reproductive castes are expected to be rare in non-hybridizing populations, but within hybrid zones they may be evolutionarily stable and thus much more likely to occur. PMID:12350248

  19. A New Method for Distinguishing Colony Social Forms of the Fire Ant, Solenopsis invicta

    PubMed Central

    Shoemaker, DeWayne; Ascunce, Marina S.

    2010-01-01

    Two distinct forms of colony social organization occur in the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae): colonies of the monogyne social form are headed by a single egg-laying queen, whereas those of the polygyne social form contain multiple egg-laying queens. This major difference in social organization is associated with genetic variation at a single gene (Gp-9) whereby all polygyne queens possess at least one b-like allele, while monogyne queens lack such b-like alleles and instead harbor B-like alleles only. Further, a recent study of native populations revealed that all b-like alleles in polygyne queens consistently contain three diagnostic amino acid residues: possession of only one or two of these critical residues is not sufficient for polygyny. TaqMan® allelic discrimination assays were developed to survey the variable nucleotide sites associated with these three critical amino acid residues. The assays were validated by surveying nests of known social form from the species' introduced in the USA and from native South American ranges, as well as by comparing the results to Gp-9 sequence data from a subset of samples. The results demonstrate these new molecular assays consistently and accurately identify the variable nucleotides at all three sites characteristic of the B-like and b-like Gp-9 allele classes, allowing for accurate determination of colony social form. PMID:20673191

  20. A new method for distinguishing colony social forms of the fire ant, Solenopsis invicta.

    PubMed

    Shoemaker, DeWayne; Ascunce, Marina S

    2010-01-01

    Two distinct forms of colony social organization occur in the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae): colonies of the monogyne social form are headed by a single egg-laying queen, whereas those of the polygyne social form contain multiple egg-laying queens. This major difference in social organization is associated with genetic variation at a single gene (Gp-9) whereby all polygyne queens possess at least one b-like allele, while monogyne queens lack such b-like alleles and instead harbor B-like alleles only. Further, a recent study of native populations revealed that all b-like alleles in polygyne queens consistently contain three diagnostic amino acid residues: possession of only one or two of these critical residues is not sufficient for polygyny. TaqMan allelic discrimination assays were developed to survey the variable nucleotide sites associated with these three critical amino acid residues. The assays were validated by surveying nests of known social form from the species' introduced in the USA and from native South American ranges, as well as by comparing the results to Gp-9 sequence data from a subset of samples. The results demonstrate these new molecular assays consistently and accurately identify the variable nucleotides at all three sites characteristic of the B-like and b-like Gp-9 allele classes, allowing for accurate determination of colony social form.

  1. Evolution of gene expression in fire ants: the effects of developmental stage, caste, and species.

    PubMed

    Ometto, Lino; Shoemaker, DeWayne; Ross, Kenneth G; Keller, Laurent

    2011-04-01

    Ants provide remarkable examples of equivalent genotypes developing into divergent and discrete phenotypes. Diploid eggs can develop either into queens, which specialize in reproduction, or workers, which participate in cooperative tasks such as building the nest, collecting food, and rearing the young. In contrast, the differentiation between males and females generally depends upon whether eggs are fertilized, with fertilized (diploid) eggs giving rise to females and unfertilized (haploid) eggs giving rise to males. To obtain a comprehensive picture of the relative contributions of gender (sex), caste, developmental stage, and species divergence to gene expression evolution, we investigated gene expression patterns in pupal and adult queens, workers, and males of two species of fire ants, Solenopsis invicta and S. richteri. Microarray hybridizations revealed that variation in gene expression profiles is influenced more by developmental stage than by caste membership, sex, or species identity. The second major contributor to variation in gene expression was the combination of sex and caste. Although workers and queens share equivalent diploid nuclear genomes, they have highly distinctive patterns of gene expression in both the pupal and the adult stages, as might be expected given their extraordinary level of phenotypic differentiation. Overall, the difference in the proportion of differentially expressed genes was greater between workers and males than between workers and queens or queens and males, consistent with the fact that workers and males share neither gender nor reproductive capability. Moreover, between-species comparisons revealed that the greatest difference in gene expression patterns occurred in adult workers, a finding consistent with the fact that adult workers most directly experience the distinct external environments characterizing the different habitats occupied by the two species. Thus, much of the evolution of gene expression in ants may

  2. Pleiotropic effects of juvenile hormone in ant queens and the escape from the reproduction-immunocompetence trade-off.

    PubMed

    Pamminger, Tobias; Treanor, David; Hughes, William O H

    2016-01-13

    The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction-survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction-immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction-immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens.

  3. Ant-seed mutualisms: Can red imported fire ants sour the relationship?

    USGS Publications Warehouse

    Zettler, J.A.; Spira, T.P.; Allen, C.R.

    2001-01-01

    Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. In recovered seeds fed to ant colonies, fire ants scarified 80% of S. canadensis seeds and destroyed 86% of V. rotundifolia seeds. Our study is the first to document that red imported fire ants are attracted to and remove seeds of species adapted for ant dispersal. Moreover, fire ants might damage these seeds and discard them in sites unfavorable for germination and seedling establishment. ?? 2001 Elsevier Science Ltd. All rights reserved.

  4. Uncoupling Flight and Reproduction in Ants: Evolution of Ergatoid Queens in Two Lineages of Megalomyrmex (Hymenoptera: Formicidae)

    PubMed Central

    Peeters, Christian; Adams, Rachelle M. M.

    2016-01-01

    Megalomyrmex Forel (Myrmicinae: Solenopsidini) consists of 44 species with diverse life history strategies. Most species are predatory and may also tend honeydew-producing insects. A morphologically derived group of species are social parasites that consume the brood and fungus garden within fungus-growing ant nests. The reproductive strategies of Megalomyrmex queens are somewhat aligned with these life-style patterns. Predatory species in the leoninus species group are large in body size and have ergatoid (i.e., permanently wingless) queens whereas the social parasitic species are smaller and typically have winged queens. We examined two ergatoid phenotypes of Megalomyrmex foreli Emery and Megalomyrmex wallacei Mann and compared them to winged species, one a social lestobiotic or “thief ant” parasite (Megalomyrmex mondabora Brandão) and the other a predator (Megalomyrmex modestus Emery). Megalomyrmex foreli colonies have a single queen with an enlarged gaster that is morphologically distinct from workers. Megalomyrmex wallacei colonies have several queens that are similar in body size to workers. Queens in both species showed a simplification of the thorax, but there was a dramatic difference in the number of ovarioles. Megalomyrmex foreli had 60–80 ovarioles compared to eight in M. wallacei and M. mondabora and M. modestus had 22–28. Along with flight loss in queens, there is an obligate shift to dependent colony founding (also called budding or fission) consequently influencing dispersal patterns. These constraints in life history traits may help explain the variation in nesting biology among Megalomyrmex species. PMID:27620557

  5. Costs and constraints conspire to produce honest signaling: insights from an ant queen pheromone.

    PubMed

    Holman, Luke

    2012-07-01

    Signal costs and evolutionary constraints have both been proposed as ultimate explanations for the ubiquity of honest signaling, but the interface between these two factors is unclear. Here, I propose a pluralistic interpretation, and use game theory to demonstrate that evolutionary constraints determine whether signals evolve to be costly or cheap. Specifically, when the costs or benefits of signaling are strongly influenced by the sender's quality, low-cost signals evolve. The model reaffirms that cheap and costly signals can both be honest, and predicts that expensive signals should have more positive allometric slopes than cheap ones. The new framework is applied to an experimental study of an ant queen pheromone that honestly signals fecundity. Juvenile hormone was found to have opposing, dose-dependent effects on pheromone production and fecundity and was fatal at high doses, indicating that endocrine-mediated trade-offs preclude dishonesty. Several lines of evidence suggest that the realized cost of pheromone production may be nontrivial, and the antagonistic effects of juvenile hormone indicate the presence of significant evolutionary constraints. I conclude that the honesty of queen pheromones and other signals is likely enforced by both the cost of dishonesty and a suite of evolutionary constraints.

  6. Molecular variation at a candidate gene implicated in the regulation of fire ant social behavior.

    PubMed

    Gotzek, Dietrich; Shoemaker, D Dewayne; Ross, Kenneth G

    2007-11-07

    The fire ant Solenopsis invicta and its close relatives display an important social polymorphism involving differences in colony queen number. Colonies are headed by either a single reproductive queen (monogyne form) or multiple queens (polygyne form). This variation in social organization is associated with variation at the gene Gp-9, with monogyne colonies harboring only B-like allelic variants and polygyne colonies always containing b-like variants as well. We describe naturally occurring variation at Gp-9 in fire ants based on 185 full-length sequences, 136 of which were obtained from S. invicta collected over much of its native range. While there is little overall differentiation between most of the numerous alleles observed, a surprising amount is found in the coding regions of the gene, with such substitutions usually causing amino acid replacements. This elevated coding-region variation may result from a lack of negative selection acting to constrain amino acid replacements over much of the protein, different mutation rates or biases in coding and non-coding sequences, negative selection acting with greater strength on non-coding than coding regions, and/or positive selection acting on the protein. Formal selection analyses provide evidence that the latter force played an important role in the basal b-like lineages coincident with the emergence of polygyny. While our data set reveals considerable paraphyly and polyphyly of S. invicta sequences with respect to those of other fire ant species, the b-like alleles of the socially polymorphic species are monophyletic. An expanded analysis of colonies containing alleles of this clade confirmed the invariant link between their presence and expression of polygyny. Finally, our discovery of several unique alleles bearing various combinations of b-like and B-like codons allows us to conclude that no single b-like residue is completely predictive of polygyne behavior and, thus, potentially causally involved in its

  7. Consuming fire ants reduces northern bobwhite survival and weight gain

    USGS Publications Warehouse

    Myers, P.E.; Allen, Craig R.; Birge, Hannah E.

    2014-01-01

    Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein source, making it difficult to disentangle their net effect on bobwhite chicks. To help investigate these effects, we conducted a laboratory experiment to understand (1) whether or not bobwhites consume fire ants, and (2) how the benefits of this consumption compare to the deleterious impacts of bobwhite chick exposure to fire ants. Sixty bobwhite chicks were separated into two groups of 30; one group was provided with starter feed only and the second group was provided with feed and fire ants. Bobwhite chicks were observed feeding on fire ants. Chicks that fed on fire ants had reduced survival and weight gain. Our results show that, while fire ants increase potential food sources for northern bobwhite, their net effect on bobwhite chicks is deleterious. This information will help inform land managers and commercial bobwhite rearing operations.

  8. Evolution of long centromeres in fire ants.

    PubMed

    Huang, Yu-Ching; Lee, Chih-Chi; Kao, Chia-Yi; Chang, Ni-Chen; Lin, Chung-Chi; Shoemaker, DeWayne; Wang, John

    2016-09-15

    Centromeres are essential for accurate chromosome segregation, yet sequence conservation is low even among closely related species. Centromere drive predicts rapid turnover because some centromeric sequences may compete better than others during female meiosis. In addition to sequence composition, longer centromeres may have a transmission advantage. We report the first observations of extremely long centromeres, covering on average 34 % of the chromosomes, in the red imported fire ant Solenopsis invicta. By comparison, cytological examination of Solenopsis geminata revealed typical small centromeric constrictions. Bioinformatics and molecular analyses identified CenSol, the major centromeric satellite DNA repeat. We found that CenSol sequences are very similar between the two species but the CenSol copy number in S. invicta is much greater than that in S. geminata. In addition, centromere expansion in S. invicta is not correlated with the duplication of CenH3. Comparative analyses revealed that several closely related fire ant species also possess long centromeres. Our results are consistent with a model of simple runaway centromere expansion due to centromere drive. We suggest expanded centromeres may be more prevalent in hymenopteran insects, which use haplodiploid sex determination, than previously considered.

  9. LINC Modeling of August 19, 2004 Queen City Barrel Company Fire In Cincinnati, OH

    SciTech Connect

    Dillon, M B; Nasstrom, J S; Baskett, R L; Pobanz, B M

    2004-09-14

    This report details the information received, assumptions made, actions taken, and products delivered by the Lawrence Livermore National Laboratory (LLNL) during the August 19, 2004 fire at the Queen City Barrel Company (QCB) in Cincinnati, OH. During the course of the event, LLNL provided four sets of plume model products to various Cincinnati emergency response organizations.

  10. Fire disturbance disrupts an acacia ant-plant mutualism in favor of a subordinate ant species.

    PubMed

    Sensenig, Ryan L; Kimuyu, Duncan K; Ruiz Guajardo, Juan C; Veblen, Kari E; Riginos, Corinna; Young, Truman P

    2017-05-01

    Although disturbance theory has been recognized as a useful framework in examining the stability of ant-plant mutualisms, very few studies have examined the effects of fire disturbance on these mutualisms. In myrmecophyte-dominated savannas, fire and herbivory are key drivers that could influence ant-plant mutualisms by causing complete colony mortality and/or decreasing colony size, which potentially could alter dominance hierarchies if subordinate species are more fire resilient. We used a large-scale, replicated fire experiment to examine long-term effects of fire on acacia-ant community composition. To determine if fire shifted ant occupancy from a competitive dominant to a subordinate ant species, we surveyed the acacia-ant community in 6-7 yr old burn sites and examined how the spatial scale of these burns influenced ant community responses. We then used two short-term fire experiments to explore possible mechanisms for the shifts in community patterns observed. Because survival of ant colonies is largely dependent on their ability to detect and escape an approaching fire, we first tested the evacuation response of all four ant species when exposed to smoke (fire signal). Then to better understand how fire and its interaction with large mammal herbivory affect the density of ants per tree, we quantified ant worker density in small prescribed burns within herbivore exclusion plots. We found clear evidence suggesting that fire disturbance favored the subordinate ant Crematogaster nigriceps more than the dominant and strong mutualist ant C. mimosae, whereby C. nigriceps (1) was the only species to occupy a greater proportion of trees in 6-7 yr old burn sites compared to unburned sites, (2) had higher burn/unburn tree ratios with increasing burn size, and (3) evacuated significantly faster than C. mimosae in the presence of smoke. Fire and herbivory had opposite effects on ant density per meter of branch for both C. nigriceps and C. mimosae, with fire

  11. Laboratory host specificicty testing of the fire ant microsporidian pathogen Vairimorpha invictae (Microsporidia: Burenellidae)

    USDA-ARS?s Scientific Manuscript database

    The host specificity of Vairimorpha invictae, a microsporidian pathogen of fire ants in South America, was assessed in the laboratory with the tropical fire ant, Solenopsis geminata, the southern fire ant, Solenopsis xyloni, and the Argentine ant, Linepithema humile. The two fire ant species are fo...

  12. Thelohania solenopsae as a factor of fire ant populations

    USDA-ARS?s Scientific Manuscript database

    The inadvertent introduction of fire ants into the United States over 70 years ago initially resulted in large-scale efforts to eradicate the invasive pest. Large populations, mobility, and ability to occupy diverse habitats make fire ants a dominant arthropod in infested regions and very difficult...

  13. Uncoupling Flight and Reproduction in Ants: Evolution of Ergatoid Queens in Two Lineages of Megalomyrmex (Hymenoptera: Formicidae).

    PubMed

    Peeters, Christian; Adams, Rachelle M M

    2016-01-01

    Megalomyrmex Forel (Myrmicinae: Solenopsidini) consists of 44 species with diverse life history strategies. Most species are predatory and may also tend honeydew-producing insects. A morphologically derived group of species are social parasites that consume the brood and fungus garden within fungus-growing ant nests. The reproductive strategies of Megalomyrmex queens are somewhat aligned with these life-style patterns. Predatory species in the leoninus species group are large in body size and have ergatoid (i.e., permanently wingless) queens whereas the social parasitic species are smaller and typically have winged queens. We examined two ergatoid phenotypes of Megalomyrmex foreli Emery and Megalomyrmex wallacei Mann and compared them to winged species, one a social lestobiotic or "thief ant" parasite (Megalomyrmex mondabora Brandão) and the other a predator (Megalomyrmex modestus Emery). Megalomyrmex foreli colonies have a single queen with an enlarged gaster that is morphologically distinct from workers. Megalomyrmex wallacei colonies have several queens that are similar in body size to workers. Queens in both species showed a simplification of the thorax, but there was a dramatic difference in the number of ovarioles. Megalomyrmex foreli had 60-80 ovarioles compared to eight in M. wallacei and M. mondabora and M. modestus had 22-28. Along with flight loss in queens, there is an obligate shift to dependent colony founding (also called budding or fission) consequently influencing dispersal patterns. These constraints in life history traits may help explain the variation in nesting biology among Megalomyrmex species. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

  14. Are variations in cuticular hydrocarbons of queens and workers a reliable signal of fertility in the ant Harpegnathos saltator?

    PubMed Central

    Liebig, Jürgen; Peeters, Christian; Oldham, Neil J.; Markstädter, Claus; Hölldobler, Bert

    2000-01-01

    One of the key features of insect societies is the division of labor in reproduction between one or a few fertile individuals and many sterile nestmates that function as helpers. The behavioral and physiological mechanisms regulating reproduction in ant societies are still not very well understood, especially in species in which all colony members are reproductively totipotent. In the ponerine ant Harpegnathos saltator, queen-worker dimorphism is very limited, and a few mated workers reproduce (“gamergates”) once the founding queen becomes senescent. Worker oviposition is regulated by highly directed aggressive interactions among nestmates, who can recognize different levels of ovarian activity. We show that variations in cuticular hydrocarbons (CHC) correlate with oogenesis, both for queens and workers. 13,23-Dimethylheptatriacontane is present in egg-layers, but not in infertile workers and queens. Proportions of other CHCs vary as well, resulting in clear separation of the ants in a multivariate analysis. Egg-layers are characterized by an elongation of the chain length of CHCs. We used solid-phase microextraction to measure CHCs in live ants that were experimentally induced to start producing eggs. Over a period of 118 days, CHC profiles of infertile workers changed completely to that of reproductives. The effect of age can be excluded in this modification. This striking correlation of ovarian activity with CHC variation and its correspondence with the observed recognition behavior exhibited by the workers toward egg-laying nestmates suggests that CHCs serve as a fertility signal in the ant H. saltator, a reliable basis for regulating reproduction. PMID:10760282

  15. Introduced fire ants can exclude native ants from critical mutualist-provided resources.

    PubMed

    Wilder, Shawn M; Barnum, Thomas R; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

    2013-05-01

    Animals frequently experience resource imbalances in nature. For ants, one resource that may be particularly valuable for both introduced and native species is high-carbohydrate honeydew from hemipteran mutualists. We conducted field and laboratory experiments: (1) to test if red imported fire ants (Solenopsis invicta) competed with native ants for access to mutualisms with aphids, and (2) to quantify the effects of aphid honeydew presence or absence on colony growth of native ants. We focused on native dolichoderine ants (Formicidae, Dolichoderinae) because they are abundant ants that have omnivorous diets that frequently include mutualist-provided carbohydrates. At two sites in the southeastern US, native dolichoderine ants were far less frequent, and fire ants more frequent, at carbohydrate baits than would be expected based on their frequency in pitfall traps. A field experiment confirmed that a native ant species, Dorymyrmex bureni, was only found tending aphids when populations of S. invicta were suppressed. In the laboratory, colonies of native dolichoderine ants with access to both honeydew and insect prey had twice as many workers and over twice as much brood compared to colonies fed only ad libitum insect prey. Our results provide the first experimental evidence that introduced ants compete for access to mutualist-provided carbohydrates with native ants and that these carbohydrates represent critical resources for both introduced and native ants. These results challenge traditional paradigms of arthropod and ant nutrition and contribute to growing evidence of the importance of nutrition in mediating ecological interactions.

  16. Colony-level impacts of parasitoid flies on fire ants.

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

    The red imported fire ant is becoming a global ecological problem, having invaded the United States, Puerto Rico, New Zealand and, most recently, Australia. In its established areas, this pest is devastating natural biodiversity. Early attempts to halt fire ant expansion with pesticides actually enhanced its spread. Phorid fly parasitoids from South America have now been introduced into the United States as potential biological control agents of the red imported fire ant, but the impact of these flies on fire ant populations is currently unknown. In the laboratory, we show that an average phorid density of as little as one attacking fly per 200 foraging ants decreased colony protein consumption nearly twofold and significantly reduced numbers of large-sized workers 50 days later. The high impact of a single phorid occurred mainly because ants decreased foraging rates in the presence of the flies. Our experiments, the first (to our knowledge) to link indirect and direct effects of phorids on fire ants, demonstrate that colonies can be stressed with surprisingly low parasitoid densities. We interpret our findings with regard to the more complex fire ant-phorid interactions in the field. PMID:12204130

  17. Workers select mates for queens: a possible mechanism of gene flow restriction between supercolonies of the invasive Argentine ant

    NASA Astrophysics Data System (ADS)

    Sunamura, Eiriki; Hoshizaki, Sugihiko; Sakamoto, Hironori; Fujii, Takeshi; Nishisue, Koji; Suzuki, Shun; Terayama, Mamoru; Ishikawa, Yukio; Tatsuki, Sadahiro

    2011-05-01

    Some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. The Argentine ant Linepithema humile forms much larger supercolonies in introduced ranges than in its native range. In both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restriction is unknown. In this species, queens do not undertake nuptial flight, and males have to travel to foreign nests and cope with workers before gaining access to alien queens. In this study, we hypothesized that male Argentine ants receive interference from workers of alien supercolonies. To test this hypothesis, we conducted behavioral and chemical experiments using ants from two supercolonies in Japan. Workers attacked males from alien supercolonies but not those from their own supercolonies. The level of aggression against alien males was similar to that against alien workers. The frequency of severe aggression against alien males increased as the number of recipient workers increased. Cuticular hydrocarbon profiles, which serve as cues for nestmate recognition, of workers and males from the same supercolony were very similar. Workers are likely to distinguish alien males from males of their own supercolony using the profiles. It is predicted that males are subject to considerable aggression from workers when they intrude into the nests of alien supercolonies. This may be a mechanism underlying the restricted gene flow between supercolonies of Argentine ants. The Argentine ant may possess a distinctive reproductive system, where workers participate in selecting mates for their queens. We argue that the aggression of workers against alien males is a novel form of reproductive interference.

  18. Workers select mates for queens: a possible mechanism of gene flow restriction between supercolonies of the invasive Argentine ant.

    PubMed

    Sunamura, Eiriki; Hoshizaki, Sugihiko; Sakamoto, Hironori; Fujii, Takeshi; Nishisue, Koji; Suzuki, Shun; Terayama, Mamoru; Ishikawa, Yukio; Tatsuki, Sadahiro

    2011-05-01

    Some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. The Argentine ant Linepithema humile forms much larger supercolonies in introduced ranges than in its native range. In both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restriction is unknown. In this species, queens do not undertake nuptial flight, and males have to travel to foreign nests and cope with workers before gaining access to alien queens. In this study, we hypothesized that male Argentine ants receive interference from workers of alien supercolonies. To test this hypothesis, we conducted behavioral and chemical experiments using ants from two supercolonies in Japan. Workers attacked males from alien supercolonies but not those from their own supercolonies. The level of aggression against alien males was similar to that against alien workers. The frequency of severe aggression against alien males increased as the number of recipient workers increased. Cuticular hydrocarbon profiles, which serve as cues for nestmate recognition, of workers and males from the same supercolony were very similar. Workers are likely to distinguish alien males from males of their own supercolony using the profiles. It is predicted that males are subject to considerable aggression from workers when they intrude into the nests of alien supercolonies. This may be a mechanism underlying the restricted gene flow between supercolonies of Argentine ants. The Argentine ant may possess a distinctive reproductive system, where workers participate in selecting mates for their queens. We argue that the aggression of workers against alien males is a novel form of reproductive interference.

  19. PBAN/pyrokinin peptides in the central nervous system of the fire ant, Solenopsis invicta.

    PubMed

    Choi, Man-Yeon; Raina, Ashok; Vander Meer, Robert K

    2009-02-01

    The pyrokinin/pheromone-biosynthesis-activating neuropeptide (PBAN) family of peptides found in insects is characterized by a 5-amino-acid C-terminal sequence, FXPRLamide. The pentapeptide is the active core required for diverse physiological functions, including the stimulation of pheromone biosynthesis in female moths, muscle contraction, induction of embryonic diapause, melanization, acceleration of puparium formation, and termination of pupal diapause. We have used immunocytochemical techniques to demonstrate the presence of pyrokinin/PBAN-like peptides in the central nervous system of the fire ant, Solenopsis invicta. Polyclonal antisera against the C-terminal end of PBAN have revealed the location of the peptide-producing cell bodies and axons in the central nervous system. Immunoreactive material is detectable in at least three groups of neurons in the subesophageal ganglion and corpora cardiaca of all adult sexual forms. The ventral nerve cord of adults consists of two segmented thoracic ganglia and four segmented abdominal ganglia. Two immunoreactive pairs of neurons are present in the thoracic ganglia, and three neuron pairs in each of the first three abdominal ganglia. The terminal abdominal ganglion has no immunoreactive neurons. PBAN immunoreactive material found in abdominal neurons appears to be projected to perisympathetic organs connected to the abdominal ganglia. These results indicate that the fire ant nervous system contains pyrokinin/PBAN-like peptides, and that these peptides are released into the hemolymph. In support of our immunocytochemical results, significant pheromonotropic activity is found in fire ant brain-subesophageal ganglion extracts from all adult fire ant forms (queens, female and male alates, and workers) when extracts are injected into decapitated females of Helicoverpa zea. This is the first demonstration of the presence of pyrokinin/PBAN-like peptides and pheromonotropic activity in an ant species.

  20. The genome of the fire ant Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    Ants have evolved very complex societies and are key ecosystem members. Some of them are also major pests, as exemplified by the fire ant Solenopsis invicta. We present here the draft genome of S. invicta, assembled from 454 and Illumina reads obtained from a focal haploid male and his brothers. In ...

  1. Molecular and social regulation of worker division of labour in fire ants.

    PubMed

    Manfredini, Fabio; Lucas, Christophe; Nicolas, Michael; Keller, Laurent; Shoemaker, Dewayne; Grozinger, Christina M

    2014-02-01

    Reproductive and worker division of labour (DOL) is a hallmark of social insect societies. Despite a long-standing interest in worker DOL, the molecular mechanisms regulating this process have only been investigated in detail in honey bees, and little is known about the regulatory mechanisms operating in other social insects. In the fire ant Solenopsis invicta, one of the most studied ant species, workers are permanently sterile and the tasks performed are modulated by the worker's internal state (age and size) and the outside environment (social environment), which potentially includes the effect of the queen presence through chemical communication via pheromones. However, the molecular mechanisms underpinning these processes are unknown. Using a whole-genome microarray platform, we characterized the molecular basis for worker DOL and we explored how a drastic change in the social environment (i.e. the sudden loss of the queen) affects global gene expression patterns of worker ants. We identified numerous genes differentially expressed between foraging and nonforaging workers in queenright colonies. With a few exceptions, these genes appear to be distinct from those involved in DOL in bees and wasps. Interestingly, after the queen was removed, foraging workers were no longer distinct from nonforaging workers at the transcriptomic level. Furthermore, few expression differences were detected between queenright and queenless workers when we did not consider the task performed. Thus, the social condition of the colony (queenless vs. queenright) appears to impact the molecular pathways underlying worker task performance, providing strong evidence for social regulation of DOL in S. invicta. Published 2013. This article is a U.S. Government work and is in the public domain in the U.S.A.

  2. Applied Ecology and Control of Imported Fire Ants and Argentine Ants

    USDA-ARS?s Scientific Manuscript database

    The red imported fire ant, Solenopsis invicta Buren, and Argentine ant, Linepithema humile (Mayr), are invasive species that are major pests in urban, natural, and agricultural habitats. The goal of this dissertation was to study aspects the chemical sensitivity, behavior, and ecology of each specie...

  3. Pleiotropic effects of juvenile hormone in ant queens and the escape from the reproduction–immunocompetence trade-off

    PubMed Central

    Pamminger, Tobias; Treanor, David; Hughes, William O. H.

    2016-01-01

    The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction–survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction–immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction–immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens. PMID:26763704

  4. Hierarchical analysis of genetic structure in native fire ant populations: results from three classes of molecular markers.

    PubMed

    Ross, K G; Krieger, M J; Shoemaker, D D; Vargo, E L; Keller, L

    1997-10-01

    We describe genetic structure at various scales in native populations of the fire ant Solenopsis invicta using two classes of nuclear markers, allozymes and microsatellites, and markers of the mitochondrial genome. Strong structure was found at the nest level in both the monogyne (single queen) and polygyne (multiple queen) social forms using allozymes. Weak but significant microgeographic structure was detected above the nest level in polygyne populations but not in monogyne populations using both classes of nuclear markers. Pronounced mitochondrial DNA (mtDNA) differentiation was evident also at this level in the polygyne form only. These microgeographic patterns are expected because polygyny in ants is associated with restricted local gene flow due mainly to limited vagility of queens. Weak but significant nuclear differentiation was detected between sympatric social forms, and strong mtDNA differentiation also was found at this level. Thus, queens of each form seem unable to establish themselves in nests of the alternate type, and some degree of assortative mating by form may exist as well. Strong differentiation was found between the two study regions using all three sets of markers. Phylogeographic analyses of the mtDNA suggest that recent limitations on gene flow rather than longstanding barriers to dispersal are responsible for this large-scale structure.

  5. The Morphometry of Solenopsis Fire Ants

    PubMed Central

    Tschinkel, Walter R.

    2013-01-01

    Size-related changes of body shape were explored in 15 polymorphic species of Solenopsis fire ants by analyzing body weight along with linear measurements of 24 body parts. Log regression slopes were used to detect changes of shape with increasing size. Within species, the largest workers weighed from about 5 to 30-fold as much as the smallest. The range of within-species body lengths varied from 1.6 mm to 4 mm. As worker size increased, the gaster tended to make up a larger proportion of body length, usually at the cost of the petiole, and rarely at the cost of head length or mesosoma length. In most, the relative volume of the gaster increased and that of the head and mesosoma decreased. Most also showed an increasingly “humped” mesosoma. For all species, head shape changed from barrel-shaped to heart-shaped as worker size increased. Antennae became relatively shorter as the relative size of the club decreased. Shape changes of the legs were more variable. S. geminata was exceptional in the extreme nature of its head shape change, and was the only species in which relative head volume increased and gaster volume decreased with increasing body size. With the exception of S. geminata, the allometric rules governing shape are remarkably similar across species, suggesting a genus-level developmental scheme that is not easily modified by evolution. It also suggests that the evolution of shape is highly constrained by these conserved growth rules, and that it acts primarily (perhaps only) through allometric growth. The results are discussed in light of the growth of imaginal discs in a resource-limited body (the pupa). The substantial variation of allometries within species and across localities is also discussed in relation to using allometric patterns to identify species or to construct phylogenies. PMID:24260250

  6. Fecundity and longevity of Argentine ant (Hymenoptera: Formicidae) queens in response to irradiation

    USDA-ARS?s Scientific Manuscript database

    Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. As little is known about irradiation effects on ants, radiotolerance of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae...

  7. Molecular Variation at a Candidate Gene Implicated in the Regulation of Fire Ant Social Behavior

    PubMed Central

    Gotzek, Dietrich; Shoemaker, D. DeWayne; Ross, Kenneth G.

    2007-01-01

    The fire ant Solenopsis invicta and its close relatives display an important social polymorphism involving differences in colony queen number. Colonies are headed by either a single reproductive queen (monogyne form) or multiple queens (polygyne form). This variation in social organization is associated with variation at the gene Gp-9, with monogyne colonies harboring only B-like allelic variants and polygyne colonies always containing b-like variants as well. We describe naturally occurring variation at Gp-9 in fire ants based on 185 full-length sequences, 136 of which were obtained from S. invicta collected over much of its native range. While there is little overall differentiation between most of the numerous alleles observed, a surprising amount is found in the coding regions of the gene, with such substitutions usually causing amino acid replacements. This elevated coding-region variation may result from a lack of negative selection acting to constrain amino acid replacements over much of the protein, different mutation rates or biases in coding and non-coding sequences, negative selection acting with greater strength on non-coding than coding regions, and/or positive selection acting on the protein. Formal selection analyses provide evidence that the latter force played an important role in the basal b-like lineages coincident with the emergence of polygyny. While our data set reveals considerable paraphyly and polyphyly of S. invicta sequences with respect to those of other fire ant species, the b-like alleles of the socially polymorphic species are monophyletic. An expanded analysis of colonies containing alleles of this clade confirmed the invariant link between their presence and expression of polygyny. Finally, our discovery of several unique alleles bearing various combinations of b-like and B-like codons allows us to conclude that no single b-like residue is completely predictive of polygyne behavior and, thus, potentially causally involved in its

  8. Consequences of prescribed fire and grazing on grassland ant communities.

    PubMed

    Underwood, Emma C; Christian, Caroline E

    2009-04-01

    Prescribed fire and livestock grazing are used for the management and restoration of native grasslands the world over; however, the effects of these management techniques on ant communities are unclear. We examined the response of ants to these disturbances in grasslands in northern California. Twenty-four 30 by 30 m plots were established across two sites that received one of four treatments: grazing, fire, grazing and fire, or no treatment. Ants were censused using 240 pitfall traps with one preburn and two postburn samples (14 d and 1 yr after burning). We analyzed ant abundance using broadly defined groups based on feeding habit and/or habitat use and detected no grazing effect but a significant fire effect that differed by group. Immediate postfire sampling showed an increase in cryptic species (particularly Brachymyrmex depilis). One year after the fire, no response was detected for cryptic species, but burned plots had greater abundance of seed harvesters. Analysis of vegetation showed burned plots had significantly greater forb cover, which might have provided greater food resources, and also lower biomass, which might have facilitated foraging. Understanding the effects of these management tools on ant abundance complements our understanding of their effect on vegetation and assists conservation practitioners effectively manage grassland ecosystems both in California and beyond.

  9. Wolbachia wSinvictaA Infections in Natural Populations of the Fire Ant Solenopsis invicta: Testing for Phenotypic Effects

    PubMed Central

    Bouwma, Andrew M.; Shoemaker, DeWayne

    2011-01-01

    Wolbachia are intracellular bacteria that commonly infect many arthropods and some nematodes. In arthropods, these maternally transmitted bacteria often induce a variety of phenotypic effects to enhance their own spread within host populations. Wolbachia phenotypic effects generally either provide benefits to infected host females (cytoplasmic incompatibility, positive fitness effects) or bias host sex ratio in favor of females (male-killing, parthenogenesis, feminization), all of which increase the relative production of infected females in host populations. Wolbachia surveys have found infections to be exceedingly common in ants, but little is known at this juncture as to what phenotypic effects, if any, they induce in this group. Previous studies have demonstrated that individuals from native populations of the invasive fire ant Solenopsis invicta commonly harbor one or more of three Wolbachia variants. One of the variants, wSinvictaA, typically occurs at low prevalence in S. invicta populations, appears to have been transmitted horizontally into S. invicta three or more times, and has been lost repeatedly from host lineages over time. In order to determine the phenotypic effects and likely population dynamics of wSinvictaA infections in these ants, brood production patterns of newly mated fire ant queens were studied during simulated claustral founding and measured wSinvictaA transmission fidelity within mature single-queen families. No clear evidence was found for Wolbachia-mduced cytoplasmic incompatibility, significant fitness effects, or male-killing. Maternal transmission was perfect to both virgin queens and males. Possible mechanisms for how this variant could be maintained in host populations are discussed. PMID:21526927

  10. The foundress’s dilemma: group selection for cooperation among queens of the harvester ant, Pogonomyrmex californicus

    PubMed Central

    Shaffer, Zachary; Sasaki, Takao; Haney, Brian; Janssen, Marco; Pratt, Stephen C.; Fewell, Jennifer H.

    2016-01-01

    The evolution of cooperation is a fundamental problem in biology, especially for non-relatives, where indirect fitness benefits cannot counter within-group inequalities. Multilevel selection models show how cooperation can evolve if it generates a group-level advantage, even when cooperators are disadvantaged within their group. This allows the possibility of group selection, but few examples have been described in nature. Here we show that group selection can explain the evolution of cooperative nest founding in the harvester ant Pogonomyrmex californicus. Through most of this species’ range, colonies are founded by single queens, but in some populations nests are instead founded by cooperative groups of unrelated queens. In mixed groups of cooperative and single-founding queens, we found that aggressive individuals had a survival advantage within their nest, but foundress groups with such non-cooperators died out more often than those with only cooperative members. An agent-based model shows that the between-group advantage of the cooperative phenotype drives it to fixation, despite its within-group disadvantage, but only when population density is high enough to make between-group competition intense. Field data show higher nest density in a population where cooperative founding is common, consistent with greater density driving the evolution of cooperative foundation through group selection. PMID:27465430

  11. Effect of a Founder Event on Variation in the Genetic Sex-Determining System of the Fire Ant Solenopsis Invicta

    PubMed Central

    Ross, K. G.; Vargo, E. L.; Keller, L.; Trager, J. C.

    1993-01-01

    Effects of a recent founder event on genetic diversity in wild populations of the fire ant Solenopsis invicta were studied, with particular attention given to the genetic sex-determining system. Diploid males are far more common relative to haploid males in introduced populations than in native populations of fire ants, and queens that produce diploid males account for a significantly larger proportion of the mated queens in introduced than in native populations. Differences between native and introduced populations in attributes of the mating systems (i.e., queen mating frequency or level of inbreeding) can be excluded as factors contributing to these different levels of diploid male production. Thus, we conclude that diploid males have increased in frequency in introduced populations because of a loss of allelic diversity at the sex-determining locus (loci). This loss of sex alleles has generated a substantial increase in the estimated segregational genetic load associated with production of sterile diploid males in introduced populations over the load in native populations. The loss of allelic diversity in the sex-determining system in introduced S. invicta is paralleled by a loss of electrophoretically detectable rare alleles at protein-encoding loci. Such concordance between these different types of markers is predicted because each of the many sex alleles present in the native populations is expected to be rare. Estimates of expected heterozygosity (H(exp)) based on 76 electrophoretic loci do not differ significantly between the native and introduced fire ant populations, illustrating the lack of sensitivity of this measure for detecting many types of bottlenecks. PMID:8293983

  12. Workers and alate queens of Solenopsis geminata share qualitatively similar but quantitatively different venom alkaloid chemistry

    USDA-ARS?s Scientific Manuscript database

    The cis and trans alkaloids from body extracts of workers and alate queens of the tropical fire ant, Solenopsis geminata (Hymenoptera: Formicidae), were successfully separated by silica gel chromatography, identified, and quantitated by GC-MS analysis. Both workers and alate queens produce primarily...

  13. Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates...

  14. Dynamics and shape of large fire ant rafts

    PubMed Central

    Mlot, Nathan J.; Tovey, Craig; Hu, David L.

    2012-01-01

    To survive floods, fire ants link their bodies together to build waterproof rafts. Such rafts can be quite large, exceeding 100,000 individuals in size. In this study, we make two improvements on a previously reported model on the construction rate of rafts numbering between 3,000 and 10,000 individuals. That model was based upon experimental observations of randomly-directed linear ant trajectories atop the raft. Here, we report anomalous behavior of ants atop larger rafts of up to 23,000 ants. As rafts increase in size, the behavior of ants approaches diffusion, which is in closer alignment with other studies on the foraging and scouting patterns of ants. We incorporate this ant behavior into the model. Our modified model predicts more accurately the growth of large rafts. Our previous model also relied on an assumption of raft circularity. We show that this assumption is not necessary for large rafts, because it follows from the random directionality of the ant trajectories. Our predicted relationship between raft size and circularity closely fits experimental data. PMID:23336030

  15. Advances in Research on the Venom Chemistry of Imported Fire Ants

    USDA-ARS?s Scientific Manuscript database

    Workers of the imported fire ants, including red imported fire ants, Solenopsis invicta Buren, black imported fire ants, S. richteri Forel, and their hybrid (S. invicta × S. richteri), are vicious stingers. Since the venomous sting is a significant medical problem to humans, the chemistry of import...

  16. Abundance of -1,6-piperideine alkaloids in imported fire ants

    USDA-ARS?s Scientific Manuscript database

    Workers of imported fire ants, including red imported fire ants, Solenopsis invicta Buren, black imported fire ants, S. richteri Forel, and their hybrid (S. invicta × S. richteri), are vicious stingers. Since the venomous sting is a significant medical problem to humans, the chemistry of imported f...

  17. 78 FR 70530 - Notice of Determination; New and Revised Treatments for the Imported Fire Ant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... No. APHIS-2012-0064] Notice of Determination; New and Revised Treatments for the Imported Fire Ant... the public that we are adding or revising certain treatment schedules for the Imported Fire Ant... revised treatments in the imported fire ant program. Based on the treatment evaluation document,...

  18. The molecular clockwork of the fire ant Solenopsis invicta.

    PubMed

    Ingram, Krista K; Kutowoi, Alexander; Wurm, Yannick; Shoemaker, Dewayne; Meier, Rudolf; Bloch, Guy

    2012-01-01

    The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta) genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a social insect with an independent evolutionary origin of sociality. Gene trees for the eight core clock genes, period, cycle, clock, cryptochrome-m, timeout, vrille, par domain protein 1 & clockwork orange, show ant species grouping closely with honeybees and Nasonia wasps as an outgroup to the social Hymenoptera. Expression patterns for these genes suggest that the ant clock functions similar to the honeybee clock, with period and cry-m mRNA levels increasing during the night and cycle and clockwork orange mRNAs cycling approximately anti-phase to period. Gene models for five of these genes also parallel honeybee models. In particular, the single ant cryptochrome is an ortholog of the mammalian-type (cry-m), rather than Drosophila-like protein (cry-d). Additionally, we find a conserved VPIFAL C-tail region in clockwork orange shared by insects but absent in vertebrates. Overall, our characterization of the ant clock demonstrates that two social insect lineages, ants and bees, share a similar, mammalian-like circadian clock. This study represents the first characterization of clock genes in an ant and is a key step towards understanding socially-regulated plasticity in circadian rhythms by facilitating comparative studies on the organization of circadian clockwork.

  19. The Molecular Clockwork of the Fire Ant Solenopsis invicta

    PubMed Central

    Ingram, Krista K.; Kutowoi, Alexander; Wurm, Yannick; Shoemaker, DeWayne; Meier, Rudolf; Bloch, Guy

    2012-01-01

    The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta) genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a social insect with an independent evolutionary origin of sociality. Gene trees for the eight core clock genes, period, cycle, clock, cryptochrome-m, timeout, vrille, par domain protein 1 & clockwork orange, show ant species grouping closely with honeybees and Nasonia wasps as an outgroup to the social Hymenoptera. Expression patterns for these genes suggest that the ant clock functions similar to the honeybee clock, with period and cry-m mRNA levels increasing during the night and cycle and clockwork orange mRNAs cycling approximately anti-phase to period. Gene models for five of these genes also parallel honeybee models. In particular, the single ant cryptochrome is an ortholog of the mammalian-type (cry-m), rather than Drosophila-like protein (cry-d). Additionally, we find a conserved VPIFAL C-tail region in clockwork orange shared by insects but absent in vertebrates. Overall, our characterization of the ant clock demonstrates that two social insect lineages, ants and bees, share a similar, mammalian-like circadian clock. This study represents the first characterization of clock genes in an ant and is a key step towards understanding socially-regulated plasticity in circadian rhythms by facilitating comparative studies on the organization of circadian clockwork. PMID:23152747

  20. Multiple functions of fire ant, Solenopsis invicta, mandibular gland products

    USDA-ARS?s Scientific Manuscript database

    : Alarm pheromones are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality in social insects. Recently, we identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of the fire ant, Solenopsis invicta. We continu...

  1. AREAWIDE SUPPRESSION OF FIRE ANTS: DEMONSTRATION PROJECT IN MISSISSIPPI, 2006

    USDA-ARS?s Scientific Manuscript database

    The USDA-ARS demonstration project for the suppression of imported fire ants has entered its sixth year. In 2005, Mississippi State University joined the project monitoring sites in Clay and Grenada Counties. The Areawide project integrates biological control agents with the chemical ...

  2. Potential use of Solenopsis invicta viruses to control fire ants.

    USDA-ARS?s Scientific Manuscript database

    The imported fire ant, Solenopsis invicta was introduced into the U.S. between 1918 and 1945. Since that time, they have expanded their U.S. range to include some 138 million hectares. Their introduction has had significant economic consequences with costs associated with damage and control effort...

  3. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem.

    PubMed

    Stuble, Katharine L; Kirkman, L Katherine; Carroll, C Ronald; Sanders, Nathan J

    2011-06-01

    The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable. ©2011 Society for Conservation Biology.

  4. Toxicity of formic acid against red imported fire ants, Solenopsis invicta Buren

    USDA-ARS?s Scientific Manuscript database

    BACKGROUND: Formic acid is a common defensive chemical of formicine ants. Ants often compete with other ants for resources. However, the toxicity of formic acid to any ant species has not been well understood. This study examined the toxicity of formic acid against the red imported fire ants, Sole...

  5. The fire ant social chromosome supergene variant Sb shows low diversity but high divergence from SB.

    PubMed

    Pracana, Rodrigo; Priyam, Anurag; Levantis, Ilya; Nichols, Richard A; Wurm, Yannick

    2017-02-21

    Variation in social behavior is common yet little is known about the genetic architectures underpinning its evolution. A rare exception is in the fire ant Solenopsis invicta: Alternative variants of a supergene region determine whether a colony will have exactly one or up to dozens of queens. The two variants of this region are carried by a pair of "social chromosomes", SB and Sb, which resemble a pair of sex chromosomes. Recombination is suppressed between the two chromosomes in the supergene region. While the X-like SB can recombine with itself in SB/SB queens, recombination is effectively absent in the Y-like Sb because Sb/Sb queens die before reproducing. Here, we analyze whole genome sequences of eight haploid SB males and eight haploid Sb males. We find extensive SB-Sb di↵erentiation throughout the >19Mb long supergene region. We find no evidence of "evolutionary strata" with different levels of divergence comparable to those reported in several sex chromosomes. A high proportion of substitutions between the SB and Sb haplotypes are nonsynonymous, suggesting inefficacy of purifying selection in Sb sequences, similar to that for Y-linked sequences in XY systems. Finally, we show that the Sb haplotype of the supergene region has 635-fold less nucleotide diversity than the rest of the genome. We discuss how this reduction could be due to a recent selective sweep affecting Sb specifically or associated with a population bottleneck during the invasion of North America by the sampled population. This article is protected by copyright. All rights reserved.

  6. Global invasion history of the fire ant Solenopsis invicta.

    PubMed

    Ascunce, Marina S; Yang, Chin-Cheng; Oakey, Jane; Calcaterra, Luis; Wu, Wen-Jer; Shih, Cheng-Jen; Goudet, Jérôme; Ross, Kenneth G; Shoemaker, DeWayne

    2011-02-25

    The fire ant Solenopsis invicta is a significant pest that was inadvertently introduced into the southern United States almost a century ago and more recently into California and other regions of the world. An assessment of genetic variation at a diverse set of molecular markers in 2144 fire ant colonies from 75 geographic sites worldwide revealed that at least nine separate introductions of S. invicta have occurred into newly invaded areas and that the main southern U.S. population is probably the source of all but one of these introductions. The sole exception involves a putative serial invasion from the southern United States to California to Taiwan. These results illustrate in stark fashion a severe negative consequence of an increasingly massive and interconnected global trade and travel system.

  7. Short-term effects of fire on Sky Island ant communities

    Treesearch

    Elliot B. Wilkinson; Edward G. Lebrun; Mary Lou Spencer; Caroline Whitby; Chris Kleine

    2005-01-01

    Few studies investigating effects of fire on ant communities have been conducted worldwide, and none in the biologically diverse and fire prone region of the Sky Islands. Ant genera richness and total abundance are significantly higher in burned areas. Ant community structure changes between unburned and burned sites, implying that disturbance may influence the role of...

  8. Molecular phylogeny of fire ants of the Solenopsis saevissima species-group based on mtDNA sequences.

    PubMed

    Shoemaker, D DeWayne; Ahrens, Michael E; Ross, Kenneth G

    2006-01-01

    The systematics of South American fire ants (Solenopsis saevissima species-group) has been plagued by difficulties in recognizing species and their relationships on the basis of morphological characters. We surveyed mtDNA sequences from 623 individuals representing 13 described and undescribed species within the species-group and 18 individuals representing other major Solenopsis lineages to generate a phylogeny of the mitochondrial genome. Our analyses support the monophyly of the S. saevissima species-group, consistent with a single Neotropical origin and radiation of this important group of ants, as well as the monophyly of the socially polymorphic species within the group, consistent with a single origin of polygyny (multiple queens per colony) as a derived form of social organization. The mtDNA sequences of the inquiline social parasite S. daguerrei form a clade that appears to be distantly related to sequences from the several host species, consistent with the view that advanced social parasitism did not evolve via sympatric speciation of intraspecific parasites. An important general finding is that species-level polyphyly of the mtDNA appears to be the rule in this group of ants. The existence of multiple divergent mtDNA lineages within several nominal species (including the pest S. invicta) suggests that the pattern of widespread polyphyly often stems from morphological delimitation that overcircumscribes species. However, in two cases the mtDNA polyphyly likely results from recent interspecific hybridization. While resolving species boundaries and relationships is important for understanding general patterns of diversification of South American fire ants, these issues are of added importance because invasive fire ants are emerging as global pests and becoming important model organisms for evolutionary research.

  9. Thelytokous parthenogenesis, male clonality and genetic caste determination in the little fire ant: new evidence and insights from the lab.

    PubMed

    Foucaud, J; Estoup, A; Loiseau, A; Rey, O; Orivel, J

    2010-08-01

    Previous studies indicate that some populations of the little fire ant, Wasmannia auropunctata, display an unusual reproduction system polymorphism. Although some populations have a classical haplodiploid reproduction system, in other populations queens are produced by thelytokous parthenogenesis, males are produced by a male clonality system and workers are produced sexually. An atypical genetic caste determination system was also suggested. However, these conclusions were indirectly inferred from genetic studies on field population samples. Here we set up experimental laboratory nests that allow the control of the parental relationships between individuals. The queens heading those nests originated from either putatively clonal or sexual populations. We characterized the male, queen and worker offspring they produced at 12 microsatellite loci. Our results unambiguously confirm the unique reproduction system polymorphism mentioned above and that male clonality is strictly associated with thelytokous parthenogenesis. We also observed direct evidence of the rare production of sexual gynes and arrhenotokous males in clonal populations. Finally, we obtained evidence of a genetic basis for caste determination. The evolutionary significance of the reproduction system polymorphism and genetic caste determination as well as future research opportunities are discussed.

  10. Forest edges and fire ants alter the seed shadow of an ant-dispersed plant.

    PubMed

    Ness, J H

    2004-02-01

    Exotic species invade fragmented, edge-rich habitats readily, yet the distinct impacts of habitat edges and invaders on native biota are rarely distinguished. Both appear detrimental to ant-dispersed plants such as bloodroot, Sanguinaria canadensis. Working in northeastern Georgia (USA), an area characterized by a rich ant-dispersed flora, fragmented forests, and invasions by the red imported fire ant, Solenopsis invicta, I monitored the interactions between ants and S. canadensis seeds in uninvaded forest interiors, uninvaded forest edges, invaded forest interiors, and invaded forest edges. I observed 95% of the seed dispersal events that occurred within the 60-min observation intervals. Seed collection rates were similar among all four (habitat x invasion) groups. The presence of invasive ants had a strong effect on seed dispersal distance: S. invicta collected most seeds in invaded sites, but was a poorer disperser than four of five native ant taxa. Habitat type (interior versus edge) had no effect on seed dispersal distance, but it had a strong effect on seed dispersal direction. Dispersal towards the edge was disproportionately rare in uninvaded forest edges, and ants in those habitats moved the average dispersed seed approximately 70 cm away from that edge. Dispersal direction was also skewed away from the edge in uninvaded forest interiors and invaded forest edges, albeit non-significantly. This biased dispersal may help explain the rarity of myrmecochorous plants in younger forests and edges, and their poor ability to disperse between fragments. This is the first demonstration that forest edges and S. invicta invasion influence seed dispersal destination and distance, respectively. These forces act independently.

  11. Field Trapping the Little Fire Ant, Wasmannia auropunctata

    PubMed Central

    Derstine, Nathan T.; Troyer, Elisa J.; Suttles, Caitlyn N.; Siderhurst, Leigh A.; Jang, Eric B.; Siderhurst, Matthew S.

    2012-01-01

    Two detection methods for the little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae), both employing the pheromone attractant 2,5-dimethyl-3-(2-methylbutyl)pyrazine (2-MeBu-diMePy), were compared with peanut butter based detection, in order to evaluate differences in species specificity and detection reliability. Trapping was conducted using a transect through a macadamia orchard on the island of Hawaii. The transect consisted of a series of three-tree plots, each plot contained a peanut butter coated stick (the most common detection method used for W. auropunctata in Hawaii), a one—way trap treated with 2-MeBu-diMePy, and a piece of double-sided tape treated with 2-MeBu-diMePy. While there were no differences in the number of W. auropunctata counted with each detection method, and no differences in detection reliability (detecting the known presence of W. auropunctata in a plot), the pheromone—incorporating methods showed greater species specificity, retaining W. auropunctata almost exclusively. These results demonstrate the potential of pheromone—detection methods to selectively capture target ant species even when other ants are present and abundant. Combined data from all three detection methods and a previous visual survey along the transect showed a marked difference in the frequency of cohabitation among ant species. Of the 10 ant species collected, W. auropunctata was found as the sole ant species on a given tree at a significantly higher frequency than all other ant species except Pheidole fervens. 94% percent of the trees with W. auropunctata had only W. auropunctata, supporting previous observations that this species tends to displace other ant species. In addition, W. auropunctata microhabitat preferences were investigated using one—way traps containing 2-MeBu-diMePy, which were placed in three arboreal and three non—arboreal locations. While the number of ants captured did not differ by trap placement, when grouped

  12. Field trapping the little fire ant, Wasmannia auropunctata.

    PubMed

    Derstine, Nathan T; Troyer, Elisa J; Suttles, Caitlyn N; Siderhurst, Leigh A; Jang, Eric B; Siderhurst, Matthew S

    2012-01-01

    Two detection methods for the little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae), both employing the pheromone attractant 2,5-dimethyl-3-(2-methylbutyl)pyrazine (2-MeBu-diMePy), were compared with peanut butter based detection, in order to evaluate differences in species specificity and detection reliability. Trapping was conducted using a transect through a macadamia orchard on the island of Hawaii. The transect consisted of a series of three-tree plots, each plot contained a peanut butter coated stick (the most common detection method used for W. auropunctata in Hawaii), a one-way trap treated with 2-MeBu-diMePy, and a piece of double-sided tape treated with 2-MeBu-diMePy. While there were no differences in the number of W. auropunctata counted with each detection method, and no differences in detection reliability (detecting the known presence of W. auropunctata in a plot), the pheromone-incorporating methods showed greater species specificity, retaining W. auropunctata almost exclusively. These results demonstrate the potential of pheromone-detection methods to selectively capture target ant species even when other ants are present and abundant. Combined data from all three detection methods and a previous visual survey along the transect showed a marked difference in the frequency of cohabitation among ant species. Of the 10 ant species collected, W. auropunctata was found as the sole ant species on a given tree at a significantly higher frequency than all other ant species except Pheidole fervens. 94% percent of the trees with W. auropunctata had only W. auropunctata, supporting previous observations that this species tends to displace other ant species. In addition, W. auropunctata microhabitat preferences were investigated using one-way traps containing 2-MeBu-diMePy, which were placed in three arboreal and three non-arboreal locations. While the number of ants captured did not differ by trap placement, when grouped, captures were

  13. Red imported fire ant impacts on upland arthropods in Southern Mississippi

    USGS Publications Warehouse

    Epperson, D.M.; Allen, C.R.

    2010-01-01

    Red imported fire ants (Solenopsis invicta) have negative impacts on a broad array of invertebrate species. We investigated the impacts of fire ants on the upland arthropod community on 20???40 ha study sites in southern Mississippi. Study sites were sampled from 19972000 before, during, and after fire ant bait treatments to reduce fire ant populations. Fire ant abundance was assessed with bait transects on all sites, and fire ant population indices were estimated on a subset of study sites. Species richness and diversity of other ant species was also assessed from bait transects. Insect biomass and diversity was determined from light trap samples. Following treatments, fire ant abundance and population indices were significantly reduced, and ant species diversity and richness were greater on treated sites. Arthropod biomass, species diversity and species richness estimated from light trap samples were negatively correlated with fire ant abundance, but there were no observable treatment effects. Solenopsis invicta has the potential to negatively impact native arthropod communities resulting in a potential loss of both species and function.

  14. Mitochondrial genome evolution in fire ants (Hymenoptera: Formicidae).

    PubMed

    Gotzek, Dietrich; Clarke, Jessica; Shoemaker, DeWayne

    2010-10-07

    Complete mitochondrial genome sequences have become important tools for the study of genome architecture, phylogeny, and molecular evolution. Despite the rapid increase in available mitogenomes, the taxonomic sampling often poorly reflects phylogenetic diversity and is often also biased to represent deeper (family-level) evolutionary relationships. We present the first fully sequenced ant (Hymenoptera: Formicidae) mitochondrial genomes. We sampled four mitogenomes from three species of fire ants, genus Solenopsis, which represent various evolutionary depths. Overall, ant mitogenomes appear to be typical of hymenopteran mitogenomes, displaying a general A+T-bias. The Solenopsis mitogenomes are slightly more compact than other hymentoperan mitogenomes (~15.5 kb), retaining all protein coding genes, ribosomal, and transfer RNAs. We also present evidence of recombination between the mitogenomes of the two conspecific Solenopsis mitogenomes. Finally, we discuss potential ways to improve the estimation of phylogenies using complete mitochondrial genome sequences. The ant mitogenome presents an important addition to the continued efforts in studying hymenopteran mitogenome architecture, evolution, and phylogenetics. We provide further evidence that the sampling across many taxonomic levels (including conspecifics and congeners) is useful and important to gain detailed insights into mitogenome evolution. We also discuss ways that may help improve the use of mitogenomes in phylogenetic analyses by accounting for non-stationary and non-homogeneous evolution among branches.

  15. Mitochondrial genome evolution in fire ants (Hymenoptera: Formicidae)

    PubMed Central

    2010-01-01

    Background Complete mitochondrial genome sequences have become important tools for the study of genome architecture, phylogeny, and molecular evolution. Despite the rapid increase in available mitogenomes, the taxonomic sampling often poorly reflects phylogenetic diversity and is often also biased to represent deeper (family-level) evolutionary relationships. Results We present the first fully sequenced ant (Hymenoptera: Formicidae) mitochondrial genomes. We sampled four mitogenomes from three species of fire ants, genus Solenopsis, which represent various evolutionary depths. Overall, ant mitogenomes appear to be typical of hymenopteran mitogenomes, displaying a general A+T-bias. The Solenopsis mitogenomes are slightly more compact than other hymentoperan mitogenomes (~15.5 kb), retaining all protein coding genes, ribosomal, and transfer RNAs. We also present evidence of recombination between the mitogenomes of the two conspecific Solenopsis mitogenomes. Finally, we discuss potential ways to improve the estimation of phylogenies using complete mitochondrial genome sequences. Conclusions The ant mitogenome presents an important addition to the continued efforts in studying hymenopteran mitogenome architecture, evolution, and phylogenetics. We provide further evidence that the sampling across many taxonomic levels (including conspecifics and congeners) is useful and important to gain detailed insights into mitogenome evolution. We also discuss ways that may help improve the use of mitogenomes in phylogenetic analyses by accounting for non-stationary and non-homogeneous evolution among branches. PMID:20929580

  16. Invasive Fire Ants Reduce Reproductive Success and Alter the Reproductive Strategies of a Native Vertebrate Insectivore

    PubMed Central

    Ligon, Russell A.; Siefferman, Lynn; Hill, Geoffrey E.

    2011-01-01

    Background Introduced organisms can alter ecosystems by disrupting natural ecological relationships. For example, red imported fire ants (Solenopsis invicta) have disrupted native arthropod communities throughout much of their introduced range. By competing for many of the same food resources as insectivorous vertebrates, fire ants also have the potential to disrupt vertebrate communities. Methodology/Principal Findings To explore the effects of fire ants on a native insectivorous vertebrate, we compared the reproductive success and strategies of eastern bluebirds (Sialia sialis) inhabiting territories with different abundances of fire ants. We also created experimental dyads of adjacent territories comprised of one territory with artificially reduced fire ant abundance (treated) and one territory that was unmanipulated (control). We found that more bluebird young fledged from treated territories than from adjacent control territories. Fire ant abundance also explained significant variation in two measures of reproductive success across the study population: number of fledglings and hatching success of second clutches. Furthermore, the likelihood of bluebird parents re-nesting in the same territory was negatively influenced by the abundance of foraging fire ants, and parents nesting in territories with experimentally reduced abundances of fire ants produced male-biased broods relative to pairs in adjacent control territories. Conclusions/Significance Introduced fire ants altered both the reproductive success (number of fledglings, hatching success) and strategies (decision to renest, offspring sex-ratio) of eastern bluebirds. These results illustrate the negative effects that invasive species can have on native biota, including species from taxonomically distant groups. PMID:21799904

  17. Invasive fire ants reduce reproductive success and alter the reproductive strategies of a native vertebrate insectivore.

    PubMed

    Ligon, Russell A; Siefferman, Lynn; Hill, Geoffrey E

    2011-01-01

    Introduced organisms can alter ecosystems by disrupting natural ecological relationships. For example, red imported fire ants (Solenopsis invicta) have disrupted native arthropod communities throughout much of their introduced range. By competing for many of the same food resources as insectivorous vertebrates, fire ants also have the potential to disrupt vertebrate communities. To explore the effects of fire ants on a native insectivorous vertebrate, we compared the reproductive success and strategies of eastern bluebirds (Sialia sialis) inhabiting territories with different abundances of fire ants. We also created experimental dyads of adjacent territories comprised of one territory with artificially reduced fire ant abundance (treated) and one territory that was unmanipulated (control). We found that more bluebird young fledged from treated territories than from adjacent control territories. Fire ant abundance also explained significant variation in two measures of reproductive success across the study population: number of fledglings and hatching success of second clutches. Furthermore, the likelihood of bluebird parents re-nesting in the same territory was negatively influenced by the abundance of foraging fire ants, and parents nesting in territories with experimentally reduced abundances of fire ants produced male-biased broods relative to pairs in adjacent control territories. Introduced fire ants altered both the reproductive success (number of fledglings, hatching success) and strategies (decision to renest, offspring sex-ratio) of eastern bluebirds. These results illustrate the negative effects that invasive species can have on native biota, including species from taxonomically distant groups.

  18. Raft Formation by the Red Imported Fire Ant, Solenopsis invicta

    PubMed Central

    Adams, Benjamin J.; Hooper-Bùi, Linda M.; Strecker, Rachel M.; O'Brien, Daniel M.

    2011-01-01

    The raft behavior of the invasive red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), has been documented for over a century. However, no rigorous tests have been performed elucidating the structure, limits, and important characteristics of this behavior. Rafting makes S. invicta competitive in both native and foreign environments. Further understanding of this behavior will provide critical advancement to the comprehension of this ant's global invasion ecology. Though speculations exist, no one has looked at the movements of individuals within the raft formation, the longevity of rafts, raft success rate, or the importance of different life stages and varying types of adults to raft formation. Furthermore, bubble use has been extensively studied in arthropods, but it has never been documented in social insects. The use of bubbles as a means of floatation has never before been noted in raft formation. This study shows that ants trapped under water escape by lifting themselves to the air-water interface through the use of bubbles collected from submerged substrate. The presence of larvae was noted to increase colony survival and maximize raft longevity due in part their ability to hold bubbles under hydrophobic setae. PMID:22950473

  19. Mutualism Between Fire Ants and Mealybugs Reduces Lady Beetle Predation.

    PubMed

    Cheng, Shoujie; Zeng, Ling; Xu, Yijuan

    2015-08-01

    Solenopsis invicta Buren is an important invasive pest that has a negative impact on biodiversity. However, current knowledge regarding the ecological effects of its interaction with honeydew-producing hemipteran insects is inadequate. To partially address this problem, we assessed whether the interaction between the two invasive species S. invicta and Phenacoccus solenopsis Tinsley mediated predation of P. solenopsis by Propylaea japonica Thunbery lady beetles using field investigations and indoor experiments. S. invicta tending significantly reduced predation by the Pr. japonica lady beetle, and this response was more pronounced for lady beetle larvae than for adults. A field investigation showed that the species richness and quantity of lady beetle species in plots with fire ants were much lower than in those without fire ants. In an olfaction bioassay, lady beetles preferred to move toward untended rather than tended mealybugs. Overall, these results suggest that mutualism between S. invicta and P. solenopsis may have a serious impact on predation of P. solenopsis by lady beetles, which could promote growth of P. solenopsis populations.

  20. The Organization of Foraging in the Fire Ant, Solenopsis invicta

    PubMed Central

    Tschinkel, Walter R.

    2011-01-01

    Although natural selection in ants acts most strongly at the colony, or superorganismal level, foraging patterns have rarely been studied at that level, focusing instead on the behavior of individual foragers or groups of foragers. The experiments and observations in this paper reveal in broad strokes how colonies of the fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), allocate their available labor to foraging, how they disperse that force within their territory, and how this force changes with colony size, season and worker age. Territory area is positively related to colony size and the number of foragers, more so during the spring than fall. Changes of colony size and territory area are driven by seasonal variation of sexual and worker production, which in turn drive seasonal variation of worker age-distribution. During spring sexual production, colonies shrink because worker production falls below replacement. This loss is proportional to colony size, causing forager density in the spring to be negatively related to colony and territory size. In the fall, colonies emphasize worker production, bringing colony size back up. However, because smaller colonies curtailed spring worker production less than larger ones, their fall forager populations are proportionally greater, causing them to gain territory at the expense of large colonies. Much variation of territory area remains unexplained and can probably be attributed to pressure from neighboring colonies. Boundaries between territories are characterized by “no ants' zones” mostly devoid of fire ants. The forager population can be divided into a younger group of recruitable workers that wait for scouts to activate them to help retrieve large food finds. About one-third of the recruits wait near openings in the foraging tunnels that underlie the entire territory, while two-thirds wait in the nest. Recruitment to food is initially very rapid and local from the foraging tunnels, while sustained

  1. The organization of foraging in the fire ant, Solenopsis invicta.

    PubMed

    Tschinkel, Walter R

    2011-01-01

    Although natural selection in ants acts most strongly at the colony, or superorganismal level, foraging patterns have rarely been studied at that level, focusing instead on the behavior of individual foragers or groups of foragers. The experiments and observations in this paper reveal in broad strokes how colonies of the fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), allocate their available labor to foraging, how they disperse that force within their territory, and how this force changes with colony size, season and worker age. Territory area is positively related to colony size and the number of foragers, more so during the spring than fall. Changes of colony size and territory area are driven by seasonal variation of sexual and worker production, which in turn drive seasonal variation of worker age-distribution. During spring sexual production, colonies shrink because worker production falls below replacement. This loss is proportional to colony size, causing forager density in the spring to be negatively related to colony and territory size. In the fall, colonies emphasize worker production, bringing colony size back up. However, because smaller colonies curtailed spring worker production less than larger ones, their fall forager populations are proportionally greater, causing them to gain territory at the expense of large colonies. Much variation of territory area remains unexplained and can probably be attributed to pressure from neighboring colonies. Boundaries between territories are characterized by "no ants' zones" mostly devoid of fire ants. The forager population can be divided into a younger group of recruitable workers that wait for scouts to activate them to help retrieve large food finds. About one-third of the recruits wait near openings in the foraging tunnels that underlie the entire territory, while two-thirds wait in the nest. Recruitment to food is initially very rapid and local from the foraging tunnels, while sustained

  2. Toxicity and efficacy of two emulsifiable concentrates of 2-tridecanone against red imported fire ants

    USDA-ARS?s Scientific Manuscript database

    BACKGROUND: 2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is the only ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecan...

  3. Sampling high-altitude and stratified mating flights of red imported fire ant.

    PubMed

    Fritz, Gary N; Fritz, Ann H; Vander Meer, Robert K

    2011-05-01

    With the exception of an airplane equipped with nets, no method has been developed that successfully samples red imported fire ant, Solenopsis invicta Buren, sexuals in mating/dispersal flights throughout their potential altitudinal trajectories. We developed and tested a method for sampling queens and males during mating flights at altitudinal intervals reaching as high as "140 m. Our trapping system uses an electric winch and a 1.2-m spindle bolted to a swiveling platform. The winch dispenses up to 183 m of Kevlar-core, nylon rope and the spindle stores 10 panels (0.9 by 4.6 m each) of nylon tulle impregnated with Tangle-Trap. The panels can be attached to the rope at various intervals and hoisted into the air by using a 3-m-diameter, helium-filled balloon. Raising or lowering all 10 panels takes approximately 15-20 min. This trap also should be useful for altitudinal sampling of other insects of medical importance.

  4. Study on the Repellency of Callicarpenal and Intermedeol against Workers of Imported Fire Ants

    USDA-ARS?s Scientific Manuscript database

    Repellency of callicarpenal and intermedeol, two terpenoids isolated from American beautyberry and Japanese beautyberry, were tested against workers of red imported fire ants, Solenopsis invicta Buren, black imported fire ants, Solenopsis richteri Forel, and a hybrid of these two species using diggi...

  5. Mitigating the allergic effects of fire ant envenomation with biologically-based population reduction

    USDA-ARS?s Scientific Manuscript database

    The purpose of this review is to describe current efforts to use biological control agents to reduce fire ant population levels, thus, ultimately reducing the number of human sting and allergic reaction incidents. Climate change and worldwide fire ant expansion will increase the frequency of human e...

  6. Interspecific Variation of delta-1,6-piperideines in Imported Fire Ants

    USDA-ARS?s Scientific Manuscript database

    DELTA-1,6-piperideines have been recently reported in the venom of the red imported fire ants, Solenopsis invicta Buren and the black imported fire ants, S. richteri Forel. However, they have never been quantified in either species. Furthermore, there is no information available about those piperi...

  7. Esterase in imported fire ants, Solenopsis invicata and S. richteri (Hymenoptera: Formicidae): activity, kinetics and variation

    USDA-ARS?s Scientific Manuscript database

    Black imported fire ant, Solenopsis richteri, is closely related to the notorious red imported fire ant, Solenopsis invicta. Despite being very similar in biology and behavior, S. invicta is a much more successful invader. In contrast to S. invicta that has invaded numberous countries and regions,...

  8. Arthropod prey of imported fire ants (Hymenopter: formicidae) in Mississippi sweetpotato fields

    USDA-ARS?s Scientific Manuscript database

    Imported fire ants, Solenopsis invicta (Buren) are generally considered pests. They have also been viewed as beneficial predators feeding on other insect pests of agricultural and medical importance in various agroecosystems. This study documents the foraging habits of fire ants in sweetpotato. Swee...

  9. Dose response of red imported fire ant colonies treated with Solenopsis invicta virus 3

    USDA-ARS?s Scientific Manuscript database

    Baiting tests were conducted to evaluate the effect of increasing Solenopsis invicta virus 3 (SINV-3) doses on fire ant colonies. Actively growing, early stage, fire ant (Solenopsis invicta) laboratory colonies were pulse-exposed to six concentrations of SINV-3 in a 10% sucrose bait and monitored r...

  10. Infection characteristics of Solenopsis invicta virus-2 in the red imported fire ant, Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    Solenopsis invicta virus-2 (SINV-2) is the second virus identified from the fire ant, Solenopsis invicta, Buren. SINV-2 is unique among positive—strand RNA viruses from insects by possessing four cistrons in a monopartite genome. Fire ant colonies testing positive for SINV-2 by RT-PCR did not exhi...

  11. Phorid fly, Pseudacteon tricuspis, response to alkylpyrazine analogs of a fire ant, Solenopsis invicta, alarm pheromone

    USDA-ARS?s Scientific Manuscript database

    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...

  12. The large decapitating fly Pseudacteon litoralis (Diptera: Phoridae): Successfully established on fire ant populations in Alabama

    USDA-ARS?s Scientific Manuscript database

    The large fire ant decapitating fly, Pseudacteon litoralis Borgmeier from northeastern Argentina was successfully released as a self-sustaining biocontrol agent of imported fire ants in south central Alabama in 2005. Five years later, this fly is firmly established at this site and has expanded out...

  13. Positive-strand RNA viruses infecting the Red Imported Fire Ant, Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    The black imported fire ant (Solenopsis richteri) and red imported fire ant (S. invicta) are invasive species that were introduced into the United States between 1918 and 1945. Since that time, they have expanded their U.S. range to include some 138 million hectares from Virginia, south to Florida,...

  14. The fire ant (Hymenoptera: Formicidae) pathogen, Vairimorpha invictae (Microsporidia: Burenellidae), not detected in Florida

    USDA-ARS?s Scientific Manuscript database

    Surveys were conducted to search specifically for the microsporidian pathogen Vairimorpha. invictae in red imported fire ants, Solenopsis invicta, in the U.S. This pathogen is associated with colony decline and reductions in fire ant populations in S. America and is considered to be a promising bio...

  15. The role of habitat in the persistence of fire ant populations.

    PubMed

    Tschinkel, Walter R; King, Joshua R

    2013-01-01

    The association of the exotic fire ant, Solenopsis invicta with man-modified habitats has been amply demonstrated, but the fate of such populations if ecological succession proceeds has rarely been investigated. Resurvey of a fire ant population in a longleaf pine plantation after 25 years showed that the recovery of the site from habitat disturbance was associated with a large fire ant population decline. Most of the persisting colonies were associated with the disturbance caused by vehicle tracks. In a second study, mature monogyne fire ant colonies that had been planted in experimental plots in native groundcover of the north Florida longleaf pine forest had mostly vanished six years later. These observations and experiments show that S. invicta colonies rarely persist in the native habitat of these pine forests, probably because they are not replaced when they die. A single site harbored a modest population of polygyne fire ants whose persistence was probably facilitated by reproduction through colony fission.

  16. The Role of Habitat in the Persistence of Fire Ant Populations

    PubMed Central

    Tschinkel, Walter R.; King, Joshua R.

    2013-01-01

    The association of the exotic fire ant, Solenopsis invicta with man-modified habitats has been amply demonstrated, but the fate of such populations if ecological succession proceeds has rarely been investigated. Resurvey of a fire ant population in a longleaf pine plantation after 25 years showed that the recovery of the site from habitat disturbance was associated with a large fire ant population decline. Most of the persisting colonies were associated with the disturbance caused by vehicle tracks. In a second study, mature monogyne fire ant colonies that had been planted in experimental plots in native groundcover of the north Florida longleaf pine forest had mostly vanished six years later. These observations and experiments show that S. invicta colonies rarely persist in the native habitat of these pine forests, probably because they are not replaced when they die. A single site harbored a modest population of polygyne fire ants whose persistence was probably facilitated by reproduction through colony fission. PMID:24205272

  17. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  18. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  19. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  20. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  1. A survey of Imported Fire Ant (Hymenoptera: Formicidae), species and social forms across four counties in east-central Mississippi

    USDA-ARS?s Scientific Manuscript database

    Molecular technology allows researchers to definitively identify red imported fire ants as either monoygyne or polygyne based on the alleles present at the Gp-9 locus. This technique has not previously been applied to hybrid individuals of the red imported fire ant and the black imported fire ant. S...

  2. Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils.

    PubMed

    Vieira, Alexsandro Santana; Camargo-Mathias, Maria Izabel; Roces, Flavio

    2015-09-01

    Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Pseudacteon decapitating flies: Potential vectors of a fire ant virus?

    SciTech Connect

    Valles, S.M.; Porter, S.D.

    2007-03-15

    Solenopsis invicta virus (SINV-1) is a positive-stranded RNA virus recently found to infect all stages of the red imported fire ant, Solenopsis invicta (Valles et al. 2004; Valles and Strong 2005). SINV-1 and a second genotype have been tentatively assigned to the Dicistroviridae (Mayo 2002). Infected individuals or colonies did not exhibit any immediate, discernible symptoms in the field. However, under stress from introduction into the laboratory, brood death was often observed among infected colonies, ultimately leading to the death of the entire colony (Valles et al. 2004). These characteristics are consistent with other insect-infecting positive-stranded RNA viruses. They often persist as inapparent, asymptomatic infections that, under certain conditions, induce replication within the host, resulting in observable symptoms and often death (Christian and Scotti 1998; Fernandez et al. 2002). The SINV infection rate among colonies was reported to be around 25% in Gainesville, Florida (Valles et al. 2004; Valles and Strong 2005). SINV vertical and horizontal transmission were inferred based on RT-PCR detection of virus genome in eggs and successful colony to colony transfer under lab conditions (Valles et al. 2004). However, the exact mechanisms by which the virus is spread from nest to nest in the field are unknown. Our results indicate that SINV does not replicate within Pseudacteon decapitating flies that parasitize S. invicta. Flies appeared to develop normally from SINV-infected S. invicta workers. Mechanical transmission of SINV to uninfected ants by oviposition appears unlikely.

  4. Crab regulation of cross-ecosystem resource transfer by marine foraging fire ants.

    PubMed

    Garcia, Erica A; Bertness, Mark D; Alberti, Juan; Silliman, Brian R

    2011-08-01

    Permeability of boundaries in biological systems is regulated by biotic and/or abiotic factors. Despite this knowledge, the role of biotic factors in regulating resource transfer across ecosystem boundaries has received little study. Additionally, little is known about how cross-ecosystem resource transfer affects source populations. We used experiments, observations and stable isotopes, to evaluate: (1) the proportion of intertidal-foraging black fire ant (Solenopsis richteri) diet derived from marine sources, (2) how black fire ant cross-ecosystem resource transfer is altered by the dominant bioengineer in the intertidal, a burrowing crab (Neohelice granulata), (3) the top-down impact of these terrestrial ants on a marine resource, and (4) the effect of marine resources on recipient black fire ants. We found that more than 85% of the black fire ant diet is derived from marine sources, the number of intertidal foraging ants doubles in the absence of crab burrows, and that ants cause a 50% reduction in intertidal polychaetes. Also, ant mound density is three times greater adjacent to marine systems. This study reveals that cross-ecosystem foraging terrestrial ants can clearly have strong impacts on marine resources. Furthermore, ecosystem engineers that modify and occupy habitat in these ecosystem boundaries can strongly regulate the degree of cross-ecosystem resource transfer and resultant top down impacts.

  5. Arthropod prey of imported fire ants (Hymenoptera: Formicidae) in Mississippi sweetpotato fields.

    PubMed

    Rashid, Tahir; Chen, Jian; Vogt, James T; McLeod, Paul J

    2013-08-01

    The red imported fire ants, Solenopsis invicta (Buren), are generally considered pests. They have also been viewed as beneficial predators feeding on other insect pests of various agroecosystems. This study documents the foraging habits of fire ants in a sweetpotato field in Mississippi. Fire ant foraging trails connecting outside colonies to a sweetpotato field were exposed and foraging ants moving out of the field toward the direction of the colony were collected along with the solid food particles they were carrying. The food material was classified as arthropod or plant in origin. The arthropod particles were identified to orders. Fire ant foragers carried more arthropods than plant material. Coleoptera and Homoptera were the most abundant groups preyed upon. These insect orders contain various economically important pests of sweetpotato. Other major hexapod groups included the orders Hemiptera, Diptera and Collembola. The quantity of foraged material varied over the season. No damage to sweetpotato roots could be attributed to fire ant feeding. Imported fire ant foraging may reduce the number of insect pests in sweetpotato fields. © 2012 Institute of Zoology, Chinese Academy of Sciences.

  6. Propagule pressure and colony social organization are associated with the successful invasion and rapid range expansion of fire ants in China.

    PubMed

    Yang, Chin-Cheng; Ascunce, Marina S; Luo, Li-Zhi; Shao, Jing-Guo; Shih, Cheng-Jen; Shoemaker, DeWayne

    2012-02-01

    We characterized patterns of genetic variation in populations of the fire ant Solenopsis invicta in China using mitochondrial DNA sequences and nuclear microsatellite loci to test predictions as to how propagule pressure and subsequent dispersal following establishment jointly shape the invasion success of this ant in this recently invaded area. Fire ants in Wuchuan (Guangdong Province) are genetically differentiated from those found in other large infested areas of China. The immediate source of ants in Wuchuan appears to be somewhere near Texas, which ranks first among the southern USA infested states in the exportation of goods to China. Most colonies from spatially distant, outlying areas in China are genetically similar to one another and appear to share a common source (Wuchuan, Guangdong Province), suggesting that long-distance jump dispersal has been a prevalent means of recent spread of fire ants in China. Furthermore, most colonies at outlier sites are of the polygyne social form (featuring multiple egg-laying queens per nest), reinforcing the important role of this social form in the successful invasion of new areas and subsequent range expansion following invasion. Several analyses consistently revealed characteristic signatures of genetic bottlenecks for S. invicta populations in China. The results of this study highlight the invasive potential of this pest ant, suggest that the magnitude of international trade may serve as a predictor of propagule pressure and indicate that rates and patterns of subsequent range expansion are partly determined by the interplay between species traits and the trade and transportation networks. © Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

  7. An Environmentally Improved Method of Fire Ant Control for High Maintenance Areas,

    DTIC Science & Technology

    A study was conducted to evaluate the use of aluminum phosphide ( Phostoxin (R)) for fire ant control. A simple probe was developed to inject Phostoxin ...treatment procedures. The Phostoxin degraded within 72 hours, eliminating any residual pesticide type material. (Author)

  8. Bionomics of Orasema simplex (Hymenoptera: Eucharitidae) a parasitoid of Solenopsis fire ants (Hymenoptera: Formicidae) in Argentina

    USDA-ARS?s Scientific Manuscript database

    Biological characteristics of the parasitoid Orasema simplex Heraty (Hymenoptera: Eucharitidae), a potential candidate for the biological control of fire ants in the United States were investigated. Female survivorship, fertility and oviposition preferences were studied in the laboratory. Naturally ...

  9. Hyperspectral Remote Sensing of Seasonally-Acquired Imported Fire Ant Mound Features (Hymenoptera: Formicidae) in Turfgrass

    USDA-ARS?s Scientific Manuscript database

    Invasive mound-building imported fire ants (Solenopsis spp.) impact soil quality and turfgrass nutrient management in sod production, recreational, residential, and commercial settings. Ground-based hyperspectral studies focused on the seasonal monitoring of reflectance characteristics of imported f...

  10. Fire ants actively control spacing and orientation within self-assemblages.

    PubMed

    Foster, Paul C; Mlot, Nathan J; Lin, Angela; Hu, David L

    2014-06-15

    To overcome obstacles and survive harsh environments, fire ants link their bodies together to form self-assemblages such as rafts, bridges and bivouacs. Such structures are examples of self-assembling and self-healing materials, as ants can quickly create and break links with one another in response to changes in their environment. Because ants are opaque, the arrangement of the ants within these three-dimensional networks was previously unknown. In this experimental study, we applied micro-scale computed tomography, or micro-CT, to visualize the connectivity, arrangement and orientation of ants within an assemblage. We identified active and geometric mechanisms that ants use to obtain favorable packing properties with respect to well-studied packing of inert objects such as cylinders. Ants use their legs to push against their neighbors, doubling their spacing relative to random packing of cylinders. These legs also permit active control of their orientation, an ability ants use to arrange themselves perpendicularly rather than in parallel. Lastly, we found an important role of ant polymorphism in promoting self-aggregation: a large distribution of ant sizes permits small ants to fit between the legs of larger ants, a phenomenon that increases the number of average connections per ant. These combined mechanisms lead to low packing fraction and high connectivity, which increase raft buoyancy and strength during flash floods.

  11. Colony growth of two species of Solenopsis fire ants(Hymenoptera: Formicidae) reared with crickets and beef liver

    USDA-ARS?s Scientific Manuscript database

    Most diets for rearing fire ants and other ants contain insects such as crickets or mealworms. Unfortunately, insect diets are expensive, especially for large rearing operations, and are not always easily available. This study was designed to examine colony growth of Solenopsis fire ants on beef liv...

  12. Distribution, abundance and persistence of Orasema spp. (Hym:Eucharitidae) parasitic on fire ants in South America

    USDA-ARS?s Scientific Manuscript database

    Parasitoid wasps of the genus Orasema Cameron have been considered as potential candidates for biological control of imported fire ants in the United States. Surveys were conducted for their occurrence in fire ant colonies across southern South America. In Argentina, 443 ant colonies were excavated ...

  13. Seasonal Dynamics of Hyperspectral Reflectance Patterns Influencing Detection of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass

    USDA-ARS?s Scientific Manuscript database

    Invasive mound-building imported fire ants impact soil quality and turfgrass nutrient management affecting an estimated 8.1 million hectares in sod production, recreational, and residential settings in the southeastern U.S. Reflectance characteristics of imported fire ant mound features (i.e., ant m...

  14. Alkylpyrazines: Alarm pheromone components of the little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera, Formicidae)

    USDA-ARS?s Scientific Manuscript database

    The previous identification of 2,5-dimethyl-3-(3-methylbutyl) pyrazine as the mandibular alarm pheromone of the little fire ant, Wasmannia auropunctata (Roger), has been found to be incorrect. Gas chromatography-mass spectrometry (GC-MS) of ant extracts suggested the correct structure to be the reg...

  15. Differential Field Responses of the Little Fire Ants, Wasmannia auropunctata(Roger), to Alarm Pheromone Enantiomers

    USDA-ARS?s Scientific Manuscript database

    The little fire ant,Wasmannia auropunctata(Roger)(Hymenoptera: Formicidae),is an invasive ant with negative impacts on both biodiversity and agriculture throughout the tropics and subtropics. Since the discovery of W.auropunctata in Puna in 1999,it has established across the eastern side of Hawaii I...

  16. 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.

  17. Pseudacteon decapitating fly parasitism rates in fire ant colonies around Gainesville, Florida

    USDA-ARS?s Scientific Manuscript database

    In order to assess the impacts of phorid flies on fire ants in the Gainesville area, we collected 3 g of worker ants from 36 colonies. A total of 672 parasitized workers were recovered from the 36 colony samples. Confirmed parasitism rates ranged from 0-5% with an average of about 0.5%. Including c...

  18. Histiostoma Blomquisti N. SP. (Acari: Histiostomatidae) A phoretic mite of the red imported ant, Solenopsis Invicta Buren (Hymenoptera: Formicidae).

    Treesearch

    Stefan Wirth; John Moser

    2010-01-01

    The new species Histiostoma bJol1lquisti n. sp., associated with the Red Imported Fire Ant, Solenopsis invicta, is described by its deutonymph. A putative adult female is depicted. The deutonymphs only attach to female alates, dealates and queens of S. invicta. While queens may be covered by more than 200 deutonymphs over their entire bodies, the numbers of deutonymphs...

  19. Estimation of the number of founders of an invasive pest insect population: the fire ant Solenopsis invicta in the USA

    PubMed Central

    Ross, Kenneth G; Shoemaker, D. DeWayne

    2008-01-01

    Determination of the number of founders responsible for the establishment of invasive populations is important for developing biologically based management practices, predicting the invasive potential of species, and making inferences about ecological and evolutionary processes. The fire ant Solenopsis invicta is a major invasive pest insect first introduced into the USA from its native South American range in the mid-1930s. We use data from diverse genetic markers surveyed in the source population and the USA to estimate the number of founders of this introduced population. Data from different classes of nuclear markers (microsatellites, allozymes, sex-determination locus) and mitochondrial DNA are largely congruent in suggesting that 9–20 unrelated mated queens comprised the initial founder group to colonize the USA at Mobile, Alabama. Estimates of founder group size based on expanded samples from throughout the southern USA were marginally higher than this, consistent with the hypothesis of one or more secondary introductions of the ant into the USA. The rapid spread and massive population build-up of introduced S. invicta occurred despite the loss of substantial genetic variation associated with the relatively small invasive propagule size, a pattern especially surprising in light of the substantial genetic load imposed by the loss of variation at the sex-determination locus. PMID:18577505

  20. An experimental study of competition between fire ants and Argentine ants in their native range.

    PubMed

    LeBrun, E G; Tillberg, C V; Suarez, A V; Folgarait, P J; Smith, C R; Holway, D A

    2007-01-01

    An understanding of why introduced species achieve ecological success in novel environments often requires information about the factors that limit the abundance of these taxa in their native ranges. Although numerous recent studies have evaluated the importance of natural enemies in this context, relatively few have examined how ecological success may result from differences in the magnitude of interference competition between communities in the native and introduced ranges of nonnative species. Here we examine how native-range competitive environments may relate to invasion success for two important invasive species, the red imported fire ant (Solenopsis invicta) and the Argentine ant (Linepithema humile), in a region of native-range sympatry. At two study sites in northern Argentina, we used stable-isotope analysis, a variety of observational approaches, and two different reciprocal removal experiments to test (1) whether S. invicta competes asymmetrically with L. humile (as suggested by the 20th century pattern of replacement in the southeastern United States) and (2) the extent to which these two species achieve behavioral and numerical dominance. Stable-isotope analysis and activity surveys indicated that S. invicta and L. humile are both omnivores and forage during broadly overlapping portions of the diel cycle. Short-term removal experiments at baits revealed no competitive asymmetry between S. invicta and L. humile. Longer-term colony removal experiments illustrated that S. invicta and L. humile experience an approximately equal competitive release upon removal of the other. Our results indicate that neither S. invicta nor L. humile achieves the same degree of behavioral or ecological dominance where they co-occur in native populations as they do in areas where either is common in their introduced range. These results strongly suggest that interspecific competition is an important limiting factor for both S. invicta and L. humile in South America.

  1. Royal Darwinian Demons: Enforced Changes in Reproductive Efforts Do Not Affect the Life Expectancy of Ant Queens.

    PubMed

    Schrempf, Alexandra; Giehr, Julia; Röhrl, Ramona; Steigleder, Sarah; Heinze, Jürgen

    2017-04-01

    One of the central tenets of life-history theory is that organisms cannot simultaneously maximize all fitness components. This results in the fundamental trade-off between reproduction and life span known from numerous animals, including humans. Social insects are a well-known exception to this rule: reproductive queens outlive nonreproductive workers. Here, we take a step forward and show that under identical social and environmental conditions the fecundity-longevity trade-off is absent also within the queen caste. A change in reproduction did not alter life expectancy, and even a strong enforced increase in reproductive efforts did not reduce residual life span. Generally, egg-laying rate and life span were positively correlated. Queens of perennial social insects thus seem to maximize at the same time two fitness parameters that are normally negatively correlated. Even though they are not immortal, they best approach a hypothetical "Darwinian demon" in the animal kingdom.

  2. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Wang, Lei; Elliott, Brad; Jin, Xixuan; Zeng, Ling; Chen, Jian

    2015-12-01

    The antimicrobial property of volatiles produced by red imported fire ants, Solenopsis invicta, against Beauveria bassiana, a common entomopathogenic fungus, was demonstrated. The germination rate of B. bassiana spores was significantly reduced after they were exposed to volatiles within an artificial ant nest. Since the air that contained the same level of O2 and CO2 as that in artificial fire ant nests did not suppress the germination rate of B. bassiana, the observed reduction of germination rate must be caused by the toxicity of nest volatiles. Nest fumigation may be an important component of the social immune system in S. invicta.

  3. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (hymenoptera: formicidae)

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Elliott, Brad; Jin, Xixuan; Zeng, Ling; Chen, Jian

    2015-12-01

    The antimicrobial property of volatiles produced by red imported fire ants, Solenopsis invicta, against Beauveria bassiana, a common entomopathogenic fungus, was demonstrated. The germination rate of B. bassiana spores was significantly reduced after they were exposed to volatiles within an artificial ant nest. Since the air that contained the same level of O2 and CO2 as that in artificial fire ant nests did not suppress the germination rate of B. bassiana, the observed reduction of germination rate must be caused by the toxicity of nest volatiles. Nest fumigation may be an important component of the social immune system in S. invicta.

  4. Pseudacteon Phorid Flies: Host Specificity and Impacts on Solenopsis Fire Ants.

    PubMed

    Chen, Li; Fadamiro, Henry Y

    2017-09-22

    Human commerce has resulted in the spread of the imported fire ants, Solenopsis species, worldwide. Six species of parasitic Pseudacteon phorid flies that are highly host specific to the Solenopsis saevissima complex of Solenopsis fire ants have been successfully released in the southern United States. The presence of Pseudacteon phorid flies, in addition to having direct mortality effects on their host ants, modifies foraging behavior and disrupts interspecific competition between host species and other ant species in the community. Fire ant workers have evolved effective methods to cope with parasitism pressure, which may relieve population-level impacts of introduced phorid flies. This review focuses on the mechanisms underlying host location, host preference, and host-size selection of Pseudacteon phorid flies and highlights their direct and indirect effects on fire ant populations. Knowledge gained from parasitoid-ant interactions will enhance use of natural enemies as biological control agents for invasive social insects. Expected final online publication date for the Annual Review of Entomology Volume 63 is January 7, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  5. Red imported fire ant impacts on wildlife: A decade of research

    USGS Publications Warehouse

    Allen, C.R.; Epperson, D.M.; Garmestani, A.S.

    2004-01-01

    The negative impacts of biological invasion are economically and ecologically significant and, while incompletely quantified, they are clearly substantial. Ants (family Formicidae) are an important, although often overlooked, component of many terrestrial ecosystems. Six species of ants are especially striking in their global ability to invade, and their impacts. This paper focuses on the impacts of the most destructive of those species, the red imported fire ant (Solenopsis invicta), and focuses on impacts on native vertebrates. Red imported fire ants often become the dominant ant species in infested areas outside of their native range due to their aggressive foraging behavior, high reproductive capability and lack of predators and/or other strong competitors. The evidence suggests that mammals, birds and herpetofauna are vulnerable to negative impacts from fire ants, and some species are more likely to experience negative population-level impacts than other species. Assessing the ecological impacts of fire ants on wild animal populations is logistically difficult, and very few studies have combined replicated experimental manipulation with adequate spatial (>10 ha) and temporal (>1 y) scale. Thus, most studies have been observational, opportunistic, small-scale or 'natural' experiments. However, significant research, including an increase in experimental and mechanistic investigations, has occurred during the past decade, and this has led to information that can lead to better management of potentially affected species.

  6. Fire ants self-assemble into waterproof rafts to survive floods.

    PubMed

    Mlot, Nathan J; Tovey, Craig A; Hu, David L

    2011-05-10

    Why does a single fire ant Solenopsis invicta struggle in water, whereas a group can float effortlessly for days? We use time-lapse photography to investigate how fire ants S. invicta link their bodies together to build waterproof rafts. Although water repellency in nature has been previously viewed as a static material property of plant leaves and insect cuticles, we here demonstrate a self-assembled hydrophobic surface. We find that ants can considerably enhance their water repellency by linking their bodies together, a process analogous to the weaving of a waterproof fabric. We present a model for the rate of raft construction based on observations of ant trajectories atop the raft. Central to the construction process is the trapping of ants at the raft edge by their neighbors, suggesting that some "cooperative" behaviors may rely upon coercion.

  7. Fire ants self-assemble into waterproof rafts to survive floods

    PubMed Central

    Mlot, Nathan J.; Tovey, Craig A.; Hu, David L.

    2011-01-01

    Why does a single fire ant Solenopsis invicta struggle in water, whereas a group can float effortlessly for days? We use time-lapse photography to investigate how fire ants S. invicta link their bodies together to build waterproof rafts. Although water repellency in nature has been previously viewed as a static material property of plant leaves and insect cuticles, we here demonstrate a self-assembled hydrophobic surface. We find that ants can considerably enhance their water repellency by linking their bodies together, a process analogous to the weaving of a waterproof fabric. We present a model for the rate of raft construction based on observations of ant trajectories atop the raft. Central to the construction process is the trapping of ants at the raft edge by their neighbors, suggesting that some “cooperative” behaviors may rely upon coercion. PMID:21518911

  8. Dynamic thermal structure of imported fire ant mounds.

    PubMed

    Vogt, James T; Wallet, Bradley; Coy, Steven

    2008-01-01

    A study was undertaken to characterize surface temperatures of mounds of imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae) and S. richteri Forel, and their hybrid, as it relates to sun position and shape of the mounds, to better understand factors that affect absorption of solar radiation by the nest mound and to test feasibility of using thermal infrared imagery to remotely sense mounds. Mean mound surface temperature peaked shortly after solar noon and exceeded mean surface temperature of the surrounding surface. Temperature range for mounds and their surroundings peaked near solar noon, and the temperature range of the mound surface exceeded that of the surrounding area. The temperature difference between mounds and their surroundings peaked around solar noon and ranged from about 2 to 10 degrees C. Quadratic trends relating temperature measurements to time of day (expressed as percentage of daylight hours from apparent sunrise to apparent sunset) explained 77 to 88% of the variation in the data. Mounds were asymmetrical, with the apex offset on average 81.5 +/- 1.2 mm to the north of the average center. South facing aspects were about 20% larger than north facing aspects. Mound surface aspect and slope affected surface temperature; this affect was greatly influenced by time of day. Thermal infrared imagery was used to illustrate the effect of mound shape on surface temperature. These results indicate that the temperature differences between mounds and their surroundings are sufficient for detection using thermal infrared remote sensing, and predictable temporal changes in surface temperature may be useful for classifying mounds in images.

  9. Proteomic view of the venom from the fire ant Solenopsis invicta Buren.

    PubMed

    dos Santos Pinto, José R A; Fox, Eduardo G P; Saidemberg, Daniel M; Santos, Lucilene D; da Silva Menegasso, Anally R; Costa-Manso, Eliúde; Machado, Ednildo A; Bueno, Odair C; Palma, Mario S

    2012-09-07

    Fire ants are well-known by their aggressive stinging behavior, causing many stinging incidents of medical importance. The limited availability of fire ant venom for scientific and clinical uses has restricted, up to now, the knowledge about the biochemistry, immunology, and pharmacology of these venoms. For this study, S. invicta venom was obtained commercially and used for proteomic characterization. For this purpose, the combination of gel-based and gel-free proteomic strategies was used to assign the proteomic profile of the venom from the fire ant S. invicta. This experimental approach permitted the identification of 46 proteins, which were organized into four different groups according to their potential role in fire ant venom: true venom components, housekeeping proteins, body muscle proteins, and proteins involved in chemical communication. The active venom components that may not present toxic roles were classified into three subgroups according to their potential functions: self-venom protection, colony asepsis, and chemical communication. Meanwhile, the proteins classified as true toxins, based on their functions after being injected into the victims' bodies by the fire ants, were classified in five other subgroups: proteins influencing the homeostasis of the victims, neurotoxins, proteins that promote venom diffusion, proteins that cause tissue damage/inflammation, and allergens.

  10. Lack of interactions between fire ant control products and white grubs (Coleoptera: Scarabaeidae) in turfgrass.

    PubMed

    Barden, S Addison; Held, David W; Graham, L C Fudd

    2011-12-01

    Insecticides are widely used to manage turfgrass pest such as white grubs (Coleoptera: Scarabaeidae). Red imported fire ants, Solenopsis invicta (Buren) are important predators and pests in managed turfgrass. We tested the susceptibility of white grub life stages (adults, egg, and larvae) to predation by S. invicta and determined if insecticides applied for control of S. invicta would result in locally greater white grub populations. Field trials over 2 yr evaluated bifenthrin, fipronil, and hydramethylnon applied to large and small scale turfgrass plots for impacts on fire ant foraging and white grub populations. Coincident with these trials, adults, larvae, and eggs of common scarab species were evaluated for susceptibility to predation by S. invicta under field conditions. Field trials with insecticides failed to show a significant increase in white grub populations resulting from treatment of turfgrass for fire ants. This, in part, may be because of a lack of predation of S. invicta on adult and larval scarabs. Egg predation was greatest at 70% but < 20% of adults and larvae were attacked in a 24 h test. Contrary to other studies, results presented here suggest that fire ants and fire ant control products applied to turfgrass have a minimal impact on white grub populations.

  11. The red imported fire ant (Solenopsis invicta Buren) kept Y not F: predicted sNPY endogenous ligands deorphanize the short NPF (sNPF) receptor.

    PubMed

    Bajracharya, Prati; Lu, Hsiao-Ling; Pietrantonio, Patricia V

    2014-01-01

    Neuropeptides and their receptors play vital roles in controlling the physiology and behavior of animals. Short neuropeptide F (sNPF) signaling regulates several physiological processes in insects such as feeding, locomotion, circadian rhythm and reproduction, among others. Previously, the red imported fire ant (Solenopsis invicta) sNPF receptor (S. invicta sNPFR), a G protein-coupled receptor, was immunolocalized in queen and worker brain and queen ovaries. Differential distribution patterns of S. invicta sNPFR protein in fire ant worker brain were associated both with worker subcastes and with presence or absence of brood in the colony. However, the cognate ligand for this sNPFR has not been characterized and attempts to deorphanize the receptor with sNPF peptides from other insect species which ended in the canonical sequence LRLRFamide, failed. Receptor deorphanization is an important step to understand the neuropeptide receptor downstream signaling cascade. We cloned the full length cDNA of the putative S. invicta sNPF prepropeptide and identified the putative "sNPF" ligand within its sequence. The peptide ends with an amidated Tyr residue whereas in other insect species sNPFs have an amidated Phe or Trp residue at the C-terminus. We stably expressed the HA-tagged S. invicta sNPFR in CHO-K1 cells. Two S. invicta sNPFs differing at their N-terminus were synthesized that equally activated the sNPFR, SLRSALAAGHLRYa (EC50 = 3.2 nM) and SALAAGHLRYa (EC50 = 8.6 nM). Both peptides decreased the intracellular cAMP concentration, indicating signaling through the Gαi-subunit. The receptor was not activated by sNPF peptides from other insect species, honey bee long NPF (NPY) or mammalian PYY. Further, a synthesized peptide otherwise identical to the fire ant sequence but in which the C-terminal amidated amino acid residue 'Y' was switched to 'F', failed to activate the sNPFR. This discovery will now allow us to investigate the function of sNPY and its cognate

  12. Integrated pest management concepts for red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Drees, Bastiaan M; Calixto, Alejandro A; Nester, Paul R

    2013-08-01

    Management of imported fire ant species has evolved since their accidental introduction into the United States and currently uses integrated pest management concepts to design, implement, and evaluate suppression programs. Although eradication is the management goal in certain isolated infestation sites, localized goals vary dramatically in larger infestations where reinvasion of treated areas is likely. These goals are influenced by regulatory policies, medical liabilities, ecological impact, and/or economic considerations. Tactics employed in fire ant management programs presented here include cultural and biological control options along with judicious use of site-specific insecticide products. In addition, program design considerations that include management goal(s), action level(s), ant form (monogyne or polygyne), presence of nontarget ant species, size of treatment area, seasonality, implementation cost, and environmental impact are also presented. Optimally, elegant IPM programs are target specific, threshold driven, environmentally friendly and cost-effective. © 2012 Institute of Zoology, Chinese Academy of Sciences.

  13. Indirect effects of red imported fire ants on Attwater's prairie‐chicken brood survival

    PubMed Central

    Chester, Rebecca E.; Lehnen, Sarah E.; Drees, Bastiaan M.; Toepfer, John E.

    2015-01-01

    ABSTRACT The invasive red imported fire ant (Solenopsis invicta) has negatively affected a host of taxonomic groups throughout its acquired North American range. Many studies have hypothesized indirect trophic impacts, but few documented those impacts. We evaluated invertebrate abundance as a factor limiting juvenile survival of the endangered Attwater's prairie‐chicken (Tympanuchus cupido attwateri), and whether fire ants reduce invertebrate numbers and biomass. From 2009–2013, we monitored survival of Attwater's prairie‐chicken broods (n = 63) with radio telemetry during the first 2 weeks post‐hatch and collected daily invertebrate samples at brood sites. Broods located in areas with the highest median invertebrate count (338 invertebrates/25 sweeps) had a survival probability of 0.83 at 2 weeks post‐hatch compared to 0.07 for broods located in areas with the lowest median invertebrate count (18 invertebrates/25 sweeps). During 2011–2012, we evaluated the reduction of fire ants on invertebrate numbers and biomass by aerially treating areas with Extinguish Plus™ in an impact‐reference study design. Treated fields had 27% more individual invertebrates and 26% higher invertebrate biomass than reference fields. Our results clearly document that invertebrate abundance affects Attwater's prairie‐chicken brood survival and that fire ants may indirectly contribute to low brood survival by suppressing invertebrate abundance. We posit that within the fire ant's acquired North American range, fire ants are likely contributing to declines of other insectivorous species. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. PMID:26900176

  14. Effects of Invasive European Fire Ants (Myrmica rubra) on Herring Gull (Larus argentatus) Reproduction

    PubMed Central

    DeFisher, Luke E.; Bonter, David N.

    2013-01-01

    Various invasive ant species have negatively affected reproductive success in birds by disrupting nest site selection, incubation patterns, food supply, and by direct predation on nestlings. Impacts can be particularly severe when non-native ants colonize seabird nesting islands where thousands of birds may nest in high densities on the ground or in burrows or crevices. Here we report on the first documented effects of Myrmica rubra, the European fire ant, on the reproduction of birds in its non-native range. We documented herring gulls (Larus argentatus) on Appledore Island, Maine, engaging in more erratic incubation behaviors at nests infested by the ants. Newly-hatched chicks in some nests were swarmed by ants, leading to rapid chick death. Due to high overall rates of chick mortality, survival probabilities did not vary between nests with and without ant activity, however chick growth rates were slower at nests with ants than at ant-free nests. Ant infestation likely leads to longer-term fitness consequences because slower growth rates early in life may ultimately lead to lower post-fledging survival probabilities. PMID:23691168

  15. Development of a lateral flow immunoassay for rapid field detection of the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    The red imported fire ant, Solenopsis invicta, is an aggressive, highly invasive pest ant species from South America that has been introduced into North America, Asia and Australia. Quarantine efforts have been imposed in the United States to minimize the spread of the ant. There remains an acute ...

  16. Host specificity testing of the Solenopsis fire ant (Hymenoptera:Formicidae) pathogen, Kneallhazia (=Thelohania) solenopsae (Microsporidia:Thelohaniidae), in Florida

    USDA-ARS?s Scientific Manuscript database

    Post-entry host specificity testing was conducted on ants in Florida for the fire ant pathogen Kneallhazia solenopsae to determine transmission potential to native and non-target species. In addition, there was interest to assess the potential of K. solenopsae to control other pest ants. The patho...

  17. Laboratory Fire Ant colonies (Solenopsis invicta) fail to grow with Bhatkar Diet and three other artificial diets

    USDA-ARS?s Scientific Manuscript database

    Various artificial diets have been used for rearing imported fire ants; however most of these diets include insect supplements. This study was designed to examine growth of red imported fire ant colonies (Hymenoptera: Formicidae: Solenopsis invicta Buren) on four artificial diets: a chemically unde...

  18. Establishment, dispersal, and competitive impacts of a third fire ant decapitating fly (Pseudacteon obtusus) in North Central Florida

    USDA-ARS?s Scientific Manuscript database

    Self-sustaining classical biological control agents offer a hope for permanent wide-area control of imported Solenopsis fire ants in the United States because escape from abundant natural enemies left behind in Argentina is a likely reason for unusually high fire ant densities in the United States. ...

  19. Seasonal Changes in Broadband Spectral Reflectance Characteristics of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass Agroecosystems

    USDA-ARS?s Scientific Manuscript database

    Invasive mound-building imported fire ants (Solenopsis spp.) disrupt soil quality and turfgrass nutrient management in sod production, recreational, and residential settings. Ground-based implementation of hyperspectral techniques in the detection and seasonal monitoring of imported fire ant col...

  20. Expression of foraging and Gp-9 are associated with social organization in the fire ant Solenopsis invicta.

    PubMed

    Lucas, C; Nicolas, M; Keller, L

    2015-02-01

    The aim of this study was to investigate levels of expression of two major genes, the odorant binding protein Gp-9 (general protein-9) and foraging, that have been shown to be associated with behavioural polymorphisms in ants. We analysed workers and young nonreproductive queens collected from nests of the monogyne (single reproductive queen per nest) and polygyne (multiple reproductive queens) social forms of Solenopsis invicta. In workers but not young queens, the level of foraging expression was significantly associated with social form and the task performed (ie localization in the nest or foraging area). The level of expression of Gp-9 was also associated with social form and worker localization. In addition there was a higher level of expression of the Gp-9(b) allele compared with the Gp-9(B) allele in the heterozygote workers and the young nonreproductive queens. Finally, in the polygyne colonies the level of expression of foraging was not significantly associated with the Gp-9 genotype for either workers or young nonreproductive queens, suggesting that both genes have independent non-epistatic effects on behaviour in S. invicta. © 2014 The Royal Entomological Society.

  1. Fire in the Amazon: impact of experimental fuel addition on responses of ants and their interactions with myrmecochorous seeds.

    PubMed

    Paolucci, Lucas N; Maia, Maria L B; Solar, Ricardo R C; Campos, Ricardo I; Schoereder, José H; Andersen, Alan N

    2016-10-01

    The widespread clearing of tropical forests causes lower tree cover, drier microclimate, and higher and drier fuel loads of forest edges, increasing the risk of fire occurrence and its intensity. We used a manipulative field experiment to investigate the influence of fire and fuel loads on ant communities and their interactions with myrmecochorous seeds in the southern Amazon, a region currently undergoing extreme land-use intensification. Experimental fires and fuel addition were applied to 40 × 40-m plots in six replicated blocks, and ants were sampled between 15 and 30 days after fires in four strata: subterranean, litter, epigaeic, and arboreal. Fire had extensive negative effects on ant communities. Highly specialized cryptobiotic and predator species of the litter layer and epigaeic specialist predators were among the most sensitive, but we did not find evidence of overall biotic homogenization following fire. Fire reduced rates of location and transport of myrmecochorous seeds, and therefore the effectiveness of a key ecosystem service provided by ants, which we attribute to lower ant abundance and increased thermal stress. Experimental fuel addition had only minor effects on attributes of fire severity, and limited effects on ant responses to fire. Our findings indicate that enhanced fuel loads will not decrease ant diversity and ecosystem services through increased fire severity, at least in wetter years. However, higher fuel loads can still have a significant effect on ants from Amazonian rainforests because they increase the risk of fire occurrence, which has a detrimental impact on ant communities and a key ecosystem service they provide.

  2. A Review of the Biological Control of Fire Ants

    USDA-ARS?s Scientific Manuscript database

    The suppression of well-established invasive ants will likely require biological control by natural enemies. This approach is self-sustaining and can impact undetected or inaccessible populations that are the source of the continual presence and expansion of the invaders. There is an ongoing effor...

  3. Cuticular hydrocarbon profiles differentiate tropical fire ant populations (Solenopsis geminata, Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    The cuticular hydrocarbons (CHCs) from hexane rinses of workers from two Florida populations (dark and red forms) of the tropical fire ant, Solenopsis geminata, were separated by silica gel chromatography and identified by GC-MS analysis. Both the dark form and the red form produce similar CHCs with...

  4. Sociogenomics of cooperation and conflict during colony foundation in the fire ant Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    The genomic state of an individual results from the interplay between its internal condition and the external environment, which may include the social environment. The link between genes and social environment is clearly visible during the process of colony founding in the fire ant Solenopsis invic...

  5. Piperideine Alkaloids from the Poison Gland of the Red Imported Fire Ant (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    It is well known that the major chemical components in the venom of the red imported fire ants, Solenopsis invicta Buren, are 2-methyl-6-alkyl or alkenyl piperidines. After isolating the extracts of poison glands and whole worker bodies with a column chromatography, we have obtained fractions conta...

  6. Monthly fluctuation of termite caste proportions (Isoptera) within fire ant mounds (hymenoptera: formicidae)

    Treesearch

    Thomas G. Shelton; J.T. Vogt; Marla J. Tanley; Arthur G. Appel

    2003-01-01

    Monthly abundance and caste proportions of subterranean termites (Reticulitennes spp.) inhabiting red imported fire ant (Solenopsis invicta Buren) mounds were recorded during 1999 and 2000 from a relatively undisturbed forest edge in Tuskegee, Alabama. Temperature data were also recorded at these mounds; mean air, soil, and mound temperatures followed a sine model over...

  7. Supergene Gp-9 is associated polyandry and male reproductive success in fire ants

    USDA-ARS?s Scientific Manuscript database

    Supergenes are groups of loci inherited together to facilitate the co-segregation of adaptive variation. We demonstrate that facultative polyandry and male reproductive success have a simple genetic basis in the fire ant Solenopsis invicta and depend solely on male genotype within the Gp-9 supergene...

  8. Invasion Biology on Your Campus: Investigating the Red Imported Fire Ant in the Southeastern United States.

    ERIC Educational Resources Information Center

    Forys, Elizabeth A.; Kelly, William B.; Ward, David T.

    2003-01-01

    Describes a laboratory activity on invasion biology to improve students' cognitive skills as well as manual skills. Requires students to develop hypotheses in which a common invasive species will succeed. Focuses on the red imported fire ant in the Southeastern United States, which is a non-native invasive species. (Contains 17 references.) (YDS)

  9. Ontogeny of Alarm pheromone production in the fire ant, Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    Alarm pheromones are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality in social insects. Recently, we identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of the fire ant, Solenopsis invicta. We continued...

  10. Seasonal Shifts in the Hyperspectral Characterization of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass

    USDA-ARS?s Scientific Manuscript database

    Safe, expedient, and cost-effective field- to landscape-scale treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyper...

  11. SEASONAL SHIFTS IN THE HYPERSPECTRAL CHARACTERIZATION OF IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) MOUND FEATURES IN TURFGRASS

    USDA-ARS?s Scientific Manuscript database

    Safe, expedient, and cost-effective field- to landscape-scale treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyper...

  12. Invasion Biology on Your Campus: Investigating the Red Imported Fire Ant in the Southeastern United States.

    ERIC Educational Resources Information Center

    Forys, Elizabeth A.; Kelly, William B.; Ward, David T.

    2003-01-01

    Describes a laboratory activity on invasion biology to improve students' cognitive skills as well as manual skills. Requires students to develop hypotheses in which a common invasive species will succeed. Focuses on the red imported fire ant in the Southeastern United States, which is a non-native invasive species. (Contains 17 references.) (YDS)

  13. Phoretic Arthropods of the Red Imported Fire Ant in Central Louisiana.

    Treesearch

    John Moser; Stacy Blomquist

    2011-01-01

    More than 4,665 phoretic arthropods comprising29species were collected from alates of the red imported fire ant, Solenopsis inoicta Buren, preparing to fly from nests in Pineville, LA. A wide variety of taxonomic groups were represented, including two insect and 17 mite families. Most arthropods fell into two classes: 1) those that may be truly phoretic with more than...

  14. A Y-like social chromosome causes alternative colony organization in fire ants

    USDA-ARS?s Scientific Manuscript database

    Intraspecific variability in social organization is common, yet the underlying causes are rarely known1-3. In the fire ant Solenopsis invicta, the existence of two divergent forms of social organisation is under the control of a single Mendelian genomic element marked by two variants of an odorant b...

  15. IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) MOUND SHAPE CHARACTERISTICS ALONG A NORTH-SOUTH GRADIENT

    USDA-ARS?s Scientific Manuscript database

    Imported fire ant mound shape characteristics (south facing slope angle and area, mound height, and basal elongation in the plane of the ground) were quantified in 2005 and 2006 at a number of locations from about 30° 25’ N (Long Beach, Mississippi, USA) to 35° 3’ N (Fayetteville, Tennessee, USA). ...

  16. Development of genetic markers distinguishing two invasive fire ant species (Hymenoptera: Formicidae) and their hybrids

    USDA-ARS?s Scientific Manuscript database

    Three SNP markers were developed that are completely diagnostic in distinguishing the two fire ant species Solenopsis invicta and S. richteri. Although a fourth marker we developed is not fully diagnostic, it is still useful given one of the variants is confined to S. richteri. Joint use of these ma...

  17. 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.

  18. Ancient village fire escape path planning based on improved ant colony algorithm

    NASA Astrophysics Data System (ADS)

    Xia, Wei; Cao, Kang; Hu, QianChuan

    2017-06-01

    The roadways are narrow and perplexing in ancient villages, it brings challenges and difficulties for people to choose route to escape when a fire occurs. In this paper, a fire escape path planning method based on ant colony algorithm is presented according to the problem. The factors in the fire environment which influence the escape speed is introduced to improve the heuristic function of the algorithm, optimal transfer strategy, and adjustment pheromone volatile factor to improve pheromone update strategy adaptively, improve its dynamic search ability and search speed. Through simulation, the dynamic adjustment of the optimal escape path is obtained, and the method is proved to be feasible.

  19. Ecological dominance of the red imported fire ant, Solenopsis invicta, in its native range.

    PubMed

    Calcaterra, Luis A; Livore, Juan P; Delgado, Alicia; Briano, Juan A

    2008-05-01

    Despite the widespread impacts invasive species can have in introduced populations, little is known about competitive mechanisms and dominance hierarchies between invaders and similar taxa in their native range. This study examines interactions between the red imported fire ant, Solenopsis invicta, and other above-ground foraging ants in two habitats in northeastern Argentina. A combination of pitfall traps and baits was used to characterize the ant communities, their dominance relationships, and to evaluate the effect of phorid flies on the interactions. Twenty-eight ant species coexisted with S. invicta in a gallery forest gap, whereas only ten coexisted with S. invicta in a xerophytic forest grassland. S. invicta was the most numerically dominant species in the richest and complex habitat (gallery forest); however it performed better as discoverer and dominator in the simpler habitat. S. invicta was active during day and night. In spite of its poor capacity to discover resources, S. invicta showed the highest ecological dominance and the second-best behavioral dominance after Camponotus blandus. S. invicta won 78% of the interactions with other ants, mostly against its most frequent competitor, Pheidole cf. obscurithorax, dominating baits via mass recruitment and chemical aggression. P. cf. obscurithorax was the best food discoverer. S. invicta won 80% of the scarce interactions with Linepithema humile. Crematogaster quadriformis was one of the fastest foragers and the only ant that won an equal number of contests against S. invicta. The low presence of phorid flies affected the foraging rate of S. invicta, but not the outcome of interspecific interactions. This study revealed that the red imported fire ant ecologically dominated other terrestrial ants in its native range; however, other species were able to be numerically dominant or co-dominant in its presence.

  20. Are Invasive Species Stressful? The Glucocorticoid Profile of Native Lizards Exposed to Invasive Fire Ants Depends on the Context.

    PubMed

    Graham, Sean P; Freidenfelds, Nicole A; Thawley, Christopher J; Robbins, Travis R; Langkilde, Tracy

    Invasive species represent a substantial threat to native species worldwide. Research on the impacts of invasive species on wild living vertebrates has focused primarily on population-level effects. The sublethal, individual-level effects of invaders may be equally important but are poorly understood. We investigated the effects of invasive fire ants (Solenopsis invicta) on the physiological stress response of a native lizard (Sceloporus undulatus) within two experimental contexts: directly exposing lizards to a fire ant attack and housing lizards with fire ants in seminatural field enclosures. Lizards directly exposed to brief attack by fire ants had elevated concentrations of the stress hormone corticosterone (CORT), suggesting that these encounters can be physiologically stressful. However, lizards exposed for longer periods to fire ants in field enclosures had lower concentrations of CORT. This may indicate that the combined effects of confinement and fire ant exposure have pushed lizards into allostatic overload. However, lizards from fire ant enclosures appeared to have intact negative feedback controls of the stress response, evidenced by functioning adrenocorticotropic hormone responsiveness and lack of suppression of innate immunity (plasma bactericidal capacity). We review previous studies examining the stress response of wild vertebrates to various anthropogenic stressors and discuss how these-in combination with our results-underscore the importance of considering context (the length, frequency, magnitude, and types of threat) when assessing these impacts.

  1. The effects of fire on ant trophic assemblage and sex allocation

    PubMed Central

    Caut, Stephane; Jowers, Michael J; Arnan, Xavier; Pearce-Duvet, Jessica; Rodrigo, Anselm; Cerda, Xim; Boulay, Raphaël R

    2014-01-01

    Fire plays a key role in ecosystem dynamics worldwide, altering energy flows and species community structure and composition. However, the functional mechanisms underlying these effects are not well understood. Many ground-dwelling animal species can shelter themselves from exposure to heat and therefore rarely suffer direct mortality. However, fire-induced alterations to the environment may change a species' relative trophic level within a food web and its mode of foraging. We assessed how fire could affect ant resource utilization at different scales in a Mediterranean forest. First, we conducted isotopic analyses on entire ant species assemblages and their potential food resources, which included plants and other arthropods, in burned and unburned plots 1 year postfire. Second, we measured the production of males and females by nests of a fire-resilient species, Aphaenogaster gibbosa, and analyzed the differences in isotopic values among workers, males, and females to test whether fire constrained resource allocation. We found that, in spite of major modifications in biotic and abiotic conditions, fire had little impact on the relative trophic position of ant species. The studied assemblage was composed of species with a wide array of diets. They ranged from being mostly herbivorous to completely omnivorous, and a given species' trophic level was the same in burned and unburned plots. In A. gibbosa nests, sexuals had greater δ15N values than workers in both burned and unburned plots, which suggests that the former had a more protein-rich diet than the latter. Fire also appeared to have a major effect on A. gibbosa sex allocation: The proportion of nests that produced male brood was greater on burned zones, as was the mean number of males produced per nest with the same reproductive investment. Our results show that generalist ants with relatively broad diets maintained a constant trophic position, even following a major disturbance like fire. However, the

  2. The effects of fire on ant trophic assemblage and sex allocation.

    PubMed

    Caut, Stephane; Jowers, Michael J; Arnan, Xavier; Pearce-Duvet, Jessica; Rodrigo, Anselm; Cerda, Xim; Boulay, Raphaël R

    2014-01-01

    Fire plays a key role in ecosystem dynamics worldwide, altering energy flows and species community structure and composition. However, the functional mechanisms underlying these effects are not well understood. Many ground-dwelling animal species can shelter themselves from exposure to heat and therefore rarely suffer direct mortality. However, fire-induced alterations to the environment may change a species' relative trophic level within a food web and its mode of foraging. We assessed how fire could affect ant resource utilization at different scales in a Mediterranean forest. First, we conducted isotopic analyses on entire ant species assemblages and their potential food resources, which included plants and other arthropods, in burned and unburned plots 1 year postfire. Second, we measured the production of males and females by nests of a fire-resilient species, Aphaenogaster gibbosa, and analyzed the differences in isotopic values among workers, males, and females to test whether fire constrained resource allocation. We found that, in spite of major modifications in biotic and abiotic conditions, fire had little impact on the relative trophic position of ant species. The studied assemblage was composed of species with a wide array of diets. They ranged from being mostly herbivorous to completely omnivorous, and a given species' trophic level was the same in burned and unburned plots. In A. gibbosa nests, sexuals had greater δ(15)N values than workers in both burned and unburned plots, which suggests that the former had a more protein-rich diet than the latter. Fire also appeared to have a major effect on A. gibbosa sex allocation: The proportion of nests that produced male brood was greater on burned zones, as was the mean number of males produced per nest with the same reproductive investment. Our results show that generalist ants with relatively broad diets maintained a constant trophic position, even following a major disturbance like fire. However, the

  3. Monitoring Effect of Fire on Ant Assemblages in Brazilian Rupestrian Grasslands: Contrasting Effects on Ground and Arboreal Fauna.

    PubMed

    Anjos, Diego; Campos, Ricardo; Campos, Renata; Ribeiro, Sérvio

    2017-06-23

    Fire is one of the most relevant ecological disturbances in nature. Little is known about the effects of fire on biodiversity in ecosystems like rupestrian grasslands, which share characteristics with savanna and forest biomes. Brazilian rupestrian grasslands are part of an endangered ecosystem that has been modified by anthropogenic fire events that have become more intense in recent decades. In this study, we evaluated the effects of fire on ground and arboreal ant assemblages through a two-year monitoring program (24 monthly samplings). We found that fire does not change cumulative species richness after 24 months, and that fire does not affect mean ant richness, abundance, and species composition in arboreal ants. On the other hand, fire increased mean ground ant species richness and abundance, and caused a significant change in species composition. Our results indicate a weak and beneficial effect of fire only for ground ant communities, which generally agrees with results from other studies in Brazilian savannas. Taken together, results from these studies may be useful for improvement of fire suppression policy in fire-prone habitats in Brazil.

  4. GP-9s are ubiquitous proteins unlikely involved in olfactory mediation of social organization in the red imported fire ant, Solenopsis invicta.

    PubMed

    Leal, Walter S; Ishida, Yuko

    2008-01-01

    The red imported fire ant (RIFA), Solenopsis invicta, is an invasive species, accidentally introduced in the United States that can cause painful (sometimes life-threatening) stings to human, pets, and livestock. Their colonies have two social forms: monogyne and polygyne that have a single and multiple functional queens, respectively. A major gene (Gp-9), identified as a putative pheromone-binding protein on the basis of a modest amino acid sequence identity, has been suggested to influence the expression of colony social organization. Monogyne queens are reported to possess only the GP-9B alleles, whereas polygyne queens possess both GP-9B and GP-9b. Thus, both social forms are reported to express GP-9B, with GP-9b being a marker expressed in polygynes but it is absent in monogynes. Here, we report two types of polygyne colonies, one that does not express GP-9b (monogyne-like) and the other expressing both proteins, GP-9B and GP-9b. Given their expression pattern, GP-9s are hemolymph proteins, which are more likely to be involved in the transport of lipids and small ligands within the homocoel. GP-9B existed in two forms, one of them is phosphorylated. The helical-rich content of the protein resembles the secondary structures of a beetle hemolymph protein and moth pheromone-binding proteins. An olfactory role is unlikely given the lack of specific expression in the sensillar lymph. In marked contrast to GP-9s, a chemosensory protein, SinvCSP, is demonstrated to be specifically expressed in the antennae. Within the antennae, expression of SinvCSP is restricted to the last two segments, which are known to house olfactory sensilla.

  5. Dose response of red imported fire ant colonies to Solenopsis invicta virus 3.

    PubMed

    Valles, Steven M; Porter, Sanford D

    2015-10-01

    Baiting tests were conducted to evaluate the effect of increasing Solenopsis invicta virus 3 (SINV-3) dose on fire ant colonies. Actively growing early-stage fire ant (Solenopsis invicta Buren) laboratory colonies were pulse-exposed for 24 hours to six concentrations of SINV-3 (10(1), 10(3), 10(5), 10(7), 10(9) genome equivalents/μl) in 1 ml of a 10 % sucrose bait and monitored regularly for two months. SINV-3 concentration had a significant effect on colony health. Brood rating (proportion of brood to worker ants) began to depart from the control group at 19 days for the 10(9) concentration and 26 days for the 10(7) concentration. At 60 days, brood rating was significantly lower among colonies treated with 10(9), 10(7), and 10(5) SINV-3 concentrations. The intermediate concentration, 10(5), appeared to cause a chronic, low-level infection with one colony (n = 9) supporting virus replication. Newly synthesized virus was not detected in any fire ant colonies treated at the 10(1) concentration, indicating that active infections failed to be established at this level of exposure. The highest bait concentration chosen, 10(9), appeared most effective from a control aspect; mean colony brood rating at this concentration (1.1 ± 0.9 at the 60 day time point) indicated poor colony health with minimal brood production. No clear relationship was observed between the quantity of plus genome strand detected and brood rating. Conversely, there was a strong relationship between the presence of the replicative genome strand and declining brood rating, which may serve as a predictor of disease severity. Recommendations for field treatment levels to control fire ants with SINV-3 are discussed.

  6. Native and domestic browsers and grazers reduce fuels, fire temperatures, and acacia ant mortality in an African savanna.

    PubMed

    Kimuyu, Duncan M; Sensenig, Ryan L; Riginos, Corinna; Veblen, Kari E; Young, Truman P

    2014-06-01

    Despite the importance of fire and herbivory in structuring savanna systems, few replicated experiments have examined the interactive effects of herbivory and fire on plant dynamics. In addition, the effects of fire on associated ant-tree mutualisms have been largely unexplored. We carried out small controlled burns in each of 18 herbivore treatment plots of the Kenya Long-term Exclosure Experiment (KLEE), where experimentally excluding elephants has resulted in 42% greater tree densities. The KLEE design includes six different herbivore treatments that allowed us to examine how different combinations of megaherbivore wildlife, mesoherbivore wildlife, and cattle affect fire temperatures and subsequent loss of ant symbionts from Acacia trees. Before burning, we quantified herbaceous fuel loads and plant community composition. We tagged all trees, measured their height and basal diameter, and identified the resident ant species on each. We recorded weather conditions during the burns and used ceramic tiles painted with fire-sensitive paints to estimate fire temperatures at different heights and in different microsites (under vs. between trees). Across all treatments, fire temperatures were highest at 0-50 cm off the ground and hotter in the grass under trees than in the grassy areas between trees. Plots with more trees burned hotter than plots with fewer trees, perhaps because of greater fine woody debris. Plots grazed by wildlife and by cattle prior to burning had lower herbaceous fuel loads and experienced lower burn temperatures than ungrazed plots. Many trees lost their ant colonies during the burns. Ant survivorship differed by ant species and at the plot level was positively associated with previous herbivory (and lower fire temperatures). Across all treatments, ant colonies on taller trees were more likely to survive, but even some of the tallest trees lost their ant colonies. Our study marks a significant step in understanding the mechanisms that underlie the

  7. Long-term efficacy of two cricket and two liver diets for rearing laboratory fire ant colonies (Hymenoptera: Formicidae: Solenopsis Invicta)

    USDA-ARS?s Scientific Manuscript database

    Effective diets are necessary for many kinds of laboratory studies of ants. We conducted a year-long study of imported fire ant colonies reared on either chicken liver, beef liver, banded crickets, or domestic crickets all with a sugar water supplement. Fire ant colonies thrived on diets of sugar ...

  8. Do additional sugar sources affect the degree of attendance of Dysmicoccus brevipes by the fire ant Solenopsis geminata?

    USDA-ARS?s Scientific Manuscript database

    Mutualistic interactions between ants and Hemiptera are mediated to large extent by the amount and quality of sugar-rich honeydew produced. Throughout the neotropics, the fire ant Solenopsis geminata (F.) (Hymenoptera: Formicidae) is found in association with colonies of the pineapple mealybug Dysmi...

  9. Fumigant Activity of Sweet Orange Essential Oil Fractions Against Red Imported Fire Ants (Hymenoptera: Formicidae).

    PubMed

    Hu, Wei; Zhang, Ning; Chen, Hongli; Zhong, Balian; Yang, Aixue; Kuang, Fan; Ouyang, Zhigang; Chun, Jiong

    2017-08-01

    Sweet orange oil fractions were prepared by molecular distillation of cold-pressed orange oil from sample A (Citrus sinensis (L.) 'Hamlin' from America) and sample B (Citrus sinensis Osbeck 'Newhall' from China) respectively, and their fumigant activities against medium workers of red imported fire ants (Solenopsis invicta Buren) were investigated. The volatile composition of the orange oil fractions was identified and quantified using GC-MS. Fractions from sample A (A1, A2, and A3) contained 23, 37, and 48 chemical constituents, and fractions from sample B (B1, B2, and B3) contained 18, 29, and 26 chemical constituents, respectively. Monoterpenes were the most abundant components, accounting for 73.56% to 94.86% of total orange oil fractions, among which D-limonene (65.28-80.18%), β-pinene (1.71-5.58%), 3-carene (0.41-4.01%), β-phellandrene (0.58-2.10%), and linalool (0.31-2.20%) were major constituents. Fumigant bioassay indicated that all orange oil fractions exerted good fumigant toxicity against workers of fire ants at 3, 5, 10, and 20 mg/centrifuge tubes, and B1 had the strongest insecticidal potential, followed by A1, B2, A2, B3, and A3. The fractions composed of more high volatile molecules (A1 and B1) showed greater fumigant effects than others. Compounds linalool and D-limonene, which were the constituents of the orange oil, exhibited excellent fumigant toxicity against red imported fire ant workers. Linalool killed red imported fire ant workers completely at 5, 10, and 20 mg/tube after 8 h of treatment, and D-limonene induced >86% mortality at 8 h of exposure. © 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.

  10. Parasitoids and competitors influence colony-level responses in the red imported fire ant, Solenopsis invicta

    NASA Astrophysics Data System (ADS)

    Mehdiabadi, Natasha J.; Kawazoe, Elizabeth A.; Gilbert, Lawrence E.

    2004-11-01

    Social insect colonies respond to challenges set by a variable environment by reallocating work among colony members. In many social insects, such colony-level task allocation strategies are achieved through individual decisions that produce a self-organized adapting group. We investigated colony responses to parasitoids and native ant competitors in the red imported fire ant (Solenopsis invicta). Parasitoid flies affected fire ants by decreasing the proportion of workers engaged in foraging. Competitors also altered colony-level behaviours by reducing the proportion of foraging ants and by increasing the proportion of roaming majors, whose role is colony defence. Interestingly, the presence of both parasitism and competition almost always had similar effects on task allocation in comparison to each of the biotic factors on its own. Thus, our study uniquely demonstrates that the interactive effect of both parasitism and competition is not necessarily additive, implying that these biotic factors alter colony behaviour in distinct ways. More generally, our work demonstrates the importance of studying the dynamics of species interactions in a broader context.

  11. Intercontinental differences in resource use reveal the importance of mutualisms in fire ant invasions

    PubMed Central

    Wilder, Shawn M.; Holway, David A.; Suarez, Andrew V.; LeBrun, Edward G.; Eubanks, Micky D.

    2011-01-01

    Mutualisms play key roles in the functioning of ecosystems. However, reciprocally beneficial interactions that involve introduced species also can enhance invasion success and in doing so compromise ecosystem integrity. For example, the growth and competitive ability of introduced plant species can increase when fungal or microbial associates provide limiting nutrients. Mutualisms also may aid animal invasions, but how such systems may promote invasion success has received relatively little attention. Here we examine how access to food-for-protection mutualisms involving the red imported fire ant (Solenopsis invicta) aids the success of this prominent invader. Intense interspecific competition in its native Argentina constrained the ability of S. invicta to benefit from honeydew-producing Hemiptera (and other accessible sources of carbohydrates), whereas S. invicta dominated these resources in its introduced range in the United States. Consistent with this strong pattern, nitrogen isotopic data revealed that fire ants from populations in the United States occupy a lower trophic position than fire ants from Argentina. Laboratory and field experiments demonstrated that honeydew elevated colony growth, a crucial determinant of competitive performance, even when insect prey were not limiting. Carbohydrates, obtained largely through mutualistic partnerships with other organisms, thus represent critical resources that may aid the success of this widespread invasive species. These results illustrate the potential for mutualistic interactions to play a fundamental role in the establishment and spread of animal invasions. PMID:22143788

  12. Intercontinental differences in resource use reveal the importance of mutualisms in fire ant invasions.

    PubMed

    Wilder, Shawn M; Holway, David A; Suarez, Andrew V; LeBrun, Edward G; Eubanks, Micky D

    2011-12-20

    Mutualisms play key roles in the functioning of ecosystems. However, reciprocally beneficial interactions that involve introduced species also can enhance invasion success and in doing so compromise ecosystem integrity. For example, the growth and competitive ability of introduced plant species can increase when fungal or microbial associates provide limiting nutrients. Mutualisms also may aid animal invasions, but how such systems may promote invasion success has received relatively little attention. Here we examine how access to food-for-protection mutualisms involving the red imported fire ant (Solenopsis invicta) aids the success of this prominent invader. Intense interspecific competition in its native Argentina constrained the ability of S. invicta to benefit from honeydew-producing Hemiptera (and other accessible sources of carbohydrates), whereas S. invicta dominated these resources in its introduced range in the United States. Consistent with this strong pattern, nitrogen isotopic data revealed that fire ants from populations in the United States occupy a lower trophic position than fire ants from Argentina. Laboratory and field experiments demonstrated that honeydew elevated colony growth, a crucial determinant of competitive performance, even when insect prey were not limiting. Carbohydrates, obtained largely through mutualistic partnerships with other organisms, thus represent critical resources that may aid the success of this widespread invasive species. These results illustrate the potential for mutualistic interactions to play a fundamental role in the establishment and spread of animal invasions.

  13. Ant-mediated expansion of an obligate seeder species during the first years after fire.

    PubMed

    Arnan, X; Rodrigo, A; Molowny-Horas, R; Retana, J

    2010-11-01

    Most obligate seeder species build up a soil seed bank that is associated with massive seed germination in the year immediately after a fire. These species are also shade-intolerant and disappear when vegetation cover closes, creating unsuitable conditions for seedling recruitment. The only way for these plants to expand their populations is when habitats suitable for seedling recruitment arise (i.e. in years immediately after a fire). However, short primary seed dispersal of obligate seeders does not allow these plants to colonise the suitable habitats, and these habitats can only be colonised by secondary seed dispersion. We hypothesised that Fumana ericoides, an obligate-seeding small shrub, not only establishes abundantly in the first year after fire, but also expands its local range in the following years due to secondary dispersal by ants while suitable habitats are still available. We tested this hypothesis using experimental studies and a simulation model of potential population expansion in a recently burned area. Results showed that F. ericoides not only established prolifically in the year immediately after fire, but was also able to recruit new individuals and expand its population in the years following the fire, despite a low germination rate and short primary seed dispersal. Ant-mediated seed dispersal and availability of suitable habitats were key factors in this phenomenon: ants redistributed seeds in suitable habitats while they were available, which accelerated the expansion of F. ericoides because new plants established far away from the core population. © 2009 German Botanical Society and The Royal Botanical Society of The Netherlands.

  14. Allometry of Workers of the Fire Ant, Solenopsis invicta

    PubMed Central

    Tschinkel, Walter R.; Mikheyev, Alexander S.; Storz, Shonna R.

    2003-01-01

    The relationship between worker body size and the shape of their body parts was explored in the polymorphic ant, Solenopsis invicta. The data consisted of 20 measurements of body parts as well as sums of some of these measurements. Size-free shape variables were created by taking the ratios of relevant measures. After log-transformation, these ratios were regressed against the logarithm of total body length, or against the log of the size of the parent part. Slopes of zero indicated that shape did not change with size, and non-zero slopes signaled a size-related change of shape. Across the range of worker sizes, the head length retained a constant proportion to body length, but relative headwidth increased such that head shape changed from a barrel-profile to a somewhat heart-shaped profile. Antennae became relatively smaller, with the club contributing more to this decline than the other parts. The alinotum became relatively shorter and higher (more humped), and the gaster increased in both relative width and length, and therefore in volume. All three pairs of legs were isometric to body length. The component parts of the legs, with one exception, were isometric to their own total leg length. The body of S. invicta is therefore dominated by mostly modest allometries, giving large workers a somewhat different shape than small ones. None of these size-shape relationships was different for different colonies. The functional meaning of these shape changes is unknown, but that does not stop us from speculating. Abbreviation: HL head length BL body length HW1 width across the eyes HW2 width above the eyes HW3 width below the eyes PMID:15841219

  15. Variation in ant populations with elevation, tree cover, and fire in a pinyon-juniper-dominated watershed

    Treesearch

    Eugenie M. MontBlanc; Jeanne C. Chambers; Peter E. Brussard

    2007-01-01

    Climate change and fire suppression have facilitated expansion of pinyon-juniper woodlands into sagebrush- steppe ecosystems of the Great Basin, USA, resulting in a loss of biological diversity. To assess the effects of using prescribed fire in restoration efforts, ant abundance, species richness, and composition were examined pre- and post-burn along the elevation and...

  16. Toxicity and repellency of compounds from clove (Syzygium aromaticum) to red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Kafle, Lekhnath; Shih, Cheng Jen

    2013-02-01

    The toxicity and repellency of the bioactive chemicals of clove (Syzygium aromaticum) powder, eugenol, eugenol acetate, and beta-caryophyllene were evaluated against workers of the red imported fire ant, Solenopsis invicta Buren. Clove powder applied at 3 and 12 mg/cm2 provided 100% ant mortality within 6 h, and repelled 99% within 3 h. Eugenol was the fastest acting compound against red imported fire ant compared with eugenol acetate, beta-caryophyllene, and clove oil. The LT50 values inclined exponentially with the increase in the application rate of the chemical compounds tested. However, repellency did not increase with the increase in the application rate of the chemical compounds tested, but did with the increase in exposure time. Eugenol, eugenol acetate, as well as beta-caryophyllene and clove oil may provide another tool for red imported fire ant integrated pest management, particularly in situations where conventional insecticides are inappropriate.

  17. Characterization of 24 microsatellite markers in 11 species of fire ants in the genus Solenopsis (Hymenoptera: Formicidae).

    PubMed

    Ascunce, Marina S; Bouwma, Andrew M; Shoemaker, Dewayne

    2009-11-01

    The social parasite ant Solenopsis daguerrei infests colonies of several mound-building fire ant species. Twenty-four microsatellite markers were isolated from a repeat-enriched genomic library of S. daguerrei. Eleven loci were polymorphic in this ant with two to six alleles per locus. Expected heterozygosity ranged from 0.0222 to 0.7940 among loci. Most microsatellites amplified successfully across the 11 Solenopsis species tested and will be useful for evolutionary genetic studies in this diverse ant group. Published 2009. This article is a US Government work and is in the public domain in the USA.

  18. Fire ant venom alkaloids act as key attractants for the parasitic phorid fly, Pseudacteon tricuspis (Diptera: Phoridae)

    NASA Astrophysics Data System (ADS)

    Chen, Li; Sharma, Kavita R.; Fadamiro, Henry Y.

    2009-12-01

    The phorid fly, Pseudacteon tricuspis Borgmeier, is an introduced parasitoid of imported fire ants, Solenopsis spp., in the USA. Although the assumption that phorid flies use fire ant alarm pheromones for host location is probably true, we demonstrated in a previous study the possible involvement of other ant semiochemicals in the response of P. tricuspis to fire ants. This study was conducted to determine the glandular sources and identity of the semiochemicals mediating this interaction. First, we tested the electroantennogram response of P. tricuspis to extracts of key body parts and glands of workers of the red imported fire ant, S. invicta Buren. The results confirm that the poison (venom) gland/sac is the key source of compounds which elicited strong antennal activity in P. tricuspis. Follow-up studies were conducted by using a combination of bioassay-guided fractionation and behavioral bioassays to test the hypothesis that attraction of this parasitoid to fire ants is mediated by venom alkaloids. The results confirm the response of P. tricuspis to physiologically relevant amounts of the two venom alkaloid fractions ( cis and trans alkaloid fractions) of S. invicta. Further analysis by coupled gas chromatography-electroantennogram detection revealed nine venom alkaloid components including two novel 2,6-dialkylpiperideines that elicited significant antennal activity in P. tricuspis. This is the first demonstration of the role of venom alkaloids of ants as attractants for their natural enemies. We propose a semiochemical-mediated host location mechanism for P. tricuspis involving both alarm pheromones and venom alkaloids. The ecological significance of these findings, including the attraction of male P. tricuspis to fire ant venom alkaloids, possibly for mate location, is discussed.

  19. Fire ant venom alkaloids act as key attractants for the parasitic phorid fly, Pseudacteon tricuspis (Diptera: Phoridae).

    PubMed

    Chen, Li; Sharma, Kavita R; Fadamiro, Henry Y

    2009-12-01

    The phorid fly, Pseudacteon tricuspis Borgmeier, is an introduced parasitoid of imported fire ants, Solenopsis spp., in the USA. Although the assumption that phorid flies use fire ant alarm pheromones for host location is probably true, we demonstrated in a previous study the possible involvement of other ant semiochemicals in the response of P. tricuspis to fire ants. This study was conducted to determine the glandular sources and identity of the semiochemicals mediating this interaction. First, we tested the electroantennogram response of P. tricuspis to extracts of key body parts and glands of workers of the red imported fire ant, S. invicta Buren. The results confirm that the poison (venom) gland/sac is the key source of compounds which elicited strong antennal activity in P. tricuspis. Follow-up studies were conducted by using a combination of bioassay-guided fractionation and behavioral bioassays to test the hypothesis that attraction of this parasitoid to fire ants is mediated by venom alkaloids. The results confirm the response of P. tricuspis to physiologically relevant amounts of the two venom alkaloid fractions (cis and trans alkaloid fractions) of S. invicta. Further analysis by coupled gas chromatography-electroantennogram detection revealed nine venom alkaloid components including two novel 2,6-dialkylpiperideines that elicited significant antennal activity in P. tricuspis. This is the first demonstration of the role of venom alkaloids of ants as attractants for their natural enemies. We propose a semiochemical-mediated host location mechanism for P. tricuspis involving both alarm pheromones and venom alkaloids. The ecological significance of these findings, including the attraction of male P. tricuspis to fire ant venom alkaloids, possibly for mate location, is discussed.

  20. Global invasion history of the tropical fire ant: a stowaway on the first global trade routes.

    PubMed

    Gotzek, Dietrich; Axen, Heather J; Suarez, Andrew V; Helms Cahan, Sara; Shoemaker, DeWayne

    2015-01-01

    Biological invasions are largely thought to be contemporary, having recently increased sharply in the wake of globalization. However, human commerce had already become global by the mid-16th century when the Spanish connected the New World with Europe and Asia via their Manila galleon and West Indies trade routes. We use genetic data to trace the global invasion of one of the world's most widespread and invasive pest ants, the tropical fire ant, Solenopsis geminata. Our results reveal a pattern of introduction of Old World populations that is highly consistent with historical trading routes suggesting that Spanish trade introduced the tropical fire ant to Asia in the 16th century. We identify southwestern Mexico as the most likely source for the invasive populations, which is consistent with the use of Acapulco as the major Spanish port on the Pacific Ocean. From there, the Spanish galleons brought silver to Manila, which served as a hub for trade with China. The genetic data document a corresponding spread of S. geminata from Mexico via Manila to Taiwan and from there, throughout the Old World. Our descriptions of the worldwide spread of S. geminata represent a rare documented case of a biological invasion of a highly invasive and globally distributed pest species due to the earliest stages of global commerce.

  1. Fire Ant Decapitating Fly Cooperative Release Programs (1994–2008): Two Pseudacteon Species, P. tricuspis and P. curvatus, Rapidly Expand Across Imported Fire Ant Populations in the Southeastern United States

    PubMed Central

    Callcott, Anne-Marie A.; Porter, Sanford D.; Weeks, Ronald D.; “Fudd” Graham, L. C.; Johnson, Seth J.; Gilbert, Lawrence E.

    2011-01-01

    Natural enemies of the imported fire ants, Solenopsis invicta Buren S. richteri Forel (Hymenoptera: Formicidae), and their hybrid, include a suite of more than 20 fire ant decapitating phorid flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have cooperated in introducing several species as classical or self-sustaining biological control agents in the United States. As a result, two species of flies, Pseudacteon tricuspis Borgmeier and P. curvatus Borgmeier (Diptera: Phoridae), are well established across large areas of the southeastern United States. Whereas many researchers have published local and state information about the establishment and spread of these flies, here distribution data from both published and unpublished sources has been compiled for the entire United States with the goal of presenting confirmed and probable distributions as of the fall of 2008. Documented rates of expansion were also used to predict the distribution of these flies three years later in the fall of 2011. In the fall of 2008, eleven years after the first successful release, we estimate that P. tricuspis covered about 50% of the fire ant quarantined area and that it will occur in almost 65% of the quarantine area by 2011. Complete coverage of the fire ant quarantined area will be delayed or limited by this species' slow rate of spread and frequent failure to establish in more northerly portions of the fire ant range and also, perhaps, by its preference for red imported fire ants (S. invicta). Eight years after the first successful release of P. curvatus, two biotypes of this species (one biotype occurring predominantly in the black and hybrid imported fire ants and the other occurring in red imported fire ants) covered almost 60% of the fire ant quarantined area. We estimate these two biotypes will cover almost 90% of the quarantine area by 2011 and 100% by 2012 or 2013. Strategic selection of several distributional gaps

  2. Identification and expression of capa gene in the fire ant, Solenopsis invicta.

    PubMed

    Choi, Man-Yeon; Köhler, Rene; Vander Meer, Robert K; Neupert, Susanne; Predel, Reinhard

    2014-01-01

    Recent genome analyses suggested the absence of a number of neuropeptide genes in ants. One of the apparently missing genes was the capa gene. Capa gene expression in insects is typically associated with the neuroendocrine system of abdominal ganglia; mature CAPA peptides are known to regulate diuresis and visceral muscle contraction. The apparent absence of the capa gene raised questions about possible compensation of these functions. In this study, we re-examined this controversial issue and searched for a potentially unrecognized capa gene in the fire ant, Solenopsis invicta. We employed a combination of data mining and a traditional PCR-based strategy using degenerate primers designed from conserved amino acid sequences of insect capa genes. Our findings demonstrate that ants possess and express a capa gene. As shown by MALDI-TOF mass spectrometry, processed products of the S. invicta capa gene include three CAPA periviscerokinins and low amounts of a pyrokinin which does not have the C-terminal WFGPRLa motif typical of CAPA pyrokinins in other insects. The capa gene was found with two alternative transcripts in the CNS. Within the ventral nerve cord, two capa neurons were immunostained in abdominal neuromeres 2-5, respectively, and projected into ventrally located abdominal perisympathetic organs (PSOs), which are the major hormone release sites of abdominal ganglia. The ventral location of these PSOs is a characteristic feature and was also found in another ant, Atta sexdens.

  3. Crystal structure of Sol I 2: a major allergen from fire ant venom.

    PubMed

    Borer, Aline S; Wassmann, Paul; Schmidt, Margit; Hoffman, Donald R; Zhou, Jing-Jiang; Wright, Christine; Schirmer, Tilman; Marković-Housley, Zora

    2012-01-27

    Sol i 2 is a potent allergen from the venom of red imported fire ant, which contains allergens Sol i 1, Sol i 2, Sol i 3, and Sol i 4 that are known to be powerful triggers of anaphylaxis. Sol i 2 causes IgE antibody production in about one-third of individuals stung by fire ants. Baculovirus recombinant dimeric Sol i 2 was crystallized as a native and selenomethionyl-derivatized protein, and its structure has been determined by single-wavelength anomalous dispersion at 2.6 Å resolution. The overall fold of each subunit consists of five helices that enclose a central hydrophobic cavity. The structure is stabilized by three intramolecular disulfide bridges and one intermolecular disulfide bridge. The nearest structural homologue is the sequence-unrelated odorant binding protein and pheromone binding protein LUSH of the fruit fly Drosophila, which may suggest a similar biological function. To test this hypothesis, we measured the reversible binding of various pheromones, plant odorants, and other ligands to Sol i 2 by the changes in N-phenyl-1-naphthylamine fluorescence emission upon binding of ligands that compete with N-phenyl-1-naphthylamine. The highest binding affinity was observed for hydrophobic ligands such as aphid alarm pheromone (E)-β-farnesene, analogs of ant alarm pheromones, and plant volatiles decane, undecane, and β-caryophyllene. Conceivably, Sol i 2 may play a role in capturing and/or transporting small hydrophobic ligands such as pheromones, odors, fatty acids, or short-living hydrophobic primers. Molecular surface analysis, in combination with sequence alignment, can explain the serological cross-reactivity observed between some ant species. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Effect of post-fire resprouting on leaf fluctuating asymmetry, extrafloral nectar quality, and ant-plant-herbivore interactions

    NASA Astrophysics Data System (ADS)

    Alves-Silva, Estevão; Del-Claro, Kleber

    2013-06-01

    Fires in the Cerrado savanna are a severe form of disturbance, but some species are capable of resprouting afterwards. It is unknown, however, how and whether post-fire resprouting represents a stressful condition to plants and how their rapid re-growth influences both the production of biochemical compounds, and interactions with mutualistic ants. In this study, we examined the influence of post-fire resprouting on biotic interactions (ant-plant-herbivore relationships) and on plant stress. The study was performed on two groups of the extrafloral nectaried shrub Banisteriopsis campestris (Malpighiaceae); one group was recovering from fire while the other acted as control. With respect to biotic interactions, we examined whether resprouting influenced extrafloral nectar concentration (milligrams per microliter), the abundance of the ant Camponotus crassus and leaf herbivory rates. Plant stress was assessed via fluctuating asymmetry (FA) analysis, which refers to deviations from perfect symmetry in bilaterally symmetrical traits (e.g., leaves) and indicates whether species are under stress. Results revealed that FA, sugar concentration, and ant abundance were 51.7 %, 35.7 % and 21.7 % higher in resprouting plants. Furthermore, C. crassus was significantly associated with low herbivory rates, but only in resprouting plants. This study showed that post-fire resprouting induced high levels of plant stress and influenced extrafloral nectar quality and ant-herbivore relationships in B. campestris. Therefore, despite being a stressful condition to the plant, post-fire resprouting individuals had concentrated extrafloral nectar and sustained more ants, thus strengthening the outcomes of ant-plant mutualism.

  5. Compatibility of imported fire ant whole body extract with cat, ragweed, Dermatophagoides pteronyssinus, and timothy grass allergens.

    PubMed

    Rans, Tonya S; Hrabak, Todd M; Whisman, Bonnie A; Grier, Thomas J; LeFevre, Dawn M; Kwon, Paul O; Tankersley, Michael S

    2009-01-01

    Recommendations regarding the administration of imported fire ant whole body extract (IFA WBE) combined with aeroallergens or environmental allergens in a single immunotherapy injection are lacking. To evaluate the degradative effect of IFA WBE on cat, ragweed, Dermatophagoides pteronyssinus, and timothy grass allergens. Imported fire ant whole body extract was combined with extracts of cat, ragweed, D pteronyssinus, and timothy grass. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed on each sample after storage for 0, 1, 3, and 6 months at 4 degrees C. In addition, cat and ragweed combinations were evaluated by radial immunodiffusion (RID); D pteronyssinus by enzyme-linked immunosorbent assay (ELISA) inhibition; and timothy grass by ELISA inhibition and Western blot. Imported fire ant whole body extract combined with timothy grass demonstrated degradation of timothy grass allergens by SDS-PAGE, ELISA inhibition, and Western blot results. Cat and ragweed allergens were stable after mixing with IFA WBE, based on SDS-PAGE and RID analyses. Stability of D pteronyssinus allergens with IFA WBE was evident from SDS-PAGE and ELISA inhibition data. Imported fire ant whole body extract combined with timothy grass resulted in significant and rapid timothy protein degradation. Imported fire ant whole body extract mixed with cat, ragweed, or D pteronyssinus revealed aeroallergen stability, yielding the possibility of combining these extracts in a single immunotherapy injection. Compatibilities of IFA WBE with other common aeroallergens remain undetermined and thus are not recommended for single-injection immunotherapy formulations.

  6. Wolbachia infections in native and introduced populations of fire ants (Solenopsis spp.).

    PubMed

    Shoemaker, D D; Ross, K G; Keller, L; Vargo, E L; Werren, J H

    2000-12-01

    Wolbachia are cytoplasmically inherited bacteria that induce a variety of effects with fitness consequences on host arthropods, including cytoplasmic incompatibility, parthenogenesis, male-killing and feminization. We report here the presence of Wolbachia in native South American populations of the fire ant Solenopsis invicta, but the apparent absence of the bacteria in introduced populations of this pest species in the USA. The Wolbachia strains in native S. invicta are of two divergent types (A and B), and the frequency of infection varies dramatically between geographical regions and social forms of this host. Survey data reveal that Wolbachia also are found in other native fire ant species within the Solenopsis saevissima species complex from South America, including S. richteri. This latter species also has been introduced in the USA, where it lacks Wolbachia. Sequence data reveal complete phylogenetic concordance between mtDNA haplotype in S. invicta and Wolbachia infection type (A or B). In addition, the mtDNA and associated group A Wolbachia strain in S. invicta are more closely related to the mtDNA and Wolbachia strain found in S. richteri than they are to the mtDNA and associated group B Wolbachia in S. invicta. These data are consistent with historical introgression of S. richteri cytoplasmic elements into S. invicta populations, resulting in enhanced infection and mtDNA polymorphisms in S. invicta. Wolbachia may have significant fitness effects on these hosts (either directly or by cytoplasmic incompatibility) and therefore these microbes potentially could be used in biological control programmes to suppress introduced fire ant populations.

  7. Development of a lateral flow immunoassay for rapid field detection of the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Valles, Steven M; Strong, Charles A; Callcott, Anne-Marie A

    2016-07-01

    The red imported fire ant, Solenopsis invicta, is an aggressive, highly invasive pest ant species from South America that has been introduced into North America, Asia, and Australia. Quarantine efforts have been imposed in the USA to minimize further spread of the ant. To aid the quarantine efforts, there remains an acute need for a rapid, field portable method for the identification of these ants. In this report, we describe two novel monoclonal antibodies that specifically bind the S. invicta venom protein 2 produced by S. invicta. Using these monoclonal antibodies we developed a lateral flow immunoassay that provides a rapid and portable method for the identification of S. invicta ants. The lateral flow immunoassay was validated against purified S. invicta venom protein 2 and 33 unique ant species (representing 15 % of the total species and 42 % of the Myrmicinae genera found in Florida), and only S. invicta and the S. invicta/richteri hybrid produced a positive result. These monoclonal antibodies were selective to S. invicta venom protein 2 and did not bind to proteins from congeners (i.e., S. geminata or S. richteri) known to produce a S. invicta venom protein 2 ortholog. This S. invicta lateral flow immunoassay provides a new tool for regulatory agencies in the USA to enforce quarantine protocols and limit the spread of this invasive ant. Graphical Abstract Field method to detect and identify the red imported fire ant, Solenopsis invicta.

  8. Fire ants

    MedlinePlus

    ... exposure, call your local emergency number (such as 911), or your local poison center can be reached ... and call your local emergency number (such as 911) or poison control. Those who have an allergy ...

  9. The fire ant wars. Nature and science in the pesticide controversies of the late twentieth century.

    PubMed

    Buhs, Joshua Blu

    2002-09-01

    This essay uses an approach borrowed from environmental history to investigate the interaction of science and nature in a late twentieth-century controversy. This debate, over the proper response to fire ants that had been imported into the American South accidentally and then spread across the region, pitted Rachel Carson and loosely federated groups of conservationists, scientists, and citizens against the U.S. Department of Agriculture. The analysis falls into three sections: an examination of the natural history of the ants; an examination of the views of the competing factions; and an examination of how those views, transformed into action, affected the natural world. Both sides saw the ants in terms of a constellation of beliefs about the relationship between nature, science, and democracy. As various ideas were put into play, they interacted with the natural history of the insects in unexpected ways--and with consequences for the cultural authority of the antagonists. Combining insights from the history of science and environmental history helps explain how scientists gain and lose cultural authority and, more fundamentally, allows for an examination of how nature can be integrated into the history of science.

  10. Essential Balm: A Strong Repellent Against Foraging and Defending Red Imported Fire Ants (Hymenoptera: Formicidae).

    PubMed

    Wen, Yuzhen; Ma, Tao; Chen, Xuan; Liu, Zhitao; Zhu, Chengqi; Zhang, Yuanyuan; Strecker, Rachel; Henderson, Gregg; Hooper-Bùi, Linda M; Chen, Xiaoyang; Sun, Zhaohui; Wen, Xiujun; Wang, Cai

    2016-08-01

    In the present study, the repellent effects of essential balm, a traditional medicine product in China, was tested against foraging and defending red imported fire ants, Solenopsis invicta Buren, under laboratory and field conditions. The laboratory study showed that both band- (width = 1 cm) and patch-smearing of essential balm at each concentration (0.5, 1, or 2 μl/cm(2)) significantly decreased the number of S. invicta foragers within the 6-h observation period. Moreover, band-smearing of 2 μl/cm(2) essential balm and patch-smearing of 0.5, 1, and 2 μl/cm(2) essential balm inhibited most S. invicta foraging activity at 3, 6, 6, and 24 h into the experiment, respectively. The field study showed that after a disturbance was created on the S. invicta mound, there were significantly less defending ants on the substance treated (patch-smeared) with 0.5, 1, and 2 μl/cm(2) essential balm than the controls, but the number of ants on the substance of these three concentrations was similar. Our study suggested that essential balm is a strong repellent against foraging and defending S. invicta and could be applied when temporary protection from S. invicta is needed. © 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.

  11. Activity of bifenthrin, chlorfenapyr, fipronil, and thiamethoxam against red imported fire ants (Hymenoptera: Formicidae).

    PubMed

    Wiltz, B A; Suiter, D R; Gardner, W A

    2010-06-01

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Both immobilization and mortality occurred most quickly with bifenthrin, followed by thiamethoxam, chlorfenapyr, and fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30 degrees C, with three ratios of topically treated donor ant corpses to live recipients (5, 10, or 20% donors). Bifenthrin had the greatest horizontal activity of the chemicals tested. For chlorfenapyr, the only treatments having higher mortality than controls were the highest percentage donors at either 10 or 30 degrees C. Horizontal activity of fipronil was temperature dependent only with the highest proportion of donors and was lower than that ofbifenthrin but higher than that of chlorfenapyr or thiamethoxam. Mean mortality due to thiamethoxam was similar to that with chlorfenapyr. Significant mortality occurred in all of the 20 and 30 degrees C thiamethoxam treatments, but none of the 10 degrees C treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control bridge. Mortality data suggest that a reduction in recruitment rather than repellency account for this result.

  12. Differential field responses of the little fire ant, Wasmannia auropunctata (Roger), to alarm pheromone enantiomers.

    PubMed

    Yu, Yang; Jang, Eric B; Siderhurst, Matthew S

    2014-12-01

    The little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae), is an invasive ant with negative impacts on both biodiversity and agriculture throughout the tropics and subtropics. Field experiments were conducted in order to elucidate the relative attractiveness of the enantiomers of the alarm pheromones, 2,5-dimethyl-3-(2-methylbutyl)pyrazine and 3-methyl-2-(2-methylbutyl)pyrazine. The enantiomers tested were synthesized from commercially available (S)-2-methylbutan-1-ol or kinetically resolved (R)-2-methylbutan-1-ol, prepared using Pseudomonas cepacia lipase (PCL). Bioassays conducted in a macadamia orchard on the island of Hawaii demonstrated that W. auropunctata were preferentially attracted to the (S)-enantiomers of both alkyl pyrazines over the racemic mixtures in all experiments. To our knowledge, this is the first instance of differential attraction of ants to the enantiomers of chiral pyrazine pheromones despite many examples of these compounds in the literature. In addition, using a chiral column it was determined that (S)-2,5-dimethyl-3-(2-methylbutyl)pyrazine and (S)-3-methyl-2-(2-methylbutyl)pyrazine are the only enantiomers produced by W. auropunctata.

  13. Aerosol delivery of trail pheromone disrupts the foraging of the red imported fire ant, Solenopsis invicta.

    PubMed

    Suckling, David Maxwell; Stringer, Lloyd D; Corn, Joshua E; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K

    2012-12-01

    The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E-α-farnesene (91% purity) was prepared, and disruption of worker trail orientation was tested using an ethanol-based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail-following behaviour was recorded by overhead webcam and ants digitised before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm(-2)). Ants preferred 110 ng cm(-1) over 11, 1.1 and 0.11 ng cm(-1) for trail following. Within seconds of presentation of 1600 ng cm(-2), the highest dose tested, trail disruption was observed. Disruption was evident as reduced arrival success and reduction in the trail integrity statistic (r(2)), as well as increased deviation from the trail (deg). The distribution of walking track angles was also flattened. The feasibility of using aerosol for delivery of trail pheromone was demonstrated, but the need for high purity combined with the difficulty of commercial supply makes this technique impractical. However, the commercial production of Z,E-α-farnesene of high purity by industrial biotechnology or from (E)-nerolidol may be possible in future, which would facilitate further development of trail pheromone disruption of S. invicta. Copyright © 2012 Society of Chemical Industry.

  14. Toxicity and sublethal effects of sulfoxaflor on the red imported fire ant, Solenopsis invicta.

    PubMed

    Pan, Fengxiang; Lu, Yongyue; Wang, Lei

    2017-05-01

    To understand whether sulfoxaflor, a novel neonicotinoid, poses unacceptable risks to the environment, it is important to assess its effects on nontarget insects. Therefore, the effects of short-term exposure (28 days) of free-feeding sublethal concentrations (1-2μg/ml) of sulfoxaflor to the red imported fire ant, Solenopsis invicta, were investigated. The following parameters were evaluated to determine the impact of exposure: colony growth, food consumption (sugar water and locusts), and interspecific interactions. Sulfoxaflor exposure produced significant negative effects on S. invicta colony growth, with cumulative colony weight losses of 83.36% and 100.00% after treatment with 1μg/ml and 2μg/ml, respectively. The consumption of sugar water (containing sulfoxaflor) of surviving colonies decreased with increasing sulfoxaflor concentration. Moreover, the consumption of locusts decreased after treatment with 2μg/ml, but not 1μg/ml, sulfoxaflor. Sulfoxaflor treatment for 14 days led to reduced aggressiveness of S. invicta workers in interspecific confrontations (S. invicta vs. unexposed Pheidole fervida), and their probability of survival of aggressive encounters was reduced significantly to 48% of that of control ants. Our results indicate that sublethal concentrations of sulfoxaflor are likely to have a negative impact on ants.

  15. Effect of broadcast baiting on abundance patterns of red imported fire ants (Hymenoptera: Formicidae) and key local ant genera at long-term monitoring sites in Brisbane, Australia.

    PubMed

    McNaught, Melinda K; Wylie, F Ross; Harris, Evan J; Alston, Clair L; Burwell, Chris J; Jennings, Craig

    2014-08-01

    In 2001, the red imported fire ant (Solenopsis invicta Buren) was identified in Brisbane, Australia. An eradication program involving broadcast bait treatment with two insect growth regulators and a metabolic inhibitor began in September of that year and is currently ongoing. To gauge the impacts of these treatments on local ant populations, we examined long-term monitoring data and quantified abundance patterns of S. invicta and common local ant genera using a linear mixed-effects model. For S. invicta, presence in pitfalls reduced over time to zero on every site. Significantly higher numbers of S. invicta workers were collected on high-density polygyne sites, which took longer to disinfest compared with monogyne and low-density polygyne sites. For local ants, nine genus groups of the 10 most common genera analyzed either increased in abundance or showed no significant trend. Five of these genus groups were significantly less abundant at the start of monitoring on high-density polygyne sites compared with monogyne and low-density polygyne sites. The genus Pheidole significantly reduced in abundance over time, suggesting that it was affected by treatment efforts. These results demonstrate that the treatment regime used at the time successfully removed S. invicta from these sites in Brisbane, and that most local ant genera were not seriously impacted by the treatment. These results have important implications for current and future prophylactic treatment efforts, and suggest that native ants remain in treated areas to provide some biological resistance to S. invicta.

  16. Effects of worker size on the dynamics of fire ant tunnel construction

    PubMed Central

    Gravish, Nick; Garcia, Mateo; Mazouchova, Nicole; Levy, Laura; Umbanhowar, Paul B.; Goodisman, Michael A. D.; Goldman, Daniel I.

    2012-01-01

    Social insects work together to complete tasks. However, different individuals within a colony may vary in task proficiency. We investigated if fire ant (Solenopsis invicta) worker body size influenced the ability to construct tunnels—a key component of subterranean nests. We monitored excavation by worker groups in a substrate of small wetted glass particles in quasi-two-dimensional arenas. Morphological and network features of the tunnel system were measured. Total tunnel area did not differ significantly between groups of large and small workers, although the tunnel area of control sized workers was significantly larger than that of large workers. Moreover, large workers created wider but shorter tunnels, with slower growth rate of tunnel number. However, edge–vertex scaling and degree distribution of the tunnel network were similar across all treatments. In all cases, the amount of excavated material was correlated with the number of active workers. Our study reveals that morphological features of excavated tunnels show modest variation when constructed by workers of varying sizes, but topological features associated with the tunnel network are conserved. These results suggest that important behavioural aspects of tunnel construction—and thus nest building—are similar among morphologically distinct members of fire ant societies. PMID:22915634

  17. Effects of worker size on the dynamics of fire ant tunnel construction.

    PubMed

    Gravish, Nick; Garcia, Mateo; Mazouchova, Nicole; Levy, Laura; Umbanhowar, Paul B; Goodisman, Michael A D; Goldman, Daniel I

    2012-12-07

    Social insects work together to complete tasks. However, different individuals within a colony may vary in task proficiency. We investigated if fire ant (Solenopsis invicta) worker body size influenced the ability to construct tunnels--a key component of subterranean nests. We monitored excavation by worker groups in a substrate of small wetted glass particles in quasi-two-dimensional arenas. Morphological and network features of the tunnel system were measured. Total tunnel area did not differ significantly between groups of large and small workers, although the tunnel area of control sized workers was significantly larger than that of large workers. Moreover, large workers created wider but shorter tunnels, with slower growth rate of tunnel number. However, edge-vertex scaling and degree distribution of the tunnel network were similar across all treatments. In all cases, the amount of excavated material was correlated with the number of active workers. Our study reveals that morphological features of excavated tunnels show modest variation when constructed by workers of varying sizes, but topological features associated with the tunnel network are conserved. These results suggest that important behavioural aspects of tunnel construction--and thus nest building--are similar among morphologically distinct members of fire ant societies.

  18. Imported fire ant (Hymenoptera: Formicidae) mound shape characteristics along a north-south gradient.

    PubMed

    Vogt, James T; Wallet, Bradley; Freeland, Thomas B

    2008-02-01

    The nests of some mound-building ants are thought to serve an important function as passive solar collectors. To test this hypothesis, imported fire ant (Solenopsis invicta Buren, S. richteri Forel, and their hybrid) mound shape characteristics (south facing slope angle and area, mound height, and basal elongation in the plane of the ground) were quantified in 2005 and 2006 at a number of locations from approximately 30 degrees 25' N (Long Beach, MS) to 35 degrees 3' N (Fayetteville, TN). Insolation (w*h/m2), maximum sun angle (sun elevation in degrees above the horizon at noon, dependent on date and latitude), cumulative rainfall (7 and 30 d before sampling), and mean ambient temperature (7 d before sampling) for each site x date combination were used as predictive variables to explain mound shape characteristics. Steepness of south-facing mound slopes was negatively associated with maximum sun angle at higher temperatures, with predicted values falling from approximately 36 degrees at sun angle=40 degrees to 26 degrees at sun angle=70 degrees; at lower temperatures, slope remained relatively constant at 28 degrees. On average, mound height was negatively correlated with maximum sun angle. Rainfall had a net negative effect on mound height, but mound height increased slightly with maximum sun angle when rainfall was high. Mound elongation generally increased with increased mound building activity. Under favorable temperature conditions and average rainfall, imported fire ant mounds were tallest, most eccentric, and had the steepest south facing slopes during periods of low maximum sun angle. Mound shape characteristics are discussed with regard to season and their potential usefulness for remote sensing efforts.

  19. Pseudacteon decapitating flies (Diptera: Phoridae): Are they potential vectors of the fire ant pathogens Kneallhazia(=Thelohania)solenopsae (Microsporidia: Thelohaniidae)and Vairimorpha invictae (Microsporidia: Burenellidae)?

    USDA-ARS?s Scientific Manuscript database

    Fire ant decapitating flies in the genus Pseudacteon were tested for their potential as hosts or vectors of two microsporidian pathogens of the red imported fire ant, Solenopsis invicta. Decapitating flies which attacked or were reared from S. invicta workers infected by Kneallhazia (=Thelohania)...

  20. Increased incidence of red imported fire ant (Hymenoptera: Formicidae) presence in loggerhead sea turtle (Testudines: Cheloniidae) nests and observations of hatchling mortality

    USGS Publications Warehouse

    Parris, L.B.; Lamont, M.M.; Carthy, R.R.

    2002-01-01

    Hatching sea turtles may be at risk to fire ant predation during egg incubation, and especially at risk once pipped from the egg, prior to hatchling emergence from the nest. In addition to direct mortality, fire ants have the potential to inflict debilitating injuries that may directly affect survival of the young. The increased incidence of red imported fire ant induced mortality and envenomization of loggerhead sea turtle hatchlings on Cape San Blas suggests this invasive ant species may pose a serious threat to the future of this genetically distinct population.

  1. 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.

  2. How do groups of red imported fire ants (Hymenoptera: Formicidae) feed on a droplet of sugar water?

    PubMed

    Wang, Cai; Chen, Xuan; Hooper-Bùi, Linda M; Strecker, Rachel; Wen, Yu-Zhen; Qin, Wen-Quan; Ma, Tao; Sun, Zhao-Hui; Chen, Xiao-Yang; Wen, Xiu-Jun

    2016-12-28

    Many previous studies have focused on the foraging behaviors and strategies of the red imported fire ants, Solenopsis invicta Buren on solid food or granular bait; little attention has been paid to how liquid sugar is fed upon. In the present study, behavioral responses of S. invicta to 25% sucrose water droplets were observed. Five foraging patterns were identified in S. invicta colonies under laboratory conditions: (i) no feeding, no sucrose water feeding was observed; (ii) surround feeding, ants surrounded and fed along the edge of the sucrose droplet; (iii) stacked feeding, ants stacked and fed along the edge of the sucrose droplet; (iv) droplet-break feeding, ants broke the liquid droplet and sucked sucrose water that spread on surface of the substance or soil particles previously transported by ants; and (v) cover feeding, whole surface of the sucrose droplet was covered by layers of feeding ants. This is the first time cover feeding in S. invicta has been reported, which obviously requires more ants compared to the other patterns. In addition, individual ants were tracked in videos under laboratory conditions, and behavioral repertoires that led to stacking, covering and droplet-breaking were identified and described. The field investigation showed that surround feeding was most frequently performed by S. invicta foragers; however, cover feeding was not observed under field conditions during this study. Both laboratory and field studies showed colony-level variations in sugar-water feeding. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  3. Procedures to mititgate the impact of Solenopsis invicta Virus 3 in fire ant (Hymenoptera:Formicidae) rearing facilities

    USDA-ARS?s Scientific Manuscript database

    During the initial characterization of Solenopsis invicta virus 3 (SINV-3), virus-infected fire ant colonies were retrieved from the field and maintained in the laboratory rearing facility at the USDA, Gainesville, FL. During this time, all S. invicta colonies housed in the facility contracted SINV...

  4. Potential economic impact of introduction and spread of the red imported fire ant, Solenopsis invicta, in Hawaii

    USGS Publications Warehouse

    Gutrich, J.J.; VanGelder, E.; Loope, L.

    2007-01-01

    Globally, many invasive alien species have caused extensive ecological and economic damage from either accidental or intentional introduction. The red imported fire ant, Solenopsis invicta, has created billions of dollars in costs annually, spreading as an invasive species across the southern United States. In 1998, the red imported fire ant spread into California creating a highly probable future introduction via shipped products to Hawaii. This paper presents the estimation of potential economic impacts of the red imported fire ant (RIFA) to the state of Hawaii. Evaluation of impacts focuses on the economic sectors of (1) households, (2) agriculture (cattle and crop production), (3) infrastructure (cemeteries, churches, cities, electrical, telephone, and cable services, highways, hospitals and schools), (4) recreation, tourism and business (hotels/resort areas, golf courses, commercial businesses and tourists), and (5) government expenditures (with minimal intervention). The full annual economic costs of the red imported fire ant to Hawaii are estimated (in US$ 2006) to be $211 million/year, comprised of $77 million in damages and expenditures and $134 million in foregone outdoor opportunities to households and tourists. The present value of the projected costs of RIFA over a 20-year period after introduction total $2.5 billion. RIFA invasions across the globe indicate that economic cost-effective action in Hawaii entails implementation of prevention, early detection and rapid response treatment programs for RIFA. ?? 2007 Elsevier Ltd. All rights reserved.

  5. Efficacy of three citrus oil formulations against solenopsis invicta buren (Hymenoptera: Formicidae), the red imported fire ant1,2

    Treesearch

    James T. Vogt; Thormas G. Shelton; Michael E. Merchant; Scott A. Russell; Marla J. Tanley; Arthur G. Appel

    2002-01-01

    Experiments were conducted in Alabama, Oklahoma, and Texas to assess efficacy of raw citrus peel extract (orange oil) and a commercial citrus oil formulation for control of Solenopsis invicta Buren, the red imported fire ant. A recipe containing orange oil (equal parts orange oil, cattlemen's molasses, and compost tea at 47 mL L1 water),...

  6. Activity patterns and parasitism rates of fire ant decapitating flies (Diptera:Phoridae:Pseudacteon spp.) in their native Argentina

    USDA-ARS?s Scientific Manuscript database

    Technical Abstract: This work describes the annual and daily activity patterns of two parasitoid fly communities of the fire ant S. invicta (Hymenoptera: Formicidae) in their native Argentina. Pseudacteon (Diptera: Phoridae) flies were censused monthly for one year at two sites in northwestern Corr...

  7. Evidence of competition among three species of Pseudacteon decapitating flies released in the Gainesville area as fire ant biocontrol agents

    USDA-ARS?s Scientific Manuscript database

    Three species of fire ant decapitating flies have been established in the Gainesville area. The first species, Pseudacteon tricuspis, was established in 1997. The second species, Pseudacteon curvatus, was established in 2003 and the third species, Pseudacteon obtusus, was established in 2008. The s...

  8. Successful transmission of Solenopsis invicta virus 3 to Solenopsis invicta fire ant colonies in oil, sugar, and cricket bait formulations

    USDA-ARS?s Scientific Manuscript database

    Tests were conducted to evaluate whether Solenopsis invicta virus 3 (SINV-3) could be delivered in various bait formulations to fire ant colonies and measure the corresponding colony health changes associated with virus infection in Solenopsis invicta. Three bait formulations (10% sugar solution, c...

  9. Solenopsis invicta virus (sinv-1) infection and insecticide interactions in the red imported fire ant (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Controlling invasive species is a growing concern; however, pesticides can be detrimental for non-target organisms. The red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) has aggressively invaded approximately 138 million ha in the USA and causes over $6 billion in damage and ...

  10. Population genetics reveals multiple introductions and subsequent cross-province movements of the invasive fire ant Solenopsis invicta in China

    USDA-ARS?s Scientific Manuscript database

    We characterized patterns of genetic variation in populations of the invasive fire ant Solenopsis invicta in China using both mitochondrial DNA sequences and nuclear DNA microsatellites. All study samples, which were collected from 17 sites across the current infested range in China, were assigned t...

  11. Extracted Venom and Cuticular Compounds of Imported Fire Ants, Solenopsis spp., and Chemotaxonomic Applications Across a Persistent Hybrid Zone

    USDA-ARS?s Scientific Manuscript database

    Characterization of cuticular biomolecular assemblages for imported fire ants permit basic distinctions among colonies of S. invicta, S. richteri, and their hybrids; thus, providing opportunities to investigate details of landscape ecology for this species complex as well as to assess levels of inva...

  12. No Evidence for Wolbachia Phenotypic Effects in Newly Mated Queens of the Fire Ant Solenopsis invicta (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Wolbachia are intracellular bacteria that commonly infect many arthropods and some nematodes. In arthropods, these bacteria often induce phenotypic effects that enhance their own spread within host populations, despite sometimes also having deleterious effects on host fecundity and viability. Wolbac...

  13. Contact toxicities of anuran skin alkaloids against the fire ant ( Solenopsis invicta)

    NASA Astrophysics Data System (ADS)

    Weldon, Paul J.; Cardoza, Yasmin J.; Vander Meer, Robert K.; Hoffmann, W. Clint; Daly, John W.; Spande, Thomas F.

    2013-02-01

    Nearly 500 alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These cutaneous compounds, which are derived from arthropod prey of the frogs, generally are believed to deter predators. We tested the red imported fire ant ( Solenopsis invicta) for toxicosis following contact with 20 alkaloids (12 structural classes) identified from dendrobatids or other anurans. Individual ants forced to contact the dried residues of 13 compounds exhibited convulsions and/or reduced ambulation. We estimated the cutaneous concentrations of several compounds based on their reported recoveries from skin extracts of free-ranging frogs and our measurements of the skin surface areas of museum specimens. Pumiliotoxin 251D exhibited contact toxicity below its estimated cutaneous concentration in the Ecuadorian frog, Epipedobates anthonyi, an observation consistent with the hypothesized role of this compound in anuran chemical defense. Our results and those of a previous study of mosquitoes indicate that some anuran skin compounds function defensively as contact toxins against arthropods, permeating their exoskeleton.

  14. Mites (Acari: Scutacaridae) associated with the red imported fire ant, Solenopsis Invicta Buren (Hymenoptera: Formicidae), from Louisiana and Tennessee, U.S.A.

    Treesearch

    Ernst Ebermann; John C. Moser

    2008-01-01

    Four species of Scutacarus and one of Imparipes (Acari: Scutacaridae) are documented as phoretic from alates and workers of the red imported fire ant (Solenopsis invicta Buren) in Louisiana and Tennessee, U.S.A. One, Imparipes (Imparipes) louisianae)

  15. Re-investigation of venom chemistry of Solenopsis fire ants. II. Identification of novel alkaloids in S. invicta.

    PubMed

    Chen, Li; Fadamiro, Henry Y

    2009-04-01

    The venom of the red imported fire ant, Solenopsis invicta, is dominated by trans stereoisomers of 2,6-dialkylpiperidines. cis Stereoisomers of alkaloids in the venom of S. invicta were separated from trans stereoisomers by using silica gel short column chromatography and identified by coupled gas chromatography mass spectrometry (GC-MS). Seven pairs of cis and trans sterecoisomers were identified based on relative retention times and mass spectral data. The GC trace of the cis stereoisomers of S. invicta alkaloids was presented for the first time. In addition to the previously described 2,6-dialkylpiperideines, eleven novel 2,6-dialkyl-delta1,2-piperideines and 2,6-dialkyl-delta1,6-piperideines were identified from S. invicta venom. The results are discussed in relation to the evolutionary significance of these piperideines and their possible biosynthetic pathways in Solenopsis fire ants.

  16. Mirex residues in nontarget organisms after application of experimental baits for fire ant control, southwest Georgia--1971-72.

    PubMed

    Wojcik, D P; Banks, W A; Wheeler, W B; Jouvenaz, D P; Van Middelem, C H; Lofgren, C S

    1975-12-01

    Mirex, the only compound approved for control of the red imported fire ant (Solenopsis invicta) and the black imported fire ant (Solenopsis richteri), is normally applied at a rate of 1.40 kg/ha. (1.25 lb/acre). Influenced by recent studies showing that low levels of mirex are toxic to certain nontarget organisms, particularly estuarine species, authors report here on a monitoring study of mirex in three large treatment areas of southwest Georgia. Four formulations of bait were applied aerially in 1971-72. Low-level residues were observed in small terrestrial vertebrates and invertebrates and in fresh-water inhabitants. Levels detected were about the same for all baits. Maximum residues were detected 1-3 months after treatment and gradually declined to low levels of 0.02-1.16 ppm 1 year after treatment.

  17. Allomermis solenopsi n. sp. (Nematoda: Mermithidae) parasitising the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) in Argentina.

    PubMed

    Poinar, George O; Porter, Sanford D; Tang, Sha; Hyman, Bradley C

    2007-10-01

    Allomermis solenopsi n. sp. (Mermithidae: Nematoda) is described from the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) in Argentina. Diagnostic characters of the new species include stiff and erect processes on the surface of the mature egg, small female amphids, extension of the latero-medial rows of male genital papillae beyond the middle rows, an obliquely truncate spicule tip and a ventrally swollen male terminus. This is the first record of Allomermis Steiner, 1924 from South America and the first host record for members of this genus. Previous records of mermithids from Solenopsis spp. are summarised. The placement in Allomermis was confirmed by molecular analyses based on nuclear 18S ribosomal DNA sequences, the first such molecular framework for the Mermithidae. The possible life-cycle of the parasite is discussed, with the aim of using A. solenopsi as a biological control agent for fire ants in the United States.

  18. Fatty amines from little black ants, Monomorium minimum, and their biological activities against red imported fire ants, Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    Chemistry of defensive sections in the genus Monomorium has been subjected to rigorous research. The venom of little black ants, Monomorium minimum, has been reported to be dominated by insecticidal alkaloids including 2,5-dialkypyrrolidines and 2,5-dialkypyrrolines. In this study, analysis of def...

  19. Defensive chemicals of tawny crazy ants, Nylanderia fulva and their toxicity to red imported fire ants (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Nylanderia fulva (Mayr) has been reported as being able to displace Solenopsis invicta Buren, one of the most aggressive invasive ants in the world. Like S. invicta, N. fulva use chemical secretions in their defense/offense, which may contribute to their observed superior competition ability. In t...

  20. Differences in sNPF receptor-expressing neurons in brains of fire ant (Solenopsis invicta Buren) worker subcastes: indicators for division of labor and nutritional status?

    PubMed

    Castillo, Paula; Pietrantonio, Patricia V

    2013-01-01

    In the red imported fire ant, Solenopsis invicta Buren, the neuronal and molecular mechanisms related to worker division of labor are poorly understood. Workers from different subcastes (major, medium and minors) perform different tasks, which are loosely associated with their size. We hypothesized that the short neuropeptide F (sNPF) signaling system (NPY-like) could be involved in mechanisms of worker division of labor and sensing or responding to colony nutritional requirements. Thus, we investigated the expression of the short neuropeptide F receptor (sNPFR) in the brain and subesophageal ganglion (SEG) of workers from colonies with and without brood. Across worker subcastes a total of 9 clusters of immunoreactive sNPFR cells were localized in the brain and the subesophageal ganglion (SEG); some of these cells were similar to those observed previously in the queen. Worker brain sNPFR cell clusters were found in the protocerebrum near mushroom bodies, in the central complex and in the lateral horn. Other sNPFR immunoreactive cells were found at the edge of the antennal lobes. Across subcastes, we observed both a constant and a differential pattern of sNPFR clusters, with a higher number of sNPFR cells found in minor than in major workers. Those sNPFR cells detected in all worker subcastes appear to be involved in olfaction or SEG functions. The differential expression of clusters in subcastes suggests that sNPFR signaling is involved in regulating behaviors associated with specific subcastes and thus, division of labor. Some sNPFR cells appear to be involved in nutrient sensing and/or brood care, feeding behavior and locomotion. In colonies without brood, workers showed a lower cluster number, and an overall reduced sNPFR signal. Our results suggest the sNPF signaling system is a candidate for the neurobiological control of worker division of labor and sensing brood presence, perhaps correlating with protein requirements and availability.

  1. Isolation and characterization of Solenopsis invicta virus 3, a new positive-strand RNA virus infecting the red imported fire ant, Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    We report the discovery of a new virus from the red imported fire ant, Solenopsis invicta. Solenopsis invicta virus 3 (SINV-3) represents the third virus identified from this ant species using the metagenomics approach. The single (positive)-strand RNA, monopartite, bicistronic genome of SINV-3 wa...

  2. Electroantennogram and behavioral responses of the imported fire ant, Solenopsis invicta Buren, to an alarm pheromone component and its analogues.

    PubMed

    Guan, Di; Lu, Yong-Yue; Liao, Xiao-Lan; Wang, Lei; Chen, Li

    2014-12-10

    A characteristic behavior in ants is to move rapidly to emission sources of alarm pheromones. The addition of ant alarm pheromones to bait is expected to enhance its attractiveness. To search for candidate compounds for bait enhancement in fire ant control, 13 related alkylpyrazine analogues in addition to synthetic alarm pheromone component were evaluated for electroantennogram (EAG) and behavioral activities in Solenopsis invicta. Most compounds elicited dose-dependent EAG and behavioral responses. There exists a correlation between the EAG and behavioral responses. Among the 14 tested alkylpyrazines, three compounds, 2-ethyl-3,6(5)-dimethyl pyrazine (1), 2,3,5-trimethylpyrazine (7), and 2,3-diethyl-5-methylpyrazine (12), elicited significant alarm responses at a dose range of 0.1-1000 ng. Further bait discovery bioassay with the three most active alkylpyrazines demonstrated that food bait accompanied by sample-treated filter paper disk attracted significantly more fire ant workers in the first 15 min period. EAG and behavioral bioassays with pure pheromone isomers accumulated by semi-preparative high-performance liquid chromatography demonstrated that 2-ethyl-3,6-dimethylpyrazine was significantly more active than 2-ethyl-3,5-dimethylpyrazine.

  3. Influence of the proximity and amount of human development and roads on the occurrence of the red imported fire ant in the lower Florida Keys

    USGS Publications Warehouse

    Forys, E.A.; Allen, C.R.; Wojcik, D.P.

    2002-01-01

    We examined the influence of both the proximity and extent of human developments and paved roads on the presence of the predatory, non-indigenous, red imported fire ant (Solenopsis invicta). This species was inadvertently introduced into the United States at the port of Mobile, Alabama, around 1930 and rapidly spread to many southeastern states, including Florida. More recently, S. invicta colonized the Florida Keys, an area with a high proportion of rare and endemic vertebrate and invertebrate species. We placed bait transects in transitional salt-marsh, pineland, and hardwood hammocks on 13 of the lower Florida Keys and compared habitat type, the shortest distance of the bait transect to a development or road, and area of development and roads 50, 70, 100, and 150 m around each bait transect for areas with and without red imported fire ants. Red imported fire ants were detected on 21 of the 80 transects and were equally abundant in all habitat types. While all of the development and road variables differed significantly between bait transects with and without red imported fire ants, transects that were closest to roads and that had the largest amount of development within a 150 m radii had the highest probability of presence of red imported fire ants. Recovery efforts for endangered species in areas invaded by red imported fire ants should include analyses of the cumulative impacts of roads and developments in areas near protected lands. ?? 2002 Elsevier Science Ltd. All rights reserved.

  4. Assessing genetic structure with multiple classes of molecular markers: a case study involving the introduced fire ant Solenopsis invicta.

    PubMed

    Ross, K G; Shoemaker, D D; Krieger, M J; DeHeer, C J; Keller, L

    1999-04-01

    We used 30 genetic markers of 6 different classes to describe hierarchical genetic structure in introduced populations of the fire ant Solenopsis invicta. These included four classes of presumably neutral nuclear loci (allozymes, codominant random amplified polymorphic DNAs (RAPDs), microsatellites, and dominant RAPDs), a class comprising two linked protein-coding nuclear loci under selection, and a marker of the mitochondrial DNA (mtDNA). Patterns of structure revealed by F statistics and exact tests of differentiation were highly concordant among the four classes of neutral nuclear markers, although the microsatellites were the most effective markers for detecting structure. The results from the mtDNA complemented those from the neutral nuclear markers by revealing that strong limitations to female-mediated gene flow were the cause of the local structure registered by the nuclear markers. The pattern of structure inferred from the selected nuclear loci was markedly different from the patterns derived from the other sets of markers but was predictable on the basis of the presumed mode of selection acting on these loci. In general, the results for all six classes of markers can be explained by known features of the social and reproductive biology of fire ants. Thus, the results from these diverse sets of markers, combined with detailed natural history data, provide an unusually complete picture of how the fundamental evolutionary forces of gene flow, drift, and selection govern the distribution of genetic variation within and between fire ant populations.

  5. Treatment of imported fire ant stings with mitigator sting and bite treatment--a randomized control study.

    PubMed

    Hile, David C; Coon, Troy P; Skinner, Carl G; Hile, Lisa M; Levy, Phillip; Patel, Manish M; Miller, Michael A

    2006-01-01

    To evaluate the efficacy of the commercially available product Mitigator Sting and Bite Treatment in reducing the pain after imported fire ant stings. Twenty-four volunteer subjects were exposed to imported fire ant stings on both fore-arms. The subjects received Mitigator paste on 1 arm and calamine lotion on the opposite arm, in a blinded manner, from 90 seconds to 10 minutes after exposure. Subjects recorded pain on a 100-mm visual analog scale 60 seconds, 20 minutes, and 3 days after exposure. A 2-tailed paired t test was used to compare the difference in reduction of pain over time between the Mitigator-treated arms and the calamine-treated arms. At 60 seconds, the mean visual analog scale pain score was 23.9 mm for the Mitigator group and 24.5 mm for the calamine group. At 20 minutes, the mean score was 7.6 mm (delta = 16.3) for the Mitigator group and 12.7 mm (delta = 11.8) for the calamine group. At 3 days, the mean score was 2.4 mm (delta = 21.5) for the Mitigator group and 2.9 mm (delta = 21.6) for the calamine group. There was no significant difference between groups for change in visual analog scale pain score at 60 seconds, 20 minutes (P = .256), or 3 days (P = .64). There was no significant difference in pain relief between calamine and Mitigator for imported fire ant stings.

  6. Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam against Red Imported Fire Ants (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr). Mobility impairment and lethal times were determined following topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thi...

  7. Habitat alteration increases invasive fire ant abundance to the detriment of amphibians and reptiles

    USGS Publications Warehouse

    Todd, B.D.; Rothermel, B.B.; Reed, R.N.; Luhring, T.M.; Schlatter, K.; Trenkamp, L.; Gibbons, J.W.

    2008-01-01

    Altered habitats have been suggested to facilitate red imported fire ant (Solenopsis invicta) colonization and dispersal, possibly compounding effects of habitat alteration on native wildlife. In this study, we compared colonization intensity of wood cover boards by S. invicta among four forest management treatments in South Carolina, USA: an unharvested control (>30 years old); a partially thinned stand; a clearcut with coarse woody debris retained; and a clearcut with coarse woody debris removed. Additionally, we compared dehydration rates and survival of recently metamorphosed salamanders (marbled salamanders, Ambystoma opacum, and mole salamanders, A. talpoideum) among treatments. We found that the number of wood cover boards colonized by S. invicta differed significantly among treatments, being lowest in the unharvested forest treatments and increasing with the degree of habitat alteration. Salamanders that were maintained in experimental field enclosures to study water loss were unexpectedly subjected to high levels of S. invicta predation that differed among forest treatments. All known predation by S. invicta was restricted to salamanders in clearcuts. The amount of vegetative ground cover was inversely related to the likelihood of S. invicta predation of salamanders. Our results show that S. invicta abundance increases with habitat disturbance and that this increased abundance has negative consequences for amphibians that remain in altered habitats. Our findings also suggest that the presence of invasive S. invicta may compromise the utility of cover boards and other techniques commonly used in herpetological studies in the Southeast. ?? 2007 Springer Science+Business Media B.V.

  8. Allergist referrals for systemic reactions to imported fire ants: a community survey in an endemic area.

    PubMed

    Bhutani, Sumit; Khan, David A

    2009-02-01

    Systemic reactions to imported fire ants (IFAs) are known to be the most common cause of anaphylaxis in the southeastern United States, including Texas. Despite this reaction prevalence, referrals to allergists for evaluation and treatment of IFA reactions seem to be infrequent. To evaluate the frequency of referrals for systemic reactions to IFAs in an IFA-endemic area of the Dallas/Fort Worth metroplex. A list of all practicing allergists in the Dallas/Fort Worth metroplex was generated through allergy society membership directories and local telephone book listings. Practices that performed testing and administered immunotherapy for IFA allergy were surveyed using a written questionnaire assessing new referrals for IFA systemic reactions and perceptions of referral patterns. Of 78 "allergists" initially screened, 51 indicated that they test and currently perform immunotherapy for IFA allergy. Of these 51 allergists, 35 (69%) returned completed surveys. Based on these responses, an estimated 0.6% of new patient referrals were for IFA reactions. Sixty-eight percent of respondents indicated that none to very few of all patients in their area with systemic reactions to IFA were being referred to their office for evaluation. Only 0.6% of new referrals to allergists' offices in an IFA-endemic area are for IFA systemic reactions. This is even lower than the estimated 2% prevalence of systemic reactions to IFA in the general population of an endemic area. Efforts to improve awareness of treatment for IFA systemic reactions for referring physicians and the public are needed.

  9. Pyrokinin β-Neuropeptide Affects Necrophoretic Behavior in Fire Ants (S. invicta), and Expression of β-NP in a Mycoinsecticide Increases Its Virulence

    PubMed Central

    Fan, Yanhua; Pereira, Roberto M.; Kilic, Engin; Casella, George; Keyhani, Nemat O.

    2012-01-01

    Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β -neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT50, but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed. PMID:22238569

  10. Odorant Binding Proteins of the Red Imported Fire Ant, Solenopsis invicta: An Example of the Problems Facing the Analysis of Widely Divergent Proteins

    PubMed Central

    Wurm, Yannick; Shoemaker, DeWayne

    2011-01-01

    We describe the odorant binding proteins (OBPs) of the red imported fire ant, Solenopsis invicta, obtained from analyses of an EST library and separate 454 sequencing runs of two normalized cDNA libraries. We identified a total of 18 putative functional OBPs in this ant. A third of the fire ant OBPs are orthologs to honey bee OBPs. Another third of the OBPs belong to a lineage-specific expansion, which is a common feature of insect OBP evolution. Like other OBPs, the different fire ant OBPs share little sequence similarity (∼20%), rendering evolutionary analyses difficult. We discuss the resulting problems with sequence alignment, phylogenetic analysis, and tests of selection. As previously suggested, our results underscore the importance for careful exploration of the sensitivity to the effects of alignment methods for data comprising widely divergent sequences. PMID:21305009

  11. Variation in the Outcomes of an Ant-Plant System: Fire and Leaf Fungus Infection Reduce Benefits to Plants with Extrafloral Nectaries

    PubMed Central

    Pires, L. P.; Del-Claro, K.

    2014-01-01

    Interactions between species are evolutionary malleable and may suffer changes in small timescales. Environmental disturbances, such as fire, can deeply affect species interactions, but how they influence the outcome of a mutualistic interaction has yet to be studied. In order to test the hypothesis that an environmental disturbance, in this case fire, may produce differences in the outcome of the association of ants with the extrafloral-nectaries-bearing plant Qualea multiflora Mart. (Myrtales: Vochysiaceae), a previous study was replicated, but this time after fire incidence, at the same study site and with the same plant species. Eight ant species visited Q. multiflora, and the most abundant genera were Crematogaster, Cephalotes, and Camponotus. Herbivores were found in branches with and without ants with no statistical difference, but foliar herbivory was always higher in branchs where ants were absent. Leaves were infested by fungi, and fungi spots were higher in branches where ants were present. Compared to the previous study, it was clearly observed that ant benefits to Q. multiflora varied over time. The most common ant species still protected leaves against chewing herbivores, but a new kind of leaf damage appeared, namely fungi spots. Data also support that ants may be acting as vectors of fungi spores on plants, as ant visited branches had higher fungus incidence than non-visited branches. Fire is a major source of disturbance in tropical savannas, and we suggest that it can cause strong variation in the outcomes of interactions between ants and plants with extrafloral nectaries in the Brazilian tropical savanna. PMID:25368040

  12. Variation in the outcomes of an ant-plant system: fire and leaf fungus infection reduce benefits to plants with extrafloral nectaries.

    PubMed

    Pires, L P; Del-Claro, K

    2014-01-01

    Interactions between species are evolutionary malleable and may suffer changes in small timescales. Environmental disturbances, such as fire, can deeply affect species interactions, but how they influence the outcome of a mutualistic interaction has yet to be studied. In order to test the hypothesis that an environmental disturbance, in this case fire, may produce differences in the outcome of the association of ants with the extrafloral-nectaries-bearing plant Qualea multiflora Mart. (Myrtales: Vochysiaceae), a previous study was replicated, but this time after fire incidence, at the same study site and with the same plant species. Eight ant species visited Q. multiflora, and the most abundant genera were Crematogaster, Cephalotes, and Camponotus. Herbivores were found in branches with and without ants with no statistical difference, but foliar herbivory was always higher in branchs where ants were absent. Leaves were infested by fungi, and fungi spots were higher in branches where ants were present. Compared to the previous study, it was clearly observed that ant benefits to Q. multiflora varied over time. The most common ant species still protected leaves against chewing herbivores, but a new kind of leaf damage appeared, namely fungi spots. Data also support that ants may be acting as vectors of fungi spores on plants, as ant visited branches had higher fungus incidence than non-visited branches. Fire is a major source of disturbance in tropical savannas, and we suggest that it can cause strong variation in the outcomes of interactions between ants and plants with extrafloral nectaries in the Brazilian tropical savanna. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

  13. A Y-like social chromosome causes alternative colony organization in fire ants.

    PubMed

    Wang, John; Wurm, Yannick; Nipitwattanaphon, Mingkwan; Riba-Grognuz, Oksana; Huang, Yu-Ching; Shoemaker, DeWayne; Keller, Laurent

    2013-01-31

    Intraspecific variability in social organization is common, yet the underlying causes are rarely known. In the fire ant Solenopsis invicta, the existence of two divergent forms of social organization is under the control of a single Mendelian genomic element marked by two variants of an odorant-binding protein gene. Here we characterize the genomic region responsible for this important social polymorphism, and show that it is part of a pair of heteromorphic chromosomes that have many of the key properties of sex chromosomes. The two variants, hereafter referred to as the social B and social b (SB and Sb) chromosomes, are characterized by a large region of approximately 13 megabases (55% of the chromosome) in which recombination is completely suppressed between SB and Sb. Recombination seems to occur normally between the SB chromosomes but not between Sb chromosomes because Sb/Sb individuals are non-viable. Genomic comparisons revealed limited differentiation between SB and Sb, and the vast majority of the 616 genes identified in the non-recombining region are present in the two variants. The lack of recombination over more than half of the two heteromorphic social chromosomes can be explained by at least one large inversion of around 9 megabases, and this absence of recombination has led to the accumulation of deleterious mutations, including repetitive elements in the non-recombining region of Sb compared with the homologous region of SB. Importantly, most of the genes with demonstrated expression differences between individuals of the two social forms reside in the non-recombining region. These findings highlight how genomic rearrangements can maintain divergent adaptive social phenotypes involving many genes acting together by locally limiting recombination.

  14. The Eight Queens Problem.

    ERIC Educational Resources Information Center

    Olson, Alton T.

    1993-01-01

    Presents a series of solution methods to the Eight Queens Problem of placing eight queens on a chess board so that no one queen can capture another. Solution methods progress from empirical approaches to the use of computer algorithms. Geometric transformations are used to find other solutions. (MDH)

  15. Re-investigation of venom chemistry of Solenopsis fire ants. I. Identification of novel alkaloids in S. richteri.

    PubMed

    Chen, Li; Fadamiro, Henry Y

    2009-04-01

    Dialkylpiperidines are characteristic of fire ants in the genus Solenopsis (Hymenoptera: Formicidae). Workers of the black imported fire ant, S. richteri produce cis and trans stereoisomers of 2,6-dialkylpiperidines with the trans isomer predominating. We used silica gel short column chromatography to separate both stereoisomers (cis and trans) of S. richteri venom alkaloids and coupled gas chromatography mass spectrometry (GC-MS) to identify novel minor components. The identities of various peaks in GC-MS analyses of the venom fractions were based on relative retention times and mass spectral data. GC profiles verified the presence of both cis and trans stereoisomers of C15:1 and C15 in S. richteri. The GC trace of the cis stereoisomers of S. richteri alkaloids was presented for the first time. In addition to the previously described components of S. richteri venom, seven novel 2,6-dialkyl-delta1,2-piperideines and 2,6-dialkyl-delta1,6-piperideines were detected. The chemical identities of these minor components were determined by comparing with fragmentations of known compounds. Possible biosynthetic pathways for the production of cis and trans solenopsins by S. richteri are discussed.

  16. Body size, but not cooling rate, affects supercooling points in the red imported fire ant, Solenopsis invicta.

    PubMed

    Hahn, Daniel A; Martin, Adam R; Porter, Sanford D

    2008-10-01

    The level of an animal's stress resistance is set by multiple intrinsic physiological and extrinsic environmental parameters. Body size is a critical intrinsic parameter that affects numerous fitness-related organismal traits including fecundity, survival, mating success, and stress resistance. The rate of cooling is a critical extrinsic environmental factor that can affect thermal stress resistance. Workers of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), display considerable variation in adult body size. Therefore, developing ecologically realistic models of thermotolerance in this species requires a consideration of body size. We tested the hypothesis that body size and cooling rate would interact to set the supercooling point in fire ant workers by exposing workers of a range of body sizes to three different cooling regimens: a very fast ramp of -10 degrees C/min, an intermediate ramp of -1 degrees C/min, and an ecologically relevant slow ramp of -0.1 degrees C/min. Specifically, we asked whether large workers were more susceptible to differences in cooling rate than smaller workers. We found that body size had a considerable effect on supercooling point with the largest workers freezing at a temperature approximately 3 degrees C higher than the smallest workers. Cooling rate had a very small effect on supercooling point, and there was no interaction between the two factors. Therefore, the allometry of supercooling points across the range of worker body sizes does not change with cooling rate.

  17. Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior.

    PubMed

    Bockoven, Alison A; Wilder, Shawn M; Eubanks, Micky D

    2015-01-01

    Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior.

  18. Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior

    PubMed Central

    Bockoven, Alison A.; Wilder, Shawn M.; Eubanks, Micky D.

    2015-01-01

    Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior. PMID:26197456

  19. Colony-level behavioral variation correlates with differences in expression of the foraging gene in red imported fire ants.

    PubMed

    Bockoven, Alison A; Coates, Craig J; Eubanks, Micky D

    2017-09-13

    Among social insects, colony-level variation is likely to be widespread and have significant ecological consequences. Very few studies, however, have documented how genetic factors relate to behavior at the colony level. Differences in expression of the foraging gene have been associated with differences in foraging and activity of a wide variety of organisms. We quantified expression of the red imported fire ant foraging gene (sifor) in workers from 21 colonies collected across the natural range of Texas fire ant populations, but maintained under standardized, environmentally controlled conditions. Colonies varied significantly in their behavior. The most active colonies had up to 10 times more active foragers than the least active colony and more than 16 times as many workers outside the nest. Expression differences among colonies correlated with this colony-level behavioral variation. Colonies with higher sifor expression in foragers had, on average, significantly higher foraging activity, exploratory activity, and recruitment to nectar than colonies with lower expression. Expression of sifor was also strongly correlated with worker task (foraging versus working in the interior of the nest). These results provide insight into the genetic and physiological processes underlying collective differences in social behavior. Quantifying variation in expression of the foraging gene may provide an important tool for understanding and predicting the ecological consequences of colony-level behavioral variation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Queen signals in a stingless bee: suppression of worker ovary activation and spatial distribution of active compounds

    PubMed Central

    Nunes, Túlio M.; Mateus, Sidnei; Favaris, Arodi P.; Amaral, Mônica F. Z. J.; von Zuben, Lucas G.; Clososki, Giuliano C.; Bento, José M. S.; Oldroyd, Benjamin P.; Silva, Ricardo; Zucchi, Ronaldo; Silva, Denise B.; Lopes, Norberto P.

    2014-01-01

    In most species of social insect the queen signals her presence to her workers via pheromones. Worker responses to queen pheromones include retinue formation around the queen, inhibition of queen cell production and suppression of worker ovary activation. Here we show that the queen signal of the Brazilian stingless bee Friesella schrottkyi is a mixture of cuticular hydrocarbons. Stingless bees are therefore similar to ants, wasps and bumble bees, but differ from honey bees in which the queen's signal mostly comprises volatile compounds originating from the mandibular glands. This shows that cuticular hydrocarbons have independently evolved as the queen's signal across multiple taxa, and that the honey bees are exceptional. We also report the distribution of four active queen-signal compounds by Matrix-assisted laser desorption/ionization (MALDI) imaging. The results indicate a relationship between the behavior of workers towards the queen and the likely site of secretion of the queen's pheromones. PMID:25502598

  1. Combining support vector regression and ant colony optimization to reduce NOx emissions in coal-fired utility boilers

    SciTech Connect

    Ligang Zheng; Hao Zhou; Chunlin Wang; Kefa Cen

    2008-03-15

    Combustion optimization has recently demonstrated its potential to reduce NOx emissions in high capacity coal-fired utility boilers. In the present study, support vector regression (SVR), as well as artificial neural networks (ANN), was proposed to model the relationship between NOx emissions and operating parameters of a 300 MW coal-fired utility boiler. The predicted NOx emissions from the SVR model, by comparing with that of the ANN-based model, showed better agreement with the values obtained in the experimental tests on this boiler operated at different loads and various other operating parameters. The mean modeling error and the correlation factor were 1.58% and 0.94, respectively. Then, the combination of the SVR model with ant colony optimization (ACO) to reduce NOx emissions was presented in detail. The experimental results showed that the proposed approach can effectively reduce NOx emissions from the coal-fired utility boiler by about 18.69% (65 ppm). A time period of less than 6 min was required for NOx emissions modeling, and 2 min was required for a run of optimization under a PC system. The computing times are suitable for the online application of the proposed method to actual power plants. 37 refs., 8 figs., 3 tabs.

  2. Can communication disruption of red imported fire ants reduce foraging success

    USDA-ARS?s Scientific Manuscript database

    Invasive pest ants often coordinate resource retrieval and colony expansion through the use of recruitment pheromones for information sharing to optimise their foraging; we argue that the potential for disruption of trail pheromone communication deserves investigation as a new and benign ecologicall...

  3. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    In social insects, antimicrobial secretions are often used collectively for the benefit of the whole colony, which is an important component in social immunity. Many ant species build nests in which air circulation can be controlled. Volatile antimicrobial agents would be ideal in implementing socia...

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

    USDA-ARS?s Scientific Manuscript database

    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 chemical ecology examples, primarily due to the large amount of pheromone produced a...

  5. Testing sodium limitation of fire ants in the field and laboratory

    USDA-ARS?s Scientific Manuscript database

    1) Sodium is an essential dietary element and preferential foraging for high concentrations of sodium by inland herbivorous and omnivorous ants suggests it may be limiting. If so, increased sodium availability through altered deposition and anthropogenic sources may lead to increased colony growth a...

  6. BEHAVIORAL INTERACTIONS OF THE BLACK IMPORTED FIRE ANT (SOLENOPSIS RICHTERI FOREL) AND ITS PARASITOID FLY (PSEUDACTEON CURVATUS BORGMEIER) AS REVEALED BY HIGH-SPEED VIDEO.

    USDA-ARS?s Scientific Manuscript database

    High-speed video recordings were used to study the interactions between the phorid fly (Pseudacteon curvatus), and the black imported fire ant (Solenopsis richteri) in the field. Phorid flies are extremely fast agile fliers that can hover and fly in all directions. Wingbeat frequency recorded with...

  7. Gaeolaelaps Invictianus, a new and unusual species of Hypoaspidine Mite (Acari: Mesostigmata: Laelapidae) phoretic on the red imported fire ant Solenopsis Invicta Buren (Hymenoptera: Formicidae) in Louisiana, USA

    Treesearch

    David Walter; John Moser

    2010-01-01

    A new species ofhypoaspidine laelapid mite, Gaeolaelaps invictianus, associated with the red imported fire ant Solenopsis invicta Buren in the southern United States of America is described. This new species is unusual among the gamasine Mesostigmata in lacking a postanal seta in adults of both sexes and among species of Gaeolaelaps in being phoretic on dispersing male...

  8. Seasonal variation and the co-occurence of four pathogens and a group of parasites among monogyne and polygyne fire ant colonies

    USDA-ARS?s Scientific Manuscript database

    A year-long survey of was conducted to determine the seasonality and co-occurrence of four pathogens and a group of parasites in colonies of the red imported fire ant, Solenopsis invicta, in north-central Florida. S. invicta colonies were sampled and examined for the presence of Pseudacteon spp. (P...

  9. Distribution of the Formosa strain of the fire ant decapitating fly Pseudacteon curvatus (Diptera: Phoridae) three and a half years after releases in North Florida

    USDA-ARS?s Scientific Manuscript database

    The Formosa biotype of the decapitating fly Pseudacteon curvatus Borgmeier was released and successfully established as a self-sustaining biocontrol agent of the red imported fire ant Solenopsis invicta Buren at several sites around Gainesville, FL in 2003. In order to determine the status of these...

  10. Cytogenetic analysis of three species of Pseudacteon (Diptera, Phoridae) parasitoids of the fire ants using standard and molecular techniques

    PubMed Central

    2009-01-01

    Pseudacteon flies, parasitoids of worker ants, are being intensively studied as potentially effective agents in the biological control of the invasive pest fire ant genus Solenopsis (Hymenoptera: Formicidae). This is the first attempt to describe the karyotype of P. curvatus Borgmeier, P. nocens Borgmeier and P. tricuspis Borgmeier. The three species possess 2n = 6; chromosomes I and II were metacentric in the three species, but chromosome pair III was subtelocentric in P. curvatus and P. tricuspis, and telocentric in P. nocens. All three species possess a C positive band in chromosome II, lack C positive heterochromatin on chromosome I, and are mostly differentiated with respect to chromosome III. P. curvatus and P. tricuspis possess a C positive band, but at different locations, whereas this band is absent in P. nocens. Heterochromatic bands are neither AT nor GC rich as revealed by fluorescent banding. In situ hybridization with an 18S rDNA probe revealed a signal on chromosome II in a similar location to the C positive band in the three species. The apparent lack of morphologically distinct sex chromosomes is consistent with proposals of environmental sex determination in the genus. Small differences detected in chromosome length and morphology suggests that chromosomes have been highly conserved during the evolutionary radiation of Pseudacteon. Possible mechanisms of karyotype evolution in the three species are suggested. PMID:21637448

  11. Fire ant decapitating fly cooperative release programs (1994-2008): Two Pseudacteon species (P. tricuspis, P. curvatus) rapidly expand across imported fire and populations in the southeastern United States

    USDA-ARS?s Scientific Manuscript database

    Natural enemies of the imported fire ants (Solenopsis invicta Buren, S. richteri Forel, and their hybrid; Hymenoptera: Formicidae) include a suite of more than 20 phorid decapitating flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have coop...

  12. Growth and patterning are evolutionarily dissociated in the vestigial wing discs of workers of the red imported fire ant, Solenopsis invicta.

    PubMed

    Bowsher, Julia H; Wray, Gregory A; Abouheif, Ehab

    2007-12-15

    Over the last decade, it has become clear that organismal form is largely determined by developmental and evolutionary changes in the growth and pattern formation of tissues. Yet, there is little known about how these two integrated processes respond to environmental cues or how they evolve relative to one another. Here, we present the discovery of vestigial wing imaginal discs in worker larvae of the red imported fire ant, Solenopsis invicta. These vestigial wing discs are present in all worker larvae, which is uncommon for a species with a large worker size distribution. Furthermore, the growth trajectory of these vestigial discs is distinct from all of the ant species examined to date because they grow at a rate slower than the leg discs. We predicted that the growth trajectory of the vestigial wing discs would be mirrored by evolutionary changes in their patterning. We tested this prediction by examining the expression of three patterning genes, extradenticle, ultrabithorax, and engrailed, known to underlie the wing polyphenism in ants. Surprisingly, the expression patterns of these three genes in the vestigial wing discs was the same as those found in ant species with different worker size distributions and wing disc growth than fire ants. We conclude that growth and patterning are evolutionarily dissociated in the vestigial wing discs of S. invicta because patterning in these discs is conserved, whereas their growth trajectories are not. The evolutionary dissociation of growth and patterning may be an important feature of gene networks that underlie polyphenic traits.

  13. Conserved class of queen pheromones stops social insect workers from reproducing.

    PubMed

    Van Oystaeyen, Annette; Oliveira, Ricardo Caliari; Holman, Luke; van Zweden, Jelle S; Romero, Carmen; Oi, Cintia A; d'Ettorre, Patrizia; Khalesi, Mohammadreza; Billen, Johan; Wäckers, Felix; Millar, Jocelyn G; Wenseleers, Tom

    2014-01-17

    A major evolutionary transition to eusociality with reproductive division of labor between queens and workers has arisen independently at least 10 times in the ants, bees, and wasps. Pheromones produced by queens are thought to play a key role in regulating this complex social system, but their evolutionary history remains unknown. Here, we identify the first sterility-inducing queen pheromones in a wasp, bumblebee, and desert ant and synthesize existing data on compounds that characterize female fecundity in 64 species of social insects. Our results show that queen pheromones are strikingly conserved across at least three independent origins of eusociality, with wasps, ants, and some bees all appearing to use nonvolatile, saturated hydrocarbons to advertise fecundity and/or suppress worker reproduction. These results suggest that queen pheromones evolved from conserved signals of solitary ancestors.

  14. PBAN gene architecture and expression in the fire ant, Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    The PBAN/Pyrokinin peptides are a major neuropeptide family characterized by a common FXPRLamide at the C-termini. These peptides are distributed ubiquitously in the Insecta and are involved in many essential endocrine functions, e.g. pheromone production. We report the gene architecture of the fire...

  15. Contact toxicities of Anuran Skin Alkaloids against the Red Imported Fire Ant (Solenopsis invicta)

    USDA-ARS?s Scientific Manuscript database

    Nearly 500 alkaloids, representing over 20 structural classes, have been identified from the skin of poison frogs (Dendrobatidae). These cutaneous compounds, which are derived from leaf-litter arthropods eaten by the frogs, generally are believed to deter predators. We tested the red imported fire a...

  16. Esterase in Imported Fire Ants, Solenopsis invicta and S. richteri (Hymenoptera: Formicidae): Activity, Kinetics and Variation

    PubMed Central

    Chen, J.; Rashid, T.; Feng, G.

    2014-01-01

    Solenopsis invicta and Solenopsis richteri are two closely related invasive ants native to South America. Despite their similarity in biology and behavior, S. invicta is a more successful invasive species. Toxic tolerance has been found to be important to the success of some invasive species. Esterases play a crucial role in toxic tolerance of insects. Hence, we hypothesized that the more invasive S. invicta would have a higher esterase activity than S. richteri. Esterase activities were measured for workers and male and female alates of both ant species using α-naphthyl acetate and β-naphthyl acetate as substrates. Esterase activities in S. invicta were always significantly higher than those in S. richteri supporting our hypothesis. In S. invicta, male alates had the highest esterase activities followed by workers then female alates for both substrates. In S. richetri, for α-naphthyl acetate, male alates had the highest activity followed by female alates then workers, while for β-naphthyl acetate, female alates had the highest activity followed by male alates then workers. For workers, S. richteri showed significantly higher levels of variation about the mean esterase activity than S. invicta. However, S. invicta showed significantly higher levels of variation in both female and male alates. PMID:25408118

  17. Esterase in imported fire ants, Solenopsis invicta and S. richteri (Hymenoptera: Formicidae): activity, kinetics and variation.

    PubMed

    Chen, J; Rashid, T; Feng, G

    2014-11-19

    Solenopsis invicta and Solenopsis richteri are two closely related invasive ants native to South America. Despite their similarity in biology and behavior, S. invicta is a more successful invasive species. Toxic tolerance has been found to be important to the success of some invasive species. Esterases play a crucial role in toxic tolerance of insects. Hence, we hypothesized that the more invasive S. invicta would have a higher esterase activity than S. richteri. Esterase activities were measured for workers and male and female alates of both ant species using α-naphthyl acetate and β-naphthyl acetate as substrates. Esterase activities in S. invicta were always significantly higher than those in S. richteri supporting our hypothesis. In S. invicta, male alates had the highest esterase activities followed by workers then female alates for both substrates. In S. richetri, for α-naphthyl acetate, male alates had the highest activity followed by female alates then workers, while for β-naphthyl acetate, female alates had the highest activity followed by male alates then workers. For workers, S. richteri showed significantly higher levels of variation about the mean esterase activity than S. invicta. However, S. invicta showed significantly higher levels of variation in both female and male alates.

  18. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    DOE PAGES

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; ...

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), butmore » dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.« less

  19. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    SciTech Connect

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  20. Insecticide transfer efficiency and lethal load in Argentine ants

    NASA Astrophysics Data System (ADS)

    Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-10-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  1. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    PubMed Central

    Hooper-Bui, L.M.; Kwok, E.S.C.; Buchholz, B.A.; Rust, M.K.; Eastmond, D.A.; Vogel, J.S.

    2015-01-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony. PMID:26504258

  2. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants.

    PubMed

    Hooper-Bui, L M; Kwok, E S C; Buchholz, B A; Rust, M K; Eastmond, D A; Vogel, J S

    2015-10-15

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of (14)C-sucrose, (14)C-hydramethylnon, and (14)C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  3. Imported fire ants near the edge of their range: disturbance and moisture determine prevalence and impact of an invasive social insect.

    PubMed

    LeBrun, Edward G; Plowes, Robert M; Gilbert, Lawrence E

    2012-07-01

    1. Habitat disturbance and species invasions interact in natural systems, making it difficult to isolate the primary cause of ecosystem degradation. A general understanding requires case studies of how disturbance and invasion interact across a variety of ecosystem - invasive species combinations. 2. Dramatic losses in ant diversity followed the invasion of central Texas by red imported fire ants (Solenopsis invicta). However, recent manipulative studies in Florida revealed no effect on ant diversity following the removal of S. invicta from a disturbed pasture habitat, but moderate loss of diversity associated with their introduction into undisturbed habitat and no invasion occurred without disturbance. Thus, the importance of S. invicta in driving diversity loss and its ability to invade undisturbed systems is unresolved. 3. We examine the distribution and abundance of a large monogyne S. invicta population and its association with the co-occurring ant assemblage at a site in south Texas close to the aridity tolerance limit of S. invicta. 4. We document that moisture modulates S. invicta densities. Further, soil disturbing habitat manipulations greatly increase S. invicta population densities. However, S. invicta penetrates all habitats regardless of soil disturbance history. In contrast, controlled burns depress S. invicta densities. 5. In habitats where S. invicta is prevalent, it completely replaces native fire ants. However, S. invicta impacts native ants as a whole less strongly. Intriguingly, native ants responded distinctly to S. invicta in different environments. In wet, undisturbed environments, high S. invicta abundance disrupts the spatial structure of the ant assemblage by increasing clumping and is associated with reduced species density, while in dry-disturbed habitats, sites with high S. invicta abundance possess high numbers of native species. Analyses of co-occurrence indicate that reduced species density in wet

  4. Social parasitism in fire ants (Solenopsis spp.): a potential mechanism for interspecies transfer of Wolbachia.

    PubMed

    Dedeine, Franck; Ahrens, Michael; Calcaterra, Luis; Shoemaker, D Dewayne

    2005-04-01

    One possible mechanism for interspecific transfer of Wolbachia is through the intimate contact between parasites and their hosts. We surveyed 10 species of fly parasitoids (Pseudacteon spp.) and one inquiline social parasite, Solenopsis daguerrei, for the presence and sequence identity (wsp gene) of Wolbachia. Two Wolbachia variants infecting S. daguerrei were identical to known variants infecting the two common ant host species, Solenopsis invicta and Solenopsis richteri, suggesting possible transfers of Wolbachia between this parasite and their hosts have occurred. Our data also revealed an unexpectedly high diversity of Wolbachia variants within S. daguerrei: up to eight variants were found within each individual, which, to our knowledge, is the highest reported number of Wolbachia variants infecting a single individual of any host species.

  5. Feasibility of Using Template-Based and Object Based Automated Detection Methods for Quantifying Black and Hybrid Iimported Fire Ant (Solenopsis invicta Buren and S. invicta x richteri) Mound in Aerial Digital Imagery

    USDA-ARS?s Scientific Manuscript database

    Imported fire ants construct earthen nests (=mounds) that exhibit many characteristics which make them potentially good targets for remote sensing programs, including geographical orientation, topography, and bare soil surrounded by actively growing vegetation. Template based features and object-ba...

  6. Geographical transition zone of Solenopsis fire ants (Hymenoptera: Formicidae) and Pseudacteon fly parasitoids (Diptera: Phoridae) in the state of São Paulo, Brazil.

    PubMed

    Pesquero, M A; Dias, A M P M

    2011-01-01

    Solenopsis saevissima (Smith) and Solenopsis invicta Buren are the most abundant and widely distributed fire ants in Brazil. The occurrence of the two fire ant species and of their parasitoids Pseudacteon spp. is described for a climatic and phytophysiognomic transition area in the state of São Paulo. Both fire ant species have a parapatric distribution, apparently determined by the climate: S. saevissima predominates in the north part of São Paulo (Aw climate), while S. invicta in the south (Cfa climate). A sympatric area is observed between the latitudes 21ºS and 23ºS. Two different communities of parasitic decapitating flies were associated with S. saevissima in the north and with S. invicta in the south, with a sympatric area in the municipality of São Carlos (21º58'S 47º53'W). The possible causes of this biogeographic pattern are discussed. Preference tests with Pseudacteon flies challenge the association of P. litoralis Borgmeier, P. curvatus Borgmeier, P. wasmanni Schmitz, P. pradei Borgmeier and P. obtusus Borgmeier with S. saevissima, and P. dentiger Borgmeier, P. disneyi Pesquero and P. lenkoi Borgmeier & Prado with S. invicta.

  7. Defensive chemicals of tawny crazy ants, Nylanderia fulva (Hymenoptera: Formicidae) and their toxicity to red imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Chen, Jian; Rashid, Tahir; Feng, Guolei; Zhao, Liming; Oi, David; Drees, Bastiaan Bart M

    2013-12-15

    Nylanderia fulva (Mayr) has been reported as being able to displace Solenopsis invicta Buren, one of the most aggressive invasive ants in the world. Like S. invicta, N. fulva use chemical secretions in their defense/offense, which may contribute to their observed superior competition ability. In this study, the defensive chemicals of N. fulva workers and their toxicity against S. invicta workers were investigated. Like other formicine ants, N. fulva workers produce formic acid in their poison glands and 2-ketones and alkanes in Dufour glands. Of these, undecane and 2-tridecanone are two principal compounds in the Dufour gland. Topical LD50 values of 2-tridecanone and undecane against S. invicta workers ranged from 18.51 to 24.67 μg/ant and 40.39 to 84.82 μg/ant, respectively. Undecane and 2-tridecanone had significantly higher contact toxicity than formic acid, whereas formic acid had significantly higher fumigation toxicity than undecane and 2-tridecanone. The combination of 2-tridecanone as a contact toxin and formic acid as a fumigant significantly decreased KT50 values when compared to those of individual compounds. N. fulva does not seem unique in terms of the chemistry of its defensive secretion as compared to other formicine ants. However, this ant contained more than two orders of magnitude of formic acid (wt/wt) than other formicine ants and one order of magnitude of 2-tridecanone than the common crazy ant, Paratrechina longicornis (Latreille). The quantity, rather than quality, of the chemical secretion may contribute to the superior competition ability of N. fulva.

  8. Identification and characterization of Wolbachia in Solenopsis saevissima fire ants (Hymenoptera: Formicidae) in southeastern Brazil.

    PubMed

    Fernando de Souza, Rodrigo; Daivison Silva Ramalho, João; Santina de Castro Morini, Maria; Wolff, José Luiz Caldas; Araújo, Ronaldo Carvalho; Mascara, Douglas

    2009-03-01

    The genus Solenopsis appears to have evolved and radiated very rapidly in South America and then spread throughout the rest of the continent. As part of the expansion process, distribution patterns and different degrees of geographic isolation among populations of S. saevissima can be observed. We have investigated the presence of Wolbachia in 52 colonies and 1623 individuals in southeastern Brazil. Detection of Wolbachia infection was based on amplification of the 16S rRNA and wsp genes by polymerase chain reactions. Wolbachia was found in only one of the four locations investigated and it was observed that the populations were polymorphic for infection. The infection level observed increased during the period of screening. In particular, double infection (16SWA and B) increased from 44% in 2005 to 90% in 2006. The A-group of Wolbachia from the wsp sequences was determined by sequencing. However, two variant wsp sequences were detected in Wolbachia present in these populations. The alignment of our sequences with those deposited in GenBank indicated significant differences in relation to homologous sequences. Phylogenetic relationships were inferred using parsimony, and confidence intervals were estimated by bootstrapping. Then the divergence of the Wolbachia of S. saevissima in the populations studied with other variants allowed us to verify that wSS1 and dwSS2 formed a distinct clade within the A-group (>75%). These results can be useful in studies on the dynamics of ant populations.

  9. Decreased small mammal and on-host tick abundance in association with invasive red imported fire ants (Solenopsis invicta)

    PubMed Central

    Medeiros, Matthew C. I.; Hamer, Gabriel L.; Morrow, Michael E.; Eubanks, Micky D.; Teel, Pete D.

    2016-01-01

    Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were experimentally reduced. Our analysis of ticks on small mammal hosts demonstrated a threefold increase in the ticks caught per unit effort on treatment relative to control plots, and elevated tick loads (a 27-fold increase) on one common rodent species. We detected only one known human pathogen (Rickettsia parkeri), present in 1.4% of larvae and 6.7% of nymph on-host Amblyomma maculatum samples but with no significant difference between treatment and control plots. Given that host and vector population dynamics are key drivers of pathogen transmission, the reduced small mammal and tick abundance associated with S. invicta may alter pathogen transmission dynamics over broader spatial scales. PMID:27651533

  10. Decreased small mammal and on-host tick abundance in association with invasive red imported fire ants (Solenopsis invicta).

    PubMed

    Castellanos, Adrian A; Medeiros, Matthew C I; Hamer, Gabriel L; Morrow, Michael E; Eubanks, Micky D; Teel, Pete D; Hamer, Sarah A; Light, Jessica E

    2016-09-01

    Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were experimentally reduced. Our analysis of ticks on small mammal hosts demonstrated a threefold increase in the ticks caught per unit effort on treatment relative to control plots, and elevated tick loads (a 27-fold increase) on one common rodent species. We detected only one known human pathogen (Rickettsia parkeri), present in 1.4% of larvae and 6.7% of nymph on-host Amblyomma maculatum samples but with no significant difference between treatment and control plots. Given that host and vector population dynamics are key drivers of pathogen transmission, the reduced small mammal and tick abundance associated with S. invicta may alter pathogen transmission dynamics over broader spatial scales.

  11. Rodents balancing a variety of risks: invasive fire ants and indirect and direct indicators of predation risk.

    SciTech Connect

    Orrock, John, L.; Danielson, Brent, J.

    2004-06-08

    Oecologia (2004) 140: 662 - 667 We used foraging trays to compare how old field mice, Peromyscus polionotus, altered foraging in response to the presence of fire ants, Solenopsisinvicta, and in the presence of direct (predator urine) and indirect (sheltered or exposed micro habitat, moonlight, and precipitation) indicators of predation risk. Foraging reductions elicited by S. invicta were greater than reductions in response to well-documented indicators of risk (i.e., moonlit nights) and the presence of predator urine. The presence of S. invicta always led to reduced foraging, but the overall impact of S. invicta was dependent upon microhabitat and precipitation. When S. invicta was not present, foraging was greater in sheltered microhabitats compared to exposed microhabitats. S. invicta made sheltered microhabitats equivalent to more risky exposed microhabitats, and this effect was especially pronounced on nights without precipitation. The effect of S. invicta suggests that interactions with S. invicta may entail a potentially heavy cost or that presence of S. invicta may represent a more reliable indicator of imminent competition or predation compared to indirect cues of risk and predator urine. The presence of S. invicta led to reduced foraging under situations when foraging activity would otherwise be greatest (i.e., under vegetative cover), potentially reducing habitat quality for P. polionotus and the distribution of seeds consumed by rodents.

  12. Mirex incorporation in the environment: in situ decomposition of fire ant bait and its effects on two soil macroarthropods.

    PubMed

    de la Cruz, A A; Lue, K Y

    1978-01-01

    The decomposition rate of fire ant baits and the consequent leaching of the pesticide mirex from the bait were investigated for one year in three types of environments (i.e., on the ground, in the soil, and in the pond) by means of the nylon litter bag method. There was no significant difference in the decomposition rates between toxic and non-toxic baits. The bait proved to be stable and slow to decay. After one year of exposure in the field, about 75% of bait material remained in the bags that were deployed on the ground, 60% in the soil, and 25% in the pond. The removal of mirex from the bait was due to leaching from, and natural decay of the bait. The loss of mirex from the bait to the environment varied significantly among the three habitats. At the end of 12 months, mirex disappearance from baits exposed on the ground was 41.1%, in the soil 56.3%, and in the pond 83.9%. The rate of mirex loss was slower during fall and winter. The toxicities of the bait decomposed in situ for different lengths of time (12, 9, 6, 3, and 0 months) to the land isopod Armadillidium vulgare and the soil millipede oxidus gracilis were higher than the undecomposed baits. This indicated that weathered mirex baits left in the field have greater biological impact than freshly applied baits, at least on the two soil animals tested.

  13. Distribution of endosymbiotic reproductive manipulators reflects invasion process and not reproductive system polymorphism in the little fire ant Wasmannia auropunctata.

    PubMed

    Rey, Olivier; Estoup, Arnaud; Facon, Benoit; Loiseau, Anne; Aebi, Alexandre; Duron, Olivier; Vavre, Fabrice; Foucaud, Julien

    2013-01-01

    Endosymbiotic reproductive manipulators may have drastic effects on the ecological and evolutionary dynamics of their hosts. The prevalence of these endosymbionts reflects both their ability to manipulate their hosts and the history of the host populations. The little fire ant Wasmannia auropunctata displays a polymorphism in both its reproductive system (sexual versus clonal populations) and the invasive status of its populations (associated to a habitat shift). We first screened for the presence of a diverse array of reproductive parasites in sexual and clonal populations of W. auropunctata, as a means to investigate the role of endosymbionts in reproductive phenotypes. Wolbachia was the only symbiont found and we then focused on its worldwide distribution and diversity in natural populations of W. auropunctata. Using a multilocus scheme, we further characterized the Wolbachia strains present in these populations. We found that almost all the native sexual populations and only a few clonal populations are infected by Wolbachia. The presence of similar Wolbachia strains in both sexual and clonal populations indicates that they are probably not the cause of the reproductive system polymorphism. The observed pattern seems rather associated to the invasion process of W. auropunctata. In particular, the observed loss of Wolbachia in clonal populations, that recurrently emerged from sexual populations, likely resulted from natural heat treatment and/or relaxed selection during the shift in habitat associated to the invasion process.

  14. Effects of periplocoside X on midgut cells and digestive enzymes activity of the soldiers of red imported fire ant.

    PubMed

    Li, Yan; Zeng, Xin-Nian

    2013-07-01

    The pathological effects of ingested periplocoside X, an insecticidal component isolated from the root of Periploca sepium Bunge, on the midgut epithelial cells of the soldiers of red imported fire ant were studied and the symptom was described. The results showed that periplocoside X could induce a severe, time-dependent cytotoxicity in the midgut epithelial cells. An optical microscopy showed that epithelial cells swelled firstly and then lysed. Transmission electron microscopy (TEM) showed that numerous swollen lysosomes were appeared, microvilli were disrupted and sloughed off, and the numbers of the rough endoplasmic reticulum and the mitochondria decreased sharply in earlier stage. Numerous vacuoles were observed in the later stage. Finally, periplocoside X resulted in cell death by cytolysis. Assay of main three digestive enzymes activity indicated that amylase activity was significantly inhibited, but no significant changes were seen for lipase activity and total protease activity. So it is suggested that periplocoside X induced mainly to organic damage of midgut epithelium cells of insect. In all, insect midgut is one of targets for periplocoside X.

  15. Microsporidian and viral pathogens for the biological control of imported fire ants: can we walk the talk?

    USDA-ARS?s Scientific Manuscript database

    . Invasive ants are among the most serious of arthropod invaders. These ants infest a wide range of habitats and impact biodiversity, agriculture, and human health. Self-sustaining biological control is one of the few hopes for permanent regional suppression of these established invasive ants. Fo...

  16. 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.

  17. Dynamics of an ant-ant Obligate Mutualism: Colony Growth, Density Dependence and Frequency Dependence

    USDA-ARS?s Scientific Manuscript database

    In insect societies, worker versus queen development (reproductive caste) is typically governed by environmental factors, but many Pogonomyrmex seed-harvester ants exhibit strict genetic caste determination, resulting in an obligate mutualism between two reproductively isolated lineages. Same-linea...

  18. 14. Hell Gate Bridge south abutment tower. Queens, Queens Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Hell Gate Bridge south abutment tower. Queens, Queens Co., NY. Sec. 4207, MP 7.29. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  19. The evolution of multiple mating in army ants.

    PubMed

    Kronauer, Daniel J C; Johnson, Robert A; Boomsma, Jacobus J

    2007-02-01

    The evolution of mating systems in eusocial Hymenoptera is constrained because females mate only during a brief period early in life, whereas inseminated queens and their stored sperm may live for decades. Considerable research effort during recent years has firmly established that obligate multiple mating has evolved only a few times: in Apis honeybees, Vespula wasps, Pogonomyrmex harvester ants, Atta and Acromyrmex leaf-cutting ants, the ant Cataglyphis cursor, and in at least some army ants. Here we provide estimates of queen-mating frequency for New World Neivamyrmex and Old World Aenictus species, which, compared to other army ants, have relatively small colonies and little size polymorphism among workers. To provide the first overall comparative analysis of the evolution of army ant mating systems, we combine these new results with previous estimates for African Dorylus and New World Eciton army ants, which have very large colonies and considerable worker polymorphism. We show that queens of Neivamyrmex and Aenictus mate with the same high numbers of males (usually ca. 10-20) as do queens of army ant species with very large colony sizes. We infer that multiple queen mating is ancestral in army ants and has evolved over 100 million years ago as part of the army ant adaptive syndrome. A comparison of army ants and honeybees suggests that mating systems in these two distantly related groups may have been convergently shaped by strikingly similar selective pressures.

  20. Chemical profiles, division of labor and social status in Pachycondyla queens (Hymenoptera: Formicidae)

    NASA Astrophysics Data System (ADS)

    Tentschert, J.; Kolmer, K.; Hölldobler, B.; Bestmann, H.-J.; Delabie, J. H. C.; Heinze, J.

    2001-03-01

    Queens of the neotropical ponerine ant Pachycondyla cf. 'inversa' may co-operate during colony founding. One of several co-founding queens specializes in foraging, whereas the others remain in the nest and guard the brood. Division of labor is achieved by aggressive interactions, which result in the formation of dominance hierarchies. Gas chromatography and mass spectrometry of cuticular hydrocarbons obtained from live queens by SPME revealed consistent differences between the patterns of cuticular hydrocarbons of queens with high versus low rank: only high-ranking queens showed considerable amounts of cuticular pentadecane (n-C15) and heptadecene (n-C17:1). These two substances presumably originate from the queens' Dufour glands.

  1. Reclaiming the crown: queen to worker conflict over reproduction in Aphaenogaster cockerelli

    NASA Astrophysics Data System (ADS)

    Smith, Adrian A.; Hölldobler, Bert; Liebig, Jürgen

    2011-03-01

    In many social taxa, reproductively dominant individuals sometimes use aggression to secure and maintain reproductive status. In the social insects, queen aggression towards subordinate individuals or workers has been documented and is predicted to occur only in species with a small colony size and a low level of queen-worker dimorphism. We report queen aggression towards reproductive workers in the ant species Aphaenogaster cockerelli, a species with a relatively large colony size and a high level of reproductive dimorphism. Through analysis of cuticular hydrocarbon profiles, we show that queens are aggressive only to reproductively active workers. Non-reproductive workers treated with a hydrocarbon typical for reproductives are attacked by workers but not by queens, which suggests different ways of recognition. We provide possible explanations of why queen aggression is observed in this species.

  2. Insecticidal activity of Piper essential oils from the Amazon against the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae).

    PubMed

    Souto, R N P; Harada, A Y; Andrade, E H A; Maia, J G S

    2012-12-01

    Pepper plants in the genus Piper (Piperales: Piperaceae) are common in the Brazilian Amazon and many produce compounds with biological activity against insect pests. We evaluated the insecticidal effect of essential oils from Piper aduncum, Piper marginatum (chemotypes A and B), Piper divaricatum and Piper callosum against workers of the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae), as well as their chemical composition by gas chromatography and gas chromatography-mass spectrometry. The lowest median lethal concentration (LC50) in 48 h was obtained with the oil of P. aduncum (58.4 mg/L), followed by the oils of P. marginatum types A (122.4 mg/L) and B (167.0 mg/L), P. divaricatum (301.7 mg/L), and P. callosum (312.6 mg/L). The major chemical constituents were dillapiole (64.4%) in the oil of P. aduncum; p-mentha-1(7),8-diene (39.0%), 3,4-methylenedioxypropiophenone (19.0%), and (E)-β-ocimene (9.8%) in P. marginatum chemotype A and (E)-isoosmorhizole (32.2%), (E)-anethole (26.4%), isoosmorhizole (11.2%), and (Z)-anethole (6.0%) in P. marginatum chemotype B; methyleugenol (69.2%) and eugenol (16.2%) in P. divaricatum; and safrole (69.2%), methyleugenol (8.6%), and β-pinene (6.2%) in P. callosum. These chemical constituents have been previously known to possess insecticidal properties.

  3. Absence of nepotism in the harassment of duelling queens by honeybee workers.

    PubMed

    Gilley, David C

    2003-10-07

    Nepotism shapes interactions among the members of almost every animal society. However, clear evidence of nepotism within highly cooperative insect societies, such as ant, wasp and honeybee colonies, is rare. Recent empirical findings suggest that nepotism occurs within honeybee colonies where kin-selection theory most strongly predicts its existence: during the lethal queen-queen duels that determine which of several young queens will become the colony's next queen. In this study, I test whether worker bees act nepotistically by hindering duelling queens that are distantly related to themselves. I accomplished this by observing labelled workers harassing duelling queen bees in observation hives and subsequently by determining worker-queen relatedness using DNA microsatellites. I show that the workers that harassed duelling queens were neither more-closely nor more-distantly related to them than were workers selected randomly from the colony. Thus, workers did not behave nepotistically by hindering half-sister queens more than full-sister queens. These results demonstrate that under certain conditions, natural selection limits the evolution of nepotism within animal societies despite strong theoretical predictions for its existence.

  4. Isolation and characterization of Solenopsis invicta virus 3, a new positive-strand RNA virus infecting the red imported fire ant, Solenopsis invicta

    SciTech Connect

    Valles, Steven M.; Hashimoto, Yoshifumi

    2009-06-05

    We report the discovery of a new virus from the red imported fire ant, Solenopsis invicta. Solenopsis invicta virus 3 (SINV-3) represents the third virus discovered from this ant species using the metagenomics approach. The single (positive)-strand RNA, monopartite, bicistronic genome of SINV-3 was sequenced in entirety (GenBank accession number (FJ528584)), comprised of 10,386 nucleotides, and polyadenylated at the 3' terminus. This genome size was confirmed by Northern analysis. The genome revealed 2 large open reading frames (ORFs) in the sense orientation with an untranslated region (UTR) at each end and between the two ORFs. The 5' proximal ORF (ORF 1) encoded a predicted protein of 299.1 kDa (2580 amino acids). The 3' proximal ORF (ORF 2) encoded a predicted protein of 73.2 kDa (651 amino acids). RNA-dependent RNA polymerase (RdRp), helicase, and protease domains were recognized in ORF 1. SDS-PAGE separation of purified SINV-3 particles yielded 2 bands (ostensibly capsid proteins) with a combined molecular mass of 77.3 kDa which was similar to the mass predicted by ORF 2 (73.2 kDa). Phylogenetic analysis of the conserved amino acid sequences containing domains I to VIII of the RdRp from dicistroviruses, iflaviruses, plant small RNA viruses, picornaviruses, and 4 unassigned positive-strand RNA viruses revealed a trichotomous phenogram with SINV-3 and Kelp fly virus comprising a unique cluster. Electron microscopic examination of negatively stained samples of SINV-3 revealed isometric particles with apparent projections and a diameter of 27.3 +- 1.3 nm. SINV-3 was successfully transmitted to uninfected workers by feeding. The minus (replicative) strand of SINV-3 was detected in worker ants indicating replication of the virus. The possibility of using SINV-3 as a microbial control agent for fire ants is discussed.

  5. Goddard Queen Visit

    NASA Image and Video Library

    2007-05-07

    Queen Elizabeth II and Prince Philip, The Duke of Edinburgh look on as Goddard employees demonstrate “Science on a Sphere.” This system, developed by the National Oceanic and Atmospheric Administration (NOAA), uses computers and four video projectors to display animated images on the outside of a 6-foot diameter sphere. Photo Credit: (NASA/Pat Izzo)

  6. Goddard Queen Visit

    NASA Image and Video Library

    2007-05-07

    Queen Elizabeth II and NASA Administrator Michael Griffin plant a commemorative tree on the grounds of the visitor's center during a visit to NASA's Goddard Space Flight Center, Tuesday, May 8, 2007, in Greenbelt, Md. The Royal couple's appearance was one of the last stops on a six-day visit to the United States. Photo Credit (NASA/Debbie McCallum)

  7. Exploitation and interference competition between the invasive Argentine ant, Linepithema humile, and native ant species.

    PubMed

    Human, Kathleen G; Gordon, Deborah M

    1996-02-01

    Interactions between the invasive Argentine ant, Linepithema humile, and native ant species were studied in a 450-ha biological reserve in northern California. Along the edges of the invasion, the presence of Argentine ants significantly reduced the foraging success of native ant species, and vice versa. Argentine ants were consistently better than native ants at exploiting food sources: Argentine ants found and recruited to bait more consistently and in higher numbers than native ant species, and they foraged for longer periods throughout the day. Native ants and Argentine ants frequently fought when they recruited to the same bait, and native ant species were displaced from bait during 60% of these encounters. In introduction experiments, Argentine ants interfered with the foraging of native ant species, and prevented the establishment of new colonies of native ant species by preying upon winged native ant queens. The Argentine ants' range within the preserve expanded by 12 ha between May 1993 and May 1994, and 13 between September 1993 and September 1994, with a corresponding reduction of the range of native ant species. Although some native ants persist locally at the edges of the invasion of Argentine ants, most eventually disappear from invaded areas. Both interference and exploitation competition appear to be important in the displacement of native ant species from areas invaded by Argentine ants.

  8. An Automatic System for Continuously Monitoring Digging Volume of Red Imported Fire Ants (Hymenoptera: Formicidae) in the Laboratory

    USDA-ARS?s Scientific Manuscript database

    In studying the dynamics of ant nest excavation, the nest volume has to be continuously monitored. One common method to estimate nest volume is to weigh the substrate excavated by the ants and then convert the weight into volume. In many laboratory studies, sand has been used as a digging substrat...

  9. Cloning and Expression of Multiple Cytochrome P450 Genes: Induction by Fipronil in Workers of the Red Imported Fire Ant (Solenopsis invicta Buren).

    PubMed

    Zhang, Baizhong; Zhang, Lei; Cui, Rukun; Zeng, Xinnian; Gao, Xiwu

    2016-01-01

    Both exogenous and endogenous compounds can induce the expression of cytochrome P450 genes. The insect cytochrome P450 genes related to insecticide resistance are likely to be expressed as the "first line of defense" when challenged with insecticides. In this study, four cytochrome P450 genes, SinvCYP6B1, SinvCYP6A1, SinvCYP4C1, and SinvCYP4G15, were firstly isolated from workers of the red imported fire ant (Solenopsis invicta) through rapid amplification of cDNA ends (RACE) and sequenced. The fipronil induction profiles of the four cytochrome P450 genes and the two previously isolated CYP4AB1 and CYP4AB2 were characterized in workers. The results revealed that the expression of SinvCYP6B1, SinvCYP6A1, CYP4AB2, and SinvCYP4G15, increased 1.4-fold and 1.3-fold more than those of acetone control, respectively, after 24 h exposure to fipronil at concentrations of 0.25 μg mL-1 (median lethal dose) and 0.56 μg mL-1 (90% lethal dose), while no significant induction of the expression of CYP4AB1 and SinvCYP4C1 was detected. Among these genes, SinvCYP6B1 was the most significantly induced, and its maximum expression was 3.6-fold higher than that in acetone control. These results might suggest that multiple cytochrome P450 genes are co-up-regulated in workers of the fire ant through induction mechanism when challenged with fipronil. These findings indicated that cytochrome P450 genes play an important role in the detoxification of insecticides and provide a theoretical basis for the mechanisms of insecticide metabolism in the fire ant.

  10. Daughters inherit colonies from mothers in the 'living-fossil' ant Nothomyrmecia macrops

    NASA Astrophysics Data System (ADS)

    Sanetra, Matthias; Crozier, Ross H.

    2002-02-01

    Newly mated queens of monogynous (single queen) ants usually found their colonies independently, without the assistance of workers. In polygynous (multiple queen) species queens are often adopted back into their natal nest and new colonies are established by budding. We report that the Australian 'living-fossil' ant, Nothomyrmecia macrops, is exceptional in that its single queen can be replaced by one of the colony's daughters. This type of colony founding is an interesting alternative reproductive strategy in monogynous ants, which maximizes fitness under kin selection. Successive queen replacement results in a series of reproductives over time (serial polygyny), making these colonies potentially immortal. Workers raise nieces and nephews (relatedness ≤ 0.375) the year after queen replacement. Although N. macrops is 'primitive' in many other respects, colony inheritance is likely to be a derived specialization resulting from ecological constraints on solitary founding.

  11. Larval regulation of worker reproduction in the polydomous ant Novomessor cockerelli.

    PubMed

    Ebie, Jessica D; Hölldobler, Bert; Liebig, Jürgen

    2015-12-01

    Although workers in many ant species are capable of producing their own offspring, they generally rear the queen's offspring instead. There are various mechanisms that regulate worker reproduction including inhibitory effects of ant brood. Colonies of the ant Novomessor cockerelli are monogynous and polydomous resulting in a large portion of nest workers being physically isolated from the queen for extended periods of time. Some workers experimentally isolated from the queen in laboratory nests lay viable eggs, which develop into males. We investigate the mechanism that regulates worker fertility in subnests separated from the queen by giving queenless worker groups queen-produced larvae, queen-produced eggs, or no brood. Our findings show that larvae delay the time to worker egg-laying, but eggs have no effect. Larval inhibition is a likely mechanism that contributes to the regulation of worker reproduction in N. cockerellli because larvae are easily transported to subnests that do not contain a queen.

  12. Larval regulation of worker reproduction in the polydomous ant Novomessor cockerelli

    NASA Astrophysics Data System (ADS)

    Ebie, Jessica D.; Hölldobler, Bert; Liebig, Jürgen

    2015-12-01

    Although workers in many ant species are capable of producing their own offspring, they generally rear the queen's offspring instead. There are various mechanisms that regulate worker reproduction including inhibitory effects of ant brood. Colonies of the ant Novomessor cockerelli are monogynous and polydomous resulting in a large portion of nest workers being physically isolated from the queen for extended periods of time. Some workers experimentally isolated from the queen in laboratory nests lay viable eggs, which develop into males. We investigate the mechanism that regulates worker fertility in subnests separated from the queen by giving queenless worker groups queen-produced larvae, queen-produced eggs, or no brood. Our findings show that larvae delay the time to worker egg-laying, but eggs have no effect. Larval inhibition is a likely mechanism that contributes to the regulation of worker reproduction in N. cockerellli because larvae are easily transported to subnests that do not contain a queen.

  13. 'Snow Queen' Animation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This animation consists of two close-up images of 'Snow Queen,' taken several days apart, by the Robotic Arm Camera (RAC) aboard NASA's Phoenix Mars Lander.

    Snow Queen is the informal name for a patch of bright-toned material underneath the lander.

    Thruster exhaust blew away surface soil covering Snow Queen when Phoenix landed on May 25, 2008, exposing this hard layer comprising several smooth rounded cavities beneath the lander. The RAC images show how Snow Queen visibly changed between June 15, 2008, the 21st Martian day, or sol, of the mission and July 9, 2008, the 44th sol.

    Cracks as long as 10 centimeters (about four inches) appeared. One such crack is visible at the left third and the upper third of the Sol 44 image. A seven millimeter (one-third inch) pebble or clod appears just above and slightly to the right of the crack in the Sol 44 image. Cracks also appear in the lower part of the left third of the image. Other pieces noticeably shift, and some smooth texture has subtly roughened.

    The Phoenix team carefully positioned and focused RAC the same way in both images. Each image is about 60 centimeters, or about two feet, wide. The object protruding in from the top on the right half of the images is Phoenix's thermal and electrical conductivity probe.

    Snow Queen and other ice exposed by Phoenix landing and trenching operations on northern polar Mars is the first time scientists have been able to monitor Martian ice at a place where temperatures are cold enough that the ice doesn't immediately sublimate, or vaporize, away.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  14. Fire!

    ERIC Educational Resources Information Center

    Jones, Rebecca

    1996-01-01

    The number of school fires is up nationwide. This article describes unsafe school conditions, problems with new fire codes, and the factors that contribute to school fires. Installation of sprinkler systems is recommended. A fire-safety checklist is included. (LMI)

  15. Fire Ant Bites

    MedlinePlus

    ... Osteopathic Medicine Disease Database Contributors Doctor Derm App Skin Facts Aging and Sun Damage Beauty Myths Preventing Sun Damage Skin Cancer Detection Skin Disease Links Sun Safety Document ...

  16. Tissue, developmental, and caste-specific expression of odorant binding proteins in a eusocial insect, the red imported fire ant, Solenopsis invicta.

    PubMed

    Zhang, Wei; Wanchoo, Arun; Ortiz-Urquiza, Almudena; Xia, Yuxian; Keyhani, Nemat O

    2016-10-21

    Insects interact with the surrounding environment via chemoreception, and in social insects such as ants, chemoreception functions to mediate diverse behaviors including food acquisition, self/non-self recognition, and intraspecific communication. The invasive red imported fire ant, Solenopsis invicta, has spread worldwide, displaying a remarkable environmental adaptability. Odorant binding proteins (OBPs) are chemical compound carriers, involved in diverse physiological processes including odor detection and chemical transport. S. invicta contains a highly divergent 17-member OBP gene family, that includes an ant-specific expansion and the social organization implicated Gp-9 (OBP3) gene. A systematic gene expression analysis of the SiOBP repertoire was performed across social caste (workers, male and female alates), tissues (antennae, head, thorax, and abdomen), and developmental stages (egg, larvae, and pupae), revealing that although SiOBPs were expressed in the antennae, the major regions of expression were in the head and thorax across all castes, and the abdomen in male and female alates. SiOBPs were very highly expressed in female alates and at somewhat lower levels in male alates and workers. SiOBPs were differentially expressed, with unique signatures in various castes and tissues, suggesting functionality of SiOBPs beyond olfaction Expression patterns of SiOBP subgroups also showed relationships with their evolutionary relatedness.

  17. Tissue, developmental, and caste-specific expression of odorant binding proteins in a eusocial insect, the red imported fire ant, Solenopsis invicta

    PubMed Central

    Zhang, Wei; Wanchoo, Arun; Ortiz-Urquiza, Almudena; Xia, Yuxian; Keyhani, Nemat O.

    2016-01-01

    Insects interact with the surrounding environment via chemoreception, and in social insects such as ants, chemoreception functions to mediate diverse behaviors including food acquisition, self/non-self recognition, and intraspecific communication. The invasive red imported fire ant, Solenopsis invicta, has spread worldwide, displaying a remarkable environmental adaptability. Odorant binding proteins (OBPs) are chemical compound carriers, involved in diverse physiological processes including odor detection and chemical transport. S. invicta contains a highly divergent 17-member OBP gene family, that includes an ant-specific expansion and the social organization implicated Gp-9 (OBP3) gene. A systematic gene expression analysis of the SiOBP repertoire was performed across social caste (workers, male and female alates), tissues (antennae, head, thorax, and abdomen), and developmental stages (egg, larvae, and pupae), revealing that although SiOBPs were expressed in the antennae, the major regions of expression were in the head and thorax across all castes, and the abdomen in male and female alates. SiOBPs were very highly expressed in female alates and at somewhat lower levels in male alates and workers. SiOBPs were differentially expressed, with unique signatures in various castes and tissues, suggesting functionality of SiOBPs beyond olfaction Expression patterns of SiOBP subgroups also showed relationships with their evolutionary relatedness. PMID:27765943

  18. Implications of stridulation behavior in the red and black imported fire ants, Solenopsis invicta Buren and Solenopsis richteri Forel, and their hybrid

    NASA Astrophysics Data System (ADS)

    Marquess, Jake

    Stridulation elicits a variety of behavioral responses in the Formicidae: distress, alarm and recruitment of nestmates. The intent of my research is to broaden the understanding of stridulation by investigating the morphology, multiple behaviors in which stridulation has been observed, and the behavioral response to the playback of these stridulatory signals in two closely related species, Solenopsis invicta, S. richteri, and their hybrid. A SEM examination of head width and the stridulatory organs of imported fire ant workers found the number of ridges on the "file" ( pars striden) to be positively correlated with body size. The increase in ridge number in relation to body size suggests that the number of pulses in each pulse train of the stridulation signal should increase as body size increases. Stridulation was not correlated with excavation behavior, but grinding, an incidental sound resulting from soil excavation, is a reliable indicator of excavation behavior. Absence of stridulation upon initial discovery of the food source and low amount of stridulation observed with ten or less ants present at the food source indicates that stridulation does not serve as an initial short range recruitment signal to nearby nestmates. Furthermore, over 90% of the total stridulation observed was recorded with 30 or more ants present at the food source. Finally, the time between calls decreased and the number of stridulations increased as more ants arrived at the food source. Stridulation in dyadic encounters between ants occurs almost exclusively during non-nestmate conspecitic interactions. Restrained ants or "defenders" accounted for 92.9% of the total stridulation observed compared to just 3.4% for "attackers." Restraint between the head and thorax or "neck" evoked the highest level of stridulation in majors. Stridulation during non-nestmate interactions is size specific, as trials involving majors had nearly twice as much stridulation (88.3%), than trials with mediums

  19. 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.

  20. Fire

    Treesearch

    John R. Jones; Norbert V. DeByle

    1985-01-01

    In some areas, many aspen stands are all the same age, dating from a single great fire or a year of widespread fires (fig. 1). The 1879 fire in the Jackson Hole region of Wyoming (Loope and Gruell 1973) and the 1904 fires in Arizona's White Mountains (Kallander 1969) are examples. Choate (1966) found that almost all aspen stands in New Mexico were even-aged, many...

  1. FIRE

    Atmospheric Science Data Center

    2017-03-16

    Projects:  FIRE Definition/Description:  The F irst I SCCP R egional E xperiments (FIRE) have been designed to improve data products and cloud/radiation ... circulation models (GCMs). Specifically, the goals of FIRE are (1) to improve basic understanding of the interaction of physical ...

  2. Intragenomic conflict over queen determination favours genomic imprinting in eusocial Hymenoptera

    PubMed Central

    Dobata, Shigeto; Tsuji, Kazuki

    2012-01-01

    Colonies of eusocial Hymenoptera, such as ants, bees and wasps, have long been recognized as candidates for the study of genomic imprinting on the grounds of evolutionary conflicts that arise from close interactions among colony members and relatedness asymmetry owing to haplodiploidy. Although a general kinship theory of genomic imprinting predicts its occurrence under various circumstances of the colony life cycle, new theoretical approaches are required to account for the specifics of real colonies based on recent advances in molecular-level understanding of ants and honeybees. Using a multivariate quantitative genetic model, we examined the potential impact of genomic imprinting on genes that determine the carrier female's propensity to develop into the queen caste. When queen overproduction owing to the increased propensity comes at a colony-level cost, the conflict between maternally and paternally inherited genes in polyandrous (queen multiple mating) colonies favours genomic imprinting. Moreover, we show that the genomic imprinting can occur even under monandry (queen single mating), once incorporating the costs differentially experienced by new males and new queens. Our model predicts the existence of imprinted ‘genetic royal cheats’ with patriline-specific expression in polyandrous colonies, and seems consistent with the paternal effect on queen determination in monandrous Argentine ants. PMID:22378809

  3. Intragenomic conflict over queen determination favours genomic imprinting in eusocial Hymenoptera.

    PubMed

    Dobata, Shigeto; Tsuji, Kazuki

    2012-07-07

    Colonies of eusocial Hymenoptera, such as ants, bees and wasps, have long been recognized as candidates for the study of genomic imprinting on the grounds of evolutionary conflicts that arise from close interactions among colony members and relatedness asymmetry owing to haplodiploidy. Although a general kinship theory of genomic imprinting predicts its occurrence under various circumstances of the colony life cycle, new theoretical approaches are required to account for the specifics of real colonies based on recent advances in molecular-level understanding of ants and honeybees. Using a multivariate quantitative genetic model, we examined the potential impact of genomic imprinting on genes that determine the carrier female's propensity to develop into the queen caste. When queen overproduction owing to the increased propensity comes at a colony-level cost, the conflict between maternally and paternally inherited genes in polyandrous (queen multiple mating) colonies favours genomic imprinting. Moreover, we show that the genomic imprinting can occur even under monandry (queen single mating), once incorporating the costs differentially experienced by new males and new queens. Our model predicts the existence of imprinted 'genetic royal cheats' with patriline-specific expression in polyandrous colonies, and seems consistent with the paternal effect on queen determination in monandrous Argentine ants.

  4. 12. New York Connecting RR: Hell Gate Bridge. Queens, Queens ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. New York Connecting RR: Hell Gate Bridge. Queens, Queens Co., NY. Sec. 4207, MP 7.29. (See HAER No. NY-88 for further documentation on this site). - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  5. 11. New York Connecting RR: Hell Gate Bridge. Queens, Queens ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. New York Connecting RR: Hell Gate Bridge. Queens, Queens Co., NY. Sec. 4207, MP 7.29. (See HAER No. NY-88 for further documentation on this site). - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  6. 13. New York Connecting RR: Hell Gate Bridge. Queens, Queens ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. New York Connecting RR: Hell Gate Bridge. Queens, Queens Co., NY. Sec. 4207, MP 7.29. (See HAER No. NY-88 for further documentation on this site). - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  7. Effect of gland extracts on digging and residing preferences of red imported fire ant workers (Hymenoptera: formicidae)

    USDA-ARS?s Scientific Manuscript database

    There was evidence that ant-derived chemical stimuli were involved in regulating the digging behavior in Solenopsis invicta Buren. Unfortunately however, the source gland(s) and chemistry of such stimuli have never been revealed. In this study, extracts of mandibular, Dufour, postpharyngeal and po...

  8. Loss of microbial (pathogen) infections associated with recent invasions of the red imported fire ant Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    Loss of natural enemies during colonization is a prominent hypothesis explaining enhanced performance of invasive species in introduced areas. Numerous studies have tested this enemy release hypothesis in a wide range of taxa but few studies have focused on invasive ants. We conducted extensive surv...

  9. Effects of piperidine and piperideine alkaloids from the venom of red imported fire ants, Solenopsis invicta Buren, on Pythium ultimum Trow growth in vitro and the application of piperideine alkaloids to control cucumber..

    USDA-ARS?s Scientific Manuscript database

    Pythium ultimum Trow is a plant pathogen that causes significant yield losses on many economically important crops. Chemical seed treatment has been used for disease control. In searching for alternatives, the venom alkaloids from red imported fire ant were tested against P. ultimum in vitro and to ...

  10. "Sculpture of a Benin Queen."

    ERIC Educational Resources Information Center

    Guip, David

    1987-01-01

    Offers an art lesson for grades K-3 based on an early 19th century sculpture of the head of a Benin Queen. Presents background on the relevance of Queen Mother's position in Benin culture. Discusses importance of regalia and scarification associated with Benin heads. Includes suggestions for classroom activities. (BR)

  11. Phorid flies, Pseudacteon spp. (Diptera: Phoridae), affect forager size ratios of red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae) in Texas.

    PubMed

    Puckett, R T; Harris, M K

    2010-10-01

    Multiple species of Pseudacteon phorid flies (Diptera: Phoridae) are currently being released throughout the southern United States to aid biological control of red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae). It is anticipated that these flies will interfere with S. invicta foraging, allowing native ant assemblages to outcompete S. invicta for available resources. Numerous studies have shown a decrease in S. invicta foraging intensity when exposed to phorids. This study documents a behavioral change in phorid-exposed S. invicta colonies at a phorid release site in central Texas. Significant differences in forager size ratios were detected between phorid-exposed and phorid-absent colonies. A similar phenomenon was recently documented in the native range of these insects in South America as well. Experimental manipulation of ratios of S. invicta worker sizes has been shown to have important effects on colony success. This newly documented phorid-mediated S. invicta colony-level effect represents a significant shift in S. invicta foraging dynamics and may provide an additional mechanism by which phorids can influence S. invicta populations in their United States range.

  12. Prevalence and impact of the microsporidium Thelohania solenopsae (Microsporidia) on wild populations of red imported fire ants, Solenopsis invicta, in Louisiana.

    PubMed

    Milks, Maynard L; Fuxa, James R; Richter, Arthur R

    2008-02-01

    We surveyed 165 sites to determine the ecological factors that might influence the distribution and prevalence of Thelohania solenopsae, and its effect on the demography of the red imported fire ant (Solenopsis invicta) in Louisiana. The microsporidium was found in 9.9% of colonies and at 16% of sites. Its distribution was clumped within the state with the majority of infected colonies and sites occurring in two infection patches. The proportion of polygyne colonies was a strong (positive) predictor of the proportion of infected colonies at a site. Infected monogyne colonies, however, still accounted for nearly 20% of infected colonies, a much higher proportion than anticipated. Several other factors, including the numbers of colonies at a site, precipitation, proximity to commercial waterways and ports, and type of habitat were also retained in the multiple logistic regression model describing T. solenopsae prevalence. The microsporidium appears to adversely affect the occurrence of brood, and possibly the size of S. invicta colonies and the mass of workers. It, however, was not included in the multiple regression model of the number of colonies or the density of ants at a site. Although our findings do not imply causation, they have identified several variables that might influence the epizootiology of T. solenopsae. Future work should concentrate on experimentally manipulating these variables to confirm these relationships.

  13. Social coercion of larval development in an ant species

    NASA Astrophysics Data System (ADS)

    Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

    2016-04-01

    Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

  14. AN UNUSUAL PATTERN OF GENE FLOW BETWEEN THE TWO SOCIAL FORMS OF THE FIRE ANT SOLENOPSIS INVICTA.

    PubMed

    Ross, Kenneth G; Shoemaker, D DeWayne

    1993-10-01

    Uncertainty over the role of shifts in social behavior in the process of speciation in social insects has stimulated interest in determining the extent of gene flow between conspecific populations differing in colony social organization. Allele and genotype frequencies at 12 neutral polymorphic protein markers, as well as the numbers of alleles at the sex-determining locus (loci), are shown here to be consistent with significant ongoing gene flow between two geographically adjacent populations of Solenopsis invicta that differ in colony queen number. Data from a thirteenth protein marker that is under strong differential selection in the two social forms confirm that such gene flow occurs. Data from this selected locus, combined with knowledge of the reproductive biology of the two social forms, further suggest that interform gene flow is largely unidirectional and mediated through males only. This unusual pattern of gene flow results from the influence of the unique social enviroments of the two forms on the behavior of workers and on the reproductive physiology of sexuals. © 1993 The Society for the Study of Evolution.

  15. New species and records of Pseudacteon Coquillett, 1907 (Diptera, Phoridae), parasitoids of the fire ant Solenopsis geminata group (Hymenoptera, Formicidae).

    PubMed

    Pereira, Thalles Platiny Lavinscky; Delabie, Jacques Hubert Charles; Bravo, Freddy

    2015-09-29

    The genus Pseudacteon Coquillett (Diptera, Phoridae) has a worldwide distribution and comprises parasitic myrmecophilous species that decapitate host ants. Seventy one species are known in the genus, 41 of them occur in the Neotropical Region and are 25 from Brazil. In northeastern Brazil, there are only records for two species, Pseudacteon dentiger Borgmeier and Pseudacteon antiguensis Malloch. In this paper, two new species of the genus are described from female specimens, Pseudacteon pesqueroi new spec. and Pseudacteon plowesi new spec., and also, new records of three Pseudacteon species for the Brazilian Northeast are given.

  16. Thelytokous parthenogenesis and its consequences on inbreeding in an ant.

    PubMed

    Pearcy, M; Hardy, O; Aron, S

    2006-05-01

    Thelytokous parthenogenesis, that is, the production of diploid daughters from unfertilized eggs, may involve various cytological mechanisms, each having a different impact on the genetic structure of populations. Here, we determined the cytological mechanism of thelytokous parthenogenesis and its impact on inbreeding in the ant Cataglyphis cursor, a species where queens use both sexual and asexual reproduction to produce, respectively, workers and new queens. It has been suggested that thelytokous parthenogenesis in C. cursor might have been selected for to face high queen mortality and, originally, to allow workers to replace the queen when she passes away. We first determined the mode of thelytokous parthenogenesis by comparing the rate of transition to homozygosity at four highly polymorphic loci to expectations under the different modes of parthenogenesis. Our data show that thelytoky is achieved through automictic parthenogenesis with central fusion. We then estimated the proportion of colonies headed by worker-produced queens in a natural population. We designed a model linking the observed homozygosity in queens to the proportion of queens produced by workers, based on the assumption that (i) parthenogenesis is automictic with central fusion and (ii) queen lineage is asexually produced, resulting in an increase of the inbreeding over generations, whereas workers are sexually produced and therefore not inbred. Our results indicate that more than 60% of the colonies should be headed by a worker-produced queen, suggesting that queen's lifespan is low in this species.

  17. Gigantism in honeybees: Apis cerana queens reared in mixed-species colonies

    NASA Astrophysics Data System (ADS)

    Tan, Ken; Hepburn, H. R.; He, Shaoyu; Radloff, S. E.; Neumann, P.; Fang, Xiang

    2006-07-01

    The development of animals depends on both genetic and environmental effects to a varying extent. Their relative influences can be evaluated in the social insects by raising the intracolonial diversity to an extreme in nests consisting of workers from more than one species. In this study, we studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the rearing of grafted queen larvae of A. cerana. A. mellifera sealed worker brood was introduced into A. cerana colonies and on emergence, the adults were accepted. Then, A. cerana larvae were grafted for queen rearing into two of these mixed-species colonies. Similarly, A. cerana larvae and A. mellifera larvae were also grafted conspecifically as controls. The success rate of A. cerana queen rearing in the test colonies was 64.5%, surpassing all previous attempts at interspecific queen rearing. After emergence, all virgin queens obtained from the three groups ( N=90) were measured morphometrically. The A. cerana queens from the mixed-species colonies differed significantly in size and pigmentation from the A. cerana control queens and closely approximated the A. mellifera queens. It is inferred that these changes in the A. cerana queens reared in the mixed-species colonies can be attributed to feeding by heterospecific nurse bees and/or chemical differences in royal jelly. Our data show a strong impact of environment on the development of queens. The results further suggest that in honeybees the cues for brood recognition can be learned by heterospecific workers after eclosion, thereby providing a novel analogy to slave making in ants.

  18. Ant allergens and hypersensitivity reactions in response to ant stings.

    PubMed

    Potiwat, Rutcharin; Sitcharungsi, Raweerat

    2015-12-01

    Hypersensitivity reactions caused by ant stings are increasingly recognized as an important cause of death by anaphylaxis. Only some species of ants ( e.g. Solenopsis spp., Myrmecia spp., and Pachycondyla spp.) cause allergic reactions. Ant species are identified by evaluating the morphologic structures of worker ants or by molecular techniques. Ant venom contains substances, including acids and alkaloids, that cause toxic reactions, and those from Solenopsis invicta or the imported fire ant have been widely studied. Piperidine alkaloids and low protein contents can cause local reactions (sterile pustules) and systemic reactions (anaphylaxis). Imported fire ant venoms are cross-reactive; for example, the Sol i 1 allergen from S. invicta has cross-reactivity with yellow jacket phospholipase. The Sol i 3 allergen is a member of the antigen 5 family that has amino acid sequence identity with vespid antigen 5. The clinical presentations of ant hypersensitivity are categorized into immediate and delayed reactions: immediate reactions, such as small local reactions, large local reactions, and systemic reactions, occur within 1-4 hours after the ant stings, whereas delayed reactions, such as serum sickness and vasculitis, usually occur more than 4 hours after the stings. Tools for the diagnosis of ant hypersensitivity are skin testing, serum specific IgE, and sting challenge tests. Management of ant hypersensitivity can be divided into immediate (epinephrine, corticosteroids), symptomatic (antihistamines, bronchodilators), supportive (fluid resuscitation, oxygen therapy), and preventive (re-sting avoidance and immunotherapy) treatments.

  19. Postmating changes in cuticular chemistry and visual appearance in Ectatomma tuberculatum queens (Formicidae: Ectatomminae)

    NASA Astrophysics Data System (ADS)

    Hora, Riviane R.; Ionescu-Hirsh, Armin; Simon, Tovit; Delabie, Jacques; Robert, Jacques; Fresneau, Dominique; Hefetz, Abraham

    2008-01-01

    In the ectatommine ant Ectatomma tuberculatum, the visual appearance of queens changes after mating and ovarian development in that their cuticle turns from shiny to matte. In this study, we have shown that this change seems to be caused by 15-fold accumulation of hydrocarbons, in particular heptacosane that covers the multiple grooves present on the cuticular surface creating a wax coat in mated fully fertile queens. Analyses of the scrapped wax revealed that it is composed largely of heptacosane. Peak-by-peak comparison of the cuticular hydrocarbon (CHC) composition of mated, virgin with developed ovaries and virgin with nondeveloped ovaries revealed significant differences between the queen groups. Although the total amount of the CHC of virgin queens with developed ovaries was not higher than virgin queens that did not have developed ovaries, the composition showed a shift toward the mated queen. While it is possible that the large accumulation of hydrocarbons may give extra physical and chemical protection to queens, we propose that the switch in the relative abundance of heptacosane and nonacosane and perhaps of other components is indicative of being a mating and fertility cue. This is the first report in social insects where external chemical changes are accompanied by changes in visual appearance.

  20. The effect of diet and opponent size on aggressive interactions involving caribbean crazy ants (Nylanderia fulva).

    PubMed

    Horn, Katherine C; Eubanks, Micky D; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants.

  1. The Effect of Diet and Opponent Size on Aggressive Interactions Involving Caribbean Crazy Ants (Nylanderia fulva)

    PubMed Central

    Horn, Katherine C.; Eubanks, Micky D.; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants. PMID:23776702

  2. Honey Ants.

    ERIC Educational Resources Information Center

    Conway, John R.

    1984-01-01

    Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

  3. Honey Ants.

    ERIC Educational Resources Information Center

    Conway, John R.

    1984-01-01

    Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

  4. Queen reproductive state modulates pheromone production and queen-worker interactions in honeybees

    PubMed Central

    Kocher, Sarah D.; Richard, Freddie-Jeanne; Tarpy, David R.

    2009-01-01

    The mandibular glands of queen honeybees produce a pheromone that modulates many aspects of worker honeybee physiology and behavior and is critical for colony social organization. The exact chemical blend produced by the queen differs between virgin and mated, laying queens. Here, we investigate the role of mating and reproductive state on queen pheromone production and worker responses. Virgin queens, naturally mated queens, and queens instrumentally inseminated with either semen or saline were collected 2 days after mating or insemination. Naturally mated queens had the most activated ovaries and the most distinct chemical profile in their mandibular glands. Instrumentally inseminated queens were intermediate between virgins and naturally mated queens for both ovary activation and chemical profiles. There were no significant differences between semen- and saline-inseminated queens. Workers were preferentially attracted to the mandibular gland extracts from queens with significantly more activated ovaries. These studies suggest that the queen pheromone blend is modulated by the reproductive status of the queens, and workers can detect these subtle differences and are more responsive to queens with higher reproductive potential. Furthermore, it appears as if insemination substance does not strongly affect physiological characteristics of honeybee queens 2 days after insemination, suggesting that the insemination process or volume is responsible for stimulating these early postmating changes in honeybee queens. PMID:22476212

  5. Fire

    Treesearch

    John A. Stanturf; Scott L. Goodrick

    2013-01-01

    Key FindingsClimate forecasts indicate that the South’s spring and fall wildfire seasons will be extended.Prescribed fires, currently conducted on roughly a 3 to 5 year rotation across much of the South, would need to become more frequent if conditions become drier.Major wildfire events, such as the 2007...

  6. Insecticidal, fumigant, and repellent activities of sweet wormwood oil and its individual components against red imported fire ant workers (Hymenoptera: Formicidae).

    PubMed

    Zhang, Ning; Tang, Liang; Hu, Wei; Wang, Kun; Zhou, You; Li, Hong; Huang, Congling; Chun, Jiong; Zhang, Zhixiang

    2014-01-01

    In total, 29 compounds from sweet wormwood (Artemisia annua L.) oil were identified using gas chromatography-mass spectrometry. The five active components were D-camphor, linalool, cineole, α-terpineol, and L(-)-borneol. The effectiveness of A. annua oil, as well as d-camphor, linalool, cineole, α-terpineol, and L(-)-borneol, as fumigants, contact insecticides, and repellents, were tested on the red imported fire ant Solenopsis invicta Buren. The results indicated that A. annua oil has no significant topical toxicity; however, the spray contact test revealed that it has strong insecticidal activity and the inhibitory effect is stronger during closed exposure than during open exposure. In the fumigant test, cineole and D-camphor exhibited strong fumigant toxicity on minor and major S. invicta workers. They also caused 100% mortality at 5, 3, 2, and 1 mg/centrifuge tube but not at 0.5 mg/centrifuge tube. The mortality rates of linalool, α-terpineol, and L(-)-borneol exceeded 80% at 5, 3, and 2 mg/centrifuge tube. In the repellent test, cineole and d-camphor showed significant repellency at 100, 10, and 1 mg/kg. However, linalool, α-terpineol, and L(-)-borneol significantly facilitated digging at 10 and 1 mg/kg.

  7. Monoculture of Leafcutter Ant Gardens

    PubMed Central

    Mueller, Ulrich G.; Scott, Jarrod J.; Ishak, Heather D.; Cooper, Michael; Rodrigues, Andre

    2010-01-01

    Background Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. Methodology/Principal Findings Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens) and extended lifespans (10–20 years). In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells), and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. Conclusions/Significance Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants), an analog of artificial selection. PMID:20844760

  8. Reflections on the "N" + "k" Queens Problem

    ERIC Educational Resources Information Center

    Chatham, Doug

    2009-01-01

    The "N" queens problem is a classic puzzle. It asks for an arrangement of "N" mutually non-attacking queens on an "N" x "N" chessboard. We discuss a recent variation called the "N" + "k" queens problem, where pawns are added to the chessboard to allow a greater number of non-attacking queens to be placed on it. We describe some of what is known…

  9. Acute exposure to low dose radiation disrupts reproduction and shortens survival of Wasmannia auropunctata (Hymenoptera Formicidae)queens

    USDA-ARS?s Scientific Manuscript database

    Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products exported from Hawaii. The radiotolerance of the invasive little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae: Myrmicinae), was studied to determine...

  10. Glandular Epithelium as a Possible Source of a Fertility Signal in Ectatomma tuberculatum (Hymenoptera: Formicidae) Queens

    PubMed Central

    da Hora, Riviane Rodigues; Delabie, Jacques Hubert Charles; dos Santos, Carolina Gonçalves; Serrão, José Eduardo

    2010-01-01

    The wax layer covering the insect's cuticle plays an important protective role, as for example, uncontrolled water loss. In social insects, wax production is well-known in some bees that use it for nest building. Curiously, mated-fertile queens of the ant Ectatomma tuberculatum produce an uncommon extra-wax coat and, consequently queens (mated-fertile females) are matte due to such extra cuticular hydrocarbon (CHC) coat that covers the cuticle and masks the brightness of the queens' cuticle while gynes (virgin-infertile queens) are shiny. In this study, histological analysis showed differences in the epidermis between fertile (i.e., queens or gynes with highly ovarian activity) and infertile females (gynes or workers with non developed ovaries). In fertile females the epidermis is a single layer of cubic cells found in all body segments whereas in infertile females it is a thin layer of flattened cells. Ultrastructural features showed active secretory tissue from fertile females similar to the glandular epithelium of wax-producing bees (type I gland). Different hypotheses related to the functions of the glandular epithelium exclusive to the E. tuberculatum fertile queens are discussed. PMID:20419093

  11. Glandular epithelium as a possible source of a fertility signal in Ectatomma tuberculatum (Hymenoptera: Formicidae) queens.

    PubMed

    da Hora, Riviane Rodigues; Delabie, Jacques Hubert Charles; dos Santos, Carolina Gonçalves; Serrão, José Eduardo

    2010-04-19

    The wax layer covering the insect's cuticle plays an important protective role, as for example, uncontrolled water loss. In social insects, wax production is well-known in some bees that use it for nest building. Curiously, mated-fertile queens of the ant Ectatomma tuberculatum produce an uncommon extra-wax coat and, consequently queens (mated-fertile females) are matte due to such extra cuticular hydrocarbon (CHC) coat that covers the cuticle and masks the brightness of the queens' cuticle while gynes (virgin-infertile queens) are shiny. In this study, histological analysis showed differences in the epidermis between fertile (i.e., queens or gynes with highly ovarian activity) and infertile females (gynes or workers with non developed ovaries). In fertile females the epidermis is a single layer of cubic cells found in all body segments whereas in infertile females it is a thin layer of flattened cells. Ultrastructural features showed active secretory tissue from fertile females similar to the glandular epithelium of wax-producing bees (type I gland). Different hypotheses related to the functions of the glandular epithelium exclusive to the E. tuberculatum fertile queens are discussed.

  12. 'Queen of Hearts' Oakleaf Hydrangea

    USDA-ARS?s Scientific Manuscript database

    A late-blooming oakleaf hydrangea (Hydrangea quercifolia) cultivar was released by the U.S. National Arboretum. ‘Queen of Hearts’ has grown 6.5 feet high and 11 feet wide in 11 years. In early summer, it is covered with 11-inch-long inflorescences that are held upright above the foliage. Flowers ...

  13. Neonicotinoid pesticides severely affect honey bee queens

    PubMed Central

    Williams, Geoffrey R.; Troxler, Aline; Retschnig, Gina; Roth, Kaspar; Yañez, Orlando; Shutler, Dave; Neumann, Peter; Gauthier, Laurent

    2015-01-01

    Queen health is crucial to colony survival of social bees. Recently, queen failure has been proposed to be a major driver of managed honey bee colony losses, yet few data exist concerning effects of environmental stressors on queens. Here we demonstrate for the first time that exposure to field-realistic concentrations of neonicotinoid pesticides during development can severely affect queens of western honey bees (Apis mellifera). In pesticide-exposed queens, reproductive anatomy (ovaries) and physiology (spermathecal-stored sperm quality and quantity), rather than flight behaviour, were compromised and likely corresponded to reduced queen success (alive and producing worker offspring). This study highlights the detriments of neonicotinoids to queens of environmentally and economically important social bees, and further strengthens the need for stringent risk assessments to safeguard biodiversity and ecosystem services that are vulnerable to these substances. PMID:26459072

  14. Neonicotinoid pesticides severely affect honey bee queens.

    PubMed

    Williams, Geoffrey R; Troxler, Aline; Retschnig, Gina; Roth, Kaspar; Yañez, Orlando; Shutler, Dave; Neumann, Peter; Gauthier, Laurent

    2015-10-13

    Queen health is crucial to colony survival of social bees. Recently, queen failure has been proposed to be a major driver of managed honey bee colony losses, yet few data exist concerning effects of environmental stressors on queens. Here we demonstrate for the first time that exposure to field-realistic concentrations of neonicotinoid pesticides during development can severely affect queens of western honey bees (Apis mellifera). In pesticide-exposed queens, reproductive anatomy (ovaries) and physiology (spermathecal-stored sperm quality and quantity), rather than flight behaviour, were compromised and likely corresponded to reduced queen success (alive and producing worker offspring). This study highlights the detriments of neonicotinoids to queens of environmentally and economically important social bees, and further strengthens the need for stringent risk assessments to safeguard biodiversity and ecosystem services that are vulnerable to these substances.

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

    PubMed

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

    2016-03-29

    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.

  16. Clocks for sex: loss of circadian rhythms in ants after mating?

    NASA Astrophysics Data System (ADS)

    Sharma, Vijay Kumar; Lone, Shahnaz Rahman; Goel, Anubhuthi

    This paper describes experiments on the locomotor activity rhythm of queens of the ant species Camponotus compressus, which were performed to investigate the consequences of mating on circadian clocks. Locomotor activity rhythm of virgin and mated queens was monitored individually under constant conditions of the laboratory. The locomotor activity rhythm of virgin queens entrained to a 24 h (12:12 h) laboratory light/dark (LD) cycle and free-ran under constant dim red light (RR) with a free-running period (τ) of approximately 24 h. The locomotor activity of the mated queens on the other hand was arrhythmic during the period when they were laying eggs, and robust rhythmicity appeared soon after the egg-laying phase was over. The τ of the locomotor activity rhythm of mated queens was significantly greater than that of virgin queens. These results are contrary to the commonly held belief that the role of circadian clocks in ant queens ceases after mating flights, thus suggesting that circadian clocks of ant queens are adaptively plastic and display activity patterns, perhaps depending on their physiological state and tasks in the colony.

  17. Dispersal behavior of yellowjacket (Vespula germanica) queens.

    PubMed

    Masciocchi, Maité; Martinez, Andrés S; Pereira, Ana J; Villacide, José M; Corley, Juan C

    2016-06-30

    Understanding the factors that affect animal dispersal behavior is important from both fundamental and applied perspectives. Dispersal can have clear evolutionary and ecological consequences, but for nonnative insect pests, dispersal capacity can also help to explain invasion success. Vespula germanica is a social wasp that, in the last century, has successfully invaded several regions of the world, showing one of the highest spread rates reported for a nonnative insect. In contrast with nonsocial wasps, in social species, queens are responsible for population redistribution and spread, as workers are sterile. For V. germanica, it has been observed that queen flight is limited to 2 distinct periods: early autumn, when new queens leave the nest to mate and find sheltered places in which to hibernate, and spring when new colonies are founded. Our aim was to study the flight behavior of V. germanica queens by focusing on the different periods in which dispersal occurs, characterizing as well the potential contribution of queen flight (i.e., distance) to the observed geographical spread. Our results suggest that the distances flown by nonoverwintered queens is greater than that flown by overwintered individuals, suggesting that the main queen dispersal events would occur before queens enter hibernation. This could relate to a behavioral trait of the queens to avoid the inbreeding with related drones. Additionally, given the short distances flown and remarkable geographical spread observed, we provide evidence showing that queen dispersal by flight is likely to contribute proportionately less to population spread than human-aided factors.

  18. The red imported fire ant (Solenopsis invicta) in the West Indies: distribution of natural enemies and a possible test bed for release of self-sustaining biocontrol agents

    USDA-ARS?s Scientific Manuscript database

    Sample collections of Solenopsis invicta (Hymenoptera: Formicidae) were taken from 20 islands of the West Indies and evaluated for the presence of key pathogens and parasites of this invasive pest ant. We hypothesized that bottleneck events during the introduction of this ant species in the West In...

  19. Behavioural development, fat reserves and their association with productivity in Lasius flavus founding queens

    NASA Astrophysics Data System (ADS)

    Norman, V. C.; Pamminger, T.; Hughes, W. O. H.

    2016-04-01

    Reproduction-related behaviours are key components determining individual fitness. Many behavioural traits are linked, and such trait associations often affect fitness. Here, we combine behavioural and physiological data during two critical time points of founding queens (early and late nest-founding stage) in the claustral ant Lasius flavus to assess how these factors affect their initial productivity. We show that most behavioural traits, except brood care behaviour, are plastic during queen development and demonstrate that there are alternative behavioural pathways to achieve high productivity under standardised conditions. These results indicate that queens can utilise multiple behavioural trait combinations to maximise reproductive output at the earliest, and arguably most critical, time of colony foundation.

  20. The origin and evolution of queen and fertility signals in Corbiculate bees.

    PubMed

    Caliari Oliveira, Ricardo; Oi, Cintia Akemi; do Nascimento, Mauricio Meirelles Castro; Vollet-Neto, Ayrton; Alves, Denise Araujo; Campos, Maria Claudia; Nascimento, Fabio; Wenseleers, Tom

    2015-11-16

    In social Hymenoptera (ants, bees and wasps), various chemical compounds present on the cuticle have been shown to act as fertility signals. In addition, specific queen-characteristic hydrocarbons have been implicated as sterility-inducing queen signals in ants, wasps and bumblebees. In Corbiculate bees, however, the chemical nature of queen-characteristic and fertility-linked compounds appears to be more diverse than in ants and wasps. Moreover, it remains unknown how queen signals evolved across this group and how they might have been co-opted from fertility signals in solitary ancestors. Here, we perform a phylogenetic analysis of fertility-linked compounds across 16 species of solitary and eusocial bee species, comprising both literature data as well as new primary data from a key solitary outgroup species, the oil-collecting bee Centris analis, and the highly eusocial stingless bee Scaptotrigona depilis. Our results demonstrate the presence of fertility-linked compounds belonging to 12 different chemical classes. In addition, we find that some classes of compounds (linear and branched alkanes, alkenes, esters and fatty acids) were already present as fertility-linked signals in the solitary ancestors of Corbiculate bees, while others appear to be specific to certain species. Overall, our results suggest that queen signals in Corbiculate bees are likely derived from ancestral fertility-linked compounds present in solitary bees that lacked reproductive castes. These original fertility-linked cues or signals could have been produced either as a by-product of ovarian activation or could have served other communicative purposes, such as in mate recognition or the regulation of egg-laying.

  1. Thelytokous Parthenogenesis in the Ant Myrmecina nipponica (Hymenoptera: Formicidae).

    PubMed

    Masuko, Keiichi

    2014-09-01

    Myrmecina nipponica Wheeler is a terrestrial ant nesting chiefly in the soil in forest. It is a specialized predator of oribatid mites, but also scavenges on a broad spectrum of other arthropods. In the studied population at Cape Manazuru in central Japan, M. nipponica colonies are typically monogynous, and previous dissections of queens suggested that these individuals were not inseminated, thus suggesting these ants can reproduce via thelytokous parthenogenesis. To test for thelytokous parthenogenesis in M. nipponica the spermathecae of queens (dealate gynes) from worker-containing colonies were histologically examined in detail. All specimens examined (n=5) had no spermatozoa in the spermatheca. In addition, a total of four colony-founding queens were reared in isolation in the laboratory to test whether non-inseminated females were capable of egg laying and to test whether female offspring emerged from this brood. In all of four culture replicates, only new workers were produced from the eggs those queens had laid and male offspring was absent. After the breeding experiment, the queens' spermathecae were histologically examined and no sperm were detected in their spermathecae. These results reveal that M. nipponica queens of the Manazuru population are capable of producing female offspring thelytokously. Sexual reproduction by typical gynes and also by intermorphs has been known from other local populations of M. nipponica; therefore, this species shows geographical polymorphism in sexuality.

  2. Hybridogenesis through thelytokous parthenogenesis in two Cataglyphis desert ants.

    PubMed

    Eyer, P A; Leniaud, L; Darras, H; Aron, S

    2013-02-01

    Hybridogenesis is a sexual reproductive system, whereby parents from different genetic origin hybridize. Both the maternal and paternal genomes are expressed in somatic tissues, but the paternal genome is systematically excluded from the germ line, which is therefore purely maternal. Recently, a unique case of hybridogenesis at a social level was reported in the desert ant Cataglyphis hispanica. All workers are sexually produced hybridogens, whereas sexual forms (new queens and males) are produced by queens through parthenogenesis. Thus, only maternal genes are perpetuated across generations. Here, we show that such an unusual reproductive strategy also evolved in two other species of Cataglyphis belonging to the same phylogenetic group, Cataglyphis velox and Cataglyphis mauritanica. In both species, queens mate exclusively with males originating from a different genetic lineage than their own to produce hybrid workers, while they use parthenogenesis to produce the male and female reproductive castes. In contrast to single-queen colonies of C. hispanica, colonies of C. velox and C. mauritanica are headed by several queens. Most queens within colonies share the same multilocus genotype and never transmit their mates' alleles to the reproductive castes. Social hybridogenesis in the desert ants has direct consequences on the genetic variability of populations and on caste determination. We also discuss the maintenance of this reproductive strategy within the genus Cataglyphis.

  3. Recognition in Ants: Social Origin Matters

    PubMed Central

    Meunier, Joël; Delémont, Olivier; Lucas, Christophe

    2011-01-01

    The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens) is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has an effect on their acceptance in conspecific colonies remains poorly explored. Using egg-acceptance bioassays, we tested the influence of social origin of queen-laid eggs on their acceptance by foreign workers in the ant Formica selysi. We showed that workers from both single- and multiple-queen colonies discriminated against foreign eggs from single-queen colonies, whereas they surprisingly accepted foreign eggs from multiple-queen colonies. Chemical analyses then demonstrated that social origins of eggs and workers could be discriminated on the basis of their chemical profiles, a signal generally involved in nestmate discrimination. These findings provide the first evidence in social insects that social origins of eggs interfere with nestmate discrimination and are encoded by chemical signatures. PMID:21573235

  4. Influences of pyriproxyfen on fecundity and reproduction of the Pharaoh ant (Hymenoptera: Formicidae).

    PubMed

    Tay, Jia-Wei; Lee, Chow-Yang

    2014-06-01

    The effects of the juvenile hormone analog pyriproxyfen (at concentrations of 0.1, 0.5, and 1%) on egg production, number of ovarioles, and length of oocytes were examined in queens of the Pharaoh ant Monomorium pharaonis (L.). Pyriproxyfen significantly reduced egg production in queens from week 3 onwards. Queens that were exposed to 1% pyriproxyfen stopped producing eggs at week 8. After 8 wk, ovaries were dissected from all queens, and the number of ovarioles and the length of the largest oocytes were recorded. The ovaries of queens in treated colonies were smaller than those in untreated queens, and the number of ovarioles in the ovaries was significantly lower in all pyriproxyfen-treated queens. Queens treated with the highest concentrations of pyriproxyfen tended to have significantly shorter oocytes than untreated queens. Histological studies of the ovaries revealed that pyriproxyfen caused vacuolation in the ovarioles, thickening of the tunica propria, development of small eggs, and underdevelopment of nurse cells and the follicular epithelium. Exposure to pyriproxyfen reduced egg production and induced severe morphological changes in the ovaries of queens, and the effects increased with increased concentration of pyriproxyfen.

  5. Pseudacteon calderensis, a new fly species (Diptera:Phoridae) attacking the fire ant Solenopsis interrupta (Hymenoptera:Formicidae) in northwestern Argentina

    USDA-ARS?s Scientific Manuscript database

    A new species of Pseudacteon phorid fly Pseudacteon calderis (Diptera: Phoridae) is described from females attacking worker ants of Solenopsis interrupta Santschi in Salta and Jujuy provinces, northwestern Argentina. Pseudacteon calderis differs from almost all other South American Pseudacteon speci...

  6. Electric ants: A cross-disciplinary approach to understanding insect behavior

    SciTech Connect

    Slowik, T.J.; Thorvilson, H.G.; Green, B.L.

    1996-12-31

    The response and attraction of the red imported fire ant, Solenopsis invicta, to electrical equipment was examined using an interdisciplinary approach. Entomologists specializing in fire ant behavior combined expertise with electrical engineers to investigate the economically damaging interaction of fire ants with electrical circuitry. Knowledge from the realms of physics, engineering, and biology were integrated in experimentation to test for a fire ant response to electric fields and magnetic fields associated with electrical equipment. It was determined that fire ants react to electrified conductive material and the alternating-current magnetic fields associated with electricity.

  7. Bait distribution among multiple colonies of Pharaoh ants (hymenoptera: Formicidae).

    PubMed

    Oi, D H; Vail, K M; Williams, D F

    2000-08-01

    Pharaoh ant, Monomorium pharaonis (L.), infestations often consist of several colonies located at different nest sites. To achieve control, it is desirable to suppress or eliminate the populations of a majority of these colonies. We compared the trophallactic distribution and efficacy of two ant baits, with different modes of action, among groups of four colonies of Pharaoh ants. Baits contained either the metabolic-inhibiting active ingredient hydramethylnon or the insect growth regulator (IGR) pyriproxyfen. Within 3 wk, the hydramethylnon bait reduced worker and brood populations by at least 80%, and queen reductions ranged between 73 and 100%, when nests were in proximity (within 132 cm) to the bait source. However, these nest sites were reoccupied by ants from other colonies located further from the bait source. The pyriproxyfen bait was distributed more thoroughly to all nest locations with worker populations gradually declining by 73% at all nest sites after 8 wk. Average queen reductions ranged from 31 to 49% for all nest sites throughout the study. Even though some queens survived, brood reductions were rapid in the pyriproxyfen treatment, with reductions of 95% at all locations by week 3. Unlike the metabolic inhibitor, the IGR did not kill adult worker ants quickly, thus, more surviving worker ants were available to distribute the bait to all colonies located at different nest sites. Thus, from a single bait source, the slow-acting bait toxicant provided gradual, but long-term control, whereas the fast-acting bait toxicant provided rapid, localized control for a shorter duration.

  8. Taxonomy and distribution of the ant Cataglyphis setipes (Hymenoptera: Formicidae)

    PubMed Central

    Bharti, Himender

    2015-01-01

    Abstract Taxonomy and distribution of the ant species Cataglyphis setipes (Forel, 1894) is herewith detailed. C. setipes is redescribed, based on workers, queens, and males. Photomontage images of all castes are provided. Information on the distribution and ecology of this species is also given. A key to the Indian species of Cataglyphis is presented. PMID:25859129

  9. Caste development and evolution in ants: it's all about size.

    PubMed

    Trible, Waring; Kronauer, Daniel J C

    2017-01-01

    Female ants display a wide variety of morphological castes, including workers, soldiers, ergatoid (worker-like) queens and queens. Alternative caste development within a species arises from a variable array of genetic and environmental factors. Castes themselves are also variable across species and have been repeatedly gained and lost throughout the evolutionary history of ants. Here, we propose a simple theory of caste development and evolution. We propose that female morphology varies as a function of size, such that larger individuals possess more queen-like traits. Thus, the diverse mechanisms that influence caste development are simply mechanisms that affect size in ants. Each caste-associated trait has a unique relationship with size, producing a phenotypic space that permits some combinations of worker- and queen-like traits, but not others. We propose that castes are gained and lost by modifying the regions of this phenotypic space that are realized within a species. These modifications can result from changing the size-frequency distribution of individuals within a species, or by changing the association of tissue growth and size. We hope this synthesis will help unify the literature on caste in ants, and facilitate the discovery of molecular mechanisms underlying caste development and evolution. © 2017. Published by The Company of Biologists Ltd.

  10. General Dissection of Female Ant Reproductive System and Brain

    USDA-ARS?s Scientific Manuscript database

    Dissection of the reproductive system of ant workers and queens can be useful for answering many questions. Observations of ovarian status in both female castes can be used to identify relationships between other factors and the ovaries, determine whether an individual has laid eggs, and, with more ...

  11. Ant Tower

    NASA Astrophysics Data System (ADS)

    Mlot, Nathan; Shinotsuka, Sho; Hu, David

    2010-11-01

    Ants walk via adhesive drops of fluid extruded by their feet. They also use these drops as mortar to build structures such as rafts, bridges and towers, each composed of thousands of ants linked together. We investigate experimentally the construction of triangular ant towers braced by hydrophobic walls. Particular attention is paid to the relationship between tower height and contact angle hysteresis of the wall. We rationalize tower height according to ant adhesion, and tower shape according to the constraints on a column of constant strength.

  12. Effects of overwintering temperature on the survival of the black garden ant (Lasius niger).

    PubMed

    Haatanen, Marja-Katariina; van Ooik, Tapio; Sorvari, Jouni

    2015-01-01

    The overwintering temperatures of ants might well be elevated due to climate change. We studied whether the overwintering temperature affects the survival of the queens and whole colonies of the black garden ant, Lasius niger (Linnaeus, 1758). In two consecutive years (2009, 2010) we collected mated, colony founding queens (n = 280) from the urban area of Turku, Finland. Half of the queens overwintered in +7 to +8 °C and the other half in +2 °C. After the overwintering period, we determined their survival rate and measured the body fat content, body size and immune defence (encapsulation rate) of overwintering queens. Using the same setup, we studied the survival of 1-year-old L. niger colonies (queen & workers). Overwintering at a lower temperature (+2 °C) decreased the survival of workers. The survival of colony founding queens differed between years, but unlike with workers, the overwintering temperature did not affect their survival: neither in the colony experiment nor in the single queen experiment. All of the surviving queens managed to produce their worker offspring at the same rate. The relative amount of body fat of queens was higher for those who overwintered at a lower temperature, which is likely a result of lower energy consumption. We did not detect differences in the encapsulation rate between the temperature treatment groups. The ability of colony founding queens to tolerate wide overwintering temperature variations present in urban environments may explain the success of the colony in urban areas. As the colony grows, the overwintering chambers may extend more deeply into the ground. Thus, workers may not have to cope with such cold conditions as colony founding queens.

  13. Evolution of thorax architecture in ant castes highlights trade-off between flight and ground behaviors.

    PubMed

    Keller, Roberto A; Peeters, Christian; Beldade, Patrícia

    2014-01-01

    The concerted evolution of morphological and behavioral specializations has compelling examples in ant castes. Unique to ants is a marked divergence between winged queens and wingless workers, but morphological specializations for behaviors on the ground have been overlooked. We analyzed thorax morphology of queens and workers in species from 21 of the 25 ant subfamilies. We uncovered unique skeletomuscular modifications in workers that presumably increase power and flexibility of head-thorax articulation, emphasizing that workers are not simply wingless versions of queens. We also identified two distinct types of queens and showed repeated evolutionary associations with strategies of colony foundation. Solitary founding queens that hunt have a more worker-like thorax. Our results reveal that ants invest in the relative size of thorax segments according to their tasks. Versatility of head movements allows for better manipulation of food and objects, which arguably contributed to the ants' ecological and evolutionary success. DOI: http://dx.doi.org/10.7554/eLife.01539.001.

  14. Intrinsic worker mortality depends on behavioral caste and the queens' presence in a social insect.

    PubMed

    Kohlmeier, Philip; Negroni, Matteo Antoine; Kever, Marion; Emmling, Stefanie; Stypa, Heike; Feldmeyer, Barbara; Foitzik, Susanne

    2017-04-01

    According to the classic life history theory, selection for longevity depends on age-dependant extrinsic mortality and fecundity. In social insects, the common life history trade-off between fecundity and longevity appears to be reversed, as the most fecund individual, the queen, often exceeds workers in lifespan several fold. But does fecundity directly affect intrinsic mortality also in social insect workers? And what is the effect of task on worker mortality? Here, we studied how social environment and behavioral caste affect intrinsic mortality of ant workers. We compared worker survival between queenless and queenright Temnothorax longispinosus nests and demonstrate that workers survive longer under the queens' absence. Temnothorax ant workers fight over reproduction when the queen is absent and dominant workers lay eggs. Worker fertility might therefore increase lifespan, possibly due to a positive physiological link between fecundity and longevity, or better care for fertile workers. In social insects, division of labor among workers is age-dependant with young workers caring for the brood and old ones going out to forage. We therefore expected nurses to survive longer than foragers, which is what we found. Surprisingly, inactive inside workers showed a lower survival than nurses but comparable to that of foragers. The reduced longevity of inactive workers could be due to them being older than the nurses, or due to a positive effect of activity on lifespan. Overall, our study points to behavioral caste-dependent intrinsic mortality rates and a positive association between fertility and longevity not only in queens but also in ant workers.

  15. Intrinsic worker mortality depends on behavioral caste and the queens' presence in a social insect

    NASA Astrophysics Data System (ADS)

    Kohlmeier, Philip; Negroni, Matteo Antoine; Kever, Marion; Emmling, Stefanie; Stypa, Heike; Feldmeyer, Barbara; Foitzik, Susanne

    2017-04-01

    According to the classic life history theory, selection for longevity depends on age-dependant extrinsic mortality and fecundity. In social insects, the common life history trade-off between fecundity and longevity appears to be reversed, as the most fecund individual, the queen, often exceeds workers in lifespan several fold. But does fecundity directly affect intrinsic mortality also in social insect workers? And what is the effect of task on worker mortality? Here, we studied how social environment and behavioral caste affect intrinsic mortality of ant workers. We compared worker survival between queenless and queenright Temnothorax longispinosus nests and demonstrate that workers survive longer under the queens' absence. Temnothorax ant workers fight over reproduction when the queen is absent and dominant workers lay eggs. Worker fertility might therefore increase lifespan, possibly due to a positive physiological link between fecundity and longevity, or better care for fertile workers. In social insects, division of labor among workers is age-dependant with young workers caring for the brood and old ones going out to forage. We therefore expected nurses to survive longer than foragers, which is what we found. Surprisingly, inactive inside workers showed a lower survival than nurses but comparable to that of foragers. The reduced longevity of inactive workers could be due to them being older than the nurses, or due to a positive effect of activity on lifespan. Overall, our study points to behavioral caste-dependent intrinsic mortality rates and a positive association between fertility and longevity not only in queens but also in ant workers.

  16. Extrafloral nectar content alters foraging preferences of a predatory ant

    PubMed Central

    Wilder, Shawn M.; Eubanks, Micky D.

    2010-01-01

    We tested whether the carbohydrate and amino acid content of extrafloral nectar affected prey choice by a predatory ant. Fire ants, Solenopsis invicta, were provided with artificial nectar that varied in the presence of carbohydrates and amino acids and were then provided with two prey items that differed in nutritional content, female and male crickets. Colonies of fire ants provided with carbohydrate supplements consumed less of the female crickets and frequently did not consume the high-lipid ovaries of female crickets. Colonies of fire ants provided with amino acid supplements consumed less of the male crickets. While a number of studies have shown that the presence of extrafloral nectar or honeydew can affect ant foraging activity, these results suggest that the nutritional composition of extrafloral nectar is also important and can affect subsequent prey choice by predatory ants. Our results suggest that, by altering the composition of extrafloral nectar, plants could manipulate the prey preferences of ants foraging on them. PMID:19864270

  17. Extrafloral nectar content alters foraging preferences of a predatory ant.

    PubMed

    Wilder, Shawn M; Eubanks, Micky D

    2010-04-23

    We tested whether the carbohydrate and amino acid content of extrafloral nectar affected prey choice by a predatory ant. Fire ants, Solenopsis invicta, were provided with artificial nectar that varied in the presence of carbohydrates and amino acids and were then provided with two prey items that differed in nutritional content, female and male crickets. Colonies of fire ants provided with carbohydrate supplements consumed less of the female crickets and frequently did not consume the high-lipid ovaries of female crickets. Colonies of fire ants provided with amino acid supplements consumed less of the male crickets. While a number of studies have shown that the presence of extrafloral nectar or honeydew can affect ant foraging activity, these results suggest that the nutritional composition of extrafloral nectar is also important and can affect subsequent prey choice by predatory ants. Our results suggest that, by altering the composition of extrafloral nectar, plants could manipulate the prey preferences of ants foraging on them.

  18. Confirmation of the genome position and mass of the viral protien, VP3, of Solenopsis Invicta Virus 1 (Picornavirales: Dicistroviridae) infecting the Red Imported Fire Ant (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    A predicted peptide sequence corresponding to the capsid protein VP3 of SINV-1 was used to prepare a polyclonal antibody preparation and probe SDS-PAGE separated proteins from SINV-1 particles and S. invicta ants. The SINV-1 VP3 antibody preparation recognized a 24 kDa protein from denatured SINV-1...

  19. 75 FR 68397 - DeQueen and Eastern Railroad, LLC-Acquisition and Operation Exemption-DeQueen and Eastern...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-05

    ... Surface Transportation Board DeQueen and Eastern Railroad, LLC--Acquisition and Operation Exemption--DeQueen and Eastern Railroad Company DeQueen and Eastern Railroad, LLC (DQE), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to acquire from DeQueen and Eastern Railroad Company and...

  20. Stinging ants.

    PubMed

    Rhoades, R

    2001-08-01

    Ants belong to the order Hymenoptera, along with bees, wasps, yellow jackets, etc., they are the most successful animal genera in this world. It is their selfless social structure which accounts for their huge impact. Their effect on man ranges from the parasol ant, which makes plant cultivation untenable in certain parts of South America, to Solenopsis Invicta in the southeastern United States of America, which kill ground dwelling birds and small animals, harass livestock, and renders farmland unusable. With the exception of the Bulldog Ant of Australia (which is the size of a medium cockroach) direct toxic effects are not a lethal threat to man. Human fatalities and morbidity are related to secondary infections of excoriated stings or allergic anaphylaxis. This article reviews history and recent developments regarding stinging ants around the world.

  1. [The ants: a strategy of population concentration].

    PubMed

    Zakharov, A A

    2011-01-01

    Ants are provided with a balanced system of reactions either to the original paucity of socia or to their secondary depopulation. This system can be defined as a strategy of population concentration. Both a successful reproduction of workers and queen fertilization are necessary conditions for ant communities' survival and development. Thus, the anthills must be large enough to ensure optimal conditions for reproduction. It is the strategy of population concentration that is directed to an accelerated attainment (or rehabilitation) by a socium of a state of stable development by way of concentrating the existent ant staff in an accessible number of viable nests. This strategy is realized throughout the life of ant communities by way of (a) fusing the starting family cells left by founder females, (b) fusing small anthills during artificial ant migrations, (c) uniting smaller socia or their joining other anthills, (d) reintegrating the secondary anthills (fragmentants) after an exogenous fragmentation of formicaries. Pooling and the attraction of deficient demographic resources from outside form the most efficient and quickest ways of reaching or restoring the threshold density levels. By realizing this strategy, the ants solve their paramount problems of anthill or settlement conservation at any particular time, as well as of providing some prospects for ant existence in the future. These problems are so vital for ant socia that they appear to hold priority over such other characteristics of utmost importance as genetic kinship or even species identity. The priority of social basics over genetic ones is unequivocally supported through mixed formicaries. A necessary condition for the realization of the strategy of population concentration is tolerance of highly developed social systems to the diversity of forms and to deviations from the norm. The use of one and the same mechanism at all stages of the life both of an individual socium and large ant settlements is

  2. Occurrence of antennal glands in ants.

    PubMed

    Renthal, Robert; Velasquez, Daniel; Olmos, David; Vinson, S Bradleigh

    2008-11-01

    A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non-Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus.

  3. Occurrence of Antennal Glands in Ants

    PubMed Central

    Renthal, Robert; Velasquez, Daniel; Olmos, David; Vinson, S. Bradleigh

    2010-01-01

    A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 (Isidoro et al., Insectes Sociaux 47: 236-240, 2000) left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or if they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals connected to spherical reservoirs in queens. T. bicarinatum was only non-Solenopsis species examined which showed evidence for antennal glands in the distal funiculus. PMID:18655135

  4. Natal Dispersal, Mating Patterns, and Inbreeding in the Ant Formica exsecta.

    PubMed

    Vitikainen, Emma I K; Haag-Liautard, Cathy; Sundström, Liselotte

    2015-12-01

    Sex-biased dispersal and multiple mating may prevent or alleviate inbreeding and its outcome, inbreeding depression, but studies demonstrating this in the wild are scarce. Perennial ant colonies offer a unique system to investigate the relationships between natal dispersal behavior and inbreeding. Due to the sedentary life of ant colonies and lifetime sperm storage by queens, measures of dispersal distance and mating strategy are easier to obtain than in most taxa. We used a suite of molecular markers to infer the natal colonies of queens and males in a wild population of the ant Formica exsecta. Dispersal was male biased, with median male dispersal distances (∼140 m) twice those of queens (∼60 m). The results also showed that the population was inbred and that inbreeding avoidance behaviors--sex-biased dispersal, queen dispersal distance, and multiple mating--were all ineffective in reducing homozygosity among colony workers. Queen homozygosity did not affect dispersal behavior, but more homozygous queens had lower colony-founding success and were more incestuously mated themselves, with potentially accumulating effects on colony fitness. We also provide independent evidence that dispersal is sex biased and show that our estimate corresponds well with dispersal estimates derived from population-genetic estimates.

  5. A reassessment of the mating system characteristics of the army ant Eciton burchellii

    NASA Astrophysics Data System (ADS)

    Kronauer, Daniel J. C.; Berghoff, Stefanie M.; Powell, Scott; Denny, A. Jay; Edwards, Keith J.; Franks, Nigel R.; Boomsma, Jacobus J.

    2006-08-01

    In a recent study, Denny et al. (2004a) showed that queens of the army ant, Eciton burchellii, mate with multiple males and presented estimates suggesting that they mate with more males than queens of any other ant species so far investigated. They also inferred that data were consistent with queens being inseminated repeatedly throughout their life, which would be exceptional among the social Hymenoptera and contradictory to predictions from kin selection theory. In the present study, we reanalyze these data using new software and supplement them with similar microsatellite data from other colonies of the same species. Mating frequencies in E. burchellii are indeed very high (mean observed and effective queen-mating frequencies of 12.9 each) but considerably lower than the previous estimates. We show that the number of patrilines represented in the first worker offspring of a young queen is lower than in older queens but suggest that this may be due to initial sperm clumping in the queen’s sperm storage organ, rather than to repeated inseminations. Moreover, we found no evidence for repeated mating by genotyping sequential worker generations produced by a single old queen, showing that she did not obtain new inseminations despite ample opportunities for mating.

  6. Evolution of thorax architecture in ant castes highlights trade-off between flight and ground behaviors

    PubMed Central

    Keller, Roberto A; Peeters, Christian; Beldade, Patrícia

    2014-01-01

    The concerted evolution of morphological and behavioral specializations has compelling examples in ant castes. Unique to ants is a marked divergence between winged queens and wingless workers, but morphological specializations for behaviors on the ground have been overlooked. We analyzed thorax morphology of queens and workers in species from 21 of the 25 ant subfamilies. We uncovered unique skeletomuscular modifications in workers that presumably increase power and flexibility of head–thorax articulation, emphasizing that workers are not simply wingless versions of queens. We also identified two distinct types of queens and showed repeated evolutionary associations with strategies of colony foundation. Solitary founding queens that hunt have a more worker-like thorax. Our results reveal that ants invest in the relative size of thorax segments according to their tasks. Versatility of head movements allows for better manipulation of food and objects, which arguably contributed to the ants’ ecological and evolutionary success. DOI: http://dx.doi.org/10.7554/eLife.01539.001 PMID:24399458

  7. Asexually produced Cape honeybee queens (Apis mellifera capensis) reproduce sexually.

    PubMed

    Beekman, Madeleine; Allsopp, Michael H; Lim, Julianne; Goudie, Frances; Oldroyd, Benjamin P

    2011-01-01

    Unmated workers of the Cape honeybee Apis mellifera capensis can produce female offspring including daughter queens. As worker-laid queens are produced asexually, we wondered whether these asexually produced individuals reproduce asexually or sexually. We sampled 11 colonies headed by queens known to be the clonal offspring of workers and genotyped 23 worker offspring from each queen at 5 microsatellite loci. Without exception, asexually produced queens produced female worker offspring sexually. In addition, we report the replacement of a queen by her asexually produced granddaughter, with this asexually produced queen also producing offspring sexually. Hence, once a female larva is raised as a queen, mating and sexual reproduction appears to be obligatory in this subspecies, despite the fact that worker-laid queens are derived from asexual lineages.

  8. Multiple paternity or multiple queens: two routes to greater intracolonial genetic diversity in the eusocial Hymenoptera.

    PubMed

    Hughes, W O H; Ratnieks, F L W; Oldroyd, B P

    2008-07-01

    Understanding the evolution of multiple mating by females (polyandry) is an important question in behavioural ecology. Most leading explanations for polyandry by social insect queens are based upon a postulated fitness benefit from increased intracolonial genetic diversity, which also arises when colonies are headed by multiple queens (polygyny). An indirect test of the genetic diversity hypotheses is therefore provided by the relationship between polyandry and polygyny across species, which should be negative if the genetic diversity hypotheses are correct. Here, we conduct a powerful comparative investigation of the relationship between polyandry and polygyny for 241 species of eusocial Hymenoptera (ants, bees and wasps). We find a clear and significant negative relationship between polyandry and polygyny after controlling for phylogeny. These results strongly suggest that fitness benefits resulting from increased intracolonial genetic diversity have played an important role in the evolution of polyandry, and possibly polygyny, in social insects.

  9. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response

    PubMed Central

    Böröczky, Katalin; Schal, Coby; Tarpy, David R.

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of “high-quality” queens (i.e., raised from first instar worker larvae; more queen-like) and “low-quality” queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone (“QMP”) components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the “queen-specific” developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting

  10. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response.

    PubMed

    Rangel, Juliana; Böröczky, Katalin; Schal, Coby; Tarpy, David R

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of "high-quality" queens (i.e., raised from first instar worker larvae; more queen-like) and "low-quality" queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone ("QMP") components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the "queen-specific" developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting that other external

  11. Polydomy in the ant Ectatomma opaciventre

    PubMed Central

    Tofolo, Viviane C.; Giannotti, Edilberto; Neves, Erika F.; Andrade, Luis H. C.; Lima, Sandro M.; Súarez, Yzel R.; Antonialli-Junior, William F.

    2014-01-01

    Tropical ants commonly exhibit a hyper-dispersed pattern of spatial distribution of nests. In polydomous species, nests may be satellites, that is, secondary structures of the main nest, where the queen is found. In order to evaluate whether the ant Ectatomma opaciventre Roger (Formicidae: Ectatomminae) uses the strategy of building polydomous nests, the spatial distribution pattern of 33 nests in a 1,800 m2 degraded area located in Rio Claro, SP, Brazil, were investigated using the nearest neighbor method. To complement the results of this investigation, the cuticular chemical profile of eight colonies was analyzed using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The nests of E. opaciventre presented a hyper-dispersed or regular distribution, which is the most common in ants. The analysis of the cuticular hydrocarbons apparently confirmed the hypothesis that this species is polydomous, since the chemical profiles of all studied colonies with nests at different sites were very similar to the chemical signature of the single found queen and were also different from those of colonies used as control. PMID:25373168

  12. The Pied Piper: A Parasitic Beetle’s Melodies Modulate Ant Behaviours

    PubMed Central

    Di Giulio, Andrea; Maurizi, Emanuela; Barbero, Francesca; Sala, Marco; Fattorini, Simone; Balletto, Emilio; Bonelli, Simona

    2015-01-01

    Ants use various communication channels to regulate their social organisation. The main channel that drives almost all the ants’ activities and behaviours is the chemical one, but it is long acknowledged that the acoustic channel also plays an important role. However, very little is known regarding exploitation of the acoustical channel by myrmecophile parasites to infiltrate the ant society. Among social parasites, the ant nest beetles (Paussus) are obligate myrmecophiles able to move throughout the colony at will and prey on the ants, surprisingly never eliciting aggression from the colonies. It has been recently postulated that stridulatory organs in Paussus might be evolved as an acoustic mechanism to interact with ants. Here, we survey the role of acoustic signals employed in the Paussus beetle-Pheidole ant system. Ants parasitised by Paussus beetles produce caste-specific stridulations. We found that Paussus can “speak” three different “languages”, each similar to sounds produced by different ant castes (workers, soldiers, queen). Playback experiments were used to test how host ants respond to the sounds emitted by Paussus. Our data suggest that, by mimicking the stridulations of the queen, Paussus is able to dupe the workers of its host and to be treated as royalty. This is the first report of acoustic mimicry in a beetle parasite of ants. PMID:26154266

  13. Exceptionally high levels of multiple mating in an army ant

    NASA Astrophysics Data System (ADS)

    Denny, A. Jay; Franks, Nigel R.; Powell, Scott; Edwards, Keith J.

    Most species of social insects have singly mated queens, although there are notable exceptions. Competing hypotheses have been proposed to explain the evolution of high levels of multiple mating, but this issue is far from resolved. Here we use microsatellites to investigate mating frequency in the army ant Eciton burchellii and show that queens mate with an exceptionally large number of males, eclipsing all but one other social insect species for which data are available. In addition we present evidence that suggests that mating is serial, continuing throughout the lifetime of the queen. This is the first demonstration of serial mating among social hymenoptera. We propose that high paternity within colonies is most likely to have evolved to increase genetic diversity and to counter high pathogen and parasite loads.

  14. The Evolution of Extreme Polyandry in Social Insects: Insights from Army Ants

    PubMed Central

    Barth, Matthias Benjamin; Moritz, Robin Frederik Alexander; Kraus, Frank Bernhard

    2014-01-01

    The unique nomadic life-history pattern of army ants (army ant adaptive syndrome), including obligate colony fission and strongly male-biased sex-ratios, makes army ants prone to heavily reduced effective population sizes (Ne). Excessive multiple mating by queens (polyandry) has been suggested to compensate these negative effects by increasing genetic variance in colonies and populations. However, the combined effects and evolutionary consequences of polyandry and army ant life history on genetic colony and population structure have only been studied in a few selected species. Here we provide new genetic data on paternity frequencies, colony structure and paternity skew for the five Neotropical army ants Eciton mexicanum, E. vagans, Labidus coecus, L. praedator and Nomamyrmex esenbeckii; and compare those data among a total of nine army ant species (including literature data). The number of effective matings per queen ranged from about 6 up to 25 in our tested species, and we show that such extreme polyandry is in two ways highly adaptive. First, given the detected low intracolonial relatedness and population differentiation extreme polyandry may counteract inbreeding and low Ne. Second, as indicated by a negative correlation of paternity frequency and paternity skew, queens maximize intracolonial genotypic variance by increasingly equalizing paternity shares with higher numbers of sires. Thus, extreme polyandry is not only an integral part of the army ant syndrome, but generally adaptive in social insects by improving genetic variance, even at the high end spectrum of mating frequencies. PMID:25144731

  15. The evolution of extreme polyandry in social insects: insights from army ants.

    PubMed

    Barth, Matthias Benjamin; Moritz, Robin Frederik Alexander; Kraus, Frank Bernhard

    2014-01-01

    The unique nomadic life-history pattern of army ants (army ant adaptive syndrome), including obligate colony fission and strongly male-biased sex-ratios, makes army ants prone to heavily reduced effective population sizes (Ne). Excessive multiple mating by queens (polyandry) has been suggested to compensate these negative effects by increasing genetic variance in colonies and populations. However, the combined effects and evolutionary consequences of polyandry and army ant life history on genetic colony and population structure have only been studied in a few selected species. Here we provide new genetic data on paternity frequencies, colony structure and paternity skew for the five Neotropical army ants Eciton mexicanum, E. vagans, Labidus coecus, L. praedator and Nomamyrmex esenbeckii; and compare those data among a total of nine army ant species (including literature data). The number of effective matings per queen ranged from about 6 up to 25 in our tested species, and we show that such extreme polyandry is in two ways highly adaptive. First, given the detected low intracolonial relatedness and population differentiation extreme polyandry may counteract inbreeding and low Ne. Second, as indicated by a negative correlation of paternity frequency and paternity skew, queens maximize intracolonial genotypic variance by increasingly equalizing paternity shares with higher numbers of sires. Thus, extreme polyandry is not only an integral part of the army ant syndrome, but generally adaptive in social insects by improving genetic variance, even at the high end spectrum of mating frequencies.

  16. 7 CFR 301.81-1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-1... subpart and any conditions imposed under this subpart. Imported fire ant. Living imported fire ants of the... (infested). The presence of an imported fire ant queen or a reproducing colony of imported fire ants,...

  17. 7 CFR 301.81-1 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-1... subpart and any conditions imposed under this subpart. Imported fire ant. Living imported fire ants of the... (infested). The presence of an imported fire ant queen or a reproducing colony of imported fire ants,...

  18. 7 CFR 301.81-1 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-1... subpart and any conditions imposed under this subpart. Imported fire ant. Living imported fire ants of the... (infested). The presence of an imported fire ant queen or a reproducing colony of imported fire ants,...

  19. 7 CFR 301.81-1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-1... subpart and any conditions imposed under this subpart. Imported fire ant. Living imported fire ants of the... (infested). The presence of an imported fire ant queen or a reproducing colony of imported fire ants,...

  20. Making a queen: an epigenetic analysis of the robustness of the honeybee (Apis mellifera) queen developmental pathway.

    PubMed

    He, Xu Jiang; Zhou, Lin Bin; Pan, Qi Zhong; Barron, Andrew B; Yan, Wei Yu; Zeng, Zhi Jiang

    2017-03-01

    Specialized castes are considered a key reason for the evolutionary and ecological success of the social insect lifestyle. The most essential caste distinction is between the fertile queen and the sterile workers. Honeybee (Apis mellifera) workers and queens are not genetically distinct, rather these different phenotypes are the result of epigenetically regulated divergent developmental pathways. This is an important phenomenon in understanding the evolution of social insect societies. Here, we studied the genomic regulation of the worker and queen developmental pathways, and the robustness of the pathways by transplanting eggs or young larvae to queen cells. Queens could be successfully reared from worker larvae transplanted up to 3 days age, but queens reared from older worker larvae had decreased queen body size and weight compared with queens from transplanted eggs. Gene expression analysis showed that queens raised from worker larvae differed from queens raised from eggs in the expression of genes involved in the immune system, caste differentiation, body development and longevity. DNA methylation levels were also higher in 3-day-old queen larvae raised from worker larvae compared with that raised from transplanted eggs identifying a possible mechanism stabilizing the two developmental paths. We propose that environmental (nutrition and space) changes induced by the commercial rearing practice result in a suboptimal queen phenotype via epigenetic processes, which may potentially contribute to the evolution of queen-worker dimorphism. This also has potentially contributed to the global increase in honeybee colony failure rates. © 2016 John Wiley & Sons Ltd.

  1. Evolutionary history of the little fire ant Wasmannia auropunctata before global invasion: inferring dispersal patterns, niche requirements and past and present distribution within its native range.

    PubMed

    Chifflet, L; Rodriguero, M S; Calcaterra, L A; Rey, O; Dinghi, P A; Baccaro, F B; Souza, J L P; Follett, P; Confalonieri, V A

    2016-04-01

    The evolutionary history of invasive species within their native range may involve key processes that allow them to colonize new habitats. Therefore, phylogeographic studies of invasive species within their native ranges are useful to understand invasion biology in an evolutionary context. Here we integrated classical and Bayesian phylogeographic methods using mitochondrial and nuclear DNA markers with a palaeodistribution modelling approach, to infer the phylogeographic history of the invasive ant Wasmannia auropunctata across its native distribution in South America. We discuss our results in the context of the recent establishment of this mostly tropical species in the Mediterranean region. Our Bayesian phylogeographic analysis suggests that the common ancestor of the two main clades of W. auropunctata occurred in central Brazil during the Pliocene. Clade A would have differentiated northward and clade B southward, followed by a secondary contact beginning about 380,000 years ago in central South America. There were differences in the most suitable habitats among clades when considering three distinct climatic periods, suggesting that genetic differentiation was accompanied by changes in niche requirements, clade A being a tropical lineage and clade B a subtropical and temperate lineage. Only clade B reached more southern latitudes, with a colder climate than that of northern South America. This is concordant with the adaptation of this originally tropical ant species to temperate climates prior to its successful establishment in the Mediterranean region. This study highlights the usefulness of exploring the evolutionary history of invasive species within their native ranges to better understand biological invasions. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  2. Balancing acts: drag queens, gender and faith.

    PubMed

    Sullivan-Blum, Constance R

    2004-01-01

    While engaged in research on the same-sex marriage debate in mainline denominations, I interviewed 23 LGBT Christians, four of whom were drag queens. While it is not possible to generalize from such a small sample, the drag queens in this study insist on maintaining their identity as Christians despite the hegemonic discourse that renders faith and LGBT identities mutually exclusive. They developed innovative approaches to reconciling their gender and sexual identities with their spirituality. Their innovations are potentially liberating not just for them personally, but for LGBT people generally because they challenge Christianity's rigid dichotomies of gender and sexuality.

  3. Queen Charlotte 2001 Earthquake Aftershock Sequence

    NASA Astrophysics Data System (ADS)

    Mulder, T.; Rogers, G. C.

    2012-12-01

    On Oct 12, 2001, an Mw=6.3 earthquake occurred off the Queen Charlotte Islands, BC. It was felt throughout Haida Gwaii (Queen Charlotte Islands) and the adjoining mainland. It generated a small tsunami recorded on Vancouver Island tide gauges. Moment tensor solutions show almost pure thrust faulting. There was a significant aftershock sequence associated with this event. Relocation of the catalogue aftershock sequence with respect to a key calibration event with various subsets of common stations show significant movement in the event locations. The aftershocks define an ~30 degree dipping fault plane.

  4. Effects of insemination quantity on honey bee queen physiology.

    PubMed

    Richard, Freddie-Jeanne; Tarpy, David R; Grozinger, Christina M

    2007-10-03

    Mating has profound effects on the physiology and behavior of female insects, and in honey bee (Apis mellifera) queens, these changes are permanent. Queens mate with multiple males during a brief period in their early adult lives, and shortly thereafter they initiate egg-laying. Furthermore, the pheromone profiles of mated queens differ from those of virgins, and these pheromones regulate many different aspects of worker behavior and colony organization. While it is clear that mating causes dramatic changes in queens, it is unclear if mating number has more subtle effects on queen physiology or queen-worker interactions; indeed, the effect of multiple matings on female insect physiology has not been broadly addressed. Because it is not possible to control the natural mating behavior of queens, we used instrumental insemination and compared queens inseminated with semen from either a single drone (single-drone inseminated, or SDI) or 10 drones (multi-drone inseminated, or MDI). We used observation hives to monitor attraction of workers to SDI or MDI queens in colonies, and cage studies to monitor the attraction of workers to virgin, SDI, and MDI queen mandibular gland extracts (the main source of queen pheromone). The chemical profiles of the mandibular glands of virgin, SDI, and MDI queens were characterized using GC-MS. Finally, we measured brain expression levels in SDI and MDI queens of a gene associated with phototaxis in worker honey bees (Amfor). Here, we demonstrate for the first time that insemination quantity significantly affects mandibular gland chemical profiles, queen-worker interactions, and brain gene expression. Further research will be necessary to elucidate the mechanistic bases for these effects: insemination volume, sperm and seminal protein quantity, and genetic diversity of the sperm may all be important factors contributing to this profound change in honey bee queen physiology, queen behavior, and social interactions in the colony.

  5. Effects of Insemination Quantity on Honey Bee Queen Physiology

    PubMed Central

    Richard, Freddie-Jeanne; Tarpy, David R.; Grozinger, Christina M.

    2007-01-01

    Mating has profound effects on the physiology and behavior of female insects, and in honey bee (Apis mellifera) queens, these changes are permanent. Queens mate with multiple males during a brief period in their early adult lives, and shortly thereafter they initiate egg-laying. Furthermore, the pheromone profiles of mated queens differ from those of virgins, and these pheromones regulate many different aspects of worker behavior and colony organization. While it is clear that mating causes dramatic changes in queens, it is unclear if mating number has more subtle effects on queen physiology or queen-worker interactions; indeed, the effect of multiple matings on female insect physiology has not been broadly addressed. Because it is not possible to control the natural mating behavior of queens, we used instrumental insemination and compared queens inseminated with semen from either a single drone (single-drone inseminated, or SDI) or 10 drones (multi-drone inseminated, or MDI). We used observation hives to monitor attraction of workers to SDI or MDI queens in colonies, and cage studies to monitor the attraction of workers to virgin, SDI, and MDI queen mandibular gland extracts (the main source of queen pheromone). The chemical profiles of the mandibular glands of virgin, SDI, and MDI queens were characterized using GC-MS. Finally, we measured brain expression levels in SDI and MDI queens of a gene associated with phototaxis in worker honey bees (Amfor). Here, we demonstrate for the first time that insemination quantity significantly affects mandibular gland chemical profiles, queen-worker interactions, and brain gene expression. Further research will be necessary to elucidate the mechanistic bases for these effects: insemination volume, sperm and seminal protein quantity, and genetic diversity of the sperm may all be important factors contributing to this profound change in honey bee queen physiology, queen behavior, and social interactions in the colony. PMID

  6. Life-history evolution in ants: the case of Cardiocondyla

    PubMed Central

    2017-01-01

    Ants are important components of most terrestrial habitats, and a better knowledge of the diversity of their life histories is essential to understand many aspects of ecosystem functioning. The myrmicine genus Cardiocondyla shows a wide range of colony structures, reproductive behaviours, queen and male lifespans, and habitat use. Reconstructing the evolutionary pathways of individual and social phenotypic traits suggests that the ancestral life history of Cardiocondyla was characterized by the presence of multiple, short-lived queens in small-sized colonies and a male polyphenism with winged dispersers and wingless fighters, which engage in lethal combat over female sexuals within their natal nests. Single queening, queen polyphenism, the loss of winged males and tolerance among wingless males appear to be derived traits that evolved with changes in nesting habits, colony size and the spread from tropical to seasonal environments. The aim of this review is to bring together the information on life-history evolution in Cardiocondyla and to highlight the suitability of this genus for functional genomic studies of adaptation, phenotypic plasticity, senescence, invasiveness and other key life-history traits of ants. PMID:28298341

  7. Life-history evolution in ants: the case of Cardiocondyla.

    PubMed

    Heinze, Jürgen

    2017-03-15

    Ants are important components of most terrestrial habitats, and a better knowledge of the diversity of their life histories is essential to understand many aspects of ecosystem functioning. The myrmicine genus Cardiocondyla shows a wide range of colony structures, reproductive behaviours, queen and male lifespans, and habitat use. Reconstructing the evolutionary pathways of individual and social phenotypic traits suggests that the ancestral life history of Cardiocondyla was characterized by the presence of multiple, short-lived queens in small-sized colonies and a male polyphenism with winged dispersers and wingless fighters, which engage in lethal combat over female sexuals within their natal nests. Single queening, queen polyphenism, the loss of winged males and tolerance among wingless males appear to be derived traits that evolved with changes in nesting habits, colony size and the spread from tropical to seasonal environments. The aim of this review is to bring together the information on life-history evolution in Cardiocondyla and to highlight the suitability of this genus for functional genomic studies of adaptation, phenotypic plasticity, senescence, invasiveness and other key life-history traits of ants.

  8. Cotton Rats Alter Foraging in Response to an Invasive Ant

    PubMed Central

    Darracq, Andrea K.; Conner, L. Mike; Brown, Joel S.; McCleery, Robert A.

    2016-01-01

    We assessed the effects of red imported fire ants (Solenopsis invicta; hereafter fire ant) on the foraging of hispid cotton rats (Sigmodon hispidus). We used a manipulative experiment, placing resource patches with a known amount of millet seed within areas with reduced (RIFA [–]) or ambient (RIFA [+]) numbers of fire ants. We measured giving up densities (the amount of food left within each patch) within the resource patches for 4 days to quantify the effects of fire ants on cotton rat foraging. We assessed the effects of fire ant treatment (RIFA), Day, and their interaction on cotton rat giving up densities. Giving up densities on RIFA [+] grids were nearly 2.2 times greater across all foraging days and ranged from 1.6 to 2.3 times greater from day 1 to day 4 than the RIFA [–] grids. From day 1 to day 4, mean giving up densities decreased significantly faster for the RIFA [–] than RIFA [+] treatments, 58% and 13%, respectively. Our results demonstrate that cotton rats perceive a risk of injury from fire ants, which is likely caused by interference competition, rather than direct predation. Envenomation from ants likely decrease the foraging efficiency of cotton rats resulting in more time spent foraging. Increased time spent foraging is likely stressful in terms of the opportunity for direct injury and encounters with other predators. These indirect effects may reduce an individual cotton rat’s fitness and translate into lowered population abundances. PMID:27655320

  9. Cotton Rats Alter Foraging in Response to an Invasive Ant.

    PubMed

    Darracq, Andrea K; Conner, L Mike; Brown, Joel S; McCleery, Robert A

    We assessed the effects of red imported fire ants (Solenopsis invicta; hereafter fire ant) on the foraging of hispid cotton rats (Sigmodon hispidus). We used a manipulative experiment, placing resource patches with a known amount of millet seed within areas with reduced (RIFA [-]) or ambient (RIFA [+]) numbers of fire ants. We measured giving up densities (the amount of food left within each patch) within the resource patches for 4 days to quantify the effects of fire ants on cotton rat foraging. We assessed the effects of fire ant treatment (RIFA), Day, and their interaction on cotton rat giving up densities. Giving up densities on RIFA [+] grids were nearly 2.2 times greater across all foraging days and ranged from 1.6 to 2.3 times greater from day 1 to day 4 than the RIFA [-] grids. From day 1 to day 4, mean giving up densities decreased significantly faster for the RIFA [-] than RIFA [+] treatments, 58% and 13%, respectively. Our results demonstrate that cotton rats perceive a risk of injury from fire ants, which is likely caused by interference competition, rather than direct predation. Envenomation from ants likely decrease the foraging efficiency of cotton rats resulting in more time spent foraging. Increased time spent foraging is likely stressful in terms of the opportunity for direct injury and encounters with other predators. These indirect effects may reduce an individual cotton rat's fitness and translate into lowered population abundances.

  10. Women in History--Queen Liliuokalani

    ERIC Educational Resources Information Center

    Koeppe, Tina

    2007-01-01

    This article profiles Queen Liliuokalani, Hawaii's last monarch. Liliuokalani was born in Hawaii in 1838 into the family of a high chief. She attended the Royal School, run by American missionaries, and received a high quality education and learned to love music, writing and politics. Liliuokalani was given the Christian name "Lydia" as…

  11. Queen Margaret University College's Sustainable, Community Campus

    ERIC Educational Resources Information Center

    Woodman, Susan

    2006-01-01

    The new campus of Queen Margaret University College in the United Kingdom is designed to be a sustainable educational and community resource. Early consultation with students and staff on the campus design revealed a strong desire for a sustainable environment, with plenty of green space for all to enjoy. In response to this, the design focuses on…

  12. Queen Margaret University College's Sustainable, Community Campus

    ERIC Educational Resources Information Center

    Woodman, Susan

    2006-01-01

    The new campus of Queen Margaret University College in the United Kingdom is designed to be a sustainable educational and community resource. Early consultation with students and staff on the campus design revealed a strong desire for a sustainable environment, with plenty of green space for all to enjoy. In response to this, the design focuses on…

  13. Women in History--Queen Liliuokalani

    ERIC Educational Resources Information Center

    Koeppe, Tina

    2007-01-01

    This article profiles Queen Liliuokalani, Hawaii's last monarch. Liliuokalani was born in Hawaii in 1838 into the family of a high chief. She attended the Royal School, run by American missionaries, and received a high quality education and learned to love music, writing and politics. Liliuokalani was given the Christian name "Lydia" as…

  14. Evaluating the role of reproductive constraints in ant social evolution

    PubMed Central

    Khila, Abderrahman; Abouheif, Ehab

    2010-01-01

    The reproductive division of labour is a key feature of eusociality in ants, where queen and worker castes show dramatic differences in the development of their reproductive organs. To understand the developmental and genetic basis underlying this division of labour, we performed a molecular analysis of ovary function and germ cell development in queens and workers. We show that the processes of ovarian development in queens have been highly conserved relative to the fruitfly Drosophila melanogaster. We also identify specific steps during oogenesis and embryogenesis in which ovarian and germ cell development have been evolutionarily modified in the workers. These modifications, which we call ‘reproductive constraints’, are often assumed to represent neutral degenerations that are a consequence of social evolutionary forces. Based on our developmental and functional analysis of these constraints, however, we propose and discuss the alternative hypothesis that reproductive constraints represent adaptive proximate mechanisms or traits for maintaining social harmony in ants. We apply a multi-level selection framework to help understand the role of these constraints in ant social evolution. A complete understanding of how cooperation, conflict and developmental systems evolve in social groups requires a ‘socio-evo-devo’ approach that integrates social evolutionary and developmental biology. PMID:20083637

  15. Pharaoh ant (Hymenoptera: Formicidae) colony development after consumption of pyriproxyfen baits.

    PubMed

    Vail, K M; Williams, D F

    1995-12-01

    Pharaoh ant, Monomorium pharaonis (L.), colonies were effectively controlled following ingestion of pyriproxyfen formulated in peanut butter oil. Pyriproxyfen, a juvenile hormone analog, reduced egg production in the queens, decreased the amount of brood due to delayed death in the eggs and larvae, caused death of pupae about 3 wk after treatment, and decreased the number of workers due to attrition and toxic effects. Queens, which continued to produce a small amount of eggs, eventually died. Queen death may have been caused by lack of workers required to tend them, old age or toxic effects. At concentrations of 0.25, 0.5 and 1%, pyriproxyfen was more effective than the once commercially available bait, Pharorid (methoprene) for the control of the Pharaoh ant.

  16. Irresistible ants: exposure to novel toxic prey increases consumption over multiple temporal scales.

    PubMed

    Herr, Mark W; Robbins, Travis R; Centi, Alan; Thawley, Christopher J; Langkilde, Tracy

    2016-07-01

    As species become increasingly exposed to novel challenges, it is critical to understand how evolutionary (i.e., generational) and plastic (i.e., within lifetime) responses work together to determine a species' fate or predict its distribution. The introduction of non-native species imposes novel pressures on the native species that they encounter. Understanding how native species exposed to toxic or distasteful invaders change their feeding behavior can provide insight into their ability to cope with these novel threats as well as broader questions about the evolution of this behavior. We demonstrated that native eastern fence lizards do not avoid consuming invasive fire ants following repeated exposure to this toxic prey. Rather fence lizards increased their consumption of these ants following exposure on three different temporal scales. Lizards ate more fire ants when they were exposed to this toxic prey over successive days. Lizards consumed more fire ants if they had been exposed to fire ants as juveniles 6 months earlier. Finally, lizards from populations exposed to fire ants over multiple generations consumed more fire ants than those from fire ant-free areas. These results suggest that the potentially lethal consumption of fire ants may carry benefits resulting in selection for this behavior, and learning that persists long after initial exposure. Future research on the response of native predators to venomous prey over multiple temporal scales will be valuable in determining the long-term effects of invasion by these novel threats.

  17. The Ants Have It!

    ERIC Educational Resources Information Center

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  18. The Ants Have It!

    ERIC Educational Resources Information Center

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  19. The role of microgynes in the reproductive strategy of the neotropical ant Ectatomma ruidum

    NASA Astrophysics Data System (ADS)

    Lenoir, Jean-Christophe; Lachaud, Jean-Paul; Nettel, Alejandro; Fresneau, Dominique; Poteaux, Chantal

    2011-04-01

    Miniaturized queens, microgynes, are regarded as an alternative reproductive strategy sparsely present through the ant world. The described roles of miniaturized queens include alternative short-distance dispersal morphs, an adaptation to polygyny and inquiline parasites. Some of these inquiline parasite microgynes have been described as a separate species from their host. In the poneromorph group, miniaturized queens are only reported in two Mexican populations of two Ectatomminae: Ectatomma tuberculatum, in which small queens represent an inquiline species ( Ectatomma parasiticum) and Ectatomma ruidum. E. ruidum presents apparently facultative polygyny with microgynes. We used mitochondrial DNA markers and newly developed microsatellite loci to investigate the status as well as the role of microgynes in E. ruidum. We confirmed that microgynes and macrogynes are from the same species. This species is almost exclusively monogynous and monoandrous, supernumerary dealate queens of both types being actually daughters of the mother queen. An apparently polygynous nest was more often headed by a macrogyne than a microgyne. We didn't find any inbreeding or isolation by distance in the studied population, indicating that new gynes are inseminated by unrelated males and can establish a new nest far from their natal nest. However, re-adoption of daughter queens seems to be the rule and rate of microgyny appears to be linked to nest density and environmental factors.

  20. Intergenerational effect of juvenile hormone on offspring in Pogonomyrmex harvester ants

    USDA-ARS?s Scientific Manuscript database

    Parents can influence the phenotypes of their offspring via a number of mechanisms. In harvester ants, whether female progeny develop into workers or daughter queens is strongly influenced by the age and temperature conditions experienced by their mother, which is associated with variation in mater...

  1. Queen volatiles as a modulator of Tetragonisca angustula drone behavior.

    PubMed

    Fierro, Macario M; Cruz-López, Leopoldo; Sánchez, Daniel; Villanueva-Gutiérrez, Rogel; Vandame, Remy

    2011-11-01

    Tetragonisca angustula mating occurs during the virgin queen nuptial flight, usually in the presence of a drone congregation area (DCA). The presence of virgin queen pheromone is considered the trigger for DCA establishment, although this has not been demonstrated experimentally. We established meliponaries, in different habitats, with T. angustula virgin queens during the main drone reproduction period. Eight DCAs were observed in urban areas, and all established outside or near colonies containing at least one virgin queen. The accumulation of drones in the DCAs occurred from 08:00 to 18:00 h and over 3-35 days. The number of drones in DCAs ranged from 60 to 2,000. In field trials, drones were attracted to virgin queens and also, unexpectedly, to physogastric queens. Volatiles collected from both virgin and physogastric queens elicited strong electoantennogram (EAG) responses from drones. Virgin and physogastric queen volatiles were qualitatively similar, but quantitatively different, in chemical composition. The queen's abdomen was the principal source of these compounds. Isopropyl hexanoate (IPH), the most abundant compound in virgin queen volatiles and one of the most abundant in physogastric queen volatiles, was identified as one of the compounds that elicited EAG responses and was demonstrated to attract drones in a field test.

  2. Assessing the mating 'health' of commercial honey bee queens.

    PubMed

    Tarpy, David R; Keller, Jennifer J; Caren, Joel R; Delaney, Deborah A

    2012-02-01

    Honey bee queens mate with multiple males, which increases the total genetic diversity within colonies and has been shown to confer numerous benefits for colony health and productivity. Recent surveys of beekeepers have suggested that 'poor queens' are a top management concern, thus investigating the reproductive quality and mating success of commercially produced honey bee queens is warranted. We purchased 80 commercially produced queens from large queen breeders in California and measured them for their physical size (fresh weigh and thorax width), insemination success (stored sperm counts and sperm viability), and mating number (determined by patriline genotyping of worker offspring). We found that queens had an average of 4.37 +/- 1.446 million stored sperm in their spermathecae with an average viability of 83.7 +/- 13.33%. We also found that the tested queens had mated with a high number of drones (average effective paternity frequency: 17.0 +/- 8.98). Queen "quality" significantly varied among commercial sources for physical characters but not for mating characters. These findings suggest that it may be more effective to improve overall queen reproductive potential by culling lower-quality queens rather than systematically altering current queen production practices.

  3. Ant nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The image is available at http://www.jpl.nasa.gov/pictures/wfpc .

    The nebula, imaged on July 20, 1997, and June 30, 1998, by Hubble's Wide Field and Planetary Camera 2, was observed by Drs. Raghvendra Sahai and John Trauger of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Bruce Balick of the University of Washington in Seattle; and Vincent Icke of Leiden University in the Netherlands. JPL designed and built the camera.

    The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the 'ant's' body as a pair of fiery lobes protruding from a dying, Sun- like star. The Ant Nebula is located between 3,000 and 6,000 light years from Earth in the southern constellation Norma.

    The image challenges old ideas about what happens to dying stars. This observation, along with other pictures of various remnants of dying stars called planetary nebulae, shows that our Sun's fate will probably be much more interesting, complex and dramatic than astronomers previously believed.

    Although the ejection of gas from the dying star in the Ant Nebula is violent, it does not show the chaos one might expect from an ordinary explosion, but instead shows symmetrical patterns. One possibility is that the central star has a closely orbiting companion whose gravitational tidal forces shape the outflowing gas. A second possibility is that as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Electrically charged winds, much like those in our Sun's solar wind but millions of times denser and moving at speeds up to 1,000 kilometers per second (more than 600 miles per second) from the star, follow the twisted field lines on their way

  4. Ant nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The image is available at http://www.jpl.nasa.gov/pictures/wfpc .

    The nebula, imaged on July 20, 1997, and June 30, 1998, by Hubble's Wide Field and Planetary Camera 2, was observed by Drs. Raghvendra Sahai and John Trauger of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Bruce Balick of the University of Washington in Seattle; and Vincent Icke of Leiden University in the Netherlands. JPL designed and built the camera.

    The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the 'ant's' body as a pair of fiery lobes protruding from a dying, Sun- like star. The Ant Nebula is located between 3,000 and 6,000 light years from Earth in the southern constellation Norma.

    The image challenges old ideas about what happens to dying stars. This observation, along with other pictures of various remnants of dying stars called planetary nebulae, shows that our Sun's fate will probably be much more interesting, complex and dramatic than astronomers previously believed.

    Although the ejection of gas from the dying star in the Ant Nebula is violent, it does not show the chaos one might expect from an ordinary explosion, but instead shows symmetrical patterns. One possibility is that the central star has a closely orbiting companion whose gravitational tidal forces shape the outflowing gas. A second possibility is that as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Electrically charged winds, much like those in our Sun's solar wind but millions of times denser and moving at speeds up to 1,000 kilometers per second (more than 600 miles per second) from the star, follow the twisted field lines on their way

  5. Predaceous ants, beach replenishment, and nest placement by sea turtles.

    PubMed

    Wetterer, James K; Wood, Lawrence D; Johnson, Chris; Krahe, Holly; Fitchett, Stephanie

    2007-10-01

    Ants known for attacking and killing hatchling birds and reptiles include the red imported fire ant (Solenopsis invicta Buren), tropical fire ant [Solenopsis geminata (Fabr.)], and little fire ant [Wasmannia auropunctata (Roger)]. We tested whether sea turtle nest placement influenced exposure to predaceous ants. In 2000 and 2001, we surveyed ants along a Florida beach where green turtles (Chelonia mydas L.), leatherbacks (Dermochelys coriacea Vandelli), and loggerheads (Caretta caretta L.) nest. Part of the beach was artificially replenished between our two surveys. As a result, mean beach width experienced by nesting turtles differed greatly between the two nesting seasons. We surveyed 1,548 sea turtle nests (2000: 909 nests; 2001: 639 nests) and found 22 ant species. S. invicta was by far the most common species (on 431 nests); S. geminata and W. auropunctata were uncommon (on 3 and 16 nests, respectively). In 2000, 62.5% of nests had ants present (35.9% with S. invicta), but in 2001, only 30.5% of the nests had ants present (16.4% with S. invicta). Turtle nests closer to dune vegetation had significantly greater exposure to ants. Differences in ant presence on turtle nests between years and among turtle species were closely related to differences in nest placement relative to dune vegetation. Beach replenishment significantly lowered exposure of nests to ants because on the wider beaches turtles nested farther from the dune vegetation. Selective pressures on nesting sea turtles are altered both by the presence of predaceous ants and the practice of beach replenishment.

  6. Reproductive ultrasound of the bitch and queen.

    PubMed

    Davidson, Autumn P; Baker, Tomas W

    2009-05-01

    Ultrasonographic evaluation of the reproductive tract is an important component in the evaluation of the bitch and queen. Information is obtained concerning normal events involving the reproductive system (eg, ovulation, pregnancy) as well as pathologic conditions (eg, ovarian cysts, metritis). The appearance of the female reproductive tract normally changes with phases of the cycle; these changes need to be interpreted with knowledge of the ovarian cycle. Serial ultrasonographic evaluation of the diseased reproductive tract can be very helpful in evaluating response to therapy.

  7. Multiple endosymbionts in populations of the ant Formica cinerea

    PubMed Central

    2010-01-01

    Background Many insects, including ants, are infected by maternally inherited Wolbachia endosymbiotic bacteria though other secondary endosymbionts have not been reported in ants. It has been suggested that the ability of Wolbachia to invade and remain in an ant population depends on the number of coexisting queens in a colony. We study the genetic and social structure of populations in the ant Formica cinerea which is known to have populations with either monogynous or polygynous colonies. We screen populations for several endosymbiotic bacteria to evaluate the presence of different endosymbionts, possible association between their prevalence and the social structure, and the association between endosymbiont prevalence and genetic differentiation of ant populations. Results We found three endosymbiotic bacteria; 19% of the nests were infected by Wolbachia, 3.8% by Cardinium and 33% by Serratia. There was significant variation among the populations regarding the proportion of nests infected by Serratia, Wolbachia and the pooled set of all the endosymbionts. Some individuals and colonies carried two of the bacteria, the frequency of double infections agreeing with the random expectation. The proportion of infected ants (individuals or colonies) did not correlate significantly with the population level relatedness values. The difference in the prevalence of Wolbachia between population pairs correlated significantly with the genetic distance (microsatellites) of the populations. Conclusions The discovery of several endosymbionts and co-infections by Wolbachia and Cardinium demonstrate the importance of screening several endosymbionts when evaluating their possible effects on social life and queen-worker conflicts over sex allocation. The low prevalence of Wolbachia in F. cinerea departs from the pattern observed in many other Formica ants in which all workers have been infected. It is likely that the strain of Wolbachia in F. cinerea differs from those in other

  8. Congestion and communication in confined ant traffic

    NASA Astrophysics Data System (ADS)

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

    2014-03-01

    Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

  9. Invasive ants influence native lizard populations

    USDA-ARS?s Scientific Manuscript database

    The red imported fire ant (Solenopsis invicta; hereafter RIFA) is an invasive predator found on four continents, including South America, North America, Australia, and Asia. RIFAs are implicated in the decline of native invertebrates and vertebrates throughout their invaded range. We used the easter...

  10. Honey Bees Avoiding Ant Harassment at Flowers Using Scent Cues.

    PubMed

    Sidhu, Sheena C; Wilson Rankin, Erin E

    2016-02-01

    Pollinators require resources throughout the year to maintain healthy populations. Along the urban-natural interface, floral resource availability may be limited especially when the system experiences extreme drought and fire threats. In such areas, succulents, such as Aloe spp., are commonly planted to serve as functional drought-tolerant, fire-protective landscaping, which can also support pollinator populations. However, access to this resource may be restricted by competition from other floral foragers, including invasive pests. We measured free-foraging honey bee (Apis mellifera L.) visitation rate and visitation duration to aloe flowers with and without Argentine ants (Linepithema humile (Mayr)) in a drought-stressed environment and found that bees actively avoided foraging on the ant-occupied flowers. To determine the mechanisms of avoidance, our subsequent experiments assessed visitation in the absence of ants and compared aloe flowers treated with ant pheromone to unmanipulated flowers lacking ant pheromone. Bees approached all flowers equally, but accepted flowers without ants at a higher rate than flowers with ants. Visitation duration also increased twofold on ant-excluded flowers, which suggests that Argentine ants may limit resource acquisition by bees. Honey bees similarly avoided flowers with Argentine ant pheromone and preferentially visited unmanipulated flowers at threefold higher rate. This study demonstrates that honey bees avoid foraging on floral resources with invasive Argentine ants and that bees use ant odors to avoid ant-occupied flowers. Resource limitation by this invasive pest ant may have serious implication for sustaining healthy pollinator populations at the urban-natural interface. © 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.

  11. Hybridization in East African swarm-raiding army ants

    PubMed Central

    2011-01-01

    Background Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied hybridization in East African army ants (Dorylus subgenus Anomma) using morphology, mitochondrial DNA sequences, and nuclear microsatellites. Results While the mitochondrial phylogeny had a strong geographic signal, different species were not recovered as monophyletic. At our main study site at Kakamega Forest, a mitochondrial haplotype was shared between a "Dorylus molestus-like" and a "Dorylus wilverthi-like" form. This pattern is best explained by introgression following hybridization between D. molestus and D. wilverthi. Microsatellite data from workers showed that the two morphological forms correspond to two distinct genetic clusters, with a significant proportion of individuals being classified as hybrids. Conclusions We conclude that hybridization and gene-flow between the two army ant species D. molestus and D. wilverthi has occurred, and that mating between the two forms continues to regularly produce hybrid workers. Hybridization is particularly surprising in army ants because workers have control over which males are allowed to mate with a young virgin queen inside the colony. PMID:21859477

  12. The evolution of genome size in ants

    PubMed Central

    2008-01-01

    Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae) remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta), and the two published estimates for this species differ by 146.7 Mb (0.15 pg). Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile), Neotropical army ants (genera Eciton and Labidus), trapjaw ants (Odontomachus), fungus-growing ants (Apterostigma, Atta and Sericomyrmex), harvester ants (Messor, Pheidole and Pogonomyrmex), carpenter ants (Camponotus), a fire ant (Solenopsis), and a bulldog ant (Myrmecia). Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae) and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may include occasional

  13. Interplay between insulin signaling, juvenile hormone, and vitellogenin regulates maternal effects on polyphenism in ants

    PubMed Central

    Libbrecht, Romain; Corona, Miguel; Wende, Franziska; Azevedo, Dihego O.; Serrão, Jose E.; Keller, Laurent

    2013-01-01

    Polyphenism is the phenomenon in which alternative phenotypes are produced by a single genotype in response to environmental cues. An extreme case is found in social insects, in which reproductive queens and sterile workers that greatly differ in morphology and behavior can arise from a single genotype. Experimental evidence for maternal effects on caste determination, the differential larval development toward the queen or worker caste, was recently documented in Pogonomyrmex seed harvester ants, in which only colonies with a hibernated queen produce new queens. However, the proximate mechanisms behind these intergenerational effects have remained elusive. We used a combination of artificial hibernation, hormonal treatments, gene expression analyses, hormone measurements, and vitellogenin quantification to investigate how the combined effect of environmental cues and hormonal signaling affects the process of caste determination in Pogonomyrmex rugosus. The results show that the interplay between insulin signaling, juvenile hormone, and vitellogenin regulates maternal effects on the production of alternative phenotypes and set vitellogenin as a likely key player in the intergenerational transmission of information. This study reveals how hibernation triggers the production of new queens in Pogonomyrmex ant colonies. More generally, it provides important information on maternal effects by showing how environmental cues experienced by one generation can translate into phenotypic variation in the next generation. PMID:23754378

  14. [Did the Queen of Pount suffer from cutis laxa?].

    PubMed

    Martin, Jean-Pierre

    2010-12-01

    A bas-relief of the temple of Deir el-Bahari, Luxor, Egypt, discovered in 1867 by Mariette, shows a queen (Queen of Pount) with wide cutaneous folds on arms, abdomen and legs, hyperlordosis, a steatopygia and abnormally short lower limbs. Various assumptions about the diagnosis (steatopygia, partial achondroplasia, neurofibromatosis) were proposed at the beginning of the XXth century, neither taking into account all morphological abnormalities of the queen. We propose a novel hypothesis taking into account all signs: a Cutis Laxa.

  15. A World of Ants.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1992-01-01

    Presents a discussion of interesting aspects of ants that was launched by the author's reading of "The Ants" by Holldobler and Wilson (1990). Describes how the study of the early history of ant taxonomy could be viewed as "entertaining." Their huge numbers and segregation into colonial social systems makes ants good research organisms. (PR)

  16. Matricide and queen sex allocation in a yellowjacket wasp

    NASA Astrophysics Data System (ADS)

    Loope, Kevin J.

    2016-08-01

    In many colonies of social insects, the workers compete with each other and with the queen over the production of the colony's males. In some species of social bees and wasps with annual societies, this intra-colony conflict even results in matricide—the killing of the colony's irreplaceable queen by a daughter worker. In colonies with low effective paternity and high worker-worker relatedness, workers value worker-laid males more than queen-laid males, and thus may benefit from queen killing. Workers gain by eliminating the queen because she is a competing source of male eggs and actively inhibits worker reproduction through policing. However, matricide may be costly to workers if it reduces the production of valuable new queens and workers. Here, I test a theoretical prediction regarding the timing of matricide in a wasp, Dolichovespula arenaria, recently shown to have facultative matricide based on intra-colony relatedness. Using analyses of collected, mature colonies and a surgical manipulation preventing queens from laying female eggs, I show that workers do not preferentially kill queens who are only producing male eggs. Instead, workers sometimes kill queens laying valuable females, suggesting a high cost of matricide. Although matricide is common and typically occurs only in low-paternity colonies, it seems that workers sometimes pay substantial costs in this expression of conflict over male parentage.

  17. Conservation of Queen Pheromones Across Two Species of Vespine Wasps.

    PubMed

    Oi, Cintia A; Millar, Jocelyn G; van Zweden, Jelle S; Wenseleers, Tom

    2016-11-01

    Social insects are known for their reproductive division of labor between queens and workers, whereby queens lay the majority of the colony's eggs, and workers engage mostly in non-reproductive tasks. Queens produce pheromones that signal their presence and fertility to workers, which in turn generally remain sterile. Recently, it has been discovered that specific queen-characteristic cuticular hydrocarbons (CHCs) function as queen pheromones across multiple lineages of social insects. In the common wasp, Vespula vulgaris, several long-chain linear alkanes and 3-methylalkanes were shown to act as queen signals. Here, we describe similar bioassays with a related species of highly eusocial vespine wasp, the Saxon wasp, Dolichovespula saxonica. We show that a blend of queen-characteristic hydrocarbons that are structurally related to those of the common wasp inhibit worker reproduction, suggesting conservation of queen pheromones across social wasps. Overall, our results highlight the central importance of CHCs in chemical communication among social insects in general, and as conserved queen pheromones in these social wasps in particular.

  18. Phenotypic plasticity and modularity allow for the production of novel mosaic phenotypes in ants.

    PubMed

    Londe, Sylvain; Monnin, Thibaud; Cornette, Raphaël; Debat, Vincent; Fisher, Brian L; Molet, Mathieu

    2015-01-01

    The origin of discrete novelties remains unclear. Some authors suggest that qualitative phenotypic changes may result from the reorganization of preexisting phenotypic traits during development (i.e., developmental recombination) following genetic or environmental changes. Because ants combine high modularity with extreme phenotypic plasticity (queen and worker castes), their diversified castes could have evolved by developmental recombination. We performed a quantitative morphometric study to investigate the developmental origins of novel phenotypes in the ant Mystrium rogeri, which occasionally produces anomalous 'intercastes.' Our analysis compared the variation of six morphological modules with body size using a large sample of intercastes. We confirmed that intercastes are conspicuous mosaics that recombine queen and worker modules. In addition, we found that many other individuals traditionally classified as workers or queens also exhibit some level of mosaicism. The six modules had distinct profiles of variation suggesting that each module responds differentially to factors that control body size and polyphenism. Mosaicism appears to result from each module responding differently yet in an ordered and predictable manner to intermediate levels of inducing factors that control polyphenism. The order of module response determines which mosaic combinations are produced. Because the frequency of mosaics and their canalization around a particular phenotype may evolve by selection on standing genetic variation that affects the plastic response (i.e., genetic accommodation), developmental recombination is likely to play an important role in the evolution of novel castes in ants. Indeed, we found that most mosaics have queen-like head and gaster but a worker-like thorax congruent with the morphology of ergatoid queens and soldiers, respectively. Ergatoid queens of M. oberthueri, a sister species of M. rogeri, could have evolved from intercastes produced ancestrally

  19. Trade-offs in an ant-plant-fungus mutualism.

    PubMed

    Orivel, Jérôme; Malé, Pierre-Jean; Lauth, Jérémie; Roux, Olivier; Petitclerc, Frédéric; Dejean, Alain; Leroy, Céline

    2017-03-15

    Species engaged in multiple, simultaneous mutualisms are subject to trade-offs in their mutualistic investment if the traits involved in each interaction are overlapping, which can lead to conflicts and affect the longevity of these associations. We investigate this issue via a tripartite mutualism involving an ant plant, two competing ant species and a fungus the ants cultivate to build galleries under the stems of their host plant to capture insect prey. The use of the galleries represents an innovative prey capture strategy compared with the more typical strategy of foraging on leaves. However, because of a limited worker force in their colonies, the prey capture behaviour of the ants results in a trade-off between plant protection (i.e. the ants patrol the foliage and attack intruders including herbivores) and ambushing prey in the galleries, which has a cascading effect on the fitness of all of the partners. The quantification of partners' traits and effects showed that the two ant species differed in their mutualistic investment. Less investment in the galleries (i.e. in fungal cultivation) translated into more benefits for the plant in terms of less herbivory and higher growth rates and vice versa. However, the greater vegetative growth of the plants did not produce a positive fitness effect for the better mutualistic ant species in terms of colony size and production of sexuals nor was the mutualist compensated by the wider dispersal of its queens. As a consequence, although the better ant mutualist is the one that provides more benefits to its host plant, its lower host-plant exploitation does not give this ant species a competitive advantage. The local coexistence of the ant species is thus fleeting and should eventually lead to the exclusion of the less competitive species.

  20. [Temperature and photoperiodic control of diapause induction in the ant Lepisiota semenovi (Hymenoptera, Formicidae) from Turkmenistan].

    PubMed

    Kipiatkov, V E; Lopatina, E B

    2009-01-01

    The ant L. semenovi has been found to belong to species with endogenous-heterodynamic seasonal life cycles with the obligate diapause induced predominantly by factors internal for a colony, whereas external ecological factors (photoperiods and temperature) produce merely modifying effects by accelerating or delaying the diapause onset. The photoperiodic and temperature regulation of diapause induction in larvae and queens is shown. Under effect of short days and low temperature the periods of larval pupation and queen oviposition in a colony are shortened markedly, i. e., the periods of larvae and queens occurs earlier. The daily rhythms of temperature 15/25 degrees C and particularly 20/30 degrees C as compared with constant temperatures 20 and 25 degrees C that correspond to the mean daily temperatures of the thermorhythm, inhibit manifestations of the short day effects by stimulating the non-diapause development and increasing duration of the seasonal development cycle of ant colonies. The L. semenovi photoperiodic reaction is quantitative, as development and pupation of larvae and egg-laying of queens cease sooner or later under both the short and the long days, but in the latter case significantly later. Thus, L. semenovi is one more example among very rare ant species that are revealed to have the photoperiodic regulation of the colony development seasonal cycle.