Sinergia sostenida: las polillas y el Dr. Wolcott

Treesearch

Frank H. Wadsworth

2007-01-01

The synergy between an insect colony and a curious entomologist is described. Together they determine the relative preference of insects to over 80 woody species. The relationship between wood resistance and insect attacks and wood density and chemical composition of wood is also determined. Finally, a series of chemicals is tested to increase wood resistance to attack...

Strategic and tactical use of movement information in pest management

NASA Technical Reports Server (NTRS)

Knipling, E. F.

1979-01-01

Several insect movement problems are discussed. Much more information is needed to make a better appraisal of the practical significance of the insect dispersal problem. Data on the time, rate, and extent of movement of insects are provided. Better techniques for measuring insect movement are developed. A better understanding of the importance of insect movement in the development and implementation of more effective and ecologically acceptable pest management strategies and tactics was proved.

Identification of species and geographical strains of Sitophilus oryzae and Sitophilus zeamais using the visible/near-infrared hyperspectral imaging technique.

PubMed

Cao, Yang; Zhang, Chaojie; Chen, Quansheng; Li, Yanyu; Qi, Shuai; Tian, Lin; Ren, YongLin

2015-08-01

Identifying stored-product insects is essential for granary management. Automated, computer-based classification methods are rapidly developing in many areas. A hyperspectral imaging technique could potentially be developed to identify stored-product insect species and geographical strains. This study tested and adapted the technique using four geographical strains of each of two insect species, the rice weevil and maize weevil, to collect and analyse the resultant hyperspectral data. Three characteristic images that corresponded to the dominant wavelengths, 505, 659 and 955 nm, were selected by multivariate image analysis. Each image was processed, and 22 morphological and textural features from regions of interest were extracted as the inputs for an identification model. We found the backpropagation neural network model to be the superior method for distinguishing between the insect species and geographical strains. The overall recognition rates of the classification model for insect species were 100 and 98.13% for the calibration and prediction sets respectively, while the rates of the model for geographical strains were 94.17 and 86.88% respectively. This study has demonstrated that hyperspectral imaging, together with the appropriate recognition method, could provide a potential instrument for identifying insects and could become a useful tool for identification of Sitophilus oryzae and Sitophilus zeamais to aid in the management of stored-product insects. © 2014 Society of Chemical Industry.

Interview with Dr. Stuart O. Nelson

USDA-ARS?s Scientific Manuscript database

Research equipment and techniques used in exploring effects of radio-frequency (RF) dielectric heating on materials of interest in agriculture are described. Research findings are summarized for studies on stored-grain insect control by RF selective heating of the insects and resulting insect morta...

The Repellent DEET Potentiates Carbamate Effects via Insect Muscarinic Receptor Interactions: An Alternative Strategy to Control Insect Vector-Borne Diseases.

PubMed

Abd-Ella, Aly; Stankiewicz, Maria; Mikulska, Karolina; Nowak, Wieslaw; Pennetier, Cédric; Goulu, Mathilde; Fruchart-Gaillard, Carole; Licznar, Patricia; Apaire-Marchais, Véronique; List, Olivier; Corbel, Vincent; Servent, Denis; Lapied, Bruno

2015-01-01

Insect vector-borne diseases remain one of the principal causes of human mortality. In addition to conventional measures of insect control, repellents continue to be the mainstay for personal protection. Because of the increasing pyrethroid-resistant mosquito populations, alternative strategies to reconstitute pyrethroid repellency and knock-down effects have been proposed by mixing the repellent DEET (N,N-Diethyl-3-methylbenzamide) with non-pyrethroid insecticide to better control resistant insect vector-borne diseases. By using electrophysiological, biochemichal, in vivo toxicological techniques together with calcium imaging, binding studies and in silico docking, we have shown that DEET, at low concentrations, interacts with high affinity with insect M1/M3 mAChR allosteric site potentiating agonist effects on mAChRs coupled to phospholipase C second messenger pathway. This increases the anticholinesterase activity of the carbamate propoxur through calcium-dependent regulation of acetylcholinesterase. At high concentrations, DEET interacts with low affinity on distinct M1/M3 mAChR site, counteracting the potentiation. Similar dose-dependent dual effects of DEET have also been observed at synaptic mAChR level. Additionally, binding and in silico docking studies performed on human M1 and M3 mAChR subtypes indicate that DEET only displays a low affinity antagonist profile on these M1/M3 mAChRs. These results reveal a selective high affinity positive allosteric site for DEET in insect mAChRs. Finally, bioassays conducted on Aedes aegypti confirm the synergistic interaction between DEET and propoxur observed in vitro, resulting in a higher mortality of mosquitoes. Our findings reveal an unusual allosterically potentiating action of the repellent DEET, which involves a selective site in insect. These results open exciting research areas in public health particularly in the control of the pyrethroid-resistant insect-vector borne diseases. Mixing low doses of DEET and a non-pyrethroid insecticide will lead to improvement in the efficiency treatments thus reducing both the concentration of active ingredients and side effects for non-target organisms. The discovery of this insect specific site may pave the way for the development of new strategies essential in the management of chemical use against resistant mosquitoes.

The Repellent DEET Potentiates Carbamate Effects via Insect Muscarinic Receptor Interactions: An Alternative Strategy to Control Insect Vector-Borne Diseases

PubMed Central

Abd-Ella, Aly; Stankiewicz, Maria; Mikulska, Karolina; Nowak, Wieslaw; Pennetier, Cédric; Goulu, Mathilde; Fruchart-Gaillard, Carole; Licznar, Patricia; Apaire-Marchais, Véronique; List, Olivier; Corbel, Vincent; Servent, Denis; Lapied, Bruno

2015-01-01

Insect vector-borne diseases remain one of the principal causes of human mortality. In addition to conventional measures of insect control, repellents continue to be the mainstay for personal protection. Because of the increasing pyrethroid-resistant mosquito populations, alternative strategies to reconstitute pyrethroid repellency and knock-down effects have been proposed by mixing the repellent DEET (N,N-Diethyl-3-methylbenzamide) with non-pyrethroid insecticide to better control resistant insect vector-borne diseases. By using electrophysiological, biochemichal, in vivo toxicological techniques together with calcium imaging, binding studies and in silico docking, we have shown that DEET, at low concentrations, interacts with high affinity with insect M1/M3 mAChR allosteric site potentiating agonist effects on mAChRs coupled to phospholipase C second messenger pathway. This increases the anticholinesterase activity of the carbamate propoxur through calcium-dependent regulation of acetylcholinesterase. At high concentrations, DEET interacts with low affinity on distinct M1/M3 mAChR site, counteracting the potentiation. Similar dose-dependent dual effects of DEET have also been observed at synaptic mAChR level. Additionally, binding and in silico docking studies performed on human M1 and M3 mAChR subtypes indicate that DEET only displays a low affinity antagonist profile on these M1/M3 mAChRs. These results reveal a selective high affinity positive allosteric site for DEET in insect mAChRs. Finally, bioassays conducted on Aedes aegypti confirm the synergistic interaction between DEET and propoxur observed in vitro, resulting in a higher mortality of mosquitoes. Our findings reveal an unusual allosterically potentiating action of the repellent DEET, which involves a selective site in insect. These results open exciting research areas in public health particularly in the control of the pyrethroid-resistant insect-vector borne diseases. Mixing low doses of DEET and a non-pyrethroid insecticide will lead to improvement in the efficiency treatments thus reducing both the concentration of active ingredients and side effects for non-target organisms. The discovery of this insect specific site may pave the way for the development of new strategies essential in the management of chemical use against resistant mosquitoes. PMID:25961834

Chemical-warfare techniques for insect control: insect 'pests' in Germany before and after World War I.

PubMed

Jansen, S

2000-01-01

During World War I, chemical-warfare practices were introduced into economic entomology in Germany. Fritz Haber, 'the father of chemical warfare', realized that Germany could not win the war and thus looked for 'civilian' uses for his chemical arsenal. Before the war, there was a rhetoric of dangerous 'masses' of insects but the large-scale techniques needed to deal with them had not been developed. The gap between rhetoric and practices enabled entomology to integrate chemical weapons into its working methods. This article traces transformations in the ways of seeing insects and their control from the mid-nineteenth century to after World War I.

Optic Glomeruli: Biological Circuits that Compute Target Identity

DTIC Science & Technology

2013-11-01

vitripennis. Insect Mol. Biol. Suppl. 1:121-36. Strausfeld NJ. 2012. Arthropod Brains. Evolution , Functional Elegance and Historical Significance. Harvard...Neuroscience and Center for Insect Science University of Arizona Tucson, AZ 85721 Contract No. FA8651-10-1-0001 November 2013 FINAL REPORT...PERFORMING ORGANIZATION REPORT NUMBER Department of Neuroscience and Center for Insect Science University of Arizona Tucson, AZ 85721

Area-wide control of insects with screwworm as an example

USDA-ARS?s Scientific Manuscript database

Screwworms, Cochliomyia hominivorax (Coquerel), are devastating pests of warm blooded animals. They have been eradicated from continental North America using the sterile insect technique (SIT). Proper implementation of SIT is an example of the requirements of area-wide control of insect pests. Area-...

Analysis of the genitalia rotation in the male Anopheles funestus (Diptera: Culicidae).

PubMed

Dahan, Yael Leah; Koekemoer, Lizette Leonie

2014-04-01

Anopheles funestus is a major malaria vector in Africa. Insecticide resistance has developed in populations of this species in several African countries, prompting the need to develop additional vector control methods such as the sterile insect technique (SIT). This technique requires an understanding of those underlying physiological events that lead to sexual maturity of An. funestus males, the rotation of their genitalia in particular. The aim of this study was to qualitatively and quantitatively describe genital rotation in An. funestus males as it is an essential function of sexual maturation. Genital rotation of all the males reached its final rotation stage (135-180° rotation) 36 h post emergence at 23 ± 1 °C in laboratory colonised An. funestus males. These males had a comparable rotation rate to wild caught An. funestus at the same temperature setting. A temperature change (either 18 ± 1 °C or 29 ± 1 °C versus 23 ± 1 °C) significantly influenced the genital rotation rate such that this rate increased with increasing temperature. This information enhances our knowledge of the An. funestus male biology. This is important in terms of applying the sterile insect technique as the understanding and manipulation of the rate of sexual maturation in males has implications for the timing of sterile male release. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

A fundamental approach to the sticking of insect residues to aircraft wings

NASA Technical Reports Server (NTRS)

Eiss, N. S., Jr.; Wightman, J. P.

1983-01-01

The sticking of insect residues to aircraft wings is investigated. The major topics of this review are: Experimentally tested methods, testing techniques, the effect of surface roughness height on aerodynamic drag, materials tested and, the adhesive properties of insect body fluids are reviewed.

Insect biofuel cells using trehalose included in insect hemolymph leading to an insect-mountable biofuel cell.

PubMed

Shoji, Kan; Akiyama, Yoshitake; Suzuki, Masato; Hoshino, Takayuki; Nakamura, Nobuhumi; Ohno, Hiroyuki; Morishima, Keisuke

2012-12-01

In this paper, an insect biofuel cell (BFC) using trehalose included in insect hemolymph was developed. The insect BFC is based on trehalase and glucose oxidase (GOD) reaction systems which oxidize β-glucose obtained by hydrolyzing trehalose. First, we confirmed by LC-MS that a sufficient amount of trehalose was present in the cockroach hemolymph (CHL). The maximum power density obtained using the insect BFC was 6.07 μW/cm(2). The power output was kept more than 10 % for 2.5 h by protecting the electrodes with a dialysis membrane. Furthermore, the maximum power density was increased to 10.5 μW/cm(2) by using an air diffusion cathode. Finally, we succeeded in driving a melody integrated circuit (IC) and a piezo speaker by connecting five insect BFCs in series. The results indicate that the insect BFC is a promising insect-mountable battery to power environmental monitoring micro-tools.

Estimating Aquatic Insect Populations. Introduction to Sampling.

ERIC Educational Resources Information Center

Chihuahuan Desert Research Inst., Alpine, TX.

This booklet introduces high school and junior high school students to the major groups of aquatic insects and to population sampling techniques. Chapter 1 consists of a short field guide which can be used to identify five separate orders of aquatic insects: odonata (dragonflies and damselflies); ephemeroptera (mayflies); diptera (true flies);…

Methods for Maintaining Insect Cell Cultures

PubMed Central

Lynn, Dwight E.

2002-01-01

Insect cell cultures are now commonly used in insect physiology, developmental biology, pathology, and molecular biology. As the field has advanced from methods development to a standard procedure, so has the diversity of scientists using the technique. This paper describes methods that are effective for maintaining various insect cell lines. The procedures are differentiated between loosely or non-attached cell strains, attached cell strains, and strongly adherent cell strains. PMID:15455043

Using Web-Based Key Character and Classification Instruction for Teaching Undergraduate Students Insect Identification

NASA Astrophysics Data System (ADS)

Golick, Douglas A.; Heng-Moss, Tiffany M.; Steckelberg, Allen L.; Brooks, David. W.; Higley, Leon G.; Fowler, David

2013-08-01

The purpose of the study was to determine whether undergraduate students receiving web-based instruction based on traditional, key character, or classification instruction differed in their performance of insect identification tasks. All groups showed a significant improvement in insect identifications on pre- and post-two-dimensional picture specimen quizzes. The study also determined student performance on insect identification tasks was not as good as for family-level identification as compared to broader insect orders and arthropod classification identification tasks. Finally, students erred significantly more by misidentification than misspelling specimen names on prepared specimen quizzes. Results of this study support that short web-based insect identification exercises can improve insect identification performance. Also included is a discussion of how these results can be used in teaching and future research on biological identification.

Y-Linked markers for improved population control of the tephritid fruit fly pest, Anastrepha suspensa

USDA-ARS?s Scientific Manuscript database

Insect pest control programs incorporating the sterile insect technique (SIT) rely on the mass production and release of sterilized insects to reduce the wild-type population through infertile matings. Most effective programs release only males to avoid any crop damage caused by female fruit flies o...

Quantifying interspecific variation in dispersal ability of noctuid moths using an advanced tethered flight technique.

PubMed

Jones, Hayley B C; Lim, Ka S; Bell, James R; Hill, Jane K; Chapman, Jason W

2016-01-01

Dispersal plays a crucial role in many aspects of species' life histories, yet is often difficult to measure directly. This is particularly true for many insects, especially nocturnal species (e.g. moths) that cannot be easily observed under natural field conditions. Consequently, over the past five decades, laboratory tethered flight techniques have been developed as a means of measuring insect flight duration and speed. However, these previous designs have tended to focus on single species (typically migrant pests), and here we describe an improved apparatus that allows the study of flight ability in a wide range of insect body sizes and types. Obtaining dispersal information from a range of species is crucial for understanding insect population dynamics and range shifts. Our new laboratory tethered flight apparatus automatically records flight duration, speed, and distance of individual insects. The rotational tethered flight mill has very low friction and the arm to which flying insects are attached is extremely lightweight while remaining rigid and strong, permitting both small and large insects to be studied. The apparatus is compact and thus allows many individuals to be studied simultaneously under controlled laboratory conditions. We demonstrate the performance of the apparatus by using the mills to assess the flight capability of 24 species of British noctuid moths, ranging in size from 12-27 mm forewing length (~40-660 mg body mass). We validate the new technique by comparing our tethered flight data with existing information on dispersal ability of noctuids from the published literature and expert opinion. Values for tethered flight variables were in agreement with existing knowledge of dispersal ability in these species, supporting the use of this method to quantify dispersal in insects. Importantly, this new technology opens up the potential to investigate genetic and environmental factors affecting insect dispersal among a wide range of species.

The study of insect blood-feeding behaviour. 2. Recording techniques and the use of flow charts.

PubMed

Smith, J J; Friend, W G

1987-01-01

This paper continues a discussion of approaches and methodologies we have used in our studies of feeding in haematophagous insects. Described are techniques for directly monitoring behaviour: electrical recording of feeding behaviour via resistance changes in the food canal, optical methods for monitoring mouthpart activity, and a computer technique for behavioural event recording. Also described is the use of "flow charts" or "decision diagrams" to model interrelated sequences of behaviours.

Assessing gene expression during pathogenesis: Use of qRT-PCR to follow toxin production in the entomopathogenic fungus Beauveria bassiana during infection and immune response of the insect host Triatoma infestans.

PubMed

Lobo, Luciana S; Luz, Christian; Fernandes, Éverton K K; Juárez, M Patricia; Pedrini, Nicolás

2015-06-01

Entomopathogenic fungi secrete toxic secondary metabolites during the invasion of the insect hemocoel as part of the infection process. Although these compounds have been frequently mentioned as virulence factors, the roles of many of them remain poorly understood, including the question of whether they are expressed during the infection process. A major hurdle to this issue remains the low sensitivity of biochemical detection techniques (e.g., HPLC) within the complex samples that may contain trace quantities of fungal molecules inside the insect. In this study, quantitative reverse transcription real-time PCR (qRT-PCR) was used to measure the transcript levels within the insect fungal pathogen Beauveria bassiana, that encode for the synthetase enzymes of the secondary metabolites tenellin (BbtenS), beauvericin (BbbeaS) and bassianolide (BbbslS) during the infection of Triatoma infestans, a Chagas disease insect vector. Absolute quantification was performed at different time periods after insect treatment with various concentrations of propagules, either by immersing the insects in conidial suspensions or by injecting them with blastospores. Both BbtenS and BbbeaS were highly expressed in conidia-treated insects at days 3 and 12 post-treatment. In blastospore-injected insects, BbtenS and BbbeaS expression peaked at 24h post-injection and were also highly expressed in insect cadavers. The levels of BbbslS transcripts were much lower in all conditions tested. The expression patterns of insect genes encoding proteins that belong to the T. infestans humoral immune system were also evaluated with the same technique. This qPCR-based methodology can contribute to decifering the dynamics of entomopathogenic fungal infection at the molecular level. Copyright © 2015 Elsevier Inc. All rights reserved.

Identification of metabolically active bacteria in the gut of the generalist Spodoptera littoralis via DNA stable isotope probing using 13C-glucose.

PubMed

Shao, Yongqi; Arias-Cordero, Erika M; Boland, Wilhelm

2013-11-13

Guts of most insects are inhabited by complex communities of symbiotic nonpathogenic bacteria. Within such microbial communities it is possible to identify commensal or mutualistic bacteria species. The latter ones, have been observed to serve multiple functions to the insect, i.e. helping in insect reproduction(1), boosting the immune response(2), pheromone production(3), as well as nutrition, including the synthesis of essential amino acids(4,) among others.     Due to the importance of these associations, many efforts have been made to characterize the communities down to the individual members. However, most of these efforts were either based on cultivation methods or relied on the generation of 16S rRNA gene fragments which were sequenced for final identification. Unfortunately, these approaches only identified the bacterial species present in the gut and provided no information on the metabolic activity of the microorganisms. To characterize the metabolically active bacterial species in the gut of an insect, we used stable isotope probing (SIP) in vivo employing (13)C-glucose as a universal substrate. This is a promising culture-free technique that allows the linkage of microbial phylogenies to their particular metabolic activity. This is possible by tracking stable, isotope labeled atoms from substrates into microbial biomarkers, such as DNA and RNA(5). The incorporation of (13)C isotopes into DNA increases the density of the labeled DNA compared to the unlabeled ((12)C) one. In the end, the (13)C-labeled DNA or RNA is separated by density-gradient ultracentrifugation from the (12)C-unlabeled similar one(6). Subsequent molecular analysis of the separated nucleic acid isotopomers provides the connection between metabolic activity and identity of the species. Here, we present the protocol used to characterize the metabolically active bacteria in the gut of a generalist insect (our model system), Spodoptera littoralis (Lepidoptera, Noctuidae). The phylogenetic analysis of the DNA was done using pyrosequencing, which allowed high resolution and precision in the identification of insect gut bacterial community. As main substrate, (13)C-labeled glucose was used in the experiments. The substrate was fed to the insects using an artificial diet.

Guidelines for the use of mathematics in operational area-wide integrated pest management programs using the sterile insect technique with a special focus on Tephritid Fruit Flies

USDA-ARS?s Scientific Manuscript database

Pest control managers can benefit from using mathematical approaches, particularly models, when implementing area-wide pest control programs that include sterile insect technique (SIT), especially when these are used to calculate required rates of sterile releases to result in suppression or eradica...

Microbial ecology-based methods to characterize the bacterial communities of non-model insects.

PubMed

Prosdocimi, Erica M; Mapelli, Francesca; Gonella, Elena; Borin, Sara; Crotti, Elena

2015-12-01

Among the animals of the Kingdom Animalia, insects are unparalleled for their widespread diffusion, diversity and number of occupied ecological niches. In recent years they have raised researcher interest not only because of their importance as human and agricultural pests, disease vectors and as useful breeding species (e.g. honeybee and silkworm), but also because of their suitability as animal models. It is now fully recognized that microorganisms form symbiotic relationships with insects, influencing their survival, fitness, development, mating habits and the immune system and other aspects of the biology and ecology of the insect host. Thus, any research aimed at deepening the knowledge of any given insect species (perhaps species of applied interest or species emerging as novel pests or vectors) must consider the characterization of the associated microbiome. The present review critically examines the microbiology and molecular ecology techniques that can be applied to the taxonomical and functional analysis of the microbiome of non-model insects. Our goal is to provide an overview of current approaches and methods addressing the ecology and functions of microorganisms and microbiomes associated with insects. Our focus is on operational details, aiming to provide a concise guide to currently available advanced techniques, in an effort to extend insect microbiome research beyond simple descriptions of microbial communities. Copyright © 2015 Elsevier B.V. All rights reserved.

Induction of soybean resistance to the Mexican bean beetle (Coleoptera: Coccinellidae)

Treesearch

A.L. Iverson; R.B. Hammond; L.R. Iverson

2001-01-01

We tested chemical and insect feeding-induced insect resistance on soybean plants.The chemical induction effects of jasmonic acid (JA) and salicylic acid (SA) were investigated. We also evaluated the effects of plants stressed with previous insect herbivory. A larval antibiosis screening technique (LAST) and a preference test were performed in petri dishes using...

Omaha District Final Cultural Resource Site Monitoring Plan

DTIC Science & Technology

2014-06-01

water or other potentially dangerous risks such as snakes , insects, and poisonous plants may also be encountered. The work also requires regular...such as snakes , insects, and poisonous plants may also be encountered. The work also requires regular physical exertion such as bending and walking

Synchrotron Radiation X-ray Diffraction Techniques Applied to Insect Flight Muscle.

PubMed

Iwamoto, Hiroyuki

2018-06-13

X-ray fiber diffraction is a powerful tool used for investigating the molecular structure of muscle and its dynamics during contraction. This technique has been successfully applied not only to skeletal and cardiac muscles of vertebrates but also to insect flight muscle. Generally, insect flight muscle has a highly ordered structure and is often capable of high-frequency oscillations. The X-ray diffraction studies on muscle have been accelerated by the advent of 3rd-generation synchrotron radiation facilities, which can generate brilliant and highly oriented X-ray beams. This review focuses on some of the novel experiments done on insect flight muscle by using synchrotron radiation X-rays. These include diffraction recordings from single myofibrils within a flight muscle fiber by using X-ray microbeams and high-speed diffraction recordings from the flight muscle during the wing-beat of live insects. These experiments have provided information about the molecular structure and dynamic function of flight muscle in unprecedented detail. Future directions of X-ray diffraction studies on muscle are also discussed.

Postharvest processes of edible insects in Africa: A review of processing methods, and the implications for nutrition, safety and new products development.

PubMed

Mutungi, C; Irungu, F G; Nduko, J; Mutua, F; Affognon, H; Nakimbugwe, D; Ekesi, S; Fiaboe, K K M

2017-08-30

In many African cultures, insects are part of the diet of humans and domesticated animals. Compared to conventional food and feed sources, insects have been associated with a low ecological foot print because fewer natural resources are required for their production. To this end, the Food and Agriculture Organization of the United Nations recognized the role that edible insects can play in improving global food and nutrition security; processing technologies, as well as packaging and storage techniques that improve shelf-life were identified as being crucial. However, knowledge of these aspects in light of nutritional value, safety, and functionality is fragmentary and needs to be consolidated. This review attempts to contribute to this effort by evaluating the available evidence on postharvest processes for edible insects in Africa, with the aim of identifying areas that need research impetus. It further draws attention to potential postharvest technology options for overcoming hurdles associated with utilization of insects for food and feed. A greater research thrust is needed in processing and this can build on traditional knowledge. The focus should be to establish optimal techniques that improve presentation, quality and safety of products, and open possibilities to diversify use of edible insects for other benefits.

Cellulolytic systems in insects.

PubMed

Watanabe, Hirofumi; Tokuda, Gaku

2010-01-01

Despite the presence of many carbohydrolytic activities in insects, their cellulolytic mechanisms are poorly understood. Whereas cellulase genes are absent from the genomes of Drosophila melanogaster or Bombyx mori, other insects such as termites produce their own cellulases. Recent studies using molecular biological techniques have brought new insights into the mechanisms by which the insects and their microbial symbionts digest cellulose in the small intestine. DNA sequences of cellulase and associated genes, as well as physiological and morphological information about the digestive systems of cellulase-producing insects, may allow the efficient use of cellulosic biomass as a sustainable energy source.

Environmental Adaptations, Ecological Filtering, and Dispersal Central to Insect Invasions.

PubMed

Renault, David; Laparie, Mathieu; McCauley, Shannon J; Bonte, Dries

2018-01-07

Insect invasions, the establishment and spread of nonnative insects in new regions, can have extensive economic and environmental consequences. Increased global connectivity accelerates rates of introductions, while climate change may decrease the barriers to invader species' spread. We follow an individual-level insect- and arachnid-centered perspective to assess how the process of invasion is influenced by phenotypic heterogeneity associated with dispersal and stress resistance, and their coupling, across the multiple steps of the invasion process. We also provide an overview and synthesis on the importance of environmental filters during the entire invasion process for the facilitation or inhibition of invasive insect population spread. Finally, we highlight important research gaps and the relevance and applicability of ongoing natural range expansions in the context of climate change to gain essential mechanistic insights into insect invasions.

Impacts of Insect Herbivores on Plant Populations.

PubMed

Myers, Judith H; Sarfraz, Rana M

2017-01-31

Apparent feeding damage by insects on plants is often slight. Thus, the influences of insect herbivores on plant populations are likely minor. The role of insects on host-plant populations can be elucidated via several methods: stage-structured life tables of plant populations manipulated by herbivore exclusion and seed-addition experiments, tests of the enemy release hypothesis, studies of the effects of accidentally and intentionally introduced insect herbivores, and observations of the impacts of insect species that show outbreak population dynamics. These approaches demonstrate that some, but not all, insect herbivores influence plant population densities. At times, insect-feeding damage kills plants, but more often, it reduces plant size, growth, and seed production. Plant populations for which seed germination is site limited will not respond at the population level to reduced seed production. Insect herbivores can influence rare plant species and need to be considered in conservation programs. Alterations due to climate change in the distributions of insect herbivores indicate the possibility of new influences on host plants. Long-term studies are required to show if density-related insect behavior stabilizes plant populations or if environmental variation drives most temporal fluctuations in plant densities. Finally, insects can influence plant populations and communities through changing the diversity of nonhost species, modifying nutrient fluxes, and rejuvenating over mature forests.

A DsRed fluorescent protein marker under polyubiquitin promoter regulation allows visual and amplified gene detection of transgenic Caribbean fruit flies in liquid traps

USDA-ARS?s Scientific Manuscript database

Field population surveillance of a targeted insect pest species is critical to the evaluation of management programs such as the sterile insect technique. Use of markers to distinguish released insects from the field population is essential, but fluorescent powder dyes used on tephritid species are ...

A spatial model with pulsed releases to compare strategies for the sterile insect technique applied to the mosquito Aedes aegypti.

PubMed

Oléron Evans, Thomas P; Bishop, Steven R

2014-08-01

We present a simple mathematical model to replicate the key features of the sterile insect technique (SIT) for controlling pest species, with particular reference to the mosquito Aedes aegypti, the main vector of dengue fever. The model differs from the majority of those studied previously in that it is simultaneously spatially explicit and involves pulsed, rather than continuous, sterile insect releases. The spatially uniform equilibria of the model are identified and analysed. Simulations are performed to analyse the impact of varying the number of release sites, the interval between pulsed releases and the overall volume of sterile insect releases on the effectiveness of SIT programmes. Results show that, given a fixed volume of available sterile insects, increasing the number of release sites and the frequency of releases increases the effectiveness of SIT programmes. It is also observed that programmes may become completely ineffective if the interval between pulsed releases is greater that a certain threshold value and that, beyond a certain point, increasing the overall volume of sterile insects released does not improve the effectiveness of SIT. It is also noted that insect dispersal drives a rapid recolonisation of areas in which the species has been eradicated and we argue that understanding the density dependent mortality of released insects is necessary to develop efficient, cost-effective SIT programmes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Extracellular wire tetrode recording in brain of freely walking insects.

PubMed

Guo, Peiyuan; Pollack, Alan J; Varga, Adrienn G; Martin, Joshua P; Ritzmann, Roy E

2014-04-01

Increasing interest in the role of brain activity in insect motor control requires that we be able to monitor neural activity while insects perform natural behavior. We previously developed a technique for implanting tetrode wires into the central complex of cockroach brains that allowed us to record activity from multiple neurons simultaneously while a tethered cockroach turned or altered walking speed. While a major advance, tethered preparations provide access to limited behaviors and often lack feedback processes that occur in freely moving animals. We now present a modified version of that technique that allows us to record from the central complex of freely moving cockroaches as they walk in an arena and deal with barriers by turning, climbing or tunneling. Coupled with high speed video and cluster cutting, we can now relate brain activity to various parameters of the movement of freely behaving insects.

Traps and attractants for wood-boring insects in ponderosa pine stands in the Black Hills, South Dakota

Treesearch

Sheryl L. Costello; Jose F. Negron; William R. Jacobi

2008-01-01

Recent large-scale wildfires have increased populations of wood-boring insects in the Black Hills of South Dakota. Because little is known about possible impacts of wood-boring insects in the Black Hills, land managers are interested in developing monitoring techniques such as flight trapping with semiochemical baits. Two trap designs and four semiochemical attractants...

Insects as a Nitrogen Source for Plants

PubMed Central

Behie, Scott W.; Bidochka, Michael J.

2013-01-01

Many plants have evolved adaptations in order to survive in low nitrogen environments. One of the best-known adaptations is that of plant symbiosis with nitrogen-fixing bacteria; this is the major route by which nitrogen is incorporated into plant biomass. A portion of this plant-associated nitrogen is then lost to insects through herbivory, and insects represent a nitrogen reservoir that is generally overlooked in nitrogen cycles. In this review we show three specialized plant adaptations that allow for the recovery of insect nitrogen; that is, plants gaining nitrogen from insects. First, we show specialized adaptations by carnivorous plants in low nitrogen habitats. Insect carnivorous plants such as pitcher plants and sundews (Nepenthaceae/Sarraceniaceae and Drosera respectively) are able to obtain substantial amounts of nitrogen from the insects that they capture. Secondly, numerous plants form associations with mycorrhizal fungi that can provide soluble nitrogen from the soil, some of which may be insect-derived nitrogen, obtained from decaying insects or insect frass. Finally, a specialized group of endophytic, insect-pathogenic fungi (EIPF) provide host plants with insect-derived nitrogen. These soil-inhabiting fungi form a remarkable symbiosis with certain plant species. They can infect a wide range of insect hosts and also form endophytic associations in which they transfer insect-derived nitrogen to the plant. Root colonizing fungi are found in disparate fungal phylogenetic lineages, indicating possible convergent evolutionary strategies between taxa, evolution potentially driven by access to carbon-containing root exudates. PMID:26462427

Gold nanoparticles - against parasites and insect vectors.

PubMed

Benelli, Giovanni

2018-02-01

Nanomaterials are currently considered for many biological, biomedical and environmental purposes, due to their outstanding physical and chemical properties. The synthesis of gold nanoparticles (Au NPs) is of high interest for research in parasitology and entomology, since these nanomaterials showed promising applications, ranging from detection techniques to drug development, against a rather wide range of parasites of public health relevance, as well as on insect vectors. Here, I reviewed current knowledge about the bioactivity of Au NPs on selected insect species of public health relevance, including major mosquito vectors, such as Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The toxicity of Au NPs against helminths was reviewed, covering Schistosoma mansoni trematodes as well as Raillietina cestodes. Furthermore, I summarized the information available on the antiparasitic role of Au NPs in the fight against malaria, leishmaniosis, toxoplasmosis, trypanosomiasis, cryptosporidiosis, and microsporidian parasites affecting human and animals health. Besides, I examined the employ of Au NPs as biomarkers, tools for diagnostics and adjuvants for the induction of transmission blocking immunity in malaria vaccine research. In the final section, major challenges and future outlooks for further research are discussed, with special reference to the pressing need of further knowledge about the effect of Au NPs on other arthropod vectors, such as ticks, tsetse flies, tabanids, sandflies and blackflies, and related ecotoxicology assays. Copyright © 2017 Elsevier B.V. All rights reserved.

75 FR 47592 - Final Test Guideline; Product Performance of Skin-applied Insect Repellents of Insect and Other...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-06

... considerations affecting the design and conduct of repellent studies when human subjects are involved. Any... recommendations for the design and execution of studies to evaluate the performance of pesticide products intended... recommends appropriate study designs and methods for selecting subjects, statistical analysis, and reporting...

Integrated Insect Control May Alter Pesticide Use Pattern

ERIC Educational Resources Information Center

Worthy, Ward

1973-01-01

Discusses the use of predators, parasites, bacteria, viruses, hormones, pheromones, and sterile-male release and insect-resistance imparting techniques in pest control. Concludes with comments from chemical pesticide companies as popular attitudes toward the integrated pest management. (CC)

Remote sensing of forest insect disturbances: Current state and future directions

NASA Astrophysics Data System (ADS)

Senf, Cornelius; Seidl, Rupert; Hostert, Patrick

2017-08-01

Insect disturbance are important agents of change in forest ecosystems around the globe, yet their spatial and temporal distribution and dynamics are not well understood. Remote sensing has gained much attention in mapping and understanding insect outbreak dynamics. Consequently, we here review the current literature on the remote sensing of insect disturbances. We suggest to group studies into three insect types: bark beetles, broadleaved defoliators, and coniferous defoliators. By so doing, we systematically compare the sensors and methods used for mapping insect disturbances within and across insect types. Results suggest that there are substantial differences between methods used for mapping bark beetles and defoliators, and between methods used for mapping broadleaved and coniferous defoliators. Following from this, we highlight approaches that are particularly suited for each insect type. Finally, we conclude by highlighting future research directions for remote sensing of insect disturbances. In particular, we suggest to: 1) Separate insect disturbances from other agents; 2) Extend the spatial and temporal domain of analysis; 3) Make use of dense time series; 4) Operationalize near-real time monitoring of insect disturbances; 5) Identify insect disturbances in the context of coupled human-natural systems; and 6) Improve reference data for assessing insect disturbances. Since the remote sensing of insect disturbances has gained much interest beyond the remote sensing community recently, the future developments identified here will help integrating remote sensing products into operational forest management. Furthermore, an improved spatiotemporal quantification of insect disturbances will support an inclusion of these processes into regional to global ecosystem models.

Remote sensing of forest insect disturbances: Current state and future directions.

PubMed

Senf, Cornelius; Seidl, Rupert; Hostert, Patrick

2017-08-01

Insect disturbance are important agents of change in forest ecosystems around the globe, yet their spatial and temporal distribution and dynamics are not well understood. Remote sensing has gained much attention in mapping and understanding insect outbreak dynamics. Consequently, we here review the current literature on the remote sensing of insect disturbances. We suggest to group studies into three insect types: bark beetles, broadleaved defoliators, and coniferous defoliators. By so doing, we systematically compare the sensors and methods used for mapping insect disturbances within and across insect types. Results suggest that there are substantial differences between methods used for mapping bark beetles and defoliators, and between methods used for mapping broadleaved and coniferous defoliators. Following from this, we highlight approaches that are particularly suited for each insect type. Finally, we conclude by highlighting future research directions for remote sensing of insect disturbances. In particular, we suggest to: 1) Separate insect disturbances from other agents; 2) Extend the spatial and temporal domain of analysis; 3) Make use of dense time series; 4) Operationalize near-real time monitoring of insect disturbances; 5) Identify insect disturbances in the context of coupled human-natural systems; and 6) Improve reference data for assessing insect disturbances. Since the remote sensing of insect disturbances has gained much interest beyond the remote sensing community recently, the future developments identified here will help integrating remote sensing products into operational forest management. Furthermore, an improved spatiotemporal quantification of insect disturbances will support an inclusion of these processes into regional to global ecosystem models.

Trap Type, Chirality of a-Pinene, and Geographic Region Affect Sampling Efficiency of Root and Lower Stem Insects in Pine

Treesearch

Nadir Erbilgin; Alex Szele; Kier Dean Klepzig; Kenneth Francis Raffa

2001-01-01

Root and lower stem insects cause significant damage to conifers, vector phytopathogenic fungi, and can predispose trees to bark beetle attacks. The development of effective sampling techniques is an important component in managing these cryptic insects. We tested the effects of trap type and stereochemistry of a-pinene, in combination with ethanol, on catches of the...

Studies of the Biology of Phleboviruses in Sandflies.

DTIC Science & Technology

1984-02-01

captivity. These insects are much less prolific than mosquitoes and each generation takes approximately 6 to 8 weeks to develop. Furthermore, the daily...care of sandflies is extremely labor intensive. Therefore, new techniques for rearing the insects had to be developed. For these reasons, it was not...to mass rear sandflies and produce several thousand insects of each species per generation. In fact, our production now exceeds our experimental needs

Modelling Aedes aegypti mosquito control via transgenic and sterile insect techniques: endemics and emerging outbreaks.

PubMed

Seirin Lee, S; Baker, R E; Gaffney, E A; White, S M

2013-08-21

The invasion of pest insects often changes or destroys a native ecosystem, and can result in food shortages and disease endemics. Issues such as the environmental effects of chemical control methods, the economic burden of maintaining control strategies and the risk of pest resistance still remain, and mosquito-borne diseases such as malaria and dengue fever prevail in many countries, infecting over 100 million worldwide in 2010. One environmentally friendly method for mosquito control is the Sterile Insect Technique (SIT). This species-specific method of insect control relies on the mass rearing, sterilization and release of large numbers of sterile insects. An alternative transgenic method is the Release of Insects carrying a Dominant Lethal (RIDL). Our objective is to consider contrasting control strategies for two invasive scenarios via SIT and RIDL: an endemic case and an emerging outbreak. We investigate how the release rate and size of release region influence both the potential for control success and the resources needed to achieve it, under a range of conditions and control strategies, and we discuss advantageous strategies with respect to reducing the release resources and strategy costs (in terms of control mosquito numbers) required to achieve complete eradication of wild-type mosquitoes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nonlinear acoustics in cicada mating calls enhance sound propagation.

PubMed

Hughes, Derke R; Nuttall, Albert H; Katz, Richard A; Carter, G Clifford

2009-02-01

An analysis of cicada mating calls, measured in field experiments, indicates that the very high levels of acoustic energy radiated by this relatively small insect are mainly attributed to the nonlinear characteristics of the signal. The cicada emits one of the loudest sounds in all of the insect population with a sound production system occupying a physical space typically less than 3 cc. The sounds made by tymbals are amplified by the hollow abdomen, functioning as a tuned resonator, but models of the signal based solely on linear techniques do not fully account for a sound radiation capability that is so disproportionate to the insect's size. The nonlinear behavior of the cicada signal is demonstrated by combining the mutual information and surrogate data techniques; the results obtained indicate decorrelation when the phase-randomized and non-phase-randomized data separate. The Volterra expansion technique is used to fit the nonlinearity in the insect's call. The second-order Volterra estimate provides further evidence that the cicada mating calls are dominated by nonlinear characteristics and also suggests that the medium contributes to the cicada's efficient sound propagation. Application of the same principles has the potential to improve radiated sound levels for sonar applications.

Nondestructive detection of infested chestnuts based on NIR spectroscopy

USDA-ARS?s Scientific Manuscript database

Insect feeding is a significant postharvest problem for processors of Chestnuts (Castanea sativa, Miller). In most cases, damage from insects is 'hidden', i.e. not visually detectable on the fruit surface. Consequently, traditional sorting techniques, including manual sorting, are generally inadequa...

Social insects and selfish genes.

PubMed

Bourke, A F

2001-10-01

Sometimes science advances because of a new idea. Sometimes, it's because of a new technique. When both occur together, exciting times result. In the study of social insects, DNA-based methods for measuring relatedness now allow increasingly detailed tests of Hamilton's theory of kin selection.

When insect endosymbionts and plant endophytes mediate biological control outcomes

USDA-ARS?s Scientific Manuscript database

The identification of endosymbionts and endophytes within insect and plant tissues, respectively, has increased exponentially over the past 10-15 years, enabled largely by the proliferation of sensitive molecular techniques and publicly accessible databases of nucleotide sequences. However, the rate...

Knockdown of Midgut Genes by dsRNA-Transgenic Plant-Mediated RNA Interference in the Hemipteran Insect Nilaparvata lugens

PubMed Central

Zha, Wenjun; Peng, Xinxin; Chen, Rongzhi; Du, Bo; Zhu, Lili; He, Guangcun

2011-01-01

Background RNA interference (RNAi) is a powerful technique for functional genomics research in insects. Transgenic plants producing double-stranded RNA (dsRNA) directed against insect genes have been reported for lepidopteran and coleopteran insects, showing potential for field-level control of insect pests, but this has not been reported for other insect orders. Methodology/Principal Findings The Hemipteran insect brown planthopper (Nilaparvata lugens Stål) is a typical phloem sap feeder specific to rice (Oryza sativa L.). To analyze the potential of exploiting RNAi-mediated effects in this insect, we identified genes (Nlsid-1 and Nlaub) encoding proteins that might be involved in the RNAi pathway in N. lugens. Both genes are expressed ubiquitously in nymphs and adult insects. Three genes (the hexose transporter gene NlHT1, the carboxypeptidase gene Nlcar and the trypsin-like serine protease gene Nltry) that are highly expressed in the N. lugens midgut were isolated and used to develop dsRNA constructs for transforming rice. RNA blot analysis showed that the dsRNAs were transcribed and some of them were processed to siRNAs in the transgenic lines. When nymphs were fed on rice plants expressing dsRNA, levels of transcripts of the targeted genes in the midgut were reduced; however, lethal phenotypic effects after dsRNA feeding were not observed. Conclusions Our study shows that genes for the RNAi pathway (Nlsid-1 and Nlaub) are present in N. lugens. When insects were fed on rice plant materials expressing dsRNAs, RNA interference was triggered and the target genes transcript levels were suppressed. The gene knockdown technique described here may prove to be a valuable tool for further investigations in N. lugens. The results demonstrate the potential of dsRNA-mediated RNAi for field-level control of planthoppers, but appropriate target genes must be selected when designing the dsRNA-transgenic plants. PMID:21655219

Bacillus thuringiensis: A story of a successful bioinsecticide

PubMed Central

Bravo, Alejandra; Likitvivatanavong, Supaporn; Gill, Sarjeet S.; Soberón, Mario

2013-01-01

Bacillus thuringiensis (Bt) bacteria are insect pathogens that rely on insecticidal pore forming proteins known as Cry and Cyt toxins to kill their insect larval hosts. At least four different non-structurally related families of proteins form the Cry toxin group of toxins. The expression of certain Cry toxins in transgenic crops has contributed to an efficient control of insect pests resulting in a significant reduction in chemical insecticide use. The mode of action of the three domain Cry toxin family involves sequential interaction of these toxins with several insect midgut proteins facilitating the formation of a pre-pore oligomer structure and subsequent membrane insertion that leads to the killing of midgut insect cells by osmotic shock. In this manuscript we review recent progress in understanding the mode of action of this family of proteins in lepidopteran, dipteran and coleopteran insects. Interestingly, similar Cry-binding proteins have been identified in the three insect orders, as cadherin, aminopeptidase-N and alkaline phosphatase suggesting a conserved mode of action. Also, recent data on insect responses to Cry toxin attack is discussed. Finally, we review the different Bt based products, including transgenic crops, that are currently used in agriculture. PMID:21376122

Uptake and effectiveness of systemic insecticides as influenced by application technique

USDA-ARS?s Scientific Manuscript database

The use of systemic neonicotinoid insecticides such as Imidacloprid and Thiamethoxam have been shown to be effective against different types of insects including sucking insect like aphids, whiteflies, scales and mealybugs. The most common forms of application of these neonicotinoid insecticides ha...

Forensic entomology

NASA Astrophysics Data System (ADS)

Amendt, Jens; Krettek, Roman; Zehner, Richard

Necrophagous insects are important in the decomposition of cadavers. The close association between insects and corpses and the use of insects in medicocriminal investigations is the subject of forensic entomology. The present paper reviews the historical background of this discipline, important postmortem processes, and discusses the scientific basis underlying attempts to determine the time interval since death. Using medical techniques, such as the measurement of body temperature or analysing livor and rigor mortis, time since death can only be accurately measured for the first two or three days after death. In contrast, by calculating the age of immature insect stages feeding on a corpse and analysing the necrophagous species present, postmortem intervals from the first day to several weeks can be estimated. These entomological methods may be hampered by difficulties associated with species identification, but modern DNA techniques are contributing to the rapid and authoritative identification of necrophagous insects. Other uses of entomological data include the toxicological examination of necrophagous larvae from a corpse to identify and estimate drugs and toxicants ingested by the person when alive and the proof of possible postmortem manipulations. Forensic entomology may even help in investigations dealing with people who are alive but in need of care, by revealing information about cases of neglect.

Phenotypic Plasticity of Cuticular Hydrocarbon Profiles in Insects.

PubMed

Otte, Tobias; Hilker, Monika; Geiselhardt, Sven

2018-03-01

The insect integument is covered by cuticular hydrocarbons (CHCs) which provide protection against environmental stresses, but are also used for communication. Here we review current knowledge on environmental and insect-internal factors which shape phenotypic plasticity of solitary living insects, especially herbivorous ones. We address the dynamics of changes which may occur within minutes, but may also last weeks, depending on the species and conditions. Two different modes of changes are suggested, i.e. stepwise and gradual. A switch between two distinct environments (e.g. host plant switch by phytophagous insects) results in stepwise formation of two distinct adaptive phenotypes, while a gradual environmental change (e.g. temperature gradients) induces a gradual change of numerous adaptive CHC phenotypes. We further discuss the ecological and evolutionary consequences of phenotypic plasticity of insect CHC profiles by addressing the question at which conditions is CHC phenotypic plasticity beneficial. The high plasticity of CHC profiles might be a trade-off for insects using CHCs for communication. We discuss how insects cope with the challenge to produce and "understand" a highly plastic, environmentally dependent CHC pattern that conveys reliable and comprehensible information. Finally, we outline how phenotypic plasticity of CHC profiles may promote speciation in insects that rely on CHCs for mate recognition.

Applications of magnetic resonance spectroscopy to chitin from insect cuticles.

PubMed

Gonil, Pattarapond; Sajomsang, Warayuth

2012-11-01

Chitin is the second most abundant polysaccharide in nature after cellulose. At the present time, the main commercial sources of chitin are the crab and shrimp shells which are major waste products from the seafood industry. However, current chitin resources have some inherent problems including seasonal availability, limited supplies, and environmental pollution. As an alternative, insect cuticle is proposed as an unconventional but viable source of chitin. This review focuses on the recent sources of insect chitin and the application of various magnetic resonance spectroscopic techniques to native insect cuticles, particularly cicada sloughs and chitin extracted from insect sloughs. In addition, the physicochemical properties, isolation process, and degree of N-acetylation (DA) is reviewed and discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of Techniques for Sampling Adult Necrophilous Insects From Pig Carcasses.

PubMed

Cruise, Angela; Hatano, Eduardo; Watson, David W; Schal, Coby

2018-02-06

Studies of the pre-colonization interval and mechanisms driving necrophilous insect ecological succession depend on effective sampling of adult insects and knowledge of their diel and successional activity patterns. The number of insects trapped, their diversity, and diel periodicity were compared with four sampling methods on neonate pigs. Sampling method, time of day and decomposition age of the pigs significantly affected the number of insects sampled from pigs. We also found significant interactions of sampling method and decomposition day, time of sampling and decomposition day. No single method was superior to the other methods during all three decomposition days. Sampling times after noon yielded the largest samples during the first 2 d of decomposition. On day 3 of decomposition however, all sampling times were equally effective. Therefore, to maximize insect collections from neonate pigs, the method used to sample must vary by decomposition day. The suction trap collected the most species-rich samples, but sticky trap samples were the most diverse, when both species richness and evenness were factored into a Shannon diversity index. Repeated sampling during the noon to 18:00 hours period was most effective to obtain the maximum diversity of trapped insects. The integration of multiple sampling techniques would most effectively sample the necrophilous insect community. However, because all four tested methods were deficient at sampling beetle species, future work should focus on optimizing the most promising methods, alone or in combinations, and incorporate hand-collections of beetles. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A framework for standardizing flight characteristics for separating biology from meteorology in long-range insect transport

Treesearch

Gary L. Achtemeier

1998-01-01

Once airborne during long-range transport, to what extent is the final destination determined by the biota? It is well known that a biological mechanism initiates flight and another biological mechanism terminates flight. Therefore, efforts to answer the above question should be focused on en route insect behavior. A strategy is proposed to isolate biology...

Freight transportation and the potential for invasions of exotic insects in urban and periurban forests of the United States

Treesearch

Manuel Colunga-Garcia; Robert A. Haack; Adesoji O. Adelaja

2009-01-01

Freight transportation is an important pathway for the introduction and dissemination of exotic forest insects (EFI). Identifying the final destination of imports is critical in determining the likelihood of EFI establishment. We analyzed the use of regional freight transport information to characterize risk of urban and periurban areas to EFI introductions. Specifc...

The Sterile Insect Technique (SIT) – an introduction

USDA-ARS?s Scientific Manuscript database

Environmental concerns have been a significant motivator in the development of alternative methods to the sole use of chemicals for controlling or even eradicating insect pests. Eradication is the elimination of all individuals of a species from a geographic area where reinvasion is unlikely to occu...

Insect anaphylaxis: addressing clinical challenges.

PubMed

Tracy, James M; Lewis, Elena J; Demain, Jeffrey G

2011-08-01

Few allergic reactions are as potentially life-threatening, or frightening to the patient, as anaphylaxis. Food, medications, and insect stings are the three most common triggers of anaphylaxis, but insect allergy provides the best opportunity to understand the biology of anaphylaxis. If the physician can establish a diagnosis of insect allergy, treatment with nearly 98% effectiveness can be initiated. However, sometimes patients have a compelling history of insect sting anaphylaxis, but negative skin and blood tests. This situation presents us with a fascinating opportunity to understand the biology of insect anaphylaxis. Recent and ongoing work shows that occult mast cell disease may be critical in insect anaphylaxis. Mastocytosis, serum tryptase and basophil biology are key elements; genetic markers may potentially help us diagnose at-risk individuals and determine proper treatment. Understanding basophil activation may play an additional role both in diagnosis and knowing when therapy might be terminated. Mast cell disease, serum tryptase and basophil biology are providing an opportunity to better understand and manage insect allergy. This evolving understanding should improve long-term management of insect anaphylaxis and help us to better understand the clinical dilemma of appropriate management of the history-positive patient in which testing is unable to detect venom-specific IgE. Furthermore, omalizumab's immunomodulatory effects may play a role in difficult-to-treat insect allergy and mastocytosis. Finally, unrelated to these, but still important as an ongoing risk factor, is the continued underutilization of epinephrine for both acute and long-term management of insect anaphylaxis.

Pest control: A modelling approach. Comment on “Multiscale approach to pest insect monitoring: Random walks, pattern formation, synchronization, and networks” by S. Petrovskii, N. Petrovskaya and D. Bearup

NASA Astrophysics Data System (ADS)

Tyson, Rebecca C.

2014-09-01

Successful food production results in the delivery to market of beautiful produce, free of damage from insects. All of that produce however, is an excellent and plentiful food source, and nature has evolved a multitude of insects that compete with humans for access. There exist a number of management strategies to combat pests, including traditional crop rotation and companion planting techniques, as well as more sophisticated techniques including mating disruption using pheromones and the application of chemical sprays. Chemical sprays are extremely effective, and are in widespread use around the globe [1,12,20]. Indeed, pesticides are the dominant form of pest management in current use [10,20].

A fundamental approach to the sticking of insect residues to aircraft wings

NASA Technical Reports Server (NTRS)

Eiss, N. S., Jr.; Wightman, J. P.; Gilliam, D. R.; Siochi, E. J.

1984-01-01

A proposed testing scheme is described for obtaining data on the effects of surface roughness and surface energy on insect adhesion. The road test apparatus is discussed as well as surface preparation techniques. Uncoated and polymer coated metal substrates were analyzed by SEM/ESCA/IRS before and following collision with insects. Critical surface tensions of unexposed Nyebar and poly sulfone coatings were 10 and 33 dynes/cm, respectively, as determined from contact angles. A total of 95% of insect residues collected belong to order Diptera. Significantly less insect debris was detected on the coated plates as compared to the uncoated plates. Minimal contamination at the 5 nm level of both coated and uncoated plates occurs even after hours of exposure to road conditions as determined by ESCA analysis. The presence of nitrogen detected by ESCA on exposed plates is unequivocal evidence for insect residues left on plates.

Sterile-Insect Methods for Control of Mosquito-Borne Diseases: An Analysis

PubMed Central

Benedict, Mark; Bellini, Romeo; Clark, Gary G.; Dame, David A.; Service, Mike W.; Dobson, Stephen L.

2010-01-01

Abstract Effective vector control, and more specifically mosquito control, is a complex and difficult problem, as illustrated by the continuing prevalence (and spread) of mosquito-transmitted diseases. The sterile insect technique and similar methods control certain agricultural insect pest populations in a species-specific, environmentally sound, and effective manner; there is increased interest in applying this approach to vector control. Such an approach, like all others in use and development, is not a one-size-fits-all solution, and will be more appropriate in some situations than others. In addition, the proposed release of pest insects, and more so genetically modified pest insects, is bound to raise questions in the general public and the scientific community as to such a method's efficacy, safety, and sustainability. This article attempts to address these concerns and indicate where sterile-insect methods are likely to be useful for vector control. PMID:19725763

Simulating Flying Insects Using Dynamics and Data-Driven Noise Modeling to Generate Diverse Collective Behaviors

PubMed Central

Ren, Jiaping; Wang, Xinjie; Manocha, Dinesh

2016-01-01

We present a biologically plausible dynamics model to simulate swarms of flying insects. Our formulation, which is based on biological conclusions and experimental observations, is designed to simulate large insect swarms of varying densities. We use a force-based model that captures different interactions between the insects and the environment and computes collision-free trajectories for each individual insect. Furthermore, we model the noise as a constructive force at the collective level and present a technique to generate noise-induced insect movements in a large swarm that are similar to those observed in real-world trajectories. We use a data-driven formulation that is based on pre-recorded insect trajectories. We also present a novel evaluation metric and a statistical validation approach that takes into account various characteristics of insect motions. In practice, the combination of Curl noise function with our dynamics model is used to generate realistic swarm simulations and emergent behaviors. We highlight its performance for simulating large flying swarms of midges, fruit fly, locusts and moths and demonstrate many collective behaviors, including aggregation, migration, phase transition, and escape responses. PMID:27187068

Diversity of peptidic and proteinaceous toxins from social Hymenoptera venoms.

PubMed

Dos Santos-Pinto, José Roberto Aparecido; Perez-Riverol, Amilcar; Lasa, Alexis Musacchio; Palma, Mario Sergio

2018-06-15

Among venomous animals, Hymenoptera have been suggested as a rich source of natural toxins. Due to their broad ecological diversity, venom from Hymenoptera insects (bees, wasps and ants) have evolved differentially thus widening the types and biological functions of their components. To date, insect toxinology analysis have scarcely uncovered the complex composition of bee, wasp and ant venoms which include low molecular weight compounds, highly abundant peptides and proteins, including several allergens. In Hymenoptera, these complex mixtures of toxins represent a potent arsenal of biological weapons that are used for self-defense, to repel intruders and to capture prey. Consequently, Hymenoptera venom components have a broad range of pharmacological targets and have been extensively studied, as promising sources of new drugs and biopesticides. In addition, the identification and molecular characterization of Hymenoptera venom allergens have allowed for the rational design of component-resolved diagnosis of allergy, finally improving the outcome of venom immunotherapy (VIT). Until recently, a limited number of Hymenoptera venoms had been unveiled due to the technical limitations of the approaches used to date. Nevertheless, the application of novel techniques with high dynamic range has significantly increased the number of identified peptidic and proteinaceous toxins. Considering this, the present review summarizes the current knowledge about the most representative Hymenoptera venom peptides and proteins which are under study for a better understanding of the insect-caused envenoming process and the development of new drugs and biopesticides. Copyright © 2018 Elsevier Ltd. All rights reserved.

Injection of insect membrane in Xenopus oocyte: An original method for the pharmacological characterization of neonicotinoid insecticides.

PubMed

Crespin, Lucille; Legros, Christian; List, Olivier; Tricoire-Leignel, Hélène; Mattei, César

2016-01-01

Insect nicotinic acetylcholine receptors (nAChRs) represent a major target of insecticides, belonging to the neonicotinoid family. However, the pharmacological profile of native nAChRs is poorly documented, mainly because of a lack of knowledge of their subunit stoichiometry, their tissue distribution and the weak access to nAChR-expressing cells. In addition, the expression of insect nAChRs in heterologous systems remains hard to achieve. Therefore, the structure-activity characterization of nAChR-targeting insecticides is made difficult. The objective of the present study was to characterize insect nAChRs by an electrophysiological approach in a heterologous system naturally devoid of these receptors to allow a molecular/cellular investigation of the mode of action of neonicotinoids. Methods To overcome impediments linked to the expression of insect nAChR mRNA or cDNA, we chose to inject insect membranes from the pea aphid (Acyrthosiphon pisum) into Xenopus oocytes. This microtransplantation technique was designed to gain access to native nAChRs embedded in their membrane, through direct stimulation with nicotinic agonists. Results We provide evidence that an enriched-nAChR membrane allows us to characterize native receptors. The presence of such receptors was confirmed with fluorescent α-BgTX labeling. Electrophysiological recordings of nicotine-induced inward currents allowed us to challenge the presence of functional nAChR. We compared the effect of nicotine (NIC) with clothianidin (CLO) and we assessed the effect of thiamethoxam (TMX). Discussion This technique has been recently highlighted with mammalian and human material as a powerful functional approach, but has, to our knowledge, never been used with insect membrane. In addition, the use of the insect membrane microtransplantation opens a new and original way for pharmacological screening of neurotoxic insecticides, including neonicotinoids. Moreover, it might also be a powerful tool to investigate the pharmacological properties of insect nAChR. Copyright © 2015 Elsevier Inc. All rights reserved.

Nuke 'Em! Library Pest Control Using a Microwave.

ERIC Educational Resources Information Center

Brezner, Jerome; Luner, Philip

1989-01-01

Discusses the threats to books and periodicals posed by such insects as book lice, termites, cockroaches, silverfish, firebrats, and beetles; reviews past methods of pest control; and describes a technique for insect control using microwaves. The results of tests of microwave effects on publications are reported, necessary precautions are…

Conceptual framework and rationale

PubMed Central

Robinson, Alan S; Knols, Bart GJ; Voigt, Gabriella; Hendrichs, Jorge

2009-01-01

The sterile insect technique (SIT) has been shown to be an effective and sustainable genetic approach to control populations of selected major pest insects, when part of area-wide integrated pest management (AW-IPM) programmes. The technique introduces genetic sterility in females of the target population in the field following their mating with released sterile males. This process results in population reduction or elimination via embryo lethality caused by dominant lethal mutations induced in sperm of the released males. In the past, several field trials have been carried out for mosquitoes with varying degrees of success. New technology and experience gained with other species of insect pests has encouraged a reassessment of the use of the sterility principle as part of integrated control of malaria vectors. Significant technical and logistic hurdles will need to be overcome to develop the technology and make it effective to suppress selected vector populations, and its application will probably be limited to specific ecological situations. Using sterile males to control mosquito vector populations can only be effective as part of an AW-IPM programme. The area-wide concept entails the targeting of the total mosquito population within a defined area. It requires, therefore, a thorough understanding of the target pest population biology especially as regards mating behaviour, population dynamics, dispersal and level of reproductive isolation. The key challenges for success are: 1) devising methods to monitor vector populations and measuring competitiveness of sterile males in the field, 2) designing mass rearing, sterilization and release strategies that maintain competitiveness of the sterile male mosquitoes, 3) developing methods to separate sexes in order to release only male mosquitoes and 4) adapting suppression measures and release rates to take into account the high reproductive rate of mosquitoes. Finally, success in area-wide implementation in the field can only be achieved if close attention is paid to political, socio-economic and environmental sensitivities and an efficient management organization is established taking into account the interests of all potential stakeholders of an AW-IPM programme. PMID:19917070

United States Department of Agriculture-Agricultural Research Service stored-grain areawide integrated pest management program.

PubMed

Flinn, Paul W; Hagstrum, David W; Reed, Carl; Phillips, Tom W

2003-01-01

The USDA Agricultural Research Service (ARS) funded a demonstration project (1998-2002) for areawide IPM for stored wheat in Kansas and Oklahoma. This project was a collaboration of researchers at the ARS Grain Marketing and Production Research Center in Manhattan, Kansas, Kansas State University, and Oklahoma State University. The project utilized two elevator networks, one in each state, for a total of 28 grain elevators. These elevators stored approximately 31 million bushels of wheat, which is approximately 1.2% of the annual national production. Stored wheat was followed as it moved from farm to the country elevator and finally to the terminal elevator. During this study, thousands of grain samples were taken in concrete elevator silos. Wheat stored at elevators was frequently infested by several insect species, which sometimes reached high numbers and damaged the grain. Fumigation using aluminum phosphide pellets was the main method for managing these insect pests in elevators in the USA. Fumigation decisions tended to be based on past experience with controlling stored-grain insects, or were calendar based. Integrated pest management (IPM) requires sampling and risk benefit analysis. We found that the best sampling method for estimating insect density, without turning the grain from one bin to another, was the vacuum probe sampler. Decision support software, Stored Grain Advisor Pro (SGA Pro) was developed that interprets insect sampling data, and provides grain managers with a risk analysis report detailing which bins are at low, moderate or high risk for insect-caused economic losses. Insect density was predicted up to three months in the future based on current insect density, grain temperature and moisture. Because sampling costs money, there is a trade-off between frequency of sampling and the cost of fumigation. The insect growth model in SGA Pro reduces the need to sample as often, thereby making the program more cost-effective. SGA Pro was validated during the final year of the areawide program. Based on data from 533 bins, SGA Pro accurately predicted which bins were at low, moderate or high risk. Only in two out of 533 bins did SGA Pro incorrectly predict bins as being low risk and, in both cases, insect density was only high (> two insects kg(-1)) at the surface, which suggested recent immigration. SGA Pro is superior to calendar-based management because it ensures that grain is only treated when insect densities exceed economic thresholds (two insects kg(-1)). This approach will reduce the frequency of fumigation while maintaining high grain quality. Minimizing the use of fumigant improves worker safety and reduces both control costs and harm to the environment.

Role of phermones and kairmones for insect suppression systems and their possible health and environmental impacts.

PubMed Central

Knipling, E F

1976-01-01

Insects produce pheromones as a chemical communication system to facilitate reproduction. These highly active chemical attractants have been synthesized for some of the most important insect pests, including the boll weevil, gypsy moth, codling moth, tobacco budworm, European corn borer, and several bark beetles. While none of the synthetic sex attractants have yet been developed for use in insect control, they offer opportunities for the future both as control agents and to greatly improved insect detection. Investigations are underway on insect trapping systems employing the phermones and on air permeation techniques to disrupt insect reproduction. The pheromones are generally highly species-specific and are not likely to pose hazards to nontarget organisms in the environment. Toxicological studies indicate that they are low in toxicity to mammals, birds, and fish, but adequate toxicological data are necessary before they can be registered for use in insect control. Another new class of compounds called kaironomes has been discovered. These chemicals are involved in the detection of hosts or prey by insect parasites and predators. Kairomones may prove useful in manipulating natural or released biological agents for more effective biological control of insect pests. No information is yet available on the toxicology of these chemicals. PMID:789061

Recent Advances in Developing Insect Natural Products as Potential Modern Day Medicines

PubMed Central

Ratcliffe, Norman; Azambuja, Patricia; Mello, Cicero Brasileiro

2014-01-01

Except for honey as food, and silk for clothing and pollination of plants, people give little thought to the benefits of insects in their lives. This overview briefly describes significant recent advances in developing insect natural products as potential new medicinal drugs. This is an exciting and rapidly expanding new field since insects are hugely variable and have utilised an enormous range of natural products to survive environmental perturbations for 100s of millions of years. There is thus a treasure chest of untapped resources waiting to be discovered. Insects products, such as silk and honey, have already been utilised for thousands of years, and extracts of insects have been produced for use in Folk Medicine around the world, but only with the development of modern molecular and biochemical techniques has it become feasible to manipulate and bioengineer insect natural products into modern medicines. Utilising knowledge gleaned from Insect Folk Medicines, this review describes modern research into bioengineering honey and venom from bees, silk, cantharidin, antimicrobial peptides, and maggot secretions and anticoagulants from blood-sucking insects into medicines. Problems and solutions encountered in these endeavours are described and indicate that the future is bright for new insect derived pharmaceuticals treatments and medicines. PMID:24883072

Resilience in social insect infrastructure systems

PubMed Central

2016-01-01

Both human and insect societies depend on complex and highly coordinated infrastructure systems, such as communication networks, supply chains and transportation networks. Like human-designed infrastructure systems, those of social insects are regularly subject to disruptions such as natural disasters, blockages or breaks in the transportation network, fluctuations in supply and/or demand, outbreaks of disease and loss of individuals. Unlike human-designed systems, there is no deliberate planning or centralized control system; rather, individual insects make simple decisions based on local information. How do these highly decentralized, leaderless systems deal with disruption? What factors make a social insect system resilient, and which factors lead to its collapse? In this review, we bring together literature on resilience in three key social insect infrastructure systems: transportation networks, supply chains and communication networks. We describe how systems differentially invest in three pathways to resilience: resistance, redirection or reconstruction. We suggest that investment in particular resistance pathways is related to the severity and frequency of disturbance. In the final section, we lay out a prospectus for future research. Human infrastructure networks are rapidly becoming decentralized and interconnected; indeed, more like social insect infrastructures. Human infrastructure management might therefore learn from social insect researchers, who can in turn make use of the mature analytical and simulation tools developed for the study of human infrastructure resilience. PMID:26962030

Organic farming favours insect-pollinated over non-insect pollinated forbs in meadows and wheat fields.

PubMed

Batáry, Péter; Sutcliffe, Laura; Dormann, Carsten F; Tscharntke, Teja

2013-01-01

The aim of this study was to determine the relative effects of landscape-scale management intensity, local management intensity and edge effect on diversity patterns of insect-pollinated vs. non-insect pollinated forbs in meadows and wheat fields. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional meadows. Within fields, forbs were surveyed at the edge and in the interior. Both diversity and cover of forbs were positively affected by organic management in meadows and wheat fields. This effect, however, differed significantly between pollination types for species richness in both agroecosystem types (i.e. wheat fields and meadows) and for cover in meadows. Thus, we show for the first time in a comprehensive analysis that insect-pollinated plants benefit more from organic management than non-insect pollinated plants regardless of agroecosystem type and landscape complexity. These benefits were more pronounced in meadows than wheat fields. Finally, the community composition of insect-pollinated and non-insect-pollinated forbs differed considerably between management types. In summary, our findings in both agroecosystem types indicate that organic management generally supports a higher species richness and cover of insect-pollinated plants, which is likely to be favourable for the density and diversity of bees and other pollinators.

Organic Farming Favours Insect-Pollinated over Non-Insect Pollinated Forbs in Meadows and Wheat Fields

PubMed Central

Batáry, Péter; Sutcliffe, Laura; Dormann, Carsten F.; Tscharntke, Teja

2013-01-01

The aim of this study was to determine the relative effects of landscape-scale management intensity, local management intensity and edge effect on diversity patterns of insect-pollinated vs. non-insect pollinated forbs in meadows and wheat fields. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional meadows. Within fields, forbs were surveyed at the edge and in the interior. Both diversity and cover of forbs were positively affected by organic management in meadows and wheat fields. This effect, however, differed significantly between pollination types for species richness in both agroecosystem types (i.e. wheat fields and meadows) and for cover in meadows. Thus, we show for the first time in a comprehensive analysis that insect-pollinated plants benefit more from organic management than non-insect pollinated plants regardless of agroecosystem type and landscape complexity. These benefits were more pronounced in meadows than wheat fields. Finally, the community composition of insect-pollinated and non-insect-pollinated forbs differed considerably between management types. In summary, our findings in both agroecosystem types indicate that organic management generally supports a higher species richness and cover of insect-pollinated plants, which is likely to be favourable for the density and diversity of bees and other pollinators. PMID:23382979

Attention-like processes in insects

PubMed Central

2016-01-01

Attention is fundamentally important for sensory systems to focus on behaviourally relevant stimuli. It has therefore been an important field of study in human psychology and neuroscience. Primates, however, are not the only animals that might benefit from attention-like processes. Other animals, including insects, also have to use their senses and select one among many stimuli to forage, avoid predators and find mates. They have evolved different mechanisms to reduce the information processed by their brains to focus on only relevant stimuli. What are the mechanisms used by insects to selectively attend to visual and auditory stimuli? Do these attention-like mechanisms achieve the same functions as they do in primates? To investigate these questions, I use an established framework for investigating attention in non-human animals that proposes four fundamental components of attention: salience filters, competitive selection, top-down sensitivity control and working memory. I discuss evidence for each of these component processes in insects and compare the characteristics of these processes in insects to what we know from primates. Finally, I highlight important outstanding questions about insect attention that need to be addressed for us to understand the differences and similarities between vertebrate and insect attention. PMID:27852803

Extracellular ice phase transitions in insects.

PubMed

Hawes, T C

2014-01-01

At temperatures below their temperature of crystallization (Tc), the extracellular body fluids of insects undergo a phase transition from liquid to solid. Insects that survive the transition to equilibrium (complete freezing of the body fluids) are designated as freeze tolerant. Although this phenomenon has been reported and described in many Insecta, current nomenclature and theory does not clearly delineate between the process of transition (freezing) and the final solid phase itself (the frozen state). Thus freeze tolerant insects are currently, by convention, described in terms of the temperature at which the crystallization of their body fluids is initiated, Tc. In fact, the correct descriptor for insects that tolerate freezing is the temperature of equilibrium freezing, Tef. The process of freezing is itself a separate physical event with unique physiological stresses that are associated with ice growth. Correspondingly there are a number of insects whose physiological cryo-limits are very specifically delineated by this transitional envelope. The distinction also has considerable significance for our understanding of insect cryobiology: firstly, because the ability to manage endogenous ice growth is a fundamental segregator of cryotype; and secondly, because our understanding of internal ice management is still largely nascent.

Insect immunology and hematopoiesis.

PubMed

Hillyer, Julián F

2016-05-01

Insects combat infection by mounting powerful immune responses that are mediated by hemocytes, the fat body, the midgut, the salivary glands and other tissues. Foreign organisms that have entered the body of an insect are recognized by the immune system when pathogen-associated molecular patterns bind host-derived pattern recognition receptors. This, in turn, activates immune signaling pathways that amplify the immune response, induce the production of factors with antimicrobial activity, and activate effector pathways. Among the immune signaling pathways are the Toll, Imd, Jak/Stat, JNK, and insulin pathways. Activation of these and other pathways leads to pathogen killing via phagocytosis, melanization, cellular encapsulation, nodulation, lysis, RNAi-mediated virus destruction, autophagy and apoptosis. This review details these and other aspects of immunity in insects, and discusses how the immune and circulatory systems have co-adapted to combat infection, how hemocyte replication and differentiation takes place (hematopoiesis), how an infection prepares an insect for a subsequent infection (immune priming), how environmental factors such as temperature and the age of the insect impact the immune response, and how social immunity protects entire groups. Finally, this review highlights some underexplored areas in the field of insect immunobiology. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Vision-Based Counting and Recognition System for Flying Insects in Intelligent Agriculture.

PubMed

Zhong, Yuanhong; Gao, Junyuan; Lei, Qilun; Zhou, Yao

2018-05-09

Rapid and accurate counting and recognition of flying insects are of great importance, especially for pest control. Traditional manual identification and counting of flying insects is labor intensive and inefficient. In this study, a vision-based counting and classification system for flying insects is designed and implemented. The system is constructed as follows: firstly, a yellow sticky trap is installed in the surveillance area to trap flying insects and a camera is set up to collect real-time images. Then the detection and coarse counting method based on You Only Look Once (YOLO) object detection, the classification method and fine counting based on Support Vector Machines (SVM) using global features are designed. Finally, the insect counting and recognition system is implemented on Raspberry PI. Six species of flying insects including bee, fly, mosquito, moth, chafer and fruit fly are selected to assess the effectiveness of the system. Compared with the conventional methods, the test results show promising performance. The average counting accuracy is 92.50% and average classifying accuracy is 90.18% on Raspberry PI. The proposed system is easy-to-use and provides efficient and accurate recognition data, therefore, it can be used for intelligent agriculture applications.

A Vision-Based Counting and Recognition System for Flying Insects in Intelligent Agriculture

PubMed Central

Zhong, Yuanhong; Gao, Junyuan; Lei, Qilun; Zhou, Yao

2018-01-01

Rapid and accurate counting and recognition of flying insects are of great importance, especially for pest control. Traditional manual identification and counting of flying insects is labor intensive and inefficient. In this study, a vision-based counting and classification system for flying insects is designed and implemented. The system is constructed as follows: firstly, a yellow sticky trap is installed in the surveillance area to trap flying insects and a camera is set up to collect real-time images. Then the detection and coarse counting method based on You Only Look Once (YOLO) object detection, the classification method and fine counting based on Support Vector Machines (SVM) using global features are designed. Finally, the insect counting and recognition system is implemented on Raspberry PI. Six species of flying insects including bee, fly, mosquito, moth, chafer and fruit fly are selected to assess the effectiveness of the system. Compared with the conventional methods, the test results show promising performance. The average counting accuracy is 92.50% and average classifying accuracy is 90.18% on Raspberry PI. The proposed system is easy-to-use and provides efficient and accurate recognition data, therefore, it can be used for intelligent agriculture applications. PMID:29747429

Attention-like processes in insects.

PubMed

Nityananda, Vivek

2016-11-16

Attention is fundamentally important for sensory systems to focus on behaviourally relevant stimuli. It has therefore been an important field of study in human psychology and neuroscience. Primates, however, are not the only animals that might benefit from attention-like processes. Other animals, including insects, also have to use their senses and select one among many stimuli to forage, avoid predators and find mates. They have evolved different mechanisms to reduce the information processed by their brains to focus on only relevant stimuli. What are the mechanisms used by insects to selectively attend to visual and auditory stimuli? Do these attention-like mechanisms achieve the same functions as they do in primates? To investigate these questions, I use an established framework for investigating attention in non-human animals that proposes four fundamental components of attention: salience filters, competitive selection, top-down sensitivity control and working memory. I discuss evidence for each of these component processes in insects and compare the characteristics of these processes in insects to what we know from primates. Finally, I highlight important outstanding questions about insect attention that need to be addressed for us to understand the differences and similarities between vertebrate and insect attention. © 2016 The Author(s).

Effects of dietary esfenvalerate exposures on three aquatic insect species representing different functional feeding groups.

PubMed

Palmquist, Katherine R; Jenkins, Jeffrey J; Jepson, Paul C

2008-08-01

Given the chemical properties of synthetic pyrethroids, it is probable that compounds, including esfenvalerate, that enter surface waters may become incorporated into aquatic insect food sources. We examined the effect of dietary esfenvalerate uptake in aquatic insects representing different functional feeding groups. We used three field-collected aquatic insect species: A grazing scraper, Cinygmula reticulata McDunnough (Ephemeroptera: Heptageniidae); an omnivorous filter feeder, Brachycentrus americanus Banks (Trichoptera: Brachycentridae); and a predator, Hesperoperla pacifica Banks (Plecoptera: Perlidae). Laboratory-cultured algae were preexposed for 24 h to esfenvalerate concentrations of 0, 0.025, 0.05, and 0.1 microg/L and provided to two C. reticulata age classes (small and final-instar nymphs). Reduction in small nymph growth was observed following three weeks of feeding on algae exposed to 0.05 and 0.1 microg/L of esfenvalerate, and the highest dietary exposure reduced egg production in final-instar nymphs. The diet for B. americanus and H. pacifica consisted of dead third-instar Chironomus tentans larvae preexposed for 24 h to esfenvalerate concentrations ranging between 0.1 and 1.0 microg/L. Consumption of larvae exposed to 0.5 to 1.0 microg/L of esfenvalerate caused case abandonment and mortality in B. americanus caddisfly larvae. Although H. pacifica nymphs readily consumed esfenvalerate-exposed larvae, no adverse effects were observed during the present study. Furthermore, no evidence of esfenvalerate-induced feeding deterrence was found in any of the species tested, suggesting that aquatic insects may not be able to distinguish between pyrethroid-contaminated and uncontaminated food sources. These findings indicate that feeding deterrence is not a factor in regulating aquatic insect dietary exposures to synthetic pyrethroids.

The development of new radiation protocols for insect sterilization using long wavelength x-rays

NASA Astrophysics Data System (ADS)

Urquidi, Jacob; Brar, Ramaninder K.; Rodriguez, Stacy; Hansen, Immo

2015-07-01

Control of insect species for the protection of crops, livestock, and prevention of disease such as dengue fever and malaria is a high priority in today's global economy. Traditional methods such as pesticides have fallen out of favor because its effects are indiscriminate as well as adverse and unpredictable impacts on the environment. Modern novel techniques such as genetic modification have had trouble gaining traction due to ethics concerns and the potential for unforeseen side effects. One approach that has gained traction and has proven its efficacy is the use of ionizing radiation to affect sterility in insect species in order to scale back their population. Known as Sterile Insect Technique (SIT), it has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipertans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. We have investigated the effect of treatment with x-rays of different wavelengths on x-ray sterilized mosquito males. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males' longevity as well as an increase on the efficacy of sterilization while employing a substantially lower dose.

The development of new radiation protocols for insect sterilization using long wavelength x-rays

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

Urquidi, Jacob, E-mail: jurquidi@nmsu.edu; Brar, Ramaninder K.; Rodriguez, Stacy

Control of insect species for the protection of crops, livestock, and prevention of disease such as dengue fever and malaria is a high priority in today’s global economy. Traditional methods such as pesticides have fallen out of favor because its effects are indiscriminate as well as adverse and unpredictable impacts on the environment. Modern novel techniques such as genetic modification have had trouble gaining traction due to ethics concerns and the potential for unforeseen side effects. One approach that has gained traction and has proven its efficacy is the use of ionizing radiation to affect sterility in insect species inmore » order to scale back their population. Known as Sterile Insect Technique (SIT), it has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipertans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. We have investigated the effect of treatment with x-rays of different wavelengths on x-ray sterilized mosquito males. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males’ longevity as well as an increase on the efficacy of sterilization while employing a substantially lower dose.« less

Seasonal changes in the techniques employed by wild chimpanzees in the Mahale Mountains, Tanzania, to feed on termites (Pseudacanthotermes spiniger).

PubMed

Uehara, S

1982-01-01

During a short period, wild chimpanzees of group K in the Mahale Mountains employ a set of several techniques, including tool use, to feed on one species of termite (Pseudacanthotermes spiniger). They appear to use each technique appropriately according to phenological changes in the prey insect's activities. The chimpanzees also ingest small pieces of soil from the tower of P. spiniger's mound throughout the year. Geophagy presumably makes them visually and tactually aware of the phenological changes of the termite's reproductive cycle. Analyses of fecal samples from the chimpanzees indicate interannual fluctuations in the amount of termites ingested. On the other hand, the chimpanzees of group B, ranging to the north of group K, utilize a fishing technique to obtain another type of termite (Macrotermes?herus) on a large scale during the first half of the wet season. Fecal analysis data show that chimpanzees of group B consume far more termites than those of group K. The probability that the same or similar tool-using techniques as fishing may be employed in feeding on different types of insects by chimpanzees of different unit groups according to subtle local differences in the insect fauna of their home ranges is discussed.

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

PubMed

Hilker, Monika; Meiners, Torsten

2011-09-01

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

Impact of aquatic insect life stage and emergence strategy on sensitivity to esfenvalerate exposure.

PubMed

Palmquist, Katherine R; Jepson, Paul C; Jenkins, Jeffrey J

2008-08-01

We investigated the impact of aquatic insect life stage and emergence strategy on sensitivity to esfenvalerate, a synthetic pyrethroid insecticide, using field-collected Brachycentrus americanus Banks (Trichoptera: Brachycentridae) and Cinygmula reticulata McDunnough (Ephemeroptera: Heptageniidae) insects. Final-instar C. reticulata emergence was observed for one week following three environmentally relevant, 48-h esfenvalerate exposures (0.005, 0.01, and 0.015 microg/L). Emergence was significantly depressed following exposure to esfenvalerate and resulted from an increase in nymph mortality during the emergence process. This experiment was duplicated for late-instar C. reticulata nymphs, which were similar in size to the final-instar nymphs but were not near emergence. Late-instar C. reticulata mayflies were approximately fivefold less sensitive to esfenvalerate exposures as gauged by one-week mortality rates. Brachycentrus americanus pupal mortality was significantly increased over that in controls following 48-h esfenvalerate exposures of 0.1 and 0.2 microg/L. These response concentrations correlated closely with those for case-abandonment rates of fourth-instar B. americanus larvae (a sublethal effect of esfenvalerate exposure). Pupal mortality rates were approximately 16-fold higher than those observed in larvae. Adult female egg weight as a percentage of total body weight was significantly decreased following pupal esfenvalerate exposures of 0.05, 0.1, and 0.2 microg/L. These findings suggest that exposure to esfenvalerate may impair hemimetabolous insect emergence behaviors and may decrease fecundity in holometabolous aquatic insects.

The Hungry Fly: Hydrodynamics of feeding in the common house fly

NASA Astrophysics Data System (ADS)

Prakash, Manu; Steele, Miles

2010-11-01

A large number of insect species feed primarily on a fluid diet. To do so, they must overcome the numerous challenges that arise in the design of high-efficiency, miniature pumps. Although the morphology of insect feeding structures has been described for decades, their dynamics remain largely unknown even in the most well studied species (e.g. fruit fly). Here, we use invivo imaging and microsurgery to elucidate the design principles of feeding structures of the common house fly. Using high-resolution X-ray microscopy, we record invivo flow of sucrose solutions through the body over many hours during fly feeding. Borrowing from microsurgery techniques common in neurophysiology, we are able to perturb the pump to a stall position and thus evaluate function under load conditions. Furthermore, fluid viscosity-dependent feedback is observed for optimal pump performance. As the gut of the fly starts to fill up, feedback from the stretch receptors in the cuticle dictates the effective flow rate. Finally, via comparative analysis between the house fly, blow fly, fruit fly and bumble bees, we highlight the common design principles and the role of interfacial phenomena in feeding.

Direct visualization of hemolymph flow in the heart of a grasshopper (Schistocerca americana)

PubMed Central

Lee, Wah-Keat; Socha, John J

2009-01-01

Background Hemolymph flow patterns in opaque insects have never been directly visualized due to the lack of an appropriate imaging technique. The required spatial and temporal resolutions, together with the lack of contrast between the hemolymph and the surrounding soft tissue, are major challenges. Previously, indirect techniques have been used to infer insect heart motion and hemolymph flow, but such methods fail to reveal fine-scale kinematics of heartbeat and details of intra-heart flow patterns. Results With the use of microbubbles as high contrast tracer particles, we directly visualized hemolymph flow in a grasshopper (Schistocerca americana) using synchrotron x-ray phase-contrast imaging. In-vivo intra-heart flow patterns and the relationship between respiratory (tracheae and air sacs) and circulatory (heart) systems were directly observed for the first time. Conclusion Synchrotron x-ray phase contrast imaging is the only generally applicable technique that has the necessary spatial, temporal resolutions and sensitivity to directly visualize heart dynamics and flow patterns inside opaque animals. This technique has the potential to illuminate many long-standing questions regarding small animal circulation, encompassing topics such as retrograde heart flow in some insects and the development of flow in embryonic vertebrates. PMID:19272159

Feeding behavior of the stink bug Bagrada hilaris is changed by the electrical signals applied during EPG recordings

USDA-ARS?s Scientific Manuscript database

Feeding behavior of piercing-sucking insects is most rigorously studied using eletropenetrography (EPG). This technique utilizes an electrical circuit to record waveforms caused by voltage fluctuations when a wired insect inserts its stylet into an electrified plant. Past researchers have asserted t...

Effects of shelterwood management on flower-visiting insects and their floral resources

Treesearch

Jessica E. Fultz

2005-01-01

Habitat alteration can affect pollinating-insect community structure, decreasing the efficiency of pollinators on which many agricultural and natural ecosystems rely. Within the Tenderfoot Creek Experimental Forest (TCEF), located in the Little Belt Mountains of Central Montana, two different types of silvicultural techniques, even and group shelterwood, were applied...

A critique of silvicultural approaches to managing defoliating insects in North America

Treesearch

R.M. ​Muzika; A.M. Liebhold

2000-01-01

A variety of silvicultural techniques have been suggested for managing forest defoliating insects. The objectives focus on minimizing defoliation or minimizing damage from defoliation. The theoretical foundations of many approaches have been built upon observation and correlation, and very little reliable empirical evidence exists to support the objectives of...

A technique to artificially infest beech bark with beech scale, Cryptococcus fagisuga (Lindinger)

Treesearch

David R. Houston

1982-01-01

Beech bark disease is initiated when bark of beech trees (Fagus spp.) is attacked by the beech scale, Cryptococcus fagisuga Lindinger. The effects of the insect predispose tissues to bark cankering fungi of the genus Nectria. Critical studies of insect-fungus-host interactions had been stymied by the inability to...

Advanced imaging techniques III: a scalable and modular dome illumination system for scientific microphotography on a budget

USDA-ARS?s Scientific Manuscript database

A scalable and modular LED illumination dome for microscopic scientific photography is described and illustrated, and methods for constructing such a dome are detailed. Dome illumination for insect specimens has become standard practice across the field of insect systematics, but many dome designs ...

A flight cylinder bioassay as a simple, effective quality control test for Cydia pomonella

USDA-ARS?s Scientific Manuscript database

Assessment of quality of the sterile male insects that are being mass-reared for release in area-wide integrated pest management programmes that include a sterile insect technique component is crucial for the success of these programmes. Routine monitoring of sterile male quality needs to be carried...

Quality control tests of lab-reared Cydia pomonella and Cactoblastis cactorum field performance: Comparison of laboratory and field bioassays.

USDA-ARS?s Scientific Manuscript database

Research, operational, and commercial programs which rely on mass-reared insects of high quality and performance, need accurate methods for monitoring quality degradation during each step of production, handling and release. With continued interest in the use of the sterile insect technique (SIT) a...

Effect of rice husk biochar application to soil insect diversity on potato cultivation

NASA Astrophysics Data System (ADS)

Meilin, A.; Rubiana, R.

2018-02-01

High intensity of disease infection and the intensive use of fertilizers and pesticidescause saturated fertilizer and pesticide to the land. Remediation using biochar rice husk is one of the technology to decrease fertilizer and pesticide residue. The diversity of soil insects can be used as bioindicators because of their existence dependsg on soil structure and condition. This study was aimed to study the diversity and structure communities of soil insect in potatoes on difference husk rice biochar application. The sampling of soil insects was done on potato farmer’s land with four treatments i.e control (farmers’ technique), trichokompos without biochar, trichokompos + biochar with dose 1 ton/ha, and trichokompos + biochar with dose 2 ton / ha. At each point a single pitfall trap was installed for two nights and then it was taken for identification. The results showed that biochar application had significant effect on the number of soil insect species (P = 0.037). The soil insect species composition pattern also showed significant differences between the four treatments (R: 0.2306, Pvalue = 0.001). This mean that the application of biochar affects the number of insects species and plays a role in the formation of soil insect diversity beta patterns.

Forensic entomology: applications and limitations.

PubMed

Amendt, J; Richards, C S; Campobasso, C P; Zehner, R; Hall, M J R

2011-12-01

Forensic entomology is the science of collecting and analysing insect evidence to aid in forensic investigations. Its main application is in the determination of the minimum time since death in cases of suspicious death, either by estimating the age of the oldest necrophagous insects that developed on the corpse, or by analysing the insect species composition on the corpse. In addition, toxicological and molecular examinations of these insects may help reveal the cause of death or even the identity of a victim, by associating a larva with its last meal, for example, in cases where insect evidence is left at a scene after human remains have been deliberately removed. Some fly species can develop not only on corpses but on living bodies too, causing myiasis. Analysis of larvae in such cases can demonstrate the period of neglect of humans or animals. Without the appropriate professional collection of insect evidence, an accurate and convincing presentation of such evidence in court will be hampered or even impossible. The present paper describes the principles and methods of forensic entomology and the optimal techniques for collecting insect evidence.

Insect Fauna Associated With Anacardium occidentale (Sapindales: Anacardiaceae) in Benin, West Africa

PubMed Central

Agboton, C.; Onzo, A.; Ouessou, F. I.; Goergen, G.; Vidal, S.; Tamò, M.

2014-01-01

Abstract Cashew, Anacardium occidentale L. (Sapindales: Anacardiaceae), is an important cash crop in Benin. However, its production is threatened by several biotic factors, especially insects. In Benin, very few studies have focused on insects and just listed species commonly found on cashew worldwide. The present investigation fills this gap by presenting an exhaustive inventory of insect species associated with this crop in the country. The survey was carried out from September 2009 to August 2010 in 22 cashew orchards (5 young and 17 mature) distributed over three major agroecological zones where cashew is most produced in the country. Insects were collected using chemical knock-down technique and visual observation followed by capture with sweep net. In addition, infested plant organs were sampled and incubated to collect emerging insects. In total, 262 insect species were recorded and identified. Among them, the wood borer Apate terebrans Pallas, the leafminer Eteoryctis gemoniella Stainton, and the mirid bugs Helopeltis schoutedeni Reuter., and Helopeltis anacardii Miller., appeared as the most important insect species attacking cashew in Benin. Beneficial insects encountered included some predators, parasitoids, and pollinators. Few vertebrate predators were also recorded on the trees. Differences in agroecological conditions or in field cleanliness did not affect the number of insect species encountered in the cashew orchards. The results of this study represent an important baseline data for the design and implementation of strategies for cashew protection in Benin. PMID:25434033

Diversity and role of cave-dwelling hematophagous insects in pathogen transmission in the Afrotropical region.

PubMed

Obame-Nkoghe, Judicaël; Leroy, Eric-Maurice; Paupy, Christophe

2017-04-12

The progressive anthropization of caves for food resources or economic purposes increases human exposure to pathogens that naturally infect cave-dwelling animals. The presence of wild or domestic animals in the immediate surroundings of caves also may contribute to increasing the risk of emergence of such pathogens. Some zoonotic pathogens are transmitted through direct contact, but many others require arthropod vectors, such as blood-feeding insects. In Africa, hematophagous insects often play a key role in the epidemiology of many pathogens; however, their ecology in cave habitats remains poorly known. During the last decades, several investigations carried out in Afrotropical caves suggested the medical and veterinary importance particularly of insect taxa of the Diptera order. Therefore, the role of some of these insects as vectors of pathogens that infect cave-dwelling vertebrates has been studied. The present review summarizes these findings, brings insights into the diversity of cave-dwelling hematophagous Diptera and their involvement in pathogen transmission, and finally discusses new challenges and future research directions.

Ecological Census Techniques - 2nd Edition

NASA Astrophysics Data System (ADS)

Sutherland, Edited By William J.

2006-08-01

This is an updated version of the best selling first edition, Ecological Census Techniques, with updating, some new chapters and authors. Almost all ecological and conservation work involves carrying out a census or survey. This practically focussed book describes how to plan a census, the practical details and shows with worked examples how to analyse the results. The first three chapters describe planning, sampling and the basic theory necessary for carrying out a census. In the subsequent chapters international experts describe the appropriate methods for counting plants, insects, fish, amphibians, reptiles, mammals and birds. As many censuses also relate the results to environmental variability, there is a chapter explaining the main methods. Finally, there is a list of the most common mistakes encountered when carrying out a census. Gives worked examples and describes practical details The chapter on research planning provides an approach for planning any research, not just those relating to census techniques Latest edition of a very highly-regarded book. Includes new authors, each chapter has been updated, and additional chapters on sampling and designing research programmes have been added

Combining the Sterile Insect Technique with the Incompatible Insect Technique: I-Impact of Wolbachia Infection on the Fitness of Triple- and Double-Infected Strains of Aedes albopictus

PubMed Central

Zhang, Dongjing; Zheng, Xiaoying; Xi, Zhiyong; Bourtzis, Kostas; Gilles, Jeremie R. L.

2015-01-01

The mosquito species Aedes albopictus is a major vector of the human diseases dengue and chikungunya. Due to the lack of efficient and sustainable methods to control this mosquito species, there is an increasing interest in developing and applying the sterile insect technique (SIT) and the incompatible insect technique (IIT), separately or in combination, as population suppression approaches. Ae. albopictus is naturally double-infected with two Wolbachia strains, wAlbA and wAlbB. A new triple Wolbachia-infected strain (i.e., a strain infected with wAlbA, wAlbB, and wPip), known as HC and expressing strong cytoplasmic incompatibility (CI) in appropriate matings, was recently developed. In the present study, we compared several fitness traits of three Ae. albopictus strains (triple-infected, double-infected and uninfected), all of which were of the same genetic background (“Guangzhou City, China”) and were reared under the same conditions. Investigation of egg-hatching rate, survival of pupae and adults, sex ratio, duration of larval stages (development time from L1 to pupation), time to emergence (development time from L1 to adult emergence), wing length, female fecundity and adult longevity indicated that the presence of Wolbachia had only a minimal effect on host fitness. Based on this evidence, the HC strain is currently under consideration for mass rearing and application in a combined SIT-IIT strategy to control natural populations of Ae. albopictus in mainland China. PMID:25849812

Non-Destructive Sampling of Ancient Insect DNA

PubMed Central

Thomsen, Philip Francis; Elias, Scott; Gilbert, M. Thomas P.; Haile, James; Munch, Kasper; Kuzmina, Svetlana; Froese, Duane G.; Holdaway, Richard N.; Willerslev, Eske

2009-01-01

Background A major challenge for ancient DNA (aDNA) studies on insect remains is that sampling procedures involve at least partial destruction of the specimens. A recent extraction protocol reveals the possibility of obtaining DNA from past insect remains without causing visual morphological damage. We test the applicability of this protocol on historic museum beetle specimens dating back to AD 1820 and on ancient beetle chitin remains from permafrost (permanently frozen soil) dating back more than 47,000 years. Finally, we test the possibility of obtaining ancient insect DNA directly from non-frozen sediments deposited 3280-1800 years ago - an alternative approach that also does not involve destruction of valuable material. Methodology/Principal Findings The success of the methodological approaches are tested by PCR and sequencing of COI and 16S mitochondrial DNA (mtDNA) fragments of 77–204 base pairs (-bp) in size using species-specific and general insect primers. Conclusion/Significance The applied non-destructive DNA extraction method shows promising potential on insect museum specimens of historical age as far back as AD 1820, but less so on the ancient permafrost-preserved insect fossil remains tested, where DNA was obtained from samples up to ca. 26,000 years old. The non-frozen sediment DNA approach appears to have great potential for recording the former presence of insect taxa not normally preserved as macrofossils and opens new frontiers in research on ancient biodiversity. PMID:19337382

Resilience in social insect infrastructure systems.

PubMed

Middleton, Eliza J T; Latty, Tanya

2016-03-01

Both human and insect societies depend on complex and highly coordinated infrastructure systems, such as communication networks, supply chains and transportation networks. Like human-designed infrastructure systems, those of social insects are regularly subject to disruptions such as natural disasters, blockages or breaks in the transportation network, fluctuations in supply and/or demand, outbreaks of disease and loss of individuals. Unlike human-designed systems, there is no deliberate planning or centralized control system; rather, individual insects make simple decisions based on local information. How do these highly decentralized, leaderless systems deal with disruption? What factors make a social insect system resilient, and which factors lead to its collapse? In this review, we bring together literature on resilience in three key social insect infrastructure systems: transportation networks, supply chains and communication networks. We describe how systems differentially invest in three pathways to resilience: resistance, redirection or reconstruction. We suggest that investment in particular resistance pathways is related to the severity and frequency of disturbance. In the final section, we lay out a prospectus for future research. Human infrastructure networks are rapidly becoming decentralized and interconnected; indeed, more like social insect infrastructures. Human infrastructure management might therefore learn from social insect researchers, who can in turn make use of the mature analytical and simulation tools developed for the study of human infrastructure resilience. © 2016 The Author(s).

Molecular Genetics of Beauveria bassiana Infection of Insects.

PubMed

Ortiz-Urquiza, A; Keyhani, N O

2016-01-01

Research on the insect pathogenic filamentous fungus, Beauveria bassiana has witnessed significant growth in recent years from mainly physiological studies related to its insect biological control potential, to addressing fundamental questions regarding the underlying molecular mechanisms of fungal development and virulence. This has been in part due to a confluence of robust genetic tools and genomic resources for the fungus, and recognition of expanded ecological interactions with which the fungus engages. Beauveria bassiana is a broad host range insect pathogen that has the ability to form intimate symbiotic relationships with plants. Indeed, there is an increasing realization that the latter may be the predominant environmental interaction in which the fungus participates, and that insect parasitism may be an opportunist lifestyle evolved due to the carbon- and nitrogen-rich resources present in insect bodies. Here, we will review progress on the molecular genetics of B. bassiana, which has largely been directed toward identifying genetic pathways involved in stress response and virulence assumed to have practical applications in improving the insect control potential of the fungus. Important strides have also been made in understanding aspects of B. bassiana development. Finally, although increasingly apparent in a number of studies, there is a need for progressing beyond phenotypic mutant characterization to sufficiently investigate the molecular mechanisms underlying B. bassiana's unique and diverse lifestyles as saprophyte, insect pathogen, and plant mutualist. Copyright © 2016 Elsevier Inc. All rights reserved.

Mosquitoes meet microfluidics: High-throughput microfluidic tools for insect-parasite ecology in field conditions

NASA Astrophysics Data System (ADS)

Prakash, Manu; Mukundarajan, Haripriya

2013-11-01

A simple bite from an insect is the transmission mechanism for many deadly diseases worldwide--including malaria, yellow fever, west nile and dengue. Very little is known about how populations of numerous insect species and disease-causing parasites interact in their natural habitats due to a lack of measurement techniques. At present, vector surveillance techniques involve manual capture by using humans as live bait, which is hard to justify on ethical grounds. Individual mosquitoes are manually dissected to isolate salivary glands to detect sporozites. With typical vector infection rates being very low even in endemic areas, it is almost impossible to get an accurate picture of disease distribution, in both space and time. Here we present novel high-throughput microfluidic tools for vector surveillance, specifically mosquitoes. A two-dimensional high density array with baits provide an integrated platform for multiplex PCR for detection of both vector and parasite species. Combining techniques from engineering and field ecology, methods and tools developed here will enable high-throughput measurement of infection rates for a number of diseases in mosquito populations in field conditions. Pew Foundation.

Laboratory evaluation for a potential birth control diet for fruit fly sterilization insect technique (SIT)

USDA-ARS?s Scientific Manuscript database

A potential fruit fly steilizing diet was evaluated on fertility, mating, survival, and protein anaylsis for fruit fly species in Hawaii. Insects were continuously fed an agar diet with lufenuron(LFN) for an initial 7d after emergence and then switched to a control diet to simulate the actual field ...

Comparison of laboratory and field bioassays of lab-reared Cydia pomonella (Lepidoptera: Tortricidae) quality and field performance.

USDA-ARS?s Scientific Manuscript database

Maximum production and fitness of insect species that are mass-reared for biological control programs such as the sterile insect technique (SIT) have benefitted from the employment of quality control and quality management. With a growing interest in the use of SIT as a tactic for the suppression/e...

A technique to screen American beech for resistance to the beech scale insect (Cryptococcus fagisuga Lind.)

Treesearch

Jennifer L. Koch; David W. Carey

2014-01-01

Beech bark disease (BBD) results in high levels of initial mortality, leaving behind survivor trees that are greatly weakened and deformed. The disease is initiated by feeding activities of the invasive beech scale insect, Cryptococcus fagisuga, which creates entry points for infection by one of the Neonectria species of fungus....

The backcross sterility technique

Treesearch

V. C. Mastro; A. Pellegrini-Toole

1991-01-01

The sterile insect technique (SIT) and the induced inherited (F1) sterility technique have been investigated for a number of lepidopterous pests, including the gypsy moths. Another technique, backcross sterility, which could potentially prove as or more useful for control of pest species has been developed for the control of only one lepidopteran...

Genetics, development and composition of the insect head--a beetle's view.

PubMed

Posnien, Nico; Schinko, Johannes B; Kittelmann, Sebastian; Bucher, Gregor

2010-11-01

Many questions regarding evolution and ontogeny of the insect head remain open. Likewise, the genetic basis of insect head development is poorly understood. Recently, the investigation of gene expression data and the analysis of patterning gene function have revived interest in insect head development. Here, we argue that the red flour beetle Tribolium castaneum is a well suited model organism to spearhead research with respect to the genetic control of insect head development. We review recent molecular data and discuss its bearing on early development and morphogenesis of the head. We present a novel hypothesis on the ontogenetic origin of insect head sutures and review recent insights into the question on the origin of the labrum. Further, we argue that the study of developmental genes may identify the elusive anterior non-segmental region and present some evidence in favor of its existence. With respect to the question of evolution of patterning we show that the head Anlagen of the fruit fly Drosophila melanogaster and Tribolium differ considerably and we review profound differences of their genetic regulation. Finally, we discuss which insect model species might help us to answer the open questions concerning the genetic regulation of head development and its evolution. Copyright © 2010 Elsevier Ltd. All rights reserved.

Competition with wind-pollinated plant species alters floral traits of insect-pollinated plant species

PubMed Central

Flacher, Floriane; Raynaud, Xavier; Hansart, Amandine; Motard, Eric; Dajoz, Isabelle

2015-01-01

Plant traits related to attractiveness to pollinators (e.g. flowers and nectar) can be sensitive to abiotic or biotic conditions. Soil nutrient availability, as well as interactions among insect-pollinated plants species, can induce changes in flower and nectar production. However, further investigations are needed to determine the impact of interactions between insect-pollinated species and abiotically pollinated species on such floral traits, especially floral rewards. We carried out a pot experiment in which three insect-pollinated plant species were grown in binary mixtures with four wind-pollinated plant species, differing in their competitive ability. Along the flowering period, we measured floral traits of the insect-pollinated species involved in attractiveness to pollinators (i.e. floral display size, flower size, daily and total 1) flower production, 2) nectar volume, 3) amount of sucrose allocated to nectar). Final plant biomass was measured to quantify competitive interactions. For two out of three insect-pollinated species, we found that the presence of a wind-pollinated species can negatively impact floral traits involved in attractiveness to pollinators. This effect was stronger with wind-pollinated species that induced stronger competitive interactions. These results stress the importance of studying the whole plant community (and not just the insect-pollinated plant community) when working on plant-pollinator interactions. PMID:26335409

Modifying an Insect Cell N-Glycan Processing Pathway Using CRISPR-Cas Technology.

PubMed

Mabashi-Asazuma, Hideaki; Kuo, Chu-Wei; Khoo, Kay-Hooi; Jarvis, Donald L

2015-10-16

Fused lobes (FDL) is an enzyme that simultaneously catalyzes a key trimming reaction and antagonizes elongation reactions in the insect N-glycan processing pathway. Accordingly, FDL function accounts, at least in part, for major differences in the N-glycosylation patterns of glycoproteins produced by insect and mammalian cells. In this study, we used the CRISPR-Cas9 system to edit the fdl gene in Drosophila melanogaster S2 cells. CRISPR-Cas9 editing produced a high frequency of site-specific nucleotide insertions and deletions, reduced the production of insect-type, paucimannosidic products (Man3GlcNAc2), and led to the production of partially elongated, mammalian-type complex N-glycans (GlcNAc2Man3GlcNAc2) in S2 cells. As CRISPR-Cas9 has not been widely used to analyze or modify protein glycosylation pathways or edit insect cell genes, these results underscore its broad utility as a tool for these purposes. Our results also confirm the key role of FDL at the major branch point distinguishing insect and mammalian N-glycan processing pathways. Finally, the new FDL-deficient S2 cell derivative produced in this study will enable future bottom-up glycoengineering efforts designed to isolate insect cell lines that can efficiently produce recombinant glycoproteins with chemically predefined oligosaccharide side-chain structures.

Radar Observation of Insects - Mosquitoes

NASA Technical Reports Server (NTRS)

Frost, E.; Downing, J.

1979-01-01

Tests were conducted at several sites over the coastal lowlands of New Jersey and over a region of high plains and low mountains in Oklahoma. In one area, a salt marsh in New Jersey, extensive ground tests were combined with laboratory data on expected insect backscatter to arrive at an extremely convincing model of the insect origin of most Dot Angels. A great deal of insight was studied from radar on the buildup and dispersal of insect swarms, since radar can follow where other means of trapping and observation cannot. Data on large-scale behavior as a function of wind and topography are presented. Displayed techniques which show individual or small swarm motion within some larger cloud or mass, or which can show the overall motion over great distances were developed. The influence of wind and terrain on insect motion and dispersal is determined from radar data.

The need for higher-order averaging in the stability analysis of hovering, flapping-wing flight.

PubMed

Taha, Haithem E; Tahmasian, Sevak; Woolsey, Craig A; Nayfeh, Ali H; Hajj, Muhammad R

2015-01-05

Because of the relatively high flapping frequency associated with hovering insects and flapping wing micro-air vehicles (FWMAVs), dynamic stability analysis typically involves direct averaging of the time-periodic dynamics over a flapping cycle. However, direct application of the averaging theorem may lead to false conclusions about the dynamics and stability of hovering insects and FWMAVs. Higher-order averaging techniques may be needed to understand the dynamics of flapping wing flight and to analyze its stability. We use second-order averaging to analyze the hovering dynamics of five insects in response to high-amplitude, high-frequency, periodic wing motion. We discuss the applicability of direct averaging versus second-order averaging for these insects.

Optimization of mosquito egg production under mass rearing setting: effects of cage volume, blood meal source and adult population density for the malaria vector, Anopheles arabiensis.

PubMed

Mamai, Wadaka; Bimbile-Somda, Nanwintoum S; Maiga, Hamidou; Juarez, José Guillermo; Muosa, Zaynab A I; Ali, Adel Barakat; Lees, Rosemary Susan; Gilles, Jeremie R L

2017-01-24

Anopheles arabiensis is one of the major malaria vectors that put millions of people in endemic countries at risk. Mass-rearing of this mosquito is crucial for strategies that use sterile insect technique to suppress vector populations. The sterile insect technique (SIT) package for this mosquito species is being developed by the Insect Pest Control Subprogramme of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. To improve mass-rearing outcomes for An. arabiensis, the question of whether the egg production by females would be affected by the size of the adult holding cages, the source of the blood meal and the total number of pupae that could be loaded into the cages was addressed and finally the impact of adding additional pupae to the cage daily to maintain adult numbers on egg productivity assessed. Mass production cages of two different volumes, two different sources of blood meal (bovine and porcine) and two different population densities (cages originally loaded with either 15,000 or 20,000 pupae) were tested and evaluated on the basis of eggs produced/cage or per female. Males and females pupae with a ratio of 1:1 were added to the cages at day 1 and 2 of pupation. The emerging adults had constant access to 5% sugar solution and blood fed via the Hemotek membrane feeding system. Eggs were collected either twice a week or daily. A generalized linear model was used to identify factors which gave significantly higher egg production. Neither cage volume nor blood meal source affected egg production per cage or per female. However, increasing population density to 20,000 pupae had a negative effect on eggs produced per cage and per female. Although high density negatively impacted egg production, adding 1000 daily additional pupae compensating for daily mortality resulted in a substantial increase in egg production. Moreover, in all tests the first and the third egg batches collected were significantly higher than others eggs batches. With the equipment and protocols described here and routinely used at the Insect Pest Control Laboratory (IPCL), it was possible to produce up to 120,000 eggs/cage/day. These results demonstrated that 15,000 is the optimal number of pupae to be loaded into the Anopheles Mass production cages. Under this condition, an average of 40 eggs per female was obtained for five gonotrophic cycles. However, an improvement in egg production can be achieved by daily addition, to the original 15,000 pupae, of one thousand pupae a day. Interestingly, feeding females with bovine or porcine blood using both large and small versions of the mass production cage did not affect egg productivity.

Insect transformation with piggyBac: getting the number of injections just right

PubMed Central

Morrison, N. I.; Shimeld, S. M.

2016-01-01

Abstract The insertion of exogenous genetic cargo into insects using transposable elements is a powerful research tool with potential applications in meeting food security and public health challenges facing humanity. piggyBac is the transposable element most commonly utilized for insect germline transformation. The described efficiency of this process is variable in the published literature, and a comprehensive review of transformation efficiency in insects is lacking. This study compared and contrasted all available published data with a comprehensive data set provided by a biotechnology group specializing in insect transformation. Based on analysis of these data, with particular focus on the more complete observational data from the biotechnology group, we designed a decision tool to aid researchers' decision‐making when using piggyBac to transform insects by microinjection. A combination of statistical techniques was used to define appropriate summary statistics of piggyBac transformation efficiency by species and insect order. Publication bias was assessed by comparing the data sets. The bias was assessed using strategies co‐opted from the medical literature. The work culminated in building the Goldilocks decision tool, a Markov‐Chain Monte‐Carlo simulation operated via a graphical interface and providing guidance on best practice for those seeking to transform insects using piggyBac. PMID:27027400

A transgenic male-only strain of the New World screwworm for an improved control program using the sterile insect technique

USDA-ARS?s Scientific Manuscript database

The New World screwworm (NWS), Cochliomyia hominivorax, is a devastating pest of livestock endemic to sub-tropical and tropical regions of the Western Hemisphere. The larvae feed on the tissue of living animals, including man, and can cause death if untreated. Over 60 years ago the sterile insect te...

Quality of mass-reared codling moth (Lepidoptera: Tortricidae) after long distance transportation 1. Logistics of shipping procedures and quality parameters as measured in the laboratory.

USDA-ARS?s Scientific Manuscript database

The sterile insect technique is a proven effective control tactic against lepidopteran pests when applied in an area-wide integrated pest management programme. The construction of insect mass-rearing facilities requires considerable investment and moth control strategies that include the use of ster...

Behavioral Immunity in Insects

PubMed Central

de Roode, Jacobus C.; Lefèvre, Thierry

2012-01-01

Parasites can dramatically reduce the fitness of their hosts, and natural selection should favor defense mechanisms that can protect hosts against disease. Much work has focused on understanding genetic and physiological immunity against parasites, but hosts can also use behaviors to avoid infection, reduce parasite growth or alleviate disease symptoms. It is increasingly recognized that such behaviors are common in insects, providing strong protection against parasites and parasitoids. We review the current evidence for behavioral immunity in insects, present a framework for investigating such behavior, and emphasize that behavioral immunity may act through indirect rather than direct fitness benefits. We also discuss the implications for host-parasite co-evolution, local adaptation, and the evolution of non-behavioral physiological immune systems. Finally, we argue that the study of behavioral immunity in insects has much to offer for investigations in vertebrates, in which this topic has traditionally been studied. PMID:26466629

The sensitivity of aquatic insects to divalent metals: a comparative analysis of laboratory and field data.

PubMed

Brix, Kevin V; DeForest, David K; Adams, William J

2011-09-15

Laboratory studies have traditionally indicated that aquatic insects are relatively insensitive to metals while field studies have suggested them to be among the most sensitive aquatic invertebrate taxa. We reviewed and synthesized available studies in the literature to critically assess why this discrepancy exists. Despite the intense effort to study the effects of metals on aquatic biota over the past several decades, we found studies specific to insects to still be relatively limited. In general, the discrepancy between laboratory and field studies continues with few efforts having been made to elucidate the ecological and physiological mechanisms that underlie the relative sensitivity (or insensitivity) of aquatic insects to metals. However, given the limited data available, it appears that aquatic insects are indeed relatively insensitive to acute metal exposures. In contrast, we suggest that some aquatic insect taxa may be quite sensitive to chronic metal exposure and in some cases may not be protected by existing water quality criteria for metals. The discrepancy between laboratory and field studies with respect to chronic sensitivity appears to largely be driven by the relatively short exposure periods in laboratory studies as compared to field studies. It also appears that, in some cases, the sensitivity of aquatic insects in field studies may be the result of direct effects on primary producers, which lead to indirect effects via the food chain on aquatic insects. Finally, available evidence suggests that diet is an important source of metal accumulation in insects, but to date there have been no conclusive studies evaluating whether dietary metal accumulation causes toxicity. There is a clear need for developing a more mechanistic understanding of aquatic insect sensitivity to metals in long-term laboratory and field studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Limited mobility of target pests crucially lowers controllability when sterile insect releases are spatiotemporally biased.

PubMed

Ikegawa, Yusuke; Himuro, Chihiro

2017-05-21

The sterile insect technique (SIT) is a genetic pest control method wherein mass-reared sterile insects are periodically released into the wild, thereby impeding the successful reproduction of fertile pests. In Okinawa Prefecture, Japan, the SIT has been implemented to eradicate the West Indian sweet potato weevil Euscepes postfasciatus (Fairmaire), which is a flightless agricultural pest of sweet potatoes. It is known that E. postfasciatus is much less mobile than other insects to which the SIT has been applied. However, previous theoretical studies have rarely examined effects of low mobility of target pests and variation in the spatiotemporal evenness of sterile insect releases. To theoretically examine the effects of spatiotemporal evenness on the regional eradication of less mobile pests, we constructed a simple two-patch population model comprised of a pest and sterile insect moving between two habitats, and numerically simulated different release strategies (varying the number of released sterile insects and release intervals). We found that spatially biased releases allowed the pest to spatially escape from the sterile insect, and thus intensively lowered its controllability. However, we showed that the temporally counterbalancing spatially biased releases by swapping the number of released insects in the two habitats at every release (called temporal balancing) could greatly mitigate this negative effect and promote the controllability. We also showed that the negative effect of spatiotemporally biased releases was a result of the limited mobility of the target insect. Although directed dispersal of the insects in response to habitats of differing quality could lower the controllability in the more productive habitat, the temporal balancing could promote and eventually maximize the controllability as released insects increased. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of rhodamine B to mark the body and seminal fluid of male Aedes aegypti for mark-release-recapture experiments and estimating efficacy of sterile male releases

PubMed Central

Johnson, Brian J.; Mitchell, Sara N.; Paton, Christopher J.; Stevenson, Jessica; Staunton, Kyran M.; Snoad, Nigel; Beebe, Nigel; White, Bradley J.; Ritchie, Scott A.

2017-01-01

Background Recent interest in male-based sterile insect technique (SIT) and incompatible insect technique (IIT) to control Aedes aegypti and Aedes albopictus populations has revealed the need for an economical, rapid diagnostic tool for determining dispersion and mating success of sterilized males in the wild. Previous reports from other insects indicated rhodamine B, a thiol-reactive fluorescent dye, administered via sugar-feeding can be used to stain the body tissue and seminal fluid of insects. Here, we report on the adaptation of this technique for male Ae. aegypti to allow for rapid assessment of competitiveness (mating success) during field releases. Methodology/Principle findings Marking was achieved by feeding males on 0.1, 0.2, 0.4 or 0.8% rhodamine B (w/v) in 50% honey solutions during free flight. All concentrations produced >95% transfer to females and successful body marking after 4 days of feeding, with 0.4 and 0.8% solutions producing the longest-lasting body marking. Importantly, rhodamine B marking had no effect on male mating competitiveness and proof-of-principle field releases demonstrated successful transfer of marked seminal fluid to females under field conditions and recapture of marked males. Conclusions/Significance These results reveal rhodamine B to be a potentially useful evaluation method for male-based SIT/IIT control strategies as well as a viable body marking technique for male-based mark-release-recapture experiments without the negative side-effects of traditional marking methods. As a standalone method for use in mating competitiveness assays, rhodamine B marking is less expensive than PCR (e.g. paternity analysis) and stable isotope semen labelling methods and less time-consuming than female fertility assays used to assess competitiveness of sterilised males. PMID:28957318

Use of rhodamine B to mark the body and seminal fluid of male Aedes aegypti for mark-release-recapture experiments and estimating efficacy of sterile male releases.

PubMed

Johnson, Brian J; Mitchell, Sara N; Paton, Christopher J; Stevenson, Jessica; Staunton, Kyran M; Snoad, Nigel; Beebe, Nigel; White, Bradley J; Ritchie, Scott A

2017-09-01

Recent interest in male-based sterile insect technique (SIT) and incompatible insect technique (IIT) to control Aedes aegypti and Aedes albopictus populations has revealed the need for an economical, rapid diagnostic tool for determining dispersion and mating success of sterilized males in the wild. Previous reports from other insects indicated rhodamine B, a thiol-reactive fluorescent dye, administered via sugar-feeding can be used to stain the body tissue and seminal fluid of insects. Here, we report on the adaptation of this technique for male Ae. aegypti to allow for rapid assessment of competitiveness (mating success) during field releases. Marking was achieved by feeding males on 0.1, 0.2, 0.4 or 0.8% rhodamine B (w/v) in 50% honey solutions during free flight. All concentrations produced >95% transfer to females and successful body marking after 4 days of feeding, with 0.4 and 0.8% solutions producing the longest-lasting body marking. Importantly, rhodamine B marking had no effect on male mating competitiveness and proof-of-principle field releases demonstrated successful transfer of marked seminal fluid to females under field conditions and recapture of marked males. These results reveal rhodamine B to be a potentially useful evaluation method for male-based SIT/IIT control strategies as well as a viable body marking technique for male-based mark-release-recapture experiments without the negative side-effects of traditional marking methods. As a standalone method for use in mating competitiveness assays, rhodamine B marking is less expensive than PCR (e.g. paternity analysis) and stable isotope semen labelling methods and less time-consuming than female fertility assays used to assess competitiveness of sterilised males.

Visual control of flight speed in Drosophila melanogaster.

PubMed

Fry, Steven N; Rohrseitz, Nicola; Straw, Andrew D; Dickinson, Michael H

2009-04-01

Flight control in insects depends on self-induced image motion (optic flow), which the visual system must process to generate appropriate corrective steering maneuvers. Classic experiments in tethered insects applied rigorous system identification techniques for the analysis of turning reactions in the presence of rotating pattern stimuli delivered in open-loop. However, the functional relevance of these measurements for visual free-flight control remains equivocal due to the largely unknown effects of the highly constrained experimental conditions. To perform a systems analysis of the visual flight speed response under free-flight conditions, we implemented a 'one-parameter open-loop' paradigm using 'TrackFly' in a wind tunnel equipped with real-time tracking and virtual reality display technology. Upwind flying flies were stimulated with sine gratings of varying temporal and spatial frequencies, and the resulting speed responses were measured from the resulting flight speed reactions. To control flight speed, the visual system of the fruit fly extracts linear pattern velocity robustly over a broad range of spatio-temporal frequencies. The speed signal is used for a proportional control of flight speed within locomotor limits. The extraction of pattern velocity over a broad spatio-temporal frequency range may require more sophisticated motion processing mechanisms than those identified in flies so far. In Drosophila, the neuromotor pathways underlying flight speed control may be suitably explored by applying advanced genetic techniques, for which our data can serve as a baseline. Finally, the high-level control principles identified in the fly can be meaningfully transferred into a robotic context, such as for the robust and efficient control of autonomous flying micro air vehicles.

Physical Processes and Real-Time Chemical Measurement of the Insect Olfactory Environment

PubMed Central

Abrell, Leif; Hildebrand, John G.

2009-01-01

Odor-mediated insect navigation in airborne chemical plumes is vital to many ecological interactions, including mate finding, flower nectaring, and host locating (where disease transmission or herbivory may begin). After emission, volatile chemicals become rapidly mixed and diluted through physical processes that create a dynamic olfactory environment. This review examines those physical processes and some of the analytical technologies available to characterize those behavior-inducing chemical signals at temporal scales equivalent to the olfactory processing in insects. In particular, we focus on two areas of research that together may further our understanding of olfactory signal dynamics and its processing and perception by insects. First, measurement of physical atmospheric processes in the field can provide insight into the spatiotemporal dynamics of the odor signal available to insects. Field measurements in turn permit aspects of the physical environment to be simulated in the laboratory, thereby allowing careful investigation into the links between odor signal dynamics and insect behavior. Second, emerging analytical technologies with high recording frequencies and field-friendly inlet systems may offer new opportunities to characterize natural odors at spatiotemporal scales relevant to insect perception and behavior. Characterization of the chemical signal environment allows the determination of when and where olfactory-mediated behaviors may control ecological interactions. Finally, we argue that coupling of these two research areas will foster increased understanding of the physicochemical environment and enable researchers to determine how olfactory environments shape insect behaviors and sensory systems. PMID:18548311

Satellite data based method for general survey of forest insect disturbance in British Columbia

NASA Astrophysics Data System (ADS)

Ranson, J.; Montesano, P.

2008-12-01

Regional forest disturbances caused by insects are important to monitor and quantify because of their influence on local ecosystems and the global carbon cycle. Local damage to forest trees disrupts food supplies and shelter for a variety of organisms. Changes in the global carbon budget, its sources and its sinks affect the way the earth functions as a whole, and has an impact on global climate. Furthermore, the ability to detect nascent outbreaks and monitor the spread of regional infestations helps managers mitigate the damage done by catastrophic insect outbreaks. While detection is needed at a fine scale to support local mitigation efforts, detection at a broad regional scale is important for carbon flux modeling on the landscape scale, and needed to direct the local efforts. This paper presents a method for routinely detecting insect damage to coniferous forests using MODIS vegetation indices, thermal anomalies and land cover. The technique is validated using insect outbreak maps and accounts for fire disturbance effects. The range of damage detected may be used to interpret and quantify possible forest damage by insects.

A georeferenced Landsat digital database for forest insect-damage assessment

NASA Technical Reports Server (NTRS)

Williams, D. L.; Nelson, R. F.; Dottavio, C. L.

1985-01-01

In 1869, the gypsy moth caterpillar was introduced in the U.S. in connection with the experiments of a French scientist. Throughout the insect's period of establishment, gypsy moth populations have periodically increased to epidemic proportions. For programs concerned with preventing the insect's spread, it would be highly desirable to be able to employ a survey technique which could provide timely, accurate, and standardized assessments at a reasonable cost. A project was, therefore, initiated with the aim to demonstrate the usefulness of satellite remotely sensed data for monitoring the insect defoliation of hardwood forests in Pennsylvania. A major effort within this project involved the development of a map-registered Landsat digital database. A complete description of the database developed is provided along with information regarding the employed data management system.

New Technologies for Insect-Resistant and Herbicide-Tolerant Plants.

PubMed

Lombardo, Luca; Coppola, Gerardo; Zelasco, Samanta

2016-01-01

The advent of modern molecular biology and recombinant DNA technology has resulted in a dramatic increase in the number of insect-resistant (IR) and herbicide-tolerant (HT) plant varieties, with great economic benefits for farmers. Nevertheless, the high selection pressure generated by control strategies for weed and insect populations has led to the evolution of herbicide and pesticide resistance. In the short term, the development of new techniques or the improvement of existing ones will provide further instruments to counter the appearance of resistant weeds and insects and to reduce the use of agrochemicals. In this review, we examine some of the most promising new technologies for developing IR and HT plants, such as genome editing and antisense technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits.

PubMed

Heinloth, Tanja; Uhlhorn, Juliane; Wernet, Mathias F

2018-01-01

The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the "Dorsal Rim Area" (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster , we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision.

Aerial survey of insect-caused mortality...operation recorder gathers data quickly, cheaply

Treesearch

Steven L. Wert; Bruce Roettigering

1967-01-01

An Aerial survey using an operation recorder was made over a remote forested area of the Sierra Nevada, in central California. Data on insect-caused mortality were gathered. The survey saved several man-weeks of costly ground work that would have otherwise been required to obtain this information. The technique used proved to be an efficient and inexpensive way of...

Planting northern red oak acorns: is size and planting depth important?

Treesearch

L.R. Auchmoody; H. Clay Smith; Russell S. Walters

1994-01-01

A study was conducted in northern Pennsylvania to determine whether predation by small mammals and insects is related to the size of red oak acorns. Three sizes of acorns were used aiong with two planting techniques and three levels of overstory shading. Three-year results indicated that acorn size is not a factor in mammal and insect predation. Acorn size did not...

Neuroethology of Olfactory-Guided Behavior and Its Potential Application in the Control of Harmful Insects.

PubMed

Reisenman, Carolina E; Lei, Hong; Guerenstein, Pablo G

2016-01-01

Harmful insects include pests of crops and storage goods, and vectors of human and animal diseases. Throughout their history, humans have been fighting them using diverse methods. The fairly recent development of synthetic chemical insecticides promised efficient crop and health protection at a relatively low cost. However, the negative effects of those insecticides on human health and the environment, as well as the development of insect resistance, have been fueling the search for alternative control tools. New and promising alternative methods to fight harmful insects include the manipulation of their behavior using synthetic versions of "semiochemicals", which are natural volatile and non-volatile substances involved in the intra- and/or inter-specific communication between organisms. Synthetic semiochemicals can be used as trap baits to monitor the presence of insects, so that insecticide spraying can be planned rationally (i.e., only when and where insects are actually present). Other methods that use semiochemicals include insect annihilation by mass trapping, attract-and- kill techniques, behavioral disruption, and the use of repellents. In the last decades many investigations focused on the neural bases of insect's responses to semiochemicals. Those studies help understand how the olfactory system detects and processes information about odors, which could lead to the design of efficient control tools, including odor baits, repellents or ways to confound insects. Here we review our current knowledge about the neural mechanisms controlling olfactory responses to semiochemicals in harmful insects. We also discuss how this neuroethology approach can be used to design or improve pest/vector management strategies.

Neuroethology of Olfactory-Guided Behavior and Its Potential Application in the Control of Harmful Insects

PubMed Central

Reisenman, Carolina E.; Lei, Hong; Guerenstein, Pablo G.

2016-01-01

Harmful insects include pests of crops and storage goods, and vectors of human and animal diseases. Throughout their history, humans have been fighting them using diverse methods. The fairly recent development of synthetic chemical insecticides promised efficient crop and health protection at a relatively low cost. However, the negative effects of those insecticides on human health and the environment, as well as the development of insect resistance, have been fueling the search for alternative control tools. New and promising alternative methods to fight harmful insects include the manipulation of their behavior using synthetic versions of “semiochemicals”, which are natural volatile and non-volatile substances involved in the intra- and/or inter-specific communication between organisms. Synthetic semiochemicals can be used as trap baits to monitor the presence of insects, so that insecticide spraying can be planned rationally (i.e., only when and where insects are actually present). Other methods that use semiochemicals include insect annihilation by mass trapping, attract-and- kill techniques, behavioral disruption, and the use of repellents. In the last decades many investigations focused on the neural bases of insect's responses to semiochemicals. Those studies help understand how the olfactory system detects and processes information about odors, which could lead to the design of efficient control tools, including odor baits, repellents or ways to confound insects. Here we review our current knowledge about the neural mechanisms controlling olfactory responses to semiochemicals in harmful insects. We also discuss how this neuroethology approach can be used to design or improve pest/vector management strategies. PMID:27445858

Dynamics of transcriptomic response to infection by the nematode Heterorhabditis bacteriophora and its bacterial symbiont Photorhabdus temperata in Heliothis virescens larvae.

PubMed

An, R; Suri, K S; Jurat-Fuentes, J L; Grewal, P S

2017-10-01

Entomopathogenic nematodes in the Heterorhabditis genus and their symbiotic Photorhabdus bacteria are important biocontrol agents of insect pests and models for the study of microbe-host interactions. In this work, we used larvae of the tobacco budworm (Heliothis virescens) as a model to study its defensive mechanisms against Heterorhabditis bacteriophora nematodes carrying symbiotic Photorhabdus temperata. We first determined time points of initial nematode entry and release of bacteria into the haemolymph to perform transcriptional analysis of insect gene expression during these steps in the infective process. RNA-Sequencing analyses were then performed to profile differential gene expression in the insect during nematode invasion, bacterial release and final steps of infection, relative to the untreated controls. Our results support the theory that insect immune response genes are induced upon nematode invasion, but the majority of these genes are suppressed upon the release of bacteria by the nematodes into the haemolymph. Overall, these findings provide information on the dynamics of the insect's response to a progressing infection by this entomopathogenic nematode-bacteria complex and facilitate development of Hel. virescens as a pest model for future functional studies of the key insect defence factors. © 2017 The Royal Entomological Society.

A Technique to Screen American Beech for Resistance to the Beech Scale Insect (Cryptococcus fagisuga Lind.)

PubMed Central

Koch, Jennifer L.; Carey, David W.

2014-01-01

Beech bark disease (BBD) results in high levels of initial mortality, leaving behind survivor trees that are greatly weakened and deformed. The disease is initiated by feeding activities of the invasive beech scale insect, Cryptococcus fagisuga, which creates entry points for infection by one of the Neonectria species of fungus. Without scale infestation, there is little opportunity for fungal infection. Using scale eggs to artificially infest healthy trees in heavily BBD impacted stands demonstrated that these trees were resistant to the scale insect portion of the disease complex1. Here we present a protocol that we have developed, based on the artificial infestation technique by Houston2, which can be used to screen for scale-resistant trees in the field and in smaller potted seedlings and grafts. The identification of scale-resistant trees is an important component of management of BBD through tree improvement programs and silvicultural manipulation. PMID:24894494

Chemical ecology: studies from East Africa.

PubMed

Meinwald, J; Prestwich, G D; Nakanishi, K; Kubo, I

1978-03-17

The International Centre of Insect Physiology and Ecology (ICIPE), in Nairobi, provides a laboratory at which a multinational group of scientists pursues interdisciplinary research. In collaboration with their colleagues in biology, ICIPE chemists have characterized the sex pheromones of the tick which serves as a vector of East Coast fever and have identified a termite queen-cell-building pheromone. The structure of many anthropod defensive chemicals have been determined; most interesting of these are the trinervitenes, structurally novel diterpenoids from nasute termites. Several highly active insect antifeedants were discovered using a simple bioassay to screen selected East African plants. These antifeedants may provide leads for the development of new insect-control techniques.

Use of synchrotron tomography to image naturalistic anatomy in insects

NASA Astrophysics Data System (ADS)

Socha, John J.; De Carlo, Francesco

2008-08-01

Understanding the morphology of anatomical structures is a cornerstone of biology. For small animals, classical methods such as histology have provided a wealth of data, but such techniques can be problematic due to destruction of the sample. More importantly, fixation and physical slicing can cause deformation of anatomy, a critical limitation when precise three-dimensional data are required. Modern techniques such as confocal microscopy, MRI, and tabletop x-ray microCT provide effective non-invasive methods, but each of these tools each has limitations including sample size constraints, resolution limits, and difficulty visualizing soft tissue. Our research group at the Advanced Photon Source (Argonne National Laboratory) studies physiological processes in insects, focusing on the dynamics of breathing and feeding. To determine the size, shape, and relative location of internal anatomy in insects, we use synchrotron microtomography at the beamline 2-BM to image structures including tracheal tubes, muscles, and gut. Because obtaining naturalistic, undeformed anatomical information is a key component of our studies, we have developed methods to image fresh and non-fixed whole animals and tissues. Although motion artifacts remain a problem, we have successfully imaged multiple species including beetles, ants, fruit flies, and butterflies. Here we discuss advances in biological imaging and highlight key findings in insect morphology.

Influence of Pupation Substrate on Mass Production and Fitness of Adult Anastrepha obliqua Macquart (Diptera: Tephritidae) for Sterile Insect Technique Application.

PubMed

Aceituno-Medina, Marysol; Rivera-Ciprian, José Pedro; Hernández, Emilio

2017-12-05

Tephritid mass-rearing systems require an artificial substrate for pupation. Pupation substrate characteristics influence the quality of insects produced. Coconut fiber, as an alternative to the conventional pupation substrate vermiculite, was evaluated for Anastrepha obliqua Macquart (Diptera: Tephritidae) pupation behavior (pupation patterns, distribution, respiration rate, and pupal weight) and adult fitness (adult eclosion time, flight ability, and male mating competitiveness). Pupation percentage at 24 h, pupal weight, and flight ability were not significantly affected by substrate type. Adult eclosion levels of 50% were reached at 29.7 and 41.6 h for coconut fiber and vermiculite, respectively. Pupae distribution patterns differed between substrates because the larval aggregation level was reduced during the pupation process in coconut fiber. The pupae aggregation was three times greater in vermiculite than in coconut fiber. A higher respiratory rate in the last days of pupation and adult eclosion were recorded in the insects maintained in coconut fiber. Coconut fiber suitability as a pupation substrate for quality mass production of pupae and its implications for sterile insect technique are discussed. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Magnetoreception in eusocial insects: an update

PubMed Central

Wajnberg, Eliane; Acosta-Avalos, Daniel; Alves, Odivaldo Cambraia; de Oliveira, Jandira Ferreira; Srygley, Robert B.; Esquivel, Darci M. S.

2010-01-01

Behavioural experiments for magnetoreception in eusocial insects in the last decade are reviewed. Ants and bees use the geomagnetic field to orient and navigate in areas around their nests and along migratory paths. Bees show sensitivity to small changes in magnetic fields in conditioning experiments and when exiting the hive. For the first time, the magnetic properties of the nanoparticles found in eusocial insects, obtained by magnetic techniques and electron microscopy, are reviewed. Different magnetic oxide nanoparticles, ranging from superparamagnetic to multi-domain particles, were observed in all body parts, but greater relative concentrations in the abdomens and antennae of honeybees and ants have focused attention on these segments. Theoretical models for how these specific magnetosensory apparatuses function have been proposed. Neuron-rich ant antennae may be the most amenable to discovering a magnetosensor that will greatly assist research into higher order processing of magnetic information. The ferromagnetic hypothesis is believed to apply to eusocial insects, but interest in a light-sensitive mechanism is growing. The diversity of compass mechanisms in animals suggests that multiple compasses may function in insect orientation and navigation. The search for magnetic compasses will continue even after a magnetosensor is discovered in eusocial insects. PMID:20106876

Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet.

PubMed

Corbel, Vincent; Stankiewicz, Maria; Pennetier, Cédric; Fournier, Didier; Stojan, Jure; Girard, Emmanuelle; Dimitrov, Mitko; Molgó, Jordi; Hougard, Jean-Marc; Lapied, Bruno

2009-08-05

N,N-Diethyl-3-methylbenzamide (deet) remains the gold standard for insect repellents. About 200 million people use it every year and over 8 billion doses have been applied over the past 50 years. Despite the widespread and increased interest in the use of deet in public health programmes, controversies remain concerning both the identification of its target sites at the olfactory system and its mechanism of toxicity in insects, mammals and humans. Here, we investigated the molecular target site for deet and the consequences of its interactions with carbamate insecticides on the cholinergic system. By using toxicological, biochemical and electrophysiological techniques, we show that deet is not simply a behaviour-modifying chemical but that it also inhibits cholinesterase activity, in both insect and mammalian neuronal preparations. Deet is commonly used in combination with insecticides and we show that deet has the capacity to strengthen the toxicity of carbamates, a class of insecticides known to block acetylcholinesterase. These findings question the safety of deet, particularly in combination with other chemicals, and they highlight the importance of a multidisciplinary approach to the development of safer insect repellents for use in public health.

Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet

PubMed Central

Corbel, Vincent; Stankiewicz, Maria; Pennetier, Cédric; Fournier, Didier; Stojan, Jure; Girard, Emmanuelle; Dimitrov, Mitko; Molgó, Jordi; Hougard, Jean-Marc; Lapied, Bruno

2009-01-01

Background N,N-Diethyl-3-methylbenzamide (deet) remains the gold standard for insect repellents. About 200 million people use it every year and over 8 billion doses have been applied over the past 50 years. Despite the widespread and increased interest in the use of deet in public health programmes, controversies remain concerning both the identification of its target sites at the olfactory system and its mechanism of toxicity in insects, mammals and humans. Here, we investigated the molecular target site for deet and the consequences of its interactions with carbamate insecticides on the cholinergic system. Results By using toxicological, biochemical and electrophysiological techniques, we show that deet is not simply a behaviour-modifying chemical but that it also inhibits cholinesterase activity, in both insect and mammalian neuronal preparations. Deet is commonly used in combination with insecticides and we show that deet has the capacity to strengthen the toxicity of carbamates, a class of insecticides known to block acetylcholinesterase. Conclusion These findings question the safety of deet, particularly in combination with other chemicals, and they highlight the importance of a multidisciplinary approach to the development of safer insect repellents for use in public health. PMID:19656357

Stanislaw Smreczynskis legacy and the Department of Zoology of the Jagiellonian University of Krakow (Poland).

PubMed

Jaglarz, Mariusz K

2008-01-01

This article covers the origin and development of scientific interest in insect and amphibian developmental biology at the Department of Systematic Zoology and Zoogeography of the Jagiellonian University. The greater part of this historical account is devoted to Professor Stanislaw Smreczynski (1899-1975), the founding father of the Department, and comments on his biography and research achievements in the field of animal experimental embryology. A particular emphasis is on Smreczynski's contributions to contemporary understanding of early embryonic development of amphibians and insects as well as his expertise in Pleistocene and extant weevils (Curculionidae). A concise survey of developmental phenomena studied by some of Smreczynski's co-workers and followers is also presented, including the early embryogenesis of entognathans as well as germ cell determination and gonad formation in Drosophila virilis conducted by Jura; analysis of oogenesis in Collembola carried out by Krzysztofowicz; investigations of insects and tradigrades by Weglarska, and finally research into various aspects of ovary structure in diverse insect taxa by the Bilinski group.

Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits

PubMed Central

Heinloth, Tanja; Uhlhorn, Juliane; Wernet, Mathias F.

2018-01-01

The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the “Dorsal Rim Area” (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster, we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision. PMID:29615868

Alien Insects in Italy: Comparing Patterns from the Regional to European Level

PubMed Central

Inghilesi, Alberto F.; Mazza, Giuseppe; Cervo, Rita; Gherardi, Francesca; Sposimo, Paolo; Tricarico, Elena; Zapparoli, Marzio

2013-01-01

The introduction of species outside their native range contributes to the loss of biodiversity, alters the structure and functioning of ecosystems, and damages economy and human health. Insects are one of the taxa with the highest frequency of introduction due to their high diversity, biological properties, and close association with human activities. Here, the allodiversity of Italian entomofauna was analyzed, with a focus on Tuscany (Central Italy). A list of alien insects in Tuscany is included. The status of the alien entomofauna in Italy was updated. The number of alien insects amounts to 122 in Tuscany and 923 in Italy. An introduction rate of 98 species per decade was estimated in Italy. In Tuscany, alien insects belong to 10 orders, mostly Coleoptera (38%), Hemiptera (Sternorrhyncha and Auchenorrhyncha) (23%), and Hymenoptera (13%). They have been most often introduced through vegetable items (ornamental plants or crops). Most species come from the Nearctic region (26%) and are both phytophagous (63%) and amphigonic (80%). Differences and similarities in introduction patterns and in insect abundances across orders among regional, national, and European scales, also considering worldwide abundances, are discussed. Finally, a paucity of information regarding the negative impacts of many species, except for economic pests, phytosanitary threats, and vectors of disease, is underlined. A deeper understanding of the alien insects' ecological impact might help designate policies aimed at preventing further introductions and control the invasive populations of already established species. PMID:24219427

Evidence for Widespread Associations between Neotropical Hymenopteran Insects and Actinobacteria

PubMed Central

Matarrita-Carranza, Bernal; Moreira-Soto, Rolando D.; Murillo-Cruz, Catalina; Mora, Marielos; Currie, Cameron R.; Pinto-Tomas, Adrián A.

2017-01-01

The evolutionary success of hymenopteran insects has been associated with complex physiological and behavioral defense mechanisms against pathogens and parasites. Among these strategies are symbiotic associations between Hymenoptera and antibiotic-producing Actinobacteria, which provide protection to insect hosts. Herein, we examine associations between culturable Actinobacteria and 29 species of tropical hymenopteran insects that span five families, including Apidae (bees), Vespidae (wasps), and Formicidae (ants). In total, 197 Actinobacteria isolates were obtained from 22 of the 29 different insect species sampled. Through 16S rRNA gene sequences of 161 isolates, we show that 91% of the symbionts correspond to members of the genus Streptomyces with less common isolates belonging to Pseudonocardia and Amycolatopsis. Electron microscopy revealed the presence of filamentous bacteria with Streptomyces morphology in brood chambers of two different species of the eusocial wasps. Four fungal strains in the family Ophiocordycipitacea (Hypocreales) known to be specialized insect parasites were also isolated. Bioassay challenges between the Actinobacteria and their possible targeted pathogenic antagonist (both obtained from the same insect at the genus or species level) provide evidence that different Actinobacteria isolates produced antifungal activity, supporting the hypothesis of a defensive association between the insects and these microbe species. Finally, phylogenetic analysis of 16S rRNA and gyrB demonstrate the presence of five Streptomyces lineages associated with a broad range of insect species. Particularly our Clade I is of much interest as it is composed of one 16S rRNA phylotype repeatedly isolated from different insect groups in our sample. This phylotype corresponds to a previously described lineage of host-associated Streptomyces. These results suggest Streptomyces Clade I is a Hymenoptera host-associated lineage spanning several new insect taxa and ranging from the American temperate to the Neotropical region. Our work thus provides important insights into the widespread distribution of Actinobacteria and hymenopteran insects associations, while also pointing at novel resources that could be targeted for the discovery of active natural products with great potential in medical and biotechnological applications. PMID:29089938

Engineering the genomes of wild insect populations: challenges, and opportunities provided by synthetic Medea selfish genetic elements

PubMed Central

Chen, Chun-Hong; Ward, Catherine M.; Huang, Haixia; Su, Jessica T.; Guo, Ming

2013-01-01

Advances in insect transgenesis and our knowledge of insect physiology and genomics are making it possible to create transgenic populations of beneficial or pest insects that express novel traits. There are contexts in which we may want the transgenes responsible for these traits to spread so that all individuals within a wild population carry them, a process known as population replacement. Transgenes of interest are unlikely to confer an overall fitness benefit on those who carry them. Therefore, an essential component of any population replacement strategy is the presence of a drive mechanism that will ensure the spread of linked transgenes. We discuss contexts in which population replacement might be desirable and the requirements a drive system must satisfy to be both effective and safe. We then describe the creation of synthetic Medea elements, the first selfish genetic elements synthesized de novo, with the capability of driving population replacement, in this case in Drosophila. The strategy used to create Drosophila Medea is applicable to a number of other insect species and the Medea system satisfies key requirements for scientific and social acceptance. Finally, we highlight several challenges to implementing population replacement in the wild. PMID:20570677

Reassessing ecdysteroidogenic cells from the cell membrane receptors' perspective.

PubMed

Alexandratos, Alexandros; Moulos, Panagiotis; Nellas, Ioannis; Mavridis, Konstantinos; Dedos, Skarlatos G

2016-02-05

Ecdysteroids secreted by the prothoracic gland (PG) cells of insects control the developmental timing of their immature life stages. These cells have been historically considered as carrying out a single function in insects, namely the biochemical conversion of cholesterol to ecdysteroids and their secretion. A growing body of evidence shows that PG cells receive multiple cues during insect development so we tested the hypothesis that they carry out more than just one function in insects. We characterised the molecular nature and developmental profiles of cell membrane receptors in PG cells of Bombyx mori during the final larval stage and determined what receptors decode nutritional, developmental and physiological signals. Through iterative approaches we identified a complex repertoire of cell membrane receptors that are expressed in intricate patterns and activate previously unidentified signal transduction cascades in PG cells. The expression patterns of some of these receptors explain precisely the mechanisms that are known to control ecdysteroidogenesis. However, the presence of receptors for the notch, hedgehog and wingless signalling pathways and the expression of innate immunity-related receptors such as phagocytosis receptors, receptors for microbial ligands and Toll-like receptors call for a re-evaluation of the role these cells play in insects.

Insects as vectors: systematics and biology.

PubMed

Rodhain, F

2015-04-01

Among the many complex relationships between insects and microorganisms such as viruses, bacteria and parasites, some have resulted in the establishment of biological systems within which the insects act as a biological vector for infectious agents. It is therefore advisable to understand the identity and biology of these vectors in depth, in order to define procedures for epidemiological surveillance and anti-vector control. The following are successively reviewed in this article: Anoplura (lice), Siphonaptera (fleas), Heteroptera (bugs: Cimicidae, Triatoma, Belostomatidae), Psychodidae (sandflies), Simuliidae (black flies), Ceratopogonidae (biting midges), Culicidae (mosquitoes), Tabanidae (horseflies) and Muscidae (tsetse flies, stable flies and pupipara). The authors provide a rapid overview of the morphology, systematics, development cycle and bio-ecology of each of these groups of vectors. Finally, their medical and veterinary importance is briefly reviewed.

Technology Demonstration Plan. Evaluation of Explosives Field Analytical Techniques

DTIC Science & Technology

1999-08-01

threatening. Some symptoms of heat-related injuries are pale clammy skin , sweating, headache, weakness, dizziness, and nausea. Signs of heat stroke...include dry, hot, red skin , chills, and confusion. In the case of a suspected heat-related injury , try to cool the person down and contact medical...during the day. 9.8.6 Insect and Other Animal Stings and Bites A potential for insect (e.g., honey bees , wasps, yellow jackets), snake (e.g

Issues of convection in insect respiration: Insights from synchrotron X-ray imaging and beyond

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

Socha, John J.; Förster, Thomas D.; Greenlee, Kendra J.

2010-11-01

While it has long been known that in small animals, such as insects, sufficient gas transport could be provided by diffusion, it is now recognized that animals generate and control convective flows to improve oxygen delivery across a range of body sizes and taxa. However, size-based methodological limitations have constrained our understanding of the mechanisms that underlie the production of these convective flows. Recently, new techniques have enabled the elucidation of the anatomical structures and physiological processes that contribute to creating and maintaining bulk flow in small animals. In particular, synchrotron X-ray imaging provides unprecedented spatial and temporal resolution ofmore » internal functional morphology and is changing the way we understand gas exchange in insects. This symposium highlights recent efforts towards understanding the relationship between form, function, and control in the insect respiratory system.« less

Six-year beechnut production in New Hampshire. Forest Service research paper (Final)

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

Leak, W.B.; Graber, R.E.

1993-08-01

The Beechnut production and losses were studied over a 6-year period in 41 northern hardwood stands ranging in age from 10 to 140 years in the White Mountains of New Hampshire. Beechnut production increased consistently with stand age or diameter at base height of dominant trees and percentage of basal area composed of beech. Losses to insects, rodents, and birds before the seed reached the ground ranged from 24 to 100 percent; insects caused the greatest losses. Good seed years occurred about every third year.

Environmental restraints and life strategies: a habitat templet matrix.

PubMed

Holm, E

1988-02-01

Four basic environmental restraints on life are deduced from the requirements of life's inherent order laws. Possible life strategies to contend with these restraints are listed. The various combinations of the restraints are subsequently investigated, and appropriate combinations of life strategies are fitted. This model is finally tested against insect case histories in various environments, and is demonstrated to explain some combinations of characteristics of insects in ecosystems not covered by the r-K or r-K-A continua. The role of heterochrony in achieving appropriate life strategies is briefly discussed.

Trypanosomatidae: Phytomonas detection in plants and phytophagous insects by PCR amplification of a genus-specific sequence of the spliced leader gene.

PubMed

Serrano, M G; Nunes, L R; Campaner, M; Buck, G A; Camargo, E P; Teixeira, M M

1999-03-01

In this paper we describe a method for the detection of Phytomonas spp. from plants and phytophagous insects using the PCR technique by targeting a genus-specific sequence of the spliced leader (SL) gene. PCR amplification of DNA from 48 plant and insect isolates previously classified as Phytomonas by morphological, biochemical, and molecular criteria resulted in all cases in a 100-bp fragment that hybridized with the Phytomonas-specific spliced leader-derived probe SL3'. Moreover, this Phytomonas-specific PCR could also detect Phytomonas spp. in crude preparations of naturally infected plants and insects. This method shows no reaction with any other trypanosomatid genera or with plant and insect host DNA, revealing it to be able to detect Phytomonas spp. from fruit, latex, or phloem of various host plants as well as from salivary glands and digestive tubes of several species of insect hosts. Results demonstrated that SLPCR is a simple, fast, specific, and sensitive method that can be applied to the diagnosis of Phytomonas among cultured trypanosomatids and directly in plants and putative vector insects. Therefore, the method was shown to be a very specific and sensitive tool for diagnosis of Phytomonas without the need for isolation, culture, and DNA extraction of flagellates, a feature that is very convenient for practical and epidemiological purposes. Copyright 1999 Academic Press.

Tools for detecting insect semiochemicals: a review.

PubMed

Brezolin, Alexandra Nava; Martinazzo, Janine; Muenchen, Daniela Kunkel; de Cezaro, Alana Marie; Rigo, Aline Andressa; Steffens, Clarice; Steffens, Juliana; Blassioli-Moraes, Maria Carolina; Borges, Miguel

2018-07-01

Semiochemicals are chemical compounds that are released by many species as a means of intra- and interspecific communication. Insects have extremely advanced olfactory systems; indeed, they rely on smell when performing many of their main behaviors, such as oviposition, breeding, prey location, and defense. This characteristic of insects implies that semiochemicals could be used for various applications, including in agriculture, where they could be employed along with other tools to control pest insects. The aim of this review is to present the main techniques used and the state of the art in the detection of semiochemicals, focusing on pheromones. In addition to the traditional methods of identifying semiochemicals, such as gas chromatography coupled to a high-resolution detection mode (e.g., flame ionization (FID), electron capture (ECD), photoionization (PID), or mass spectrometry (MS)), other tools are addressed in this review, including sensors and biosensors. While these new technologies may be used under laboratory conditions to improve or complement technologies that are already being used, they are mainly intended for use as new agricultural tools for detecting and controlling pest insects in the field.

A parallel stereo reconstruction algorithm with applications in entomology (APSRA)

NASA Astrophysics Data System (ADS)

Bhasin, Rajesh; Jang, Won Jun; Hart, John C.

2012-03-01

We propose a fast parallel algorithm for the reconstruction of 3-Dimensional point clouds of insects from binocular stereo image pairs using a hierarchical approach for disparity estimation. Entomologists study various features of insects to classify them, build their distribution maps, and discover genetic links between specimens among various other essential tasks. This information is important to the pesticide and the pharmaceutical industries among others. When considering the large collections of insects entomologists analyze, it becomes difficult to physically handle the entire collection and share the data with researchers across the world. With the method presented in our work, Entomologists can create an image database for their collections and use the 3D models for studying the shape and structure of the insects thus making it easier to maintain and share. Initial feedback shows that the reconstructed 3D models preserve the shape and size of the specimen. We further optimize our results to incorporate multiview stereo which produces better overall structure of the insects. Our main contribution is applying stereoscopic vision techniques to entomology to solve the problems faced by entomologists.

Convergent bacterial microbiotas in the fungal agricultural systems of insects.

PubMed

Aylward, Frank O; Suen, Garret; Biedermann, Peter H W; Adams, Aaron S; Scott, Jarrod J; Malfatti, Stephanie A; Glavina del Rio, Tijana; Tringe, Susannah G; Poulsen, Michael; Raffa, Kenneth F; Klepzig, Kier D; Currie, Cameron R

2014-11-18

The ability to cultivate food is an innovation that has produced some of the most successful ecological strategies on the planet. Although most well recognized in humans, where agriculture represents a defining feature of civilization, species of ants, beetles, and termites have also independently evolved symbioses with fungi that they cultivate for food. Despite occurring across divergent insect and fungal lineages, the fungivorous niches of these insects are remarkably similar, indicating convergent evolution toward this successful ecological strategy. Here, we characterize the microbiota of ants, beetles, and termites engaged in nutritional symbioses with fungi to define the bacterial groups associated with these prominent herbivores and forest pests. Using culture-independent techniques and the in silico reconstruction of 37 composite genomes of dominant community members, we demonstrate that different insect-fungal symbioses that collectively shape ecosystems worldwide have highly similar bacterial microbiotas comprised primarily of the genera Enterobacter, Rahnella, and Pseudomonas. Although these symbioses span three orders of insects and two phyla of fungi, we show that they are associated with bacteria sharing high whole-genome nucleotide identity. Due to the fine-scale correspondence of the bacterial microbiotas of insects engaged in fungal symbioses, our findings indicate that this represents an example of convergence of entire host-microbe complexes. The cultivation of fungi for food is a behavior that has evolved independently in ants, beetles, and termites and has enabled many species of these insects to become ecologically important and widely distributed herbivores and forest pests. Although the primary fungal cultivars of these insects have been studied for decades, comparatively little is known of their bacterial microbiota. In this study, we show that diverse fungus-growing insects are associated with a common bacterial community composed of the same dominant members. Furthermore, by demonstrating that many of these bacteria have high whole-genome similarity across distantly related insect hosts that reside thousands of miles apart, we show that these bacteria are an important and underappreciated feature of diverse fungus-growing insects. Because of the similarities in the agricultural lifestyles of these insects, this is an example of convergence between both the life histories of the host insects and their symbiotic microbiota. Copyright © 2014 Aylward et al.

Sterile insect technique: A model for dose optimisation for improved sterile insect quality

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

Parker, A.; Mehta, K.

The sterile insect technique (SIT) is an environment-friendly pest control technique with application in the area-wide integrated control of key pests, including the suppression or elimination of introduced populations and the exclusion of new introductions. Reproductive sterility is normally induced by ionizing radiation, a convenient and consistent method that maintains a reasonable degree of competitiveness in the released insects. The cost and effectiveness of a control program integrating the SIT depend on the balance between sterility and competitiveness, but it appears that current operational programs with an SIT component are not achieving an appropriate balance. In this paper we discussmore » optimization of the sterilization process and present a simple model and procedure for determining the optimum dose. (author) [Spanish] La tecnica de insecto esteril (TIE) es una tecnologia de control de plagas favorable para el medio ambiente con una aplicacion de un control integrado de plagas claves para toda la area, incluyendo la supresion o eliminacion de poblaciones introducidas y la exclusion de nuevas introducciones. La esterilidad reproductiva es normalmente inducida por radiacion ionizada, un metodo conveniente y consistente que mantiene un grado razonable para la capacidad de competencia en insectos liberados. El costo y la eficacia de un programa de control que incluye TIE dependen en tener un balance entre la esterilidad y la capacidad para competir, pero parece que los programas operacionales corrientes con TIS como un componente no estan logrando el tener un balance apropiado. En esta publicacion, nosotros discutimos la optimizacion del proceso de esterilizacion y presentamos un modelo y procedimiento sencillos para determinar la dosis optima. (author)« less

Micro-CT Imaging of Denatured Chitin by Silver to Explore Honey Bee and Insect Pathologies

PubMed Central

Butzloff, Peter R.

2011-01-01

Background Chitin and cuticle coatings are important to the environmental and immune defense of honey bees and insect pollinators. Pesticides or environmental effects may target the biochemistry of insect chitin and cuticle coating. Denaturing of chitin involves a combination of deacetylation, intercalation, oxidation, Schweiger-peeling, and the formation of amine hydrochloride salt. The term “denatured chitin” calls attention to structural and property changes to the internal membranes and external carapace of organisms so that some properties affecting biological activities are diminished. Methodology/Principal Findings A case study was performed on honey bees using silver staining and microscopic computer-tomographic x-ray radiography (micro-CT). Silver nitrate formed counter-ion complexes with labile ammonium cations and reacted with amine hydrochloride. Silver was concentrated in the peritrophic membrane, on the abdomen, in the glossa, at intersegmental joints (tarsi), at wing attachments, and in tracheal air sacs. Imaged mono-esters and fatty acids from cuticle coating on external surfaces were apparently reduced by an alcohol pretreatment. Conclusions/Significance The technique provides 3-dimensional and sectional images of individual honey bees consistent with the chemistries of silver reaction and complex formation with denatured chitin. Environmental exposures and influences such as gaseous nitric oxide intercalant, trace oxidants such as ozone gas, oligosachharide salt conversion, exposure to acid rain, and chemical or biochemical denaturing by pesticides may be studied using this technique. Peritrophic membranes, which protect against food abrasion, microorganisms, and permit efficient digestion, were imaged. Apparent surface damage to the corneal lenses of compound eyes by dilute acid exposure consistent with chitin amine hydrochloride formation was imaged. The technique can contribute to existing insect pathology research, and may provide an additional tool for research on CCD. PMID:22110654

Insektenpheromone

NASA Astrophysics Data System (ADS)

Bestmann, H. J.; Vostrowsky, O.

1982-10-01

Pheromones — semiochemicals used by insects for intraspecific chemical communication — can be isolated and with special analytical techniques their chemical structure elucidated. With stereoselective synthesis methods, presented by the preparation of sex attractants and aggregating pheromones of moths and beetles, respectively, a synthetic access to compounds is given which can be used for behavior manipulation of insects. Aside the importance of these compounds for investigations of the sensoric process the possibility of their application in an integrated and biological pest control is discussed.

Mild-Vectolysis: A nondestructive DNA extraction method for vouchering sand flies and mosquitoes

USDA-ARS?s Scientific Manuscript database

Nondestructive techniques allow the isolation of genomic DNA, without damaging the morphological features of the specimens. Though such techniques are available for numerous insect groups, they have not been applied to any member of the medically important families of mosquitoes (Diptera: Culicidae)...

Progress in Insect-Inspired Optical Navigation Sensors

NASA Technical Reports Server (NTRS)

Thakoor, Sarita; Chahl, Javaan; Zometzer, Steve

2005-01-01

Progress has been made in continuing efforts to develop optical flight-control and navigation sensors for miniature robotic aircraft. The designs of these sensors are inspired by the designs and functions of the vision systems and brains of insects. Two types of sensors of particular interest are polarization compasses and ocellar horizon sensors. The basic principle of polarization compasses was described (but without using the term "polarization compass") in "Insect-Inspired Flight Control for Small Flying Robots" (NPO-30545), NASA Tech Briefs, Vol. 29, No. 1 (January 2005), page 61. To recapitulate: Bees use sky polarization patterns in ultraviolet (UV) light, caused by Rayleigh scattering of sunlight by atmospheric gas molecules, as direction references relative to the apparent position of the Sun. A robotic direction-finding technique based on this concept would be more robust in comparison with a technique based on the direction to the visible Sun because the UV polarization pattern is distributed across the entire sky and, hence, is redundant and can be extrapolated from a small region of clear sky in an elsewhere cloudy sky that hides the Sun.

Evolution of the Insect Desaturase Gene Family with an Emphasis on Social Hymenoptera

PubMed Central

Helmkampf, Martin; Cash, Elizabeth; Gadau, Jürgen

2015-01-01

Desaturase genes are essential for biological processes, including lipid metabolism, cell signaling, and membrane fluidity regulation. Insect desaturases are particularly interesting for their role in chemical communication, and potential contribution to speciation, symbioses, and sociality. Here, we describe the acyl-CoA desaturase gene families of 15 insects, with a focus on social Hymenoptera. Phylogenetic reconstruction revealed that the insect desaturases represent an ancient gene family characterized by eight subfamilies that differ strongly in their degree of conservation and frequency of gene gain and loss. Analyses of genomic organization showed that five of these subfamilies are represented in a highly microsyntenic region conserved across holometabolous insect taxa, indicating an ancestral expansion during early insect evolution. In three subfamilies, ants exhibit particularly large expansions of genes. Despite these expansions, however, selection analyses showed that desaturase genes in all insect lineages are predominantly undergoing strong purifying selection. Finally, for three expanded subfamilies, we show that ants exhibit variation in gene expression between species, and more importantly, between sexes and castes within species. This suggests functional differentiation of these genes and a role in the regulation of reproductive division of labor in ants. The dynamic pattern of gene gain and loss of acyl-CoA desaturases in ants may reflect changes in response to ecological diversification and an increased demand for chemical signal variability. This may provide an example of how gene family expansions can contribute to lineage-specific adaptations through structural and regulatory changes acting in concert to produce new adaptive phenotypes. PMID:25425561

Convergent bacterial microbiotas in the fungal agricultural systems of insects

DOE PAGES

Aylward, Frank O.; Suen, Garret; Biedermann, Peter H. W.; ...

2014-11-18

The ability to cultivate food is an innovation that has produced some of the most successful ecological strategies on the planet. Although most well recognized in humans, where agriculture represents a defining feature of civilization, species of ants, beetles, and termites have also independently evolved symbioses with fungi that they cultivate for food. Despite occurring across divergent insect and fungal lineages, the fungivorous niches of these insects are remarkably similar, indicating convergent evolution toward this successful ecological strategy. Here, we characterize the microbiota of ants, beetles, and termites engaged in nutritional symbioses with fungi to define the bacterial groups associatedmore » with these prominent herbivores and forest pests. Using culture-independent techniques and the in silico reconstruction of 37 composite genomes of dominant community members, we demonstrate that different insect-fungal symbioses that collectively shape ecosystems worldwide have highly similar bacterial microbiotas comprised primarily of the genera Enterobacter, Rahnella, and Pseudomonas. Although these symbioses span three orders of insects and two phyla of fungi, we show that they are associated with bacteria sharing high whole-genome nucleotide identity. Due to the fine-scale correspondence of the bacterial microbiotas of insects engaged in fungal symbioses, our findings indicate that this represents an example of convergence of entire host-microbe complexes.« less

Field performance of a genetically engineered strain of pink bollworm.

PubMed

Simmons, Gregory S; McKemey, Andrew R; Morrison, Neil I; O'Connell, Sinead; Tabashnik, Bruce E; Claus, John; Fu, Guoliang; Tang, Guolei; Sledge, Mickey; Walker, Adam S; Phillips, Caroline E; Miller, Ernie D; Rose, Robert I; Staten, Robert T; Donnelly, Christl A; Alphey, Luke

2011-01-01

Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT)--mass-release of sterile insects to mate with, and thereby control, their wild counterparts--has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field--ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area--were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests.

Convergent bacterial microbiotas in the fungal agricultural systems of insects

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

Aylward, Frank O.; Suen, Garret; Biedermann, Peter H. W.

The ability to cultivate food is an innovation that has produced some of the most successful ecological strategies on the planet. Although most well recognized in humans, where agriculture represents a defining feature of civilization, species of ants, beetles, and termites have also independently evolved symbioses with fungi that they cultivate for food. Despite occurring across divergent insect and fungal lineages, the fungivorous niches of these insects are remarkably similar, indicating convergent evolution toward this successful ecological strategy. Here, we characterize the microbiota of ants, beetles, and termites engaged in nutritional symbioses with fungi to define the bacterial groups associatedmore » with these prominent herbivores and forest pests. Using culture-independent techniques and the in silico reconstruction of 37 composite genomes of dominant community members, we demonstrate that different insect-fungal symbioses that collectively shape ecosystems worldwide have highly similar bacterial microbiotas comprised primarily of the genera Enterobacter, Rahnella, and Pseudomonas. Although these symbioses span three orders of insects and two phyla of fungi, we show that they are associated with bacteria sharing high whole-genome nucleotide identity. Due to the fine-scale correspondence of the bacterial microbiotas of insects engaged in fungal symbioses, our findings indicate that this represents an example of convergence of entire host-microbe complexes.« less

Reaching the Melting Point: Degradative Enzymes and Protease Inhibitors Involved in Baculovirus Infection and Dissemination

PubMed Central

Ishimwe, Egide; Hodgson, Jeffrey J.; Clem, Rollie J.; Passarelli, A. Lorena

2015-01-01

Baculovirus infection of a host insect involves several steps, beginning with initiation of virus infection in the midgut, followed by dissemination of infection from the midgut to other tissues in the insect, and finally culminating in “melting” or liquefaction of the host, which allows for horizontal spread of infection to other insects. While all of the viral gene products are involved in ultimately reaching this dramatic infection endpoint, this review focuses on two particular types of baculovirus-encoded proteins: degradative enzymes and protease inhibitors. Neither of these types of proteins is commonly found in other virus families, but they both play important roles in baculovirus infection. The types of degradative enzymes and protease inhibitors encoded by baculoviruses are discussed, as are the roles of these proteins in the infection process. PMID:25724418

Automated Surveillance of Fruit Flies

PubMed Central

Potamitis, Ilyas; Rigakis, Iraklis; Tatlas, Nicolaos-Alexandros

2017-01-01

Insects of the Diptera order of the Tephritidae family cause costly, annual crop losses worldwide. Monitoring traps are important components of integrated pest management programs used against fruit flies. Here we report the modification of typical, low-cost plastic traps for fruit flies by adding the necessary optoelectronic sensors to monitor the entrance of the trap in order to detect, time-stamp, GPS tag, and identify the species of incoming insects from the optoacoustic spectrum analysis of their wingbeat. We propose that the incorporation of automated streaming of insect counts, environmental parameters and GPS coordinates into informative visualization of collective behavior will finally enable better decision making across spatial and temporal scales, as well as administrative levels. The device presented is at product level of maturity as it has solved many pending issues presented in a previously reported study. PMID:28075346

Sex pheromones and their impact on pest management.

PubMed

Witzgall, Peter; Kirsch, Philipp; Cork, Alan

2010-01-01

The idea of using species-specific behavior-modifying chemicals for the management of noxious insects in agriculture, horticulture, forestry, stored products, and for insect vectors of diseases has been a driving ambition through five decades of pheromone research. Hundreds of pheromones and other semiochemicals have been discovered that are used to monitor the presence and abundance of insects and to protect plants and animals against insects. The estimated annual production of lures for monitoring and mass trapping is on the order of tens of millions, covering at least 10 million hectares. Insect populations are controlled by air permeation and attract-and-kill techniques on at least 1 million hectares. Here, we review the most important and widespread practical applications. Pheromones are increasingly efficient at low population densities, they do not adversely affect natural enemies, and they can, therefore, bring about a long-term reduction in insect populations that cannot be accomplished with conventional insecticides. A changing climate with higher growing season temperatures and altered rainfall patterns makes control of native and invasive insects an increasingly urgent challenge. Intensified insecticide use will not provide a solution, but pheromones and other semiochemicals instead can be implemented for sustainable area-wide management and will thus improve food security for a growing population. Given the scale of the challenges we face to mitigate the impacts of climate change, the time is right to intensify goal-oriented interdisciplinary research on semiochemicals, involving chemists, entomologists, and plant protection experts, in order to provide the urgently needed, and cost-effective technical solutions for sustainable insect management worldwide.

Resistance to genetic insect control: Modelling the effects of space.

PubMed

Watkinson-Powell, Benjamin; Alphey, Nina

2017-01-21

Genetic insect control, such as self-limiting RIDL 2 (Release of Insects Carrying a Dominant Lethal) technology, is a development of the sterile insect technique which is proposed to suppress wild populations of a number of major agricultural and public health insect pests. This is achieved by mass rearing and releasing male insects that are homozygous for a repressible dominant lethal genetic construct, which causes death in progeny when inherited. The released genetically engineered ('GE') insects compete for mates with wild individuals, resulting in population suppression. A previous study modelled the evolution of a hypothetical resistance to the lethal construct using a frequency-dependent population genetic and population dynamic approach. This found that proliferation of resistance is possible but can be diluted by the introgression of susceptible alleles from the released homozygous-susceptible GE males. We develop this approach within a spatial context by modelling the spread of a lethal construct and resistance trait, and the effect on population control, in a two deme metapopulation, with GE release in one deme. Results show that spatial effects can drive an increased or decreased evolution of resistance in both the target and non-target demes, depending on the effectiveness and associated costs of the resistant trait, and on the rate of dispersal. A recurrent theme is the potential for the non-target deme to act as a source of resistant or susceptible alleles for the target deme through dispersal. This can in turn have a major impact on the effectiveness of insect population control. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Insect Residue Contamination on Wing Leading Edge Surfaces: A Materials Investigation for Mitigation

NASA Technical Reports Server (NTRS)

Lorenzi, Tyler M.; Wohl, Christopher J.; Penner, Ronald K.; Smith, Joseph G.; Siochi, Emilie J.

2011-01-01

Flight tests have shown that residue from insect strikes on aircraft wing leading edge surfaces may induce localized transition of laminar to turbulent flow. The highest density of insect populations have been observed between ground level and 153 m during light winds (2.6 -- 5.1 m/s), high humidity, and temperatures from 21 -- 29 C. At a critical residue height, dependent on the airfoil and Reynolds number, boundary layer transition from laminar to turbulent results in increased drag and fuel consumption. Although this represents a minimal increase in fuel burn for conventional transport aircraft, future aircraft designs will rely on maintaining laminar flow across a larger portion of wing surfaces to reduce fuel burn during cruise. Thus, insect residue adhesion mitigation is most critical during takeoff and initial climb to maintain laminar flow in fuel-efficient aircraft configurations. Several exterior treatments investigated to mitigate insect residue buildup (e.g., paper, scrapers, surfactants, flexible surfaces) have shown potential; however, implementation has proven to be impractical. Current research is focused on evaluation of wing leading edge surface coatings that may reduce insect residue adhesion. Initial work under NASA's Environmentally Responsible Aviation Program focused on evaluation of several commercially available products (commercial off-the-shelf, COTS), polymers, and substituted alkoxy silanes that were applied to aluminum (Al) substrates. Surface energies of these coatings were determined from contact angle data and were correlated to residual insect excrescence on coated aluminum substrates using a custom-built "bug gun." Quantification of insect excrescence surface coverage was evaluated by a series of digital photographic image processing techniques.

Energy Homeostasis Control in Drosophila Adipokinetic Hormone Mutants

PubMed Central

Gáliková, Martina; Diesner, Max; Klepsatel, Peter; Hehlert, Philip; Xu, Yanjun; Bickmeyer, Iris; Predel, Reinhard; Kühnlein, Ronald P.

2015-01-01

Maintenance of biological functions under negative energy balance depends on mobilization of storage lipids and carbohydrates in animals. In mammals, glucagon and glucocorticoid signaling mobilizes energy reserves, whereas adipokinetic hormones (AKHs) play a homologous role in insects. Numerous studies based on AKH injections and correlative studies in a broad range of insect species established the view that AKH acts as master regulator of energy mobilization during development, reproduction, and stress. In contrast to AKH, the second peptide, which is processed from the Akh encoded prohormone [termed “adipokinetic hormone precursor-related peptide” (APRP)] is functionally orphan. APRP is discussed as ecdysiotropic hormone or as scaffold peptide during AKH prohormone processing. However, as in the case of AKH, final evidence for APRP functions requires genetic mutant analysis. Here we employed CRISPR/Cas9-mediated genome engineering to create AKH and AKH plus APRP-specific mutants in the model insect Drosophila melanogaster. Lack of APRP did not affect any of the tested steroid-dependent processes. Similarly, Drosophila AKH signaling is dispensable for ontogenesis, locomotion, oogenesis, and homeostasis of lipid or carbohydrate storage until up to the end of metamorphosis. During adulthood, however, AKH regulates body fat content and the hemolymph sugar level as well as nutritional and oxidative stress responses. Finally, we provide evidence for a negative autoregulatory loop in Akh gene regulation. PMID:26275422

Social immunity and the evolution of group living in insects.

PubMed

Meunier, Joël

2015-05-26

The evolution of group living requires that individuals limit the inherent risks of parasite infection. To this end, group living insects have developed a unique capability of mounting collective anti-parasite defences, such as allogrooming and corpse removal from the nest. Over the last 20 years, this phenomenon (called social immunity) was mostly studied in eusocial insects, with results emphasizing its importance in derived social systems. However, the role of social immunity in the early evolution of group living remains unclear. Here, I investigate this topic by first presenting the definitions of social immunity and discussing their applications across social systems. I then provide an up-to-date appraisal of the collective and individual mechanisms of social immunity described in eusocial insects and show that they have counterparts in non-eusocial species and even solitary species. Finally, I review evidence demonstrating that the increased risks of parasite infection in group living species may both decrease and increase the level of personal immunity, and discuss how the expression of social immunity could drive these opposite effects. By highlighting similarities and differences of social immunity across social systems, this review emphasizes the potential importance of this phenomenon in the early evolution of the multiple forms of group living in insects. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Engineering the genomes of wild insect populations: challenges, and opportunities provided by synthetic Medea selfish genetic elements.

PubMed

Hay, Bruce A; Chen, Chun-Hong; Ward, Catherine M; Huang, Haixia; Su, Jessica T; Guo, Ming

2010-10-01

Advances in insect transgenesis and our knowledge of insect physiology and genomics are making it possible to create transgenic populations of beneficial or pest insects that express novel traits. There are contexts in which we may want the transgenes responsible for these traits to spread so that all individuals within a wild population carry them, a process known as population replacement. Transgenes of interest are unlikely to confer an overall fitness benefit on those who carry them. Therefore, an essential component of any population replacement strategy is the presence of a drive mechanism that will ensure the spread of linked transgenes. We discuss contexts in which population replacement might be desirable and the requirements a drive system must satisfy to be both effective and safe. We then describe the creation of synthetic Medea elements, the first selfish genetic elements synthesized de novo, with the capability of driving population replacement, in this case in Drosophila. The strategy used to create Drosophila Medea is applicable to a number of other insect species and the Medea system satisfies key requirements for scientific and social acceptance. Finally, we highlight several challenges to implementing population replacement in the wild. Copyright 2010 Elsevier Ltd. All rights reserved.

How the bat got its buzz

PubMed Central

Ratcliffe, John M.; Elemans, Coen P. H.; Jakobsen, Lasse; Surlykke, Annemarie

2013-01-01

Since the discovery of echolocation in bats, the final phase of an attack on a flying insect, the ‘terminal buzz’, has proved enigmatic. During the buzz, bats increase information update rates by producing vocalizations up to 220 times s−1. The buzz's ubiquity in hawking and trawling bats implies its importance for hunting success. Superfast muscles, previously unknown in mammals, are responsible for the extreme vocalization rate. Some bats produce a second phase—buzz II—defined by a large drop in the fundamental frequency (F0) of their calls. By doing so, bats broaden their acoustic field of view and should thereby reduce the likelihood of insect escape. We make the case that the buzz was a critical adaptation for capturing night-flying insects, and suggest that the drop in F0 during buzz II requires novel, unidentified laryngeal mechanisms in order to counteract increasing muscle tension. Furthermore, we propose that buzz II represents a countermeasure against the evasive flight of eared prey in the evolutionary arms-race that saw the independent evolution of bat-detecting ears in various groups of night-flying insects. PMID:23302868

[Expression of goat IL-18 mature protein in insect/baculovirus and determination of bioactivity of the recombinant protein].

PubMed

Wang, Ting-Ting; Wang, Xi-Hui; Fan, Zhong-Ling; Chen, Jin-Long; Cao, Bing-Lei; Kong, Na; Hu, Jing-Dong; Zhao, Hong-Kun

2011-02-01

To express goat IL-18 in insect/baculovirus and detect the bioactivity of the recombinant protein. The mature goat interleukin-18(gIL-18) gene was cloned into the baculovirus transfer vector pFastBac Dual, and then the resulting eukaryotic expression plasmid pFastBac Dual-gIL18 was transformed into DH10Bac, followed by the identification of Bacmid-gIL18 recombinat plosmid by three antibiotics and blue-white patch. Finally, the recombinant bacmid was transfected into sf9 insect cells by Cellfectin and the transfected cells were harvested at different times. Then the expressed protein was identified by SDS-PAGE, Western blot and bioactivity assay. The recombinant protein recognized and bound to its specific antibody. Bioactivity assay showed that the recombinant protein stimulated the proliferation of lymphocytes and induced IFN-γproduction in spleen lymphocytes. The mature gIL-18 protein has been expressed successfully in insect/baculovirus expression system, and have good immunogenicity and bioactivity. The study paves a way for application of gIL-18 as an immunomodulator or immune adjuvant.

Insect gravitational biology: ground-based and shuttle flight experiments using the beetle Tribolium castaneum

NASA Technical Reports Server (NTRS)

Bennett, R. L.; Abbott, M. K.; Denell, R. E.; Spooner, B. S. (Principal Investigator)

1994-01-01

Many of the traditional experimental advantages of insects recommend their use in studies of gravitational and space biology. The fruit fly, Drosophila melanogaster, is an obvious choice for studies of the developmental significance of gravity vectors because of the unparalleled description of regulatory mechanisms controlling oogenesis and embryogenesis. However, we demonstrate that Drosophila could not survive the conditions mandated for particular flight opportunities on the Space Shuttle. With the exception of Drosophila, the red flour beetle, Tribolium castaneum, is the insect best characterized with respect to molecular embryology and most frequently utilized for past space flights. We show that Tribolium is dramatically more resistant to confinement in small sealed volumes. In preparation for flight experiments we characterize the course and timing of the onset of oogenesis in newly eclosed adult females. Finally, we present results from two shuttle flights which indicate that a number of aspects of the development and function of the female reproductive system are not demonstrably sensitive to microgravity. Available information supports the utility of this insect for future studies of gravitational biology.

Age determination of the glassy-winged sharpshooter, Homalodisca vitripennis, using wing pigmentation.

PubMed

Timmons, Chris; Hassell, Aaron; Lauziere, Isabelle; Bextine, Blake

2011-01-01

A red pigment is contained in the wing veins of the glassy-winged sharpshooter, Homalodisca vitripennis (Hemiptera: Cicadellidae). This insect is the main vector of the plant-pathogenic bacterium Xylella fastidiosa Wells (Xanthomonadales: Xanthomonadaceae), the causal agent of Pierce's disease of grapevines. Over the course of the H. vitripennis lifespan, the red pigment darkens and eventually becomes brown/black in color. These pigments are believed to be pheomelanin and eumelanin, respectively. The age of H. vitripennis can be determined by calculating the amount of red pigment found in the wings by analyzing high resolution wing photographs with image analysis software. In this study, a standard curve for the age determination of H. vitripennis was developed using laboratory-reared insects of known ages varying from 1 to 60 days. The impact of three environmental conditions on these readings was also investigated and found to have little effect on the age determination, and could be easily accounted for. Finally, field collected insects from several Central Texas vineyards were successfully analyzed for age determination suggesting that the annually reported influx of H. vitripennis was composed almost entirely of older insects.

Mixture and odorant processing in the olfactory systems of insects: a comparative perspective.

PubMed

Clifford, Marie R; Riffell, Jeffrey A

2013-11-01

Natural olfactory stimuli are often complex mixtures of volatiles, of which the identities and ratios of constituents are important for odor-mediated behaviors. Despite this importance, the mechanism by which the olfactory system processes this complex information remains an area of active study. In this review, we describe recent progress in how odorants and mixtures are processed in the brain of insects. We use a comparative approach toward contrasting olfactory coding and the behavioral efficacy of mixtures in different insect species, and organize these topics around four sections: (1) Examples of the behavioral efficacy of odor mixtures and the olfactory environment; (2) mixture processing in the periphery; (3) mixture coding in the antennal lobe; and (4) evolutionary implications and adaptations for olfactory processing. We also include pertinent background information about the processing of individual odorants and comparative differences in wiring and anatomy, as these topics have been richly investigated and inform the processing of mixtures in the insect olfactory system. Finally, we describe exciting studies that have begun to elucidate the role of the processing of complex olfactory information in evolution and speciation.

Solid Phase Micro-extraction (SPME) with In Situ Transesterification: An Easy Method for the Detection of Non-volatile Fatty Acid Derivatives on the Insect Cuticle.

PubMed

Kühbandner, Stephan; Ruther, Joachim

2015-06-01

Triacylglycerides (TAGs) and other non-volatile fatty acid derivatives (NFADs) occur in large amounts in the internal tissues of insects, but their presence on the insect cuticle is controversially discussed. Most studies investigating cuticular lipids of insects involve solvent extraction, which implies the risk of extracting lipids from internal tissues. Here, we present a new method that overcomes this problem. The method employs solid phase micro-extraction (SPME) to sample NFADs by rubbing the SPME fiber over the insect cuticle. Subsequently, the sampled NFADs are transesterified in situ with trimethyl sulfonium hydroxide (TMSH) into more volatile fatty acid methyl esters (FAMEs), which can be analyzed by standard GC/MS. We performed two types of control experiments to enable significant conclusions: (1) to rule out contamination of the GC/MS system with NFADs, and (2) to exclude the presence of free fatty acids on the insect cuticle, which would also furnish FAMEs after TMSH treatment, and thus might simulate the presence of NFADs. In combination with these two essential control experiments, the described SPME technique can be used to detect TAGs and/or other NFADs on the insect cuticle. We analyzed six insect species from four insect orders with our method and compared the results with conventional solvent extraction followed by ex situ transesterification. Several fatty acids typically found as constituents of TAGs were detected by the SPME method on the cuticle of all species analyzed. A comparison of the two methods revealed differences in the fatty acid compositions of the samples. Saturated fatty acids showed by trend higher relative abundances when sampled with the SPME method, while several minor FAMEs were detected only in the solvent extracts. Our study suggests that TAGs and maybe other NFADs are far more common on the insect cuticle than usually thought.

Revealing the microbiota of marketed edible insects through PCR-DGGE, metagenomic sequencing and real-time PCR.

PubMed

Osimani, Andrea; Milanović, Vesna; Garofalo, Cristiana; Cardinali, Federica; Roncolini, Andrea; Sabbatini, Riccardo; De Filippis, Francesca; Ercolini, Danilo; Gabucci, Claudia; Petruzzelli, Annalisa; Tonucci, Franco; Clementi, Francesca; Aquilanti, Lucia

2018-07-02

The present study aimed to identify the microbiota present in six species of processed edible insects produced in Thailand and marketed worldwide via the internet, namely, giant water bugs (Belostoma lutarium), black ants (Polyrhachis), winged termites (alates, Termitoidae), rhino beetles (Hyboschema contractum), mole crickets (Gryllotalpidae), and silkworm pupae (Bombyx mori). For each species, two samples of boiled, dried and salted insects were purchased. The microbial DNA was extracted from the insect samples and subjected to polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), high-throughput sequencing and qualitative real-time PCR assays. The microbiota of the analyzed samples were widely characterized by the presence of spore-forming bacteria mainly represented by the genera Bacillus and Clostridium. Moreover, the genera Anaerobacillus, Paenibacillus, Geobacillus, Pseudomonas, Stenotrophomonas, Massilia, Delftia, Lactobacillus, Staphylococcus, Streptococcus, Vagococcus, and Vibrio were also detected. Real-time PCR allowed for ascertainment of the absence of Coxiella burnetii, Shiga toxin-producing E. coli (STEC), and Pseudomonas aeruginosa in all samples. The results of this study confirm the importance of combining different molecular techniques to characterize the biodiversity of complex ecosystems such as edible insects. The presence of potential human pathogens suggests the need for a careful application of good manufacturing practices during insect processing. This study provides further data that will be useful in risk analyses of edible insects as a novel food source. Copyright © 2018 Elsevier B.V. All rights reserved.

Insect-controlled Robot: A Mobile Robot Platform to Evaluate the Odor-tracking Capability of an Insect.

PubMed

Ando, Noriyasu; Emoto, Shuhei; Kanzaki, Ryohei

2016-12-19

Robotic odor source localization has been a challenging area and one to which biological knowledge has been expected to contribute, as finding odor sources is an essential task for organism survival. Insects are well-studied organisms with regard to odor tracking, and their behavioral strategies have been applied to mobile robots for evaluation. This "bottom-up" approach is a fundamental way to develop biomimetic robots; however, the biological analyses and the modeling of behavioral mechanisms are still ongoing. Therefore, it is still unknown how such a biological system actually works as the controller of a robotic platform. To answer this question, we have developed an insect-controlled robot in which a male adult silkmoth (Bombyx mori) drives a robot car in response to odor stimuli; this can be regarded as a prototype of a future insect-mimetic robot. In the cockpit of the robot, a tethered silkmoth walked on an air-supported ball and an optical sensor measured the ball rotations. These rotations were translated into the movement of the two-wheeled robot. The advantage of this "hybrid" approach is that experimenters can manipulate any parameter of the robot, which enables the evaluation of the odor-tracking capability of insects and provides useful suggestions for robotic odor-tracking. Furthermore, these manipulations are non-invasive ways to alter the sensory-motor relationship of a pilot insect and will be a useful technique for understanding adaptive behaviors.

Following insects around: tools and techniques of eighteenth-century natural history.

PubMed

Terrall, Mary

2010-12-01

This paper examines the movement of the materials, ideas and practices that went into the construction of natural-historical observations in Paris and the French provinces--in particular, observations of insects. The paired notions of circulation and locality expose the complex dynamic at play in the production of knowledge about these mundane creatures. I show how the movement of things and people problematizes the notion of a single 'centre of calculation', even where a dominant figure like Réaumur was managing collections and producing authoritative texts. Réaumur was indeed managing the flow of observations, letters and specimens from his privileged vantage point in Paris, but he was not the only one doing the processing, and the objects and knowledge flowed in all directions. The paper uses correspondence among eighteenth-century naturalists of various sorts to get at the dynamics of circulation, tracing the movements of insects, bits of text or narrative, drawings, letters, questions, apparatus, books and people. My title refers to the activities of naturalists, who had to follow insects around in order to observe them, and to my own activity in following the insects in their movement through letters, conversations, specimen jars, drawings and texts. My research depends on the accumulation of details about experimental and observational practice, culled from the masses of letters that moved continually around Europe, much as the science of insects depended on the accumulation of details about insects--their physiology, habits, metamorphosis and place in the human economy and the economy of nature.

Maplike representation of celestial E-vector orientations in the brain of an insect.

PubMed

Heinze, Stanley; Homberg, Uwe

2007-02-16

For many insects, the polarization pattern of the blue sky serves as a compass cue for spatial navigation. E-vector orientations are detected by photoreceptors in a dorsal rim area of the eye. Polarized-light signals from both eyes are finally integrated in the central complex, a brain area consisting of two subunits, the protocerebral bridge and the central body. Here we show that a topographic representation of zenithal E-vector orientations underlies the columnar organization of the protocerebral bridge in a locust. The maplike arrangement is highly suited to signal head orientation under the open sky.

Evolution of DNA Methylation across Insects

PubMed Central

Vogel, Kevin J.; Moore, Allen J.; Schmitz, Robert J.

2017-01-01

DNA methylation contributes to gene and transcriptional regulation in eukaryotes, and therefore has been hypothesized to facilitate the evolution of plastic traits such as sociality in insects. However, DNA methylation is sparsely studied in insects. Therefore, we documented patterns of DNA methylation across a wide diversity of insects. We predicted that underlying enzymatic machinery is concordant with patterns of DNA methylation. Finally, given the suggestion that DNA methylation facilitated social evolution in Hymenoptera, we tested the hypothesis that the DNA methylation system will be associated with presence/absence of sociality among other insect orders. We found DNA methylation to be widespread, detected in all orders examined except Diptera (flies). Whole genome bisulfite sequencing showed that orders differed in levels of DNA methylation. Hymenopteran (ants, bees, wasps and sawflies) had some of the lowest levels, including several potential losses. Blattodea (cockroaches and termites) show all possible patterns, including a potential loss of DNA methylation in a eusocial species whereas solitary species had the highest levels. Species with DNA methylation do not always possess the typical enzymatic machinery. We identified a gene duplication event in the maintenance DNA methyltransferase 1 (DNMT1) that is shared by some Hymenoptera, and paralogs have experienced divergent, nonneutral evolution. This diversity and nonneutral evolution of underlying machinery suggests alternative DNA methylation pathways may exist. Phylogenetically corrected comparisons revealed no evidence that supports evolutionary association between sociality and DNA methylation. Future functional studies will be required to advance our understanding of DNA methylation in insects. PMID:28025279

Genome-wide comparison of genes involved in the biosynthesis, metabolism, and signaling of juvenile hormone between silkworm and other insects

PubMed Central

Cheng, Daojun; Meng, Meng; Peng, Jian; Qian, Wenliang; Kang, Lixia; Xia, Qingyou

2014-01-01

Juvenile hormone (JH) contributes to the regulation of larval molting and metamorphosis in insects. Herein, we comprehensively identified 55 genes involved in JH biosynthesis, metabolism and signaling in the silkworm (Bombyx mori) as well as 35 in Drosophila melanogaster, 35 in Anopheles gambiae, 36 in Apis mellifera, 47 in Tribolium castaneum, and 44 in Danaus plexippus. Comparative analysis showed that each gene involved in the early steps of the mevalonate (MVA) pathway, in the neuropeptide regulation of JH biosynthesis, or in JH signaling is a single copy in B. mori and other surveyed insects, indicating that these JH-related pathways or steps are likely conserved in all surveyed insects. However, each gene participating in the isoprenoid branch of JH biosynthesis and JH metabolism, together with the FPPS genes for catalyzing the final step of the MVA pathway of JH biosynthesis, exhibited an obvious duplication in Lepidoptera, including B. mori and D. plexippus. Microarray and real-time RT-PCR analysis revealed that different copies of several JH-related genes presented expression changes that correlated with the dynamics of JH titer during larval growth and metamorphosis. Taken together, the findings suggest that duplication-derived copy variation of JH-related genes might be evolutionarily associated with the variation of JH types between Lepidoptera and other insect orders. In conclusion, our results provide useful clues for further functional analysis of JH-related genes in B. mori and other insects. PMID:25071411

A Technique for Thermal Desorption Analyses Suitable for Thermally-Labile, Volatile Compounds.

PubMed

Alborn, Hans T

2018-02-01

Many plant and insect interactions are governed by odors released by the plants or insects and there exists a continual need for new or improved methods to collect and identify these odors. Our group has for some time studied below-ground, plant-produced volatile signals affecting nematode and insect behavior. The research requires repeated sampling of volatiles of intact plant/soil systems in the laboratory as well as the field with the help of probes to minimize unwanted effects on the systems we are studying. After evaluating solid adsorbent filters with solvent extraction or solid phase micro extraction fiber sample collection, we found dynamic sampling of small air volumes on Tenax TA filters followed by thermal desorption sample introduction to be the most suitable analytical technique for our applications. Here we present the development and evaluation of a low-cost and relatively simple thermal desorption technique where a cold trap cooled with liquid carbon dioxide is added as an integral part of a splitless injector. Temperature gradient-based focusing and low thermal mass minimizes aerosol formation and eliminates the need for flash heating, resulting in low sample degradation comparable to solvent-based on-column injections. Additionally, since the presence of the cold trap does not affect normal splitless injections, on-the-fly switching between splitless and thermal desorption modes can be used for external standard quantification.

Bactrocera dorsalis male sterilization by targeted RNA interference of spermatogenesis: empowering sterile insect technique programs

PubMed Central

Dong, Yong-Cheng; Wang, Zhi-Jian; Chen, Zhen-Zhong; Clarke, Anthony R.; Niu, Chang-Ying

2016-01-01

RNA interference (RNAi) is a genetic technique which has novel application for sustainable pest control. The Sterile Insect Technique (SIT) uses releases of mass-produced, sterile male insects to out-compete wild males for mates to reduce pest populations. RNAi sterilization of SIT males would have several advantages over radiation sterilization, but to achieve this appropriate target genes must first be identified and then targeted with interference technology. With this goal, eight spermatogenesis related candidate genes were cloned and tested for potential activity in Bactrocera dorsalis. The knockdown of candidate genes by oral delivery of dsRNAs did not influence the mating of male flies, but significantly affected the daily average number of eggs laid by females, and reduced egg hatching rate by 16–60%. RNAi negatively affected spermatozoa quantitatively and qualitatively. Following the mating of lola-/topi-/rac-/rho-/upd-/magu-silenced males, we recorded a significant decrease in number and length of spermatozoa in female spermatheca compared to gfp-silenced control group. In a greenhouse trial, the number of damaged oranges and B. dorsalis larvae were significantly reduced in a dsrho-treated group compared with the dsgfp group. This study provides strong evidence for the use RNAi in pest management, especially for the improvement of SIT against B. dorsalis and other species. PMID:27767174

Repair and Dredging of Bear Creek Marina Final Environmental Assessment

DTIC Science & Technology

2007-06-01

vegetation typically adapted for life in saturated soil conditions” (USACE, 1987). The majority of jurisdictional wetlands in the United States are...invertebrates, including amphipods, lancelets, insect larvae, mollusks, polychaetes, gastropods , shrimp, isopods, brachiopods, and crustaceans. Little is

The speed-accuracy tradeoff: history, physiology, methodology, and behavior

PubMed Central

Heitz, Richard P.

2014-01-01

There are few behavioral effects as ubiquitous as the speed-accuracy tradeoff (SAT). From insects to rodents to primates, the tendency for decision speed to covary with decision accuracy seems an inescapable property of choice behavior. Recently, the SAT has received renewed interest, as neuroscience approaches begin to uncover its neural underpinnings and computational models are compelled to incorporate it as a necessary benchmark. The present work provides a comprehensive overview of SAT. First, I trace its history as a tractable behavioral phenomenon and the role it has played in shaping mathematical descriptions of the decision process. Second, I present a “users guide” of SAT methodology, including a critical review of common experimental manipulations and analysis techniques and a treatment of the typical behavioral patterns that emerge when SAT is manipulated directly. Finally, I review applications of this methodology in several domains. PMID:24966810

Determination of Pyrethroids through Liquid-Liquid Extraction and GC-ECD

NASA Astrophysics Data System (ADS)

Ding, B.

2010-12-01

Storm water samples from various locations in San Diego Creek and Newport Bay watershed, southern California, were taken to study the occurrence and fate of pyrethroids. This study focused on four commonly used pyrethroids: bifenthrin, cypermethrin, permethrin, and fenpropathrin. Since the ban of DDT, usage of pyrethroids became an effective second choice. However, pyrethroids are extremely toxic to fish and aquatic organisms. They can pass through secondary wastewater treatment system, causing the final effluent to be in lethal doses to aquatic invertebrates and some insects such as mayflies. Hence, it is necessary to monitor the amount of pyrethroid concentration in storm water. As a part of this study, I attended the RISE internship program at Stanford University in this summer. In the seven weeks, I learned liquid-liquid extraction, water-bath evaporation, nitrogen evaporation, and gas chromatography-electron capture detector techniques to extract and detect the pyrethroid residues in the water sample.

The dynamic micro computed tomography at SSRF

NASA Astrophysics Data System (ADS)

Chen, R.; Xu, L.; Du, G.; Deng, B.; Xie, H.; Xiao, T.

2018-05-01

Synchrotron radiation micro-computed tomography (SR-μCT) is a critical technique for quantitative characterizing the 3D internal structure of samples, recently the dynamic SR-μCT has been attracting vast attention since it can evaluate the three-dimensional structure evolution of a sample. A dynamic μCT method, which is based on monochromatic beam, was developed at the X-ray Imaging and Biomedical Application Beamline at Shanghai Synchrotron Radiation Facility, by combining the compressed sensing based CT reconstruction algorithm and hardware upgrade. The monochromatic beam based method can achieve quantitative information, and lower dose than the white beam base method in which the lower energy beam is absorbed by the sample rather than contribute to the final imaging signal. The developed method is successfully used to investigate the compression of the air sac during respiration in a bell cricket, providing new knowledge for further research on the insect respiratory system.

Detection of Termites and Other Insects Consumed by African Great Apes using Molecular Fecal Analysis

PubMed Central

Hamad, Ibrahim; Delaporte, Eric; Raoult, Didier; Bittar, Fadi

2014-01-01

The consumption of insects by apes has previously been reported based on direct observations and/or trail signs in feces. However, DNA-based diet analyses may have the potential to reveal trophic links for these wild species. Herein, we analyzed the insect-diet diversity of 9 feces obtained from three species of African great apes, gorilla (Gorilla gorilla gorilla), chimpanzee (Pan troglodytes) and bonobo (Pan paniscus), using two mitochondrial amplifications for arthropods. A total of 1056 clones were sequenced for Cyt-b and COI gene libraries, which contained 50 and 56 operational taxonomic units (OTUs), respectively. BLAST research revealed that the OTUs belonged to 32 families from 5 orders (Diptera, Isoptera, Lepidoptera, Coleoptera, and Orthoptera). While ants were not detected by this method, the consumption of flies, beetles, moths, mosquitoes and termites was evident in these samples. Our findings indicate that molecular techniques can be used to analyze insect food items in wild animals. PMID:24675424

Towards nano-physiology of insects with atomic force microscopy.

PubMed

Dokukin, M E; Guz, N V; Sokolov, I

2011-02-01

Little study of insects with modern nanotechnology tools has been done so far. Here we use one of such tool, atomic force microscopy (AFM) to study surface oscillations of the ladybird beetles (Hippodamia convergens) measured in different parts of the insect at picometer level. This allows us to record a much broader spectral range of possible surface vibrations (up to several kHz) than the previously studied oscillations due to breathing, heartbeat cycles, coelopulses, etc. (up to 5-10Hz). Here we demonstrate three different ways with which one can identify the origins of the observed peaks - by physical positioning the probe near a specific organ, and by using biological or chemical stimuli. We report on identification of high frequency peaks associated with H. convergens heart, spiracular closer muscles, and oscillations associated with muscles activated while drinking. The method, being a relatively non-invasive technique providing a new type of information, may be useful in developing "nanophysiology" of insects. Copyright © 2010 Elsevier Ltd. All rights reserved.

Real-time phase-contrast x-ray imaging: a new technique for the study of animal form and function

PubMed Central

Socha, John J; Westneat, Mark W; Harrison, Jon F; Waters, James S; Lee, Wah-Keat

2007-01-01

Background Despite advances in imaging techniques, real-time visualization of the structure and dynamics of tissues and organs inside small living animals has remained elusive. Recently, we have been using synchrotron x-rays to visualize the internal anatomy of millimeter-sized opaque, living animals. This technique takes advantage of partially-coherent x-rays and diffraction to enable clear visualization of internal soft tissue not viewable via conventional absorption radiography. However, because higher quality images require greater x-ray fluxes, there exists an inherent tradeoff between image quality and tissue damage. Results We evaluated the tradeoff between image quality and harm to the animal by determining the impact of targeted synchrotron x-rays on insect physiology, behavior and survival. Using 25 keV x-rays at a flux density of 80 μW/mm-2, high quality video-rate images can be obtained without major detrimental effects on the insects for multiple minutes, a duration sufficient for many physiological studies. At this setting, insects do not heat up. Additionally, we demonstrate the range of uses of synchrotron phase-contrast imaging by showing high-resolution images of internal anatomy and observations of labeled food movement during ingestion and digestion. Conclusion Synchrotron x-ray phase contrast imaging has the potential to revolutionize the study of physiology and internal biomechanics in small animals. This is the only generally applicable technique that has the necessary spatial and temporal resolutions, penetrating power, and sensitivity to soft tissue that is required to visualize the internal physiology of living animals on the scale from millimeters to microns. PMID:17331247

Should I fight or should I flight? How studying insect aggression can help integrated pest management.

PubMed

Benelli, Giovanni

2015-07-01

Aggression plays a key role all across the animal kingdom, as it allows the acquisition and/or defence of limited resources (food, mates and territories) in a huge number of species. A large part of our knowledge on aggressive behaviour has been developed on insects of economic importance. How can this knowledge be exploited to enhance integrated pest management? Here, I highlight how knowledge on intraspecific aggression can help IPM both in terms of insect pests (with a focus on the enhancement of the sterile insect technique) and in terms of biological control agents (with a focus on mass-rearing optimisation). Then, I examine what implications for IPM can be outlined from knowledge about interspecific aggressive behaviour. Besides predator-pest aggressive interactions predicted by classic biological control, I focus on what IPM can learn from (i) interspecific aggression among pest species (with special reference to competitive displacement), (ii) defensive behaviour exhibited by prey against predaceous insects and (iii) conflicts among predaceous arthropods sharing the same trophic niche (with special reference to learning/sensitisation practices and artificial manipulation of chemically mediated interactions). © 2015 Society of Chemical Industry.

A continuous-exchange cell-free protein synthesis system based on extracts from cultured insect cells.

PubMed

Stech, Marlitt; Quast, Robert B; Sachse, Rita; Schulze, Corina; Wüstenhagen, Doreen A; Kubick, Stefan

2014-01-01

In this study, we present a novel technique for the synthesis of complex prokaryotic and eukaryotic proteins by using a continuous-exchange cell-free (CECF) protein synthesis system based on extracts from cultured insect cells. Our approach consists of two basic elements: First, protein synthesis is performed in insect cell lysates which harbor endogenous microsomal vesicles, enabling a translocation of de novo synthesized target proteins into the lumen of the insect vesicles or, in the case of membrane proteins, their embedding into a natural membrane scaffold. Second, cell-free reactions are performed in a two chamber dialysis device for 48 h. The combination of the eukaryotic cell-free translation system based on insect cell extracts and the CECF translation system results in significantly prolonged reaction life times and increased protein yields compared to conventional batch reactions. In this context, we demonstrate the synthesis of various representative model proteins, among them cytosolic proteins, pharmacological relevant membrane proteins and glycosylated proteins in an endotoxin-free environment. Furthermore, the cell-free system used in this study is well-suited for the synthesis of biologically active tissue-type-plasminogen activator, a complex eukaryotic protein harboring multiple disulfide bonds.

Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

NASA Astrophysics Data System (ADS)

Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; He, You; Zhou, Guangzhao; Sun, Zhibin; Zhang, Jianhua; Huang, Qingjie; Xiao, Tiqiao; Jiang, Huaidong

2016-03-01

Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ˜1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

Transgenesis and paratransgenesis to control insect-borne diseases: Current status and future challenges

PubMed Central

Coutinho-Abreu, Iliano V.; Zhu, Kun Yan; Ramalho-Ortigao, Marcelo

2009-01-01

Insect-borne diseases cause significant human morbidity and mortality. Current control and preventive methods against vector-borne diseases rely mainly on insecticides. The emergence of insecticide resistance in many disease vectors highlights the necessity to develop new strategies to control these insects. Vector transgenesis and paratransgenesis are novel strategies that aim at reducing insect vectorial capacity, or seek to eliminate transmission of pathogens such as Plasmodium sp., Trypanosoma sp., and Dengue virus currently being developed. Vector transgenesis relies on direct genetic manipulation of disease vectors making them incapable of functioning as vectors of a given pathogen. Paratransgenesis focuses on utilizing genetically modified insect symbionts to express molecules within the vector that are deleterious to pathogens they transmit. Despite the many successes achieved in developing such techniques in the last several years, many significant barriers remain and need to be overcome prior to any of these approaches become a reality. Here, we highlight the current status of these strategies, pointing out advantages and constraints, and also explore issues that need to be resolved before the establishment of transgenesis and paratransgenesis as tools to prevent vector-borne diseases. PMID:19819346

Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

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

Yao, Shengkun; Fan, Jiadong; Zong, Yunbing

Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique overmore » conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.« less

A Continuous-Exchange Cell-Free Protein Synthesis System Based on Extracts from Cultured Insect Cells

PubMed Central

Stech, Marlitt; Quast, Robert B.; Sachse, Rita; Schulze, Corina; Wüstenhagen, Doreen A.; Kubick, Stefan

2014-01-01

In this study, we present a novel technique for the synthesis of complex prokaryotic and eukaryotic proteins by using a continuous-exchange cell-free (CECF) protein synthesis system based on extracts from cultured insect cells. Our approach consists of two basic elements: First, protein synthesis is performed in insect cell lysates which harbor endogenous microsomal vesicles, enabling a translocation of de novo synthesized target proteins into the lumen of the insect vesicles or, in the case of membrane proteins, their embedding into a natural membrane scaffold. Second, cell-free reactions are performed in a two chamber dialysis device for 48 h. The combination of the eukaryotic cell-free translation system based on insect cell extracts and the CECF translation system results in significantly prolonged reaction life times and increased protein yields compared to conventional batch reactions. In this context, we demonstrate the synthesis of various representative model proteins, among them cytosolic proteins, pharmacological relevant membrane proteins and glycosylated proteins in an endotoxin-free environment. Furthermore, the cell-free system used in this study is well-suited for the synthesis of biologically active tissue-type-plasminogen activator, a complex eukaryotic protein harboring multiple disulfide bonds. PMID:24804975

Biological characteristics of Grapholita molesta (Lepidoptera: Tortricidae) induced to diapause in laboratory.

PubMed

Neto e Silva, Oscar Arnaldo Batista; Bernardi, Daniel; Botton, Marcos; Garcia, Mauro Silveira

2014-01-01

In southern Brazil, Grapholita molesta (Busck) (Lepidoptera: Tortricidae) uses diapause as survival strategy during the winter (May-August). In our study, we evaluated the effect of diapause on biological characteristics of the species for 4 months in laboratory. Newly hatched larvae of G. molesta were induced to diapause changing the photoperiod and temperature (T) (12 ± 1°C), relative humidity (RH) (70 ± 10%), and a photophase of 12 h and, when they started diapause in the prepupal stage, the conditions were kept for 4 months. Afterwards, the insects were induced to finalize the diapause process at T 25 ± 1°C, RH 70 ± 10%, and a photophase of 16 h. We evaluated the duration and viability of the larval stages and pupae, pupae weight at 24 h and sex ratio (sr), periods of preoviposition, oviposition, and postoviposition; adult life span (males and females); fecundity (daily and total); embryonic period duration and eggs viability, comparing the data with insects nondiapause. The results show that diapause greatly affected the viability of pupal-adult stages of the population (21.8%) when compared with insects' nondiapause (80.0%). Total fecundity (83.0 eggs) and mean life span (12.0 d) of insects diapause was significantly lower compared with insects nondiapause (173.0 and 17.0), respectively. However, these differences were not observed in the sr, which was similar to insects diapause (sr = 0.41) and insects nondiapause (sr = 0.49). The diapause induced for 4 months negatively affects reproduction and life span of adults of G. molesta. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Oviposition of aquatic insects in a tropical high altitude stream.

PubMed

Rios-Touma, Blanca; Encalada, A C; Prat, N

2012-12-01

The persistence of aquatic insect populations in streams depends on the recruitment of larval populations from egg masses deposited by adults, especially after disturbance. However, recruitment of aquatic populations by oviposition is a process that remains unstudied in streams and rivers. The objectives of our study were to document flying and oviposition patterns of aquatic insects in a high altitude tropical stream during both dry and wet seasons. In particular we studied 1) richness and abundance of adult forms of aquatic insects flying and ovipositing; 2) number of eggs (oviposition pattern), egg mass identity, and morphology; and 3) substrate preferences by ovipositing females. We found 2,383 aquatic insects corresponding to 28 families, with dipterans representing 89% of total individuals collected. Adult insects had lower richness (28 taxa) than larval diversity (up to 52 taxa) and distinct community composition. Richness and relative abundance of most taxa (adults) were not significantly different between seasons, behaviors, diel period, or all three. During both sampling periods we found females with eggs in a total of 15 different families (13 in the dry season and 14 in the wet season). There were no significant differences in the proportion of females with eggs between seasons, diel periods, or different behaviors (flying versus ovipositing traps) of the different female taxa. Few types of egg masses were found in rocks at the stream during both seasons, and most egg masses found corresponded to families Baetidae and Chironomidae. Finally, we provide the first description of eggs masses (size, shape, color, and number of eggs per female) of gravid females (10 taxa) and those found in the stream substrate (six taxa) of Andean macroinvertebrates. This is the first study reporting oviposition, adult diversity, and oviposition patterns of aquatic insects in the Andean region.

Dragonflies and Fireflies

ERIC Educational Resources Information Center

Mannlein, Sally

2009-01-01

Most first-graders are interested in insects. In this article, the author describes a lesson, "Dragonflies and Fireflies," which is a first-grade lesson showing drawing, symmetry, neighboring colors (analogous) and watercolor techniques.

Active and passive stabilization of body pitch in insect flight

PubMed Central

Ristroph, Leif; Ristroph, Gunnar; Morozova, Svetlana; Bergou, Attila J.; Chang, Song; Guckenheimer, John; Wang, Z. Jane; Cohen, Itai

2013-01-01

Flying insects have evolved sophisticated sensory–motor systems, and here we argue that such systems are used to keep upright against intrinsic flight instabilities. We describe a theory that predicts the instability growth rate in body pitch from flapping-wing aerodynamics and reveals two ways of achieving balanced flight: active control with sufficiently rapid reactions and passive stabilization with high body drag. By glueing magnets to fruit flies and perturbing their flight using magnetic impulses, we show that these insects employ active control that is indeed fast relative to the instability. Moreover, we find that fruit flies with their control sensors disabled can keep upright if high-drag fibres are also attached to their bodies, an observation consistent with our prediction for the passive stability condition. Finally, we extend this framework to unify the control strategies used by hovering animals and also furnish criteria for achieving pitch stability in flapping-wing robots. PMID:23697713

Relevant principal factors affecting the reproducibility of insect primary culture.

PubMed

Ogata, Norichika; Iwabuchi, Kikuo

2017-06-01

The primary culture of insect cells often suffers from problems with poor reproducibility in the quality of the final cell preparations. The cellular composition of the explants (cell number and cell types), surgical methods (surgical duration and surgical isolation), and physiological and genetic differences between donors may be critical factors affecting the reproducibility of culture. However, little is known about where biological variation (interindividual differences between donors) ends and technical variation (variance in replication of culture conditions) begins. In this study, we cultured larval fat bodies from the Japanese rhinoceros beetle, Allomyrina dichotoma, and evaluated, using linear mixed models, the effect of interindividual variation between donors on the reproducibility of the culture. We also performed transcriptome analysis of the hemocyte-like cells mainly seen in the cultures using RNA sequencing and ultrastructural analyses of hemocytes using a transmission electron microscope, revealing that the cultured cells have many characteristics of insect hemocytes.

Evolutionary ecology of the interactions between aphids and their parasitoids.

PubMed

Le Ralec, Anne; Anselme, Caroline; Outreman, Yannick; Poirié, Marylène; van Baaren, Joan; Le Lann, Cécile; van Alphen, Jacques J-M

2010-01-01

Many organisms, including entomopathogenous fungi, predators or parasites, use aphids as ressources. Parasites of aphids are mostly endoparasitoid insects, i.e. insects which lay eggs inside the body of an other insect which will die as a result of their development. In this article, we review the consequences of the numerous pecularities of aphid biology and ecology for their endoparasitoids, notably the Aphidiinae (Hymenoptera: Braconidae). We first examine the various mechanisms used by aphids for defence against these enemies. We then explore the strategies used by aphidiine parasitoids to exploit their aphid hosts. Finally, we consider the responses of both aphids and parasitoids to ecological constraints induced by seasonal cycles and to environmental variations linked to host plants and climate. The fundamental and applied interest of studying these organisms is discussed. Copyright 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Transgenic Cotton Plants Expressing Cry1Ia12 Toxin Confer Resistance to Fall Armyworm (Spodoptera frugiperda) and Cotton Boll Weevil (Anthonomus grandis).

PubMed

de Oliveira, Raquel S; Oliveira-Neto, Osmundo B; Moura, Hudson F N; de Macedo, Leonardo L P; Arraes, Fabrício B M; Lucena, Wagner A; Lourenço-Tessutti, Isabela T; de Deus Barbosa, Aulus A; da Silva, Maria C M; Grossi-de-Sa, Maria F

2016-01-01

Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests.

Transgenic Cotton Plants Expressing Cry1Ia12 Toxin Confer Resistance to Fall Armyworm (Spodoptera frugiperda) and Cotton Boll Weevil (Anthonomus grandis)

PubMed Central

de Oliveira, Raquel S.; Oliveira-Neto, Osmundo B.; Moura, Hudson F. N.; de Macedo, Leonardo L. P.; Arraes, Fabrício B. M.; Lucena, Wagner A.; Lourenço-Tessutti, Isabela T.; de Deus Barbosa, Aulus A.; da Silva, Maria C. M.; Grossi-de-Sa, Maria F.

2016-01-01

Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests. PMID:26925081

Photogrammetric reconstruction of high-resolution surface topographies and deformable wing kinematics of tethered locusts and free-flying hoverflies

PubMed Central

Walker, Simon M.; Thomas, Adrian L.R.; Taylor, Graham K.

2008-01-01

Here, we present a suite of photogrammetric methods for reconstructing insect wing kinematics, to provide instantaneous topographic maps of the wing surface. We filmed tethered locusts (Schistocerca gregaria) and free-flying hoverflies (Eristalis tenax) using four high-speed digital video cameras. We digitized multiple natural features and marked points on the wings using manual and automated tracking. Epipolar geometry was used to identify additional points on the hoverfly wing outline which were anatomically indistinguishable. The cameras were calibrated using a bundle adjustment technique that provides an estimate of the error associated with each individual data point. The mean absolute three-dimensional measurement error was 0.11 mm for the locust and 0.03 mm for the hoverfly. The error in the angle of incidence was at worst 0.51° (s.d.) for the locust and 0.88° (s.d.) for the hoverfly. The results we present are of unprecedented spatio-temporal resolution, and represent the most detailed measurements of insect wing kinematics to date. Variable spanwise twist and camber are prominent in the wingbeats of both the species, and are of such complexity that they would not be adequately captured by lower resolution techniques. The role of spanwise twist and camber in insect flight has yet to be fully understood, and accurate insect wing kinematics such as we present here are required to be sure of making valid predictions about their aerodynamic effects. PMID:18682361

Applicator Training Manual for: Forest Pest Control.

ERIC Educational Resources Information Center

Newman, Jim

Described in this manual is the use of insecticides, fungicides, and herbicides in forestry. Both diseases and insects found in hardwoods and conifers are covered. Detailed information is given on methods of herbicide application. Finally, five important environmental considerations are given. (BB)

A porin-like protein from oral secretions of Spodoptera littoralis larvae induces defense-related early events in plant leaves.

PubMed

Guo, Huijuan; Wielsch, Natalie; Hafke, Jens B; Svatoš, Aleš; Mithöfer, Axel; Boland, Wilhelm

2013-09-01

Insect herbivory on plants is a complex incident consisting of at least two different aspects, namely mechanical damage and chemical challenge, as feeding insects introduce oral secretions (OS) into the wounded tissue of the attacked plant. Mechanical wounding alone is sufficient to induce a set of defense-related reactions in host plants, but some early events such as membrane potential (Vm) changes and cytosolic Ca²⁺-elevations can be triggered only by herbivores suggesting that OS-derived molecules are involved in those processes. Following an assay-guided purification based on planar lipid bilayer membrane technique in combination with proteomic analysis, a porin-like protein (PLP) of most likely bacterial origin was determined from collected OS of Spodoptera littoralis larvae. PLP exhibited channel-forming activity. Further, early defense-related events in plant-insect interaction were evaluated by using a purified fraction and α-hemolysin (α-HL) as a commercial pore-forming compound. Both up-regulated the calmodulin-like CML42 in Arabidopsis thaliana, which only responds to oral secretion and not to wounding. An elevation of in vivo [Ca²⁺](cyt) was not observed. Because membrane channel formation is a widespread phenomenon in plant-insect interactions, this PLP might represent an example for microbial compounds from the insect gut which are initially involved in plant-insect interactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemosterilants for Control of Insects and Insect Vectors of Disease.

PubMed

Baxter, Richard H G

2016-10-01

Both historically and at present, vector control is the most generally effective means of controlling malaria transmission. Insecticides are the predominant method of vector control, but the sterile insect technique (SIT) is a complementary strategy with a successful track record in both agricultural and public health sectors. Strategies of genetic and radiation-induced sterilization of Anopheles have to date been limited by logistical and/or regulatory hurdles. A safe and effective mosquito chemosterilant would therefore be of major utility to future deployment of SIT for malaria control. Here we review the prior and current use of chemosterilants in SIT, and assess the potential for future research. Recent genomic and proteomic studies reveal opportunities for specific targeting of seminal fluid proteins, and the capacity to interfere with sperm motility and storage in the female.

Schlieren photography on freely flying hawkmoth.

PubMed

Liu, Yun; Roll, Jesse; Van Kooten, Stephen; Deng, Xinyan

2018-05-01

The aerodynamic force on flying insects results from the vortical flow structures that vary both spatially and temporally throughout flight. Due to these complexities and the inherent difficulties in studying flying insects in a natural setting, a complete picture of the vortical flow has been difficult to obtain experimentally. In this paper, Schlieren , a widely used technique for highspeed flow visualization, was adapted to capture the vortex structures around freely flying hawkmoth ( Manduca ). Flow features such as leading-edge vortex, trailing-edge vortex, as well as the full vortex system in the wake were visualized directly. Quantification of the flow from the Schlieren images was then obtained by applying a physics-based optical flow method, extending the potential applications of the method to further studies of flying insects. © 2018 The Author(s).

When social behaviour is moulded in clay: on growth and form of social insect nests.

PubMed

Perna, Andrea; Theraulaz, Guy

2017-01-01

The nests built by social insects are among the most complex structures produced by animal groups. They reveal the social behaviour of a colony and as such they potentially allow comparative studies. However, for a long time, research on nest architecture was hindered by the lack of technical tools allowing the visualisation of their complex 3D structures and the quantification of their properties. Several techniques, developed over the years, now make it possible to study the organisation of these nests and how they are built. Here, we review present knowledge of the mechanisms of nest construction, and how nest structure affects the behaviour of individual insects and the organisation of activities within a colony. © 2017. Published by The Company of Biologists Ltd.

The Plant Ribosome-Inactivating Proteins Play Important Roles in Defense against Pathogens and Insect Pest Attacks

PubMed Central

Zhu, Feng; Zhou, Yang-Kai; Ji, Zhao-Lin; Chen, Xiao-Ren

2018-01-01

Ribosome-inactivating proteins (RIPs) are toxic N-glycosidases that depurinate eukaryotic and prokaryotic rRNAs, thereby arresting protein synthesis during translation. RIPs are widely found in various plant species and within different tissues. It is demonstrated in vitro and in transgenic plants that RIPs have been connected to defense by antifungal, antibacterial, antiviral, and insecticidal activities. However, the mechanism of these effects is still not completely clear. There are a number of reviews of RIPs. However, there are no reviews on the biological functions of RIPs in defense against pathogens and insect pests. Therefore, in this report, we focused on the effect of RIPs from plants in defense against pathogens and insect pest attacks. First, we summarize the three different types of RIPs based on their physical properties. RIPs are generally distributed in plants. Then, we discuss the distribution of RIPs that are found in various plant species and in fungi, bacteria, algae, and animals. Various RIPs have shown unique bioactive properties including antibacterial, antifungal, antiviral, and insecticidal activity. Finally, we divided the discussion into the biological roles of RIPs in defense against bacteria, fungi, viruses, and insects. This review is focused on the role of plant RIPs in defense against bacteria, fungi, viruses, and insect attacks. The role of plant RIPs in defense against pathogens and insects is being comprehended currently. Future study utilizing transgenic technology approaches to study the mechanisms of RIPs will undoubtedly generate a better comprehending of the role of plant RIPs in defense against pathogens and insects. Discovering additional crosstalk mechanisms between RIPs and phytohormones or reactive oxygen species (ROS) against pathogen and insect infections will be a significant subject in the field of biotic stress study. These studies are helpful in revealing significance of genetic control that can be beneficial to engineer crops tolerance to biotic stress. PMID:29479367

Incidence of Sitophilus oryzae and other stored-product pests on cowpea in local markets in Accra: management strategies employed by retailers.

PubMed

Egbon, I N; Ayertey, J N

2013-05-01

In recent times, the unusual presence of Sitophilus on cowpea has become an issue in Ghana as it constitutes a threat to food sufficiency and food security; this, by extension, necessitated the execution of this survey to establish the specific identity of the insect and its incidence, on stored cowpea in Ghana and consequently assess the level of awareness of traders and the management strategies employed. Using internal morphological identification techniques, the insect was identified as Sitophilus oryzae with an incidence rate of 12, 22 and 20% as against 50, 41 and 42% incidence rate of Callosobruchus maculatus after 30, 60 and 90 days respectively, of undisturbed storage of cowpea within the marketing systems in Accra, Ghana. Relatively low number of retailers (35.44%, N = 79) was aware of this occurrence, with 91.14% of this employing the energy-demanding and time-consuming sieving techniques as their main control strategies. This paper draws attention to the possible worsening of food insecurity already eminent in Africa for insects are no respecters of international or geo-political boundaries as they can spread to other countries, should this observation be left unchecked.

Practical applications of insects' sexual development for pest control.

PubMed

Koukidou, M; Alphey, L

2014-01-01

Elucidation of the sex differentiation pathway in insects offers an opportunity to understand key aspects of evolutionary developmental biology. In addition, it provides the understanding necessary to manipulate insects in order to develop new synthetic genetics-based tools for the control of pest insects. Considerable progress has been made in this, especially in improvements to the sterile insect technique (SIT). Large scale sex separation is considered highly desirable or essential for most SIT targets. This separation can be provided by genetic methods based on sex-specific gene expression. Investigation of sex determination by many groups has provided molecular components and methods for this. Though the primary sex determination signal varies considerably, key regulatory genes and mechanisms remain surprisingly similar. In most cases studied so far, a primary signal is transmitted to a basal gene at the bottom of the hierarchy (dsx) through an alternative splicing cascade; dsx is itself differentially spliced in males and females. A sex-specific alternative splicing system therefore offers an attractive route to achieve female-specific expression. Experience has shown that alternative splicing modules can be developed with cross-species function; modularity and standardisation and re-use of parts are key principles of synthetic biology. Both female-killing and sex reversal (XX females to phenotypic males) can in principle also be used as efficient alternatives to sterilisation in SIT-like methods. Sexual maturity is yet another area where understanding of sexual development may be applied to insect control programmes. Further detailed understanding of this crucial aspect of insect biology will undoubtedly continue to underpin innovative practical applications. © 2014 S. Karger AG, Basel.

Using a botanical garden to assess factors influencing the colonization of exotic woody plants by phyllophagous insects.

PubMed

Kirichenko, Natalia; Kenis, M

2016-09-01

The adoption of exotic plants by indigenous herbivores in the region of introduction can be influenced by numerous factors. A botanical garden in Western Siberia was used to test various hypotheses on the adaptation of indigenous phyllophagous insects to exotic plants invasions, focusing on two feeding guilds, external leaf chewers and leaf miners. A total of 150 indigenous and exotic woody plant species were surveyed for insect damage, abundance and species richness. First, exotic woody plants were much less damaged by chewers and leaf miners than native plants, and the leaf miners' species richness was much lower on exotic than native plants. Second, exotic woody plants having a congeneric species in the region of introduction were more damaged by chewers and hosted a more abundant and species-rich community of leaf miners than plants without native congeneric species. Third, damage by chewers significantly increased with the frequency of planting of exotic host plants outside the botanical garden, and leaf miners' abundance and species richness significantly increased with residence time in the garden. Finally, no significant relationship was found between insect damage or abundance and the origin of the exotic plants. Besides the ecological implications of the results, this study also illustrates the potential of botanical gardens to test ecological hypotheses on biological invasions and insect-plant interactions on a large set of plant species.

PECASE: Soaring Mechanisms for Flapping-Wing Micro Air Vehicles

DTIC Science & Technology

2015-03-31

2015 2. REPORT TYPE Final 4. TITLE AND SUBTITLE PECASE: Soaring mechanisms for flapping - wing micro air vehicles 6. AUTHOR(S) Robert J. Wood 3...N00014-10-1-0684 Award Title: "PECASE: Soaring mechanisms for flapping - wing micro air vehicles" [previous award: N00014-08-1-0919, "Hovering Control for...Insect-Inspired Flapping - Wing Micro Air Vehicles"] Final report a. Scientific and Technical Objectives The Harvard Microrobotics Lab has

Evolution of DNA Methylation across Insects.

PubMed

Bewick, Adam J; Vogel, Kevin J; Moore, Allen J; Schmitz, Robert J

2017-03-01

DNA methylation contributes to gene and transcriptional regulation in eukaryotes, and therefore has been hypothesized to facilitate the evolution of plastic traits such as sociality in insects. However, DNA methylation is sparsely studied in insects. Therefore, we documented patterns of DNA methylation across a wide diversity of insects. We predicted that underlying enzymatic machinery is concordant with patterns of DNA methylation. Finally, given the suggestion that DNA methylation facilitated social evolution in Hymenoptera, we tested the hypothesis that the DNA methylation system will be associated with presence/absence of sociality among other insect orders. We found DNA methylation to be widespread, detected in all orders examined except Diptera (flies). Whole genome bisulfite sequencing showed that orders differed in levels of DNA methylation. Hymenopteran (ants, bees, wasps and sawflies) had some of the lowest levels, including several potential losses. Blattodea (cockroaches and termites) show all possible patterns, including a potential loss of DNA methylation in a eusocial species whereas solitary species had the highest levels. Species with DNA methylation do not always possess the typical enzymatic machinery. We identified a gene duplication event in the maintenance DNA methyltransferase 1 (DNMT1) that is shared by some Hymenoptera, and paralogs have experienced divergent, nonneutral evolution. This diversity and nonneutral evolution of underlying machinery suggests alternative DNA methylation pathways may exist. Phylogenetically corrected comparisons revealed no evidence that supports evolutionary association between sociality and DNA methylation. Future functional studies will be required to advance our understanding of DNA methylation in insects. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Microbial Community Dynamics during Rearing of Black Soldier Fly Larvae (Hermetia illucens) and Impact on Exploitation Potential.

PubMed

De Smet, Jeroen; Wynants, Enya; Cos, Paul; Van Campenhout, Leen

2018-05-01

The need to increase sustainability in agriculture, to ensure food security for the future generations, is leading to the emergence of industrial rearing facilities for insects. One promising species being industrially reared as an alternative protein source for animal feed and as a raw material for the chemical industry is the black soldier fly ( Hermetia illucens ). However, scientific knowledge toward the optimization of the productivity for this insect is scarce. One knowledge gap concerns the impact of the microbial community associated with H. illucens on the performance and health of this insect. In this review, the first steps in the characterization of the microbiota in H. illucens and the analysis of substrate-dependent dynamics in its composition are summarized and discussed. Furthermore, this review zooms in on the interactions between microorganisms and the insect during H. illucens development. Finally, attention is paid to how the microbiome research can lead to alternative valorization strategies for H. illucens , such as (i) the manipulation of the microbiota to optimize insect biomass production and (ii) the exploitation of the H. illucens -microbiota interplay for the discovery of new enzymes and novel antimicrobial strategies based on H. illucens immunity using either the whole organism or its molecules. The next decade promises to be extremely interesting for this research field and will see an emergence of the microbiological optimization of H. illucens as a sustainable insect for industrial rearing and the exploitation of its microbiome for novel biotechnological applications. Copyright © 2018 American Society for Microbiology.

Fumonisins in conventional and transgenic, insect-resistant maize intended for fuel ethanol production: implications for fermentation efficiency and DDGS co-product quality.

PubMed

Bowers, Erin L; Munkvold, Gary P

2014-09-22

Mycotoxins in maize grain intended for ethanol production are enriched in co-product dried distiller's grains and solubles (DDGS) and may be detrimental to yeast in fermentation. This study was conducted to examine the magnitude of fumonisin enrichment in DDGS and to analyze the impacts of insect injury, Fusarium ear rot severity, and fumonisin contamination on final ethanol yield. Samples of naturally-contaminated grain (0 to 35 mg/kg fumonisins) from field trials conducted in 2008-2011 were fermented and DDGS collected and analyzed for fumonisin content. Ethanol yield (determined gravimetrically) was unaffected by fumonisins in the range occurring in this study, and was not correlated with insect injury or Fusarium ear rot severity. Ethanol production was unaffected in fumonisin B1-spiked grain with concentrations from 0 to 37 mg/kg. Bacillus thuringiensis (Bt) maize often has reduced fumonisins due to its protection from insect injury and subsequent fungal infection. DDGS derived from Bt and non-Bt maize averaged 2.04 mg/kg and 8.25 mg/kg fumonisins, respectively. Fumonisins were enriched by 3.0× for 50 out of 57 hybrid × insect infestation treatment combinations; those seven that differed were <3.0 (1.56 to 2.56×). This study supports the industry assumption of three-fold fumonisin enrichment in DDGS, with measurements traceable to individual samples. Under significant insect pest pressures, DDGS derived from Bt maize hybrids were consistently lower in fumonisins than DDGS derived from non-Bt hybrids.

Fumonisins in Conventional and Transgenic, Insect-Resistant Maize Intended for Fuel Ethanol Production: Implications for Fermentation Efficiency and DDGS Co-Product Quality

PubMed Central

Bowers, Erin L.; Munkvold, Gary P.

2014-01-01

Mycotoxins in maize grain intended for ethanol production are enriched in co-product dried distiller’s grains and solubles (DDGS) and may be detrimental to yeast in fermentation. This study was conducted to examine the magnitude of fumonisin enrichment in DDGS and to analyze the impacts of insect injury, Fusarium ear rot severity, and fumonisin contamination on final ethanol yield. Samples of naturally-contaminated grain (0 to 35 mg/kg fumonisins) from field trials conducted in 2008–2011 were fermented and DDGS collected and analyzed for fumonisin content. Ethanol yield (determined gravimetrically) was unaffected by fumonisins in the range occurring in this study, and was not correlated with insect injury or Fusarium ear rot severity. Ethanol production was unaffected in fumonisin B1-spiked grain with concentrations from 0 to 37 mg/kg. Bacillus thuringiensis (Bt) maize often has reduced fumonisins due to its protection from insect injury and subsequent fungal infection. DDGS derived from Bt and non-Bt maize averaged 2.04 mg/kg and 8.25 mg/kg fumonisins, respectively. Fumonisins were enriched by 3.0× for 50 out of 57 hybrid × insect infestation treatment combinations; those seven that differed were <3.0 (1.56 to 2.56×). This study supports the industry assumption of three-fold fumonisin enrichment in DDGS, with measurements traceable to individual samples. Under significant insect pest pressures, DDGS derived from Bt maize hybrids were consistently lower in fumonisins than DDGS derived from non-Bt hybrids. PMID:25247264

The application of secondary metabolites in the study of sorghum insect resistance

NASA Astrophysics Data System (ADS)

Chunming, Bai; Yifei, Liu; Xiaochun, Lu

2018-03-01

Insect attack is one of the main factors for limiting the production of rice and sorghum. To improve resistance to pests of rice and sorghum will be of great significance for meliorating their production and quality. However, the source and material of anti-pest was scarce. In this study, we will study on the expression patterns of hydrocyanic acid biosynthesis relative genes in sorghum firstly. And we will also genetically transform them into rice and sorghum by specific and constitutive promoters and verify their pest-resistant ability. Finally, high pest-resistant genetically modified new sorghum cultivars will be bred with favorable comprehensive agronomic traits.

Candidate gene screen in the red flour beetle Tribolium reveals six3 as ancient regulator of anterior median head and central complex development.

PubMed

Posnien, Nico; Koniszewski, Nikolaus Dieter Bernhard; Hein, Hendrikje Jeannette; Bucher, Gregor

2011-12-01

Several highly conserved genes play a role in anterior neural plate patterning of vertebrates and in head and brain patterning of insects. However, head involution in Drosophila has impeded a systematic identification of genes required for insect head formation. Therefore, we use the red flour beetle Tribolium castaneum in order to comprehensively test the function of orthologs of vertebrate neural plate patterning genes for a function in insect head development. RNAi analysis reveals that most of these genes are indeed required for insect head capsule patterning, and we also identified several genes that had not been implicated in this process before. Furthermore, we show that Tc-six3/optix acts upstream of Tc-wingless, Tc-orthodenticle1, and Tc-eyeless to control anterior median development. Finally, we demonstrate that Tc-six3/optix is the first gene known to be required for the embryonic formation of the central complex, a midline-spanning brain part connected to the neuroendocrine pars intercerebralis. These functions are very likely conserved among bilaterians since vertebrate six3 is required for neuroendocrine and median brain development with certain mutations leading to holoprosencephaly.

Candidate Gene Screen in the Red Flour Beetle Tribolium Reveals Six3 as Ancient Regulator of Anterior Median Head and Central Complex Development

PubMed Central

Hein, Hendrikje Jeannette; Bucher, Gregor

2011-01-01

Several highly conserved genes play a role in anterior neural plate patterning of vertebrates and in head and brain patterning of insects. However, head involution in Drosophila has impeded a systematic identification of genes required for insect head formation. Therefore, we use the red flour beetle Tribolium castaneum in order to comprehensively test the function of orthologs of vertebrate neural plate patterning genes for a function in insect head development. RNAi analysis reveals that most of these genes are indeed required for insect head capsule patterning, and we also identified several genes that had not been implicated in this process before. Furthermore, we show that Tc-six3/optix acts upstream of Tc-wingless, Tc-orthodenticle1, and Tc-eyeless to control anterior median development. Finally, we demonstrate that Tc-six3/optix is the first gene known to be required for the embryonic formation of the central complex, a midline-spanning brain part connected to the neuroendocrine pars intercerebralis. These functions are very likely conserved among bilaterians since vertebrate six3 is required for neuroendocrine and median brain development with certain mutations leading to holoprosencephaly. PMID:22216011

Application of an Improved Proteomics Method for Abundant Protein Cleanup: Molecular and Genomic Mechanisms Study in Plant Defense*

PubMed Central

Zhang, Yixiang; Gao, Peng; Xing, Zhuo; Jin, Shumei; Chen, Zhide; Liu, Lantao; Constantino, Nasie; Wang, Xinwang; Shi, Weibing; Yuan, Joshua S.; Dai, Susie Y.

2013-01-01

High abundance proteins like ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) impose a consistent challenge for the whole proteome characterization using shot-gun proteomics. To address this challenge, we developed and evaluated Polyethyleneimine Assisted Rubisco Cleanup (PARC) as a new method by combining both abundant protein removal and fractionation. The new approach was applied to a plant insect interaction study to validate the platform and investigate mechanisms for plant defense against herbivorous insects. Our results indicated that PARC can effectively remove Rubisco, improve the protein identification, and discover almost three times more differentially regulated proteins. The significantly enhanced shot-gun proteomics performance was translated into in-depth proteomic and molecular mechanisms for plant insect interaction, where carbon re-distribution was used to play an essential role. Moreover, the transcriptomic validation also confirmed the reliability of PARC analysis. Finally, functional studies were carried out for two differentially regulated genes as revealed by PARC analysis. Insect resistance was induced by over-expressing either jacalin-like or cupin-like genes in rice. The results further highlighted that PARC can serve as an effective strategy for proteomics analysis and gene discovery. PMID:23943779

Irradiation biology of male brown marmorated stink bugs: is there scope for the sterile insect technique?

PubMed

Welsh, T J; Stringer, L D; Caldwell, R; Carpenter, J E; Suckling, D M

2017-12-01

Brown marmorated stink bugs, Halyomorpha halys Stål (Hemiptera: Pentatomidae), are regularly intercepted, but there are few eradication tools. Currently, no sterile insect technique program exists for Hemiptera. Adult males were irradiated at 4-60 Gy, mated and their progeny reared for two generations, with mortality assessed at F 1 egg, F 1 adult and F 2 egg stages. The F 1 eggs showed a dose response to irradiation between 4 and 36 Gy, with 97% sterility at 16 Gy, and higher doses producing complete egg mortality. Only rare F 1 survivors had progeny, but the F 2 generation showed identical responses between maternal and paternal lines; most egg batches showed either very low or very high mortality. Irradiation with 16 Gy resulted in 98.5% sterility, cumulative over F 1 and F 2 . Lack of a dose response at the F 2 generation precludes the use of irradiation-induced inherited sterility. The conventional sterile insect technique appears possible by irradiation of males from ∼12 to 16 Gy. The effect of radiation dose on females is not known, thus we cannot conclude whether bi-sex release is feasible so for now the release of males only is recommended. More work is needed on the competitive fitness of irradiated males, and logistics such as mass rearing or field collection, in order to determine the feasibility of the approach.

The banana code-natural blend processing in the olfactory circuitry of Drosophila melanogaster.

PubMed

Schubert, Marco; Hansson, Bill S; Sachse, Silke

2014-01-01

Odor information is predominantly perceived as complex odor blends. For Drosophila melanogaster one of the most attractive blends is emitted by an over-ripe banana. To analyze how the fly's olfactory system processes natural blends we combined the experimental advantages of gas chromatography and functional imaging (GC-I). In this way, natural banana compounds were presented successively to the fly antenna in close to natural occurring concentrations. This technique allowed us to identify the active odor components, use these compounds as stimuli and measure odor-induced Ca(2+) signals in input and output neurons of the Drosophila antennal lobe (AL), the first olfactory neuropil. We demonstrate that mixture interactions of a natural blend are very rare and occur only at the AL output level resulting in a surprisingly linear blend representation. However, the information regarding single components is strongly modulated by the olfactory circuitry within the AL leading to a higher similarity between the representation of individual components and the banana blend. This observed modulation might tune the olfactory system in a way to distinctively categorize odor components and improve the detection of suitable food sources. Functional GC-I thus enables analysis of virtually any unknown natural odorant blend and its components in their relative occurring concentrations and allows characterization of neuronal responses of complete neural assemblies. This technique can be seen as a valuable complementary method to classical GC/electrophysiology techniques, and will be a highly useful tool in future investigations of insect-insect and insect-plant chemical interactions.

Freight transportation and the potential for invasions of exotic insects in urban and periurban forests of the United States.

PubMed

Colunga-Garcia, Manuel; Haack, Robert A; Adelaja, Adesoji O

2009-02-01

Freight transportation is an important pathway for the introduction and dissemination of exotic forest insects (EFI). Identifying the final destination of imports is critical in determining the likelihood of EFI establishment. We analyzed the use of regional freight transport information to characterize risk of urban and periurban areas to EFI introductions. Specific objectives were to 1) approximate the final distribution of selected imports among urban areas of the United States, 2) characterize the final distribution of imports in terms of their spatial aggregation and dominant world region of origin, and 3) assess the effect of the final distribution of imports on the level of risk to urban and periurban forests from EFI. Freight pattern analyses were conducted for three categories of imports whose products or packaging materials are associated with EFI: wood products, nonmetallic mineral products, and machinery. The final distribution of wood products was the most evenly distributed of the three selected imports, whereas machinery was most spatially concentrated. We found that the type of import and the world region of origin greatly influence the final distribution of imported products. Risk assessment models were built based on the amount of forestland and imports for each urban area The model indicated that 84-88% of the imported tonnage went to only 4-6% of the urban areas in the contiguous United States. We concluded that freight movement information is critical for proper risk assessment of EFI. Implications of our findings and future research needs are discussed.

A Novel Methodology for Improving Plant Pest Surveillance in Vineyards and Crops Using UAV-Based Hyperspectral and Spatial Data.

PubMed

Vanegas, Fernando; Bratanov, Dmitry; Powell, Kevin; Weiss, John; Gonzalez, Felipe

2018-01-17

Recent advances in remote sensed imagery and geospatial image processing using unmanned aerial vehicles (UAVs) have enabled the rapid and ongoing development of monitoring tools for crop management and the detection/surveillance of insect pests. This paper describes a (UAV) remote sensing-based methodology to increase the efficiency of existing surveillance practices (human inspectors and insect traps) for detecting pest infestations (e.g., grape phylloxera in vineyards). The methodology uses a UAV integrated with advanced digital hyperspectral, multispectral, and RGB sensors. We implemented the methodology for the development of a predictive model for phylloxera detection. In this method, we explore the combination of airborne RGB, multispectral, and hyperspectral imagery with ground-based data at two separate time periods and under different levels of phylloxera infestation. We describe the technology used-the sensors, the UAV, and the flight operations-the processing workflow of the datasets from each imagery type, and the methods for combining multiple airborne with ground-based datasets. Finally, we present relevant results of correlation between the different processed datasets. The objective of this research is to develop a novel methodology for collecting, processing, analising and integrating multispectral, hyperspectral, ground and spatial data to remote sense different variables in different applications, such as, in this case, plant pest surveillance. The development of such methodology would provide researchers, agronomists, and UAV practitioners reliable data collection protocols and methods to achieve faster processing techniques and integrate multiple sources of data in diverse remote sensing applications.

EXPRESSION EFFICIENCY OF A SCORPION NEUROTOXIN, AAHIT, USING BACULOVIRUS IN INSECT CELLS. (R825433)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

A Guide to Energy Savings - For the Vegetable Producer.

ERIC Educational Resources Information Center

Wynn, N. A.

This booklet gives a brief overview of energy use patterns in vegetable production and gives examples of cutting the cost of energy in fertilization, weed management, insect pest management, irrigation, harvesting, use of equipment, and greenhouses. Finally, energy use recordkeeping is discussed. (BB)

Bats and birds increase crop yield in tropical agroforestry landscapes.

PubMed

Maas, Bea; Clough, Yann; Tscharntke, Teja

2013-12-01

Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management. © 2013 John Wiley & Sons Ltd/CNRS.

Sampling Daphnia's expressed genes: preservation, expansion and invention of crustacean genes with reference to insect genomes

PubMed Central

Colbourne, John K; Eads, Brian D; Shaw, Joseph; Bohuski, Elizabeth; Bauer, Darren J; Andrews, Justen

2007-01-01

Background Functional and comparative studies of insect genomes have shed light on the complement of genes, which in part, account for shared morphologies, developmental programs and life-histories. Contrasting the gene inventories of insects to those of the nematodes provides insight into the genomic changes responsible for their diversification. However, nematodes have weak relationships to insects, as each belongs to separate animal phyla. A better outgroup to distinguish lineage specific novelties would include other members of Arthropoda. For example, crustaceans are close allies to the insects (together forming Pancrustacea) and their fascinating aquatic lifestyle provides an important comparison for understanding the genetic basis of adaptations to life on land versus life in water. Results This study reports on the first characterization of cDNA libraries and sequences for the model crustacean Daphnia pulex. We analyzed 1,546 ESTs of which 1,414 represent approximately 787 nuclear genes, by measuring their sequence similarities with insect and nematode proteomes. The provisional annotation of genes is supported by expression data from microarray studies described in companion papers. Loci expected to be shared between crustaceans and insects because of their mutual biological features are identified, including genes for reproduction, regulation and cellular processes. We identify genes that are likely derived within Pancrustacea or lost within the nematodes. Moreover, lineage specific gene family expansions are identified, which suggest certain biological demands associated with their ecological setting. In particular, up to seven distinct ferritin loci are found in Daphnia compared to three in most insects. Finally, a substantial fraction of the sampled gene transcripts shares no sequence similarity with those from other arthropods. Genes functioning during development and reproduction are comparatively well conserved between crustaceans and insects. By contrast, genes that were responsive to environmental conditions (metal stress) and not sex-biased included the greatest proportion of genes with no matches to insect proteomes. Conclusion This study along with associated microarray experiments are the initial steps in a coordinated effort by the Daphnia Genomics Consortium to build the necessary genomic platform needed to discover genes that account for the phenotypic diversity within the genus and to gain new insights into crustacean biology. This effort will soon include the first crustacean genome sequence. PMID:17612412

Penetrating view of nano-structures in Aleochara verna spermatheca and flagellum by hard X-ray microscopy

NASA Astrophysics Data System (ADS)

Zhang, Kai; Li, De-E.; Hong, You-Li; Zhu, Pei-Ping; Yuan, Qing-Xi; Huang, Wan-Xia; Gao, Kun; Zhou, Hong-Zhang; Wu, Zi-Yu

2013-07-01

A penetrating view of the three-dimensional nanostructure of female spermatheca and male flagellum in the species Aleochara verna is obtained with 100-nm resolution using a hard X-ray microscope, which provides a fast noninvasive imaging technology for insect morphology. Through introducing Zernike phase contrast and heavy metal staining, images taken at 8 keV displayed sufficient contrast for observing nanoscale fine structures, such as the spermatheca cochleate duct and the subapex of the flagellum, which have some implications for the study of the sperm transfer process and genital evolution in insects. This work shows that both the spatial resolution and the contrast characteristic of hard X-ray microscopy are quite promising for insect morphology studies and, particularly, provide an attractive alternative to the destructive techniques used for investigating internal soft tissues.

Application of synchrotron radiation phase-contrast microtomography with iodine staining to Rhodnius prolixus head during ecdysis period

NASA Astrophysics Data System (ADS)

Sena, G.; Nogueira, L. P.; Braz, D.; Colaço, M. V.; Azambuja, P.; Gonzalez, M. S.; Tromba, G.; Mantuano, A.; Costa, F. N.; Barroso, R. C.

2018-05-01

Synchrotron radiation phase-contrast microtomography (SR-PHC-CT) has become an important tool in studies of insects, mainly Rhodinius prolixus, the insect vector of Chagas disease. A previous work has shown that SR-PHC-CT is an excellent technique in studies about the ecdysis process of R.prolixus head. The term ecdysis refers to the set of behaviors by which an insect extracts itself from an old exoskeleton. The exoskeleton formation is indispensable for the evolutionary success of insect species, so failure to complete ecdysis will, in most cases result in death, making this process an excellent target in the search for new insect pest management strategies. Understanding the behavior of the ecdysis process is fundamental for the non-proliferation of Chagas disease. Despite it has been possible to identify the moulting process in the first work, main structures of the R.prolixus head could not be identified. In this work, it was developed a staining protocol which enabled the identification of these important structures using Iodine at SYRMEP beamline of ELETTRA. In the 3D images, it was possible to segment essential structures in the process of ecdysis. These structures have never been presented previously in the moulting period with SR-PHC-CT.

Artificial insect wings with biomimetic wing morphology and mechanical properties.

PubMed

Liu, Zhiwei; Yan, Xiaojun; Qi, Mingjing; Zhu, Yangsheng; Huang, Dawei; Zhang, Xiaoyong; Lin, Liwei

2017-09-26

The pursuit of a high lift force for insect-scale flapping-wing micro aerial vehicles (FMAVs) requires that their artificial wings possess biomimetic wing features which are close to those of their natural counterpart. In this work, we present both fabrication and testing methods for artificial insect wings with biomimetic wing morphology and mechanical properties. The artificial cicada (Hyalessa maculaticollis) wing is fabricated through a high precision laser cutting technique and a bonding process of multilayer materials. Through controlling the shape of the wing venation, the fabrication method can achieve three-dimensional wing architecture, including cambers or corrugations. Besides the artificial cicada wing, the proposed fabrication method also shows a promising versatility for diverse wing types. Considering the artificial cicada wing's characteristics of small size and light weight, special mechanical testing systems are designed to investigate its mechanical properties. Flexural stiffness, maximum deformation rate and natural frequency are measured and compared with those of its natural counterpart. Test results reveal that the mechanical properties of the artificial cicada wing depend strongly on its vein thickness, which can be used to optimize an artificial cicada wing's mechanical properties in the future. As such, this work provides a new form of artificial insect wings which can be used in the field of insect-scale FMAVs.

The Drosophila serpins: multiple functions in immunity and morphogenesis.

PubMed

Reichhart, Jean Marc; Gubb, David; Leclerc, Vincent

2011-01-01

Members of the serpin superfamily of proteins have been found in all living organisms, although rarely in bacteria or fungi. They have been extensively studied in mammals, where many rapid physiological responses are regulated by inhibitory serpins. In addition to the inhibitory serpins, a large group of noninhibitory proteins with a conserved serpin fold have also been identified in mammals. These noninhibitory proteins have a wide range of functions, from storage proteins to molecular chaperones, hormone transporters, and tumor suppressors. In contrast, until recently, very little was known about insect serpins in general, or Drosophila serpins in particular. In the last decade, however, there has been an increasing interest in the serpin biology of insects. It is becoming clear that, like in mammals, a similar wide range of physiological responses are regulated in insects and that noninhibitory serpin-fold proteins also play key roles in insect biology. Drosophila is also an important model organism that can be used to study human pathologies (among which serpinopathies or other protein conformational diseases) and mechanisms of regulation of proteolytic cascades in health or to develop strategies for control of insect pests and disease vectors. As most of our knowledge on insect serpins comes from studies on the Drosophila immune response, we survey here the Drosophila serpin literature and describe the laboratory techniques that have been developed to study serpin-regulated responses in this model genetic organism. Copyright © 2011 Elsevier Inc. All rights reserved.

Isolation and Identification of Mosquito (Aedes aegypti) Biting-Deterrent Compounds from the Native American Ethnobotanical Remedy Plant Hierochloë odorata (Sweetgrass).

PubMed

Cantrell, Charles L; Jones, A Maxwell P; Ali, Abbas

2016-11-09

Hierochloë odorata (L.) P. Beauv. (Poaceae), commonly known as sweetgrass, has documented use as an insect repellent by the Flatheads of Montana and Blackfoot of Alberta. Both the Flatheads of Montana and Blackfoot of Alberta would use braided plant material in a sachet in clothing or burn them from one end as incense, air/clothing freshener, and insect repellent. This study evaluated the insect-repellent properties of this plant using an in vitro mosquito Aedes aegypti feeding bioassay-directed approach to identify the compound(s) responsible for the observed activities. Evaluation of crude extracts produced from H. odorata revealed that the hydrodistillate had the highest level of mosquito biting deterrence. Fractionation of this extract, followed by re-evaluation for mosquito biting deterrence, produced many active fractions, which were evaluated by spectroscopic techniques and determined to contain phytol, coumarin, and 2-methoxy-4-vinylphenol. Phytol and coumarin were both determined to be responsible for the Ae. aegypti biting deterrency. Scientific evidence reported here validates its traditional use as a biting-insect deterrent.

Development of serum-free media for lepidopteran insect cell lines.

PubMed

Agathos, Spiros N

2007-01-01

Lepidopteran insect cell culture technology has progressed to the point of becoming an essential part of one of the most successful eukaryotic expression systems and is increasingly used industrially on a large scale. Therefore, there is a constant need for convenient and low-cost culture media capable of supporting good insect cell growth and ensuring high yield of baculovirus as well as the strong expression of recombinant proteins. Vertebrate sera or invertebrate hemolymph were essential supplements in first-generation insect cell media. These supplements, however, are cumbersome and expensive for routine large-scale culture; thus, their use is now circumvented by substituting the essential growth factors present in these supplements with serum-free substances. Such non-serum supplements are typically of non-animal origin and include protein hydrolysates, lipid emulsions, and specialized substances (e.g., surfactants and shear damage protecting chemicals). These supplements need to complement the defined, synthetic basal medium to ensure that the fundamental nutritional needs of the cells are satisfied. Although there is a significant number of proprietary serum-free and low-protein or protein-free media on the market, the lack of information concerning their detailed composition is a drawback in their adoption for different applications, including their adaptation to the metabolic and kinetic analysis and monitoring of a given insect cell based bioprocess. Hence, there is wide appeal for formulating serum-free media based on a rational assessment of the metabolic requirements of the lepidopteran cells during both the growth and the production phases. Techniques such as statistical experimental design and genetic algorithms adapted to the cellular behavior and the bioreactor operation mode (batch, fed-batch, or perfusion) permit the formulation of versatile serum- and protein-free media. These techniques are illustrated with recent developments of serum-free media for the cultivation of commercially important Spodoptera frugiperda and Trichoplusia ni cell lines.

Studies of the effect of grasshopper abdominal secretion on wound healing with the use of murine model.

PubMed

Buszewska-Forajta, M; Siluk, D; Daghir-Wojtkowiak, E; Sejda, A; Staśkowiak, D; Biernat, W; Kaliszan, R

2015-12-24

Grasshopper, belonging to Chorthippus sp., is a widespread insect inhabiting Polish territory. According to folk knowledge and folk tales, the grasshopper abdominal secretion was used by villagers of Central and South-West Poland as a natural drug accelerating the wound healing process. In the reported study the hypothesis about beneficial properties of grasshopper abdominal secretion on hard to heal wounds was verified. The study was carried out with the use of a murine model (mice C57BL/6). In order to verify the beneficial properties of grasshopper abdominal secretion, the wounds of 8mm in diameter were formed on one side of each tested mouse. The influence of ethanolic extract of insects' secretion on healing process was evaluated in comparison to ethanolic solution of allantoin and 30% aqueous solution of ethanol (medium). The observation was carried out over a 14 day period. Finally the statistical analysis (ANOVA) was carried out to highlight the differences in wound healing rate between applied preparations. Moreover, qualitative composition of grasshoppers' secretion was studied with the use of GC/MS technique. During the first three days of observation, wounds treated with allantoin were healed with higher efficiency in comparison to ethanol and insect secretion preparations. The trend of healing changed from the 4th day of observation. Wounds treated with grasshoppers' abdominal secretion were closuring faster than wounds treated with allantoin or ethanol. In this part of observation, in the case of allantoin and ethanol application, the wound healing efficiency was similar. Since the 9th day of experiment the measurement of wounds size was problematic, due to crust formation. Finally at the 14th day of the study, wounds were totally healed. Morphological study enabled to observe all the phases of healing. In the 5th and 8th day, the infiltration of neutrophils and mononuclear cells in dermis was observed, which is characteristic for inflammatory phase of wound healing. On the 8th day of experiments, granulation of the tissue was clearly observed in the tested groups. Reepithelialization phase was observed from the 5th to 14th day, when the wound was totally healed. The analytical approach enabled to identify 38 compounds of hydrophobic or hydrophilic character. Among them, 6 amino acids, 14 organic acids and their derivatives, one sterol, 4 hydrocarbons, 5 carbohydrates, 2 inorganic acids, 4 alcohols, one diamine and one nucleoside were identified. The obtained results enabled to recognize the composition of grasshopper abdominal secretion. Some of the identified compounds possess therapeutic properties described in the literature. The performed in vivo study proved that application of insects secretion accelerates the healing process. The obtained results positively verified the scientific hypothesis based on ethnopharmacological premises about the beneficial properties of grasshopper abdominal secretion on wound healing process. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Study on bird's & insect's wing aerodynamics and comparison of its analytical value with standard airfoil

NASA Astrophysics Data System (ADS)

Ali, Md. Nesar; Alam, Mahbubul; Hossain, Md. Abed; Ahmed, Md. Imteaz

2017-06-01

Flight is the main mode of locomotion used by most of the world's bird & insect species. This article discusses the mechanics of bird flight, with emphasis on the varied forms of bird's & insect's wings. The fundamentals of bird flight are similar to those of aircraft. Flying animals flap their wings to generate lift and thrust as well as to perform remarkable maneuvers with rapid accelerations and decelerations. Insects and birds provide illuminating examples of unsteady aerodynamics. Lift force is produced by the action of air flow on the wing, which is an airfoil. The airfoil is shaped such that the air provides a net upward force on the wing, while the movement of air is directed downward. Additional net lift may come from airflow around the bird's & insect's body in some species, especially during intermittent flight while the wings are folded or semi-folded. Bird's & insect's flight in nature are sub-divided into two stages. They are Unpowered Flight: Gliding and Soaring & Powered Flight: Flapping. When gliding, birds and insects obtain both a vertical and a forward force from their wings. When a bird & insect flaps, as opposed to gliding, its wings continue to develop lift as before, but the lift is rotated forward to provide thrust, which counteracts drag and increases its speed, which has the effect of also increasing lift to counteract its weight, allowing it to maintain height or to climb. Flapping flight is more complicated than flight with fixed wings because of the structural movement and the resulting unsteady fluid dynamics. Flapping involves two stages: the down-stroke, which provides the majority of the thrust, and the up-stroke, which can also (depending on the bird's & insect's wings) provide some thrust. Most kinds of bird & insect wing can be grouped into four types, with some falling between two of these types. These types of wings are elliptical wings, high speed wings, high aspect ratio wings and soaring wings with slots. Hovering is used by several species of birds. Hovering, which is generating only lift through flapping alone rather than as a product of thrust, demands a lot of energy. On the other hand, for practical knowledge we also fabricate the various bird's, insect's & fighter jet wing by using random value of parameter & test those airfoil in wind tunnel. Finally for comparison & achieving analytical knowledge we also test those airfoil model in various simulation software.

Stiffness distribution in insect cuticle: a continuous or a discontinuous profile?

PubMed

Rajabi, H; Jafarpour, M; Darvizeh, A; Dirks, J-H; Gorb, S N

2017-07-01

Insect cuticle is a biological composite with a high degree of complexity in terms of both architecture and material composition. Given the complex morphology of many insect body parts, finite-element (FE) models play an important role in the analysis and interpretation of biomechanical measurements, taken by either macroscopic or nanoscopic techniques. Many previous studies show that the interpretation of nanoindentation measurements of this layered composite material is very challenging. To develop accurate FE models, it is of particular interest to understand more about the variations in the stiffness through the thickness of the cuticle. Considering the difficulties of making direct measurements, in this study, we use the FE method to analyse previously published data and address this issue numerically. For this purpose, sets of continuous or discontinuous stiffness profiles through the thickness of the cuticle were mathematically described. The obtained profiles were assigned to models developed based on the cuticle of three insect species with different geometries and layer configurations. The models were then used to simulate the mechanical behaviour of insect cuticles subjected to nanoindentation experiments. Our results show that FE models with discontinuous exponential stiffness gradients along their thickness were able to predict the stress and deformation states in insect cuticle very well. Our results further suggest that, for more accurate measurements and interpretation of nanoindentation test data, the ratio of the indentation depth to cuticle thickness should be limited to 7% rather than the traditional '10% rule'. The results of this study thus might be useful to provide a deeper insight into the biomechanical consequences of the distinct material distribution in insect cuticle and also to form a basis for more realistic modelling of this complex natural composite. © 2017 The Author(s).

A Molecular View of Autophagy in Lepidoptera

PubMed Central

2014-01-01

Metamorphosis represents a critical phase in the development of holometabolous insects, during which the larval body is completely reorganized: in fact, most of the larval organs undergo remodeling or completely degenerate before the final structure of the adult insect is rebuilt. In the past, increasing evidence emerged concerning the intervention of autophagy and apoptosis in the cell death processes that occur in larval organs of Lepidoptera during metamorphosis, but a molecular characterization of these pathways was undertaken only in recent years. In addition to developmentally programmed autophagy, there is growing interest in starvation-induced autophagy. Therefore we are now entering a new era of research on autophagy that foreshadows clarification of the role and regulatory mechanisms underlying this self-digesting process in Lepidoptera. Given that some of the most important lepidopteran species of high economic importance, such as the silkworm, Bombyx mori, belong to this insect order, we expect that this information on autophagy will be fully exploited not only in basic research but also for practical applications. PMID:25143951

Understanding regulation of the host-mediated gut symbiont population and the symbiont-mediated host immunity in the Riptortus-Burkholderia symbiosis system.

PubMed

Kim, Jiyeun Kate; Lee, Jun Beom; Jang, Ho Am; Han, Yeon Soo; Fukatsu, Takema; Lee, Bok Luel

2016-11-01

Valuable insect models have tremendously contributed to our understanding of innate immunity and symbiosis. Bean bug, Riptortus pedestris, is a useful insect symbiosis model due to harboring cultivable monospecific gut symbiont, genus Burkholderia. Bean bug is a hemimetabolous insect whose immunity is not well-understood. However, we recently identified three major antimicrobial peptides of Riptortus and examined the relationship between gut symbiosis and host immunity. We found that the presence of Burkholderia gut symbiont positively affects Riptortus immunity. From studying host regulation mechanisms of symbiont population, we revealed that the symbiotic Burkholderia cells are much more susceptible to Riptortus immune responses than the cultured cells. We further elucidated that the immune-susceptibility of the Burkholderia gut symbionts is due to the drastic change of bacterial cell envelope. Finally, we show that the immune-susceptible Burkholderia symbionts are able to prosper in host owing to the suppression of immune responses of the symbiotic midgut. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biological Characteristics of Grapholita molesta (Lepidoptera: Tortricidae) Induced to Diapause in Laboratory

PubMed Central

Silva, Oscar Arnaldo Batista Neto e; Bernardi, Daniel; Botton, Marcos; Garcia, Mauro Silveira

2014-01-01

Abstract In southern Brazil, Grapholita molesta (Busck) (Lepidoptera: Tortricidae) uses diapause as survival strategy during the winter (May–August). In our study, we evaluated the effect of diapause on biological characteristics of the species for 4 months in laboratory. Newly hatched larvae of G. molesta were induced to diapause changing the photoperiod and temperature (T) (12 ± 1°C), relative humidity (RH) (70 ± 10%), and a photophase of 12 h and, when they started diapause in the prepupal stage, the conditions were kept for 4 months. Afterwards, the insects were induced to finalize the diapause process at T 25 ± 1°C, RH 70 ± 10%, and a photophase of 16 h. We evaluated the duration and viability of the larval stages and pupae, pupae weight at 24 h and sex ratio (sr), periods of preoviposition, oviposition, and postoviposition; adult life span (males and females); fecundity (daily and total); embryonic period duration and eggs viability, comparing the data with insects nondiapause. The results show that diapause greatly affected the viability of pupal–adult stages of the population (21.8%) when compared with insects’ nondiapause (80.0%). Total fecundity (83.0 eggs) and mean life span (12.0 d) of insects diapause was significantly lower compared with insects nondiapause (173.0 and 17.0), respectively. However, these differences were not observed in the sr, which was similar to insects diapause (sr = 0.41) and insects nondiapause (sr = 0.49). The diapause induced for 4 months negatively affects reproduction and life span of adults of G. molesta. PMID:25527572

Intra- and intersegmental influences among central pattern generating networks in the walking system of the stick insect.

PubMed

Mantziaris, Charalampos; Bockemühl, Till; Holmes, Philip; Borgmann, Anke; Daun, Silvia; Büschges, Ansgar

2017-10-01

To efficiently move around, animals need to coordinate their limbs. Proper, context-dependent coupling among the neural networks underlying leg movement is necessary for generating intersegmental coordination. In the slow-walking stick insect, local sensory information is very important for shaping coordination. However, central coupling mechanisms among segmental central pattern generators (CPGs) may also contribute to this. Here, we analyzed the interactions between contralateral networks that drive the depressor trochanteris muscle of the legs in both isolated and interconnected deafferented thoracic ganglia of the stick insect on application of pilocarpine, a muscarinic acetylcholine receptor agonist. Our results show that depressor CPG activity is only weakly coupled between all segments. Intrasegmental phase relationships differ between the three isolated ganglia, and they are modified and stabilized when ganglia are interconnected. However, the coordination patterns that emerge do not resemble those observed during walking. Our findings are in line with recent studies and highlight the influence of sensory input on coordination in slowly walking insects. Finally, as a direct interaction between depressor CPG networks and contralateral motoneurons could not be observed, we hypothesize that coupling is based on interactions at the level of CPG interneurons. NEW & NOTEWORTHY Maintaining functional interleg coordination is vitally important as animals locomote through changing environments. The relative importance of central mechanisms vs. sensory feedback in this process is not well understood. We analyzed coordination among the neural networks generating leg movements in stick insect preparations lacking phasic sensory feedback. Under these conditions, the networks governing different legs were only weakly coupled. In stick insect, central connections alone are thus insufficient to produce the leg coordination observed behaviorally. Copyright © 2017 the American Physiological Society.

Climatic and Catchment-Scale Predictors of Chinese Stream Insect Richness Differ between Taxonomic Groups

PubMed Central

Tonkin, Jonathan D.; Shah, Deep Narayan; Kuemmerlen, Mathias; Li, Fengqing; Cai, Qinghua; Haase, Peter; Jähnig, Sonja C.

2015-01-01

Little work has been done on large-scale patterns of stream insect richness in China. We explored the influence of climatic and catchment-scale factors on stream insect (Ephemeroptera, Plecoptera, Trichoptera; EPT) richness across mid-latitude China. We assessed the predictive ability of climatic, catchment land cover and physical structure variables on genus richness of EPT, both individually and combined, in 80 mid-latitude Chinese streams, spanning a 3899-m altitudinal gradient. We performed analyses using boosted regression trees and explored the nature of their influence on richness patterns. The relative importance of climate, land cover, and physical factors on stream insect richness varied considerably between the three orders, and while important for Ephemeroptera and Plecoptera, latitude did not improve model fit for any of the groups. EPT richness was linked with areas comprising high forest cover, elevation and slope, large catchments and low temperatures. Ephemeroptera favoured areas with high forest cover, medium-to-large catchment sizes, high temperature seasonality, and low potential evapotranspiration. Plecoptera richness was linked with low temperature seasonality and annual mean, and high slope, elevation and warm-season rainfall. Finally, Trichoptera favoured high elevation areas, with high forest cover, and low mean annual temperature, seasonality and aridity. Our findings highlight the variable role that catchment land cover, physical properties and climatic influences have on stream insect richness. This is one of the first studies of its kind in Chinese streams, thus we set the scene for more in-depth assessments of stream insect richness across broader spatial scales in China, but stress the importance of improving data availability and consistency through time. PMID:25909190

Generic insect repellent detector from the fruit fly Drosophila melanogaster.

PubMed

Syed, Zainulabeuddin; Pelletier, Julien; Flounders, Eric; Chitolina, Rodrigo F; Leal, Walter S

2011-03-16

Insect repellents are prophylactic tools against a number of vector-borne diseases. There is growing demand for repellents outperforming DEET in cost and safety, but with the current technologies R&D of a new product takes almost 10 years, with a prohibitive cost of $30 million dollar in part due to the demand for large-scale synthesis of thousands of test compounds of which only 1 may reach the market. R&D could be expedited and cost dramatically reduced with a molecular/physiological target to streamline putative repellents for final efficacy and toxicological tests. Using olfactory-based choice assay we show here that the fruit fly is repelled by not only DEET, but also IR3535 and picaridin thus suggesting they might have "generic repellent detector(s)," which may be of practical applications in new repellent screenings. We performed single unit recordings from all olfactory sensilla in the antennae and maxillary palps. Although the ab3A neuron in the wild type flies responded to picaridin, it was unresponsive to DEET and IR3535. By contrast, a neuron housed in the palp basiconic sensilla pb1 responded to DEET, IR3535, and picaridin, with apparent sensitivity higher than that of the DEET detectors in the mosquitoes Culex quinquefasciatus and Aedes aegypti. DmOr42a was transplanted from pb1 to the "empty neuron" and showed to be sensitive to the three insect repellents. For the first time we have demonstrated that the fruit fly avoids not only DEET but also IR3535 and picaridin, and identified an olfactory receptor neuron (ORN), which is sensitive to these three major insect repellents. We have also identified the insect repellent-sensitive receptor, DmOr42a. This generic detector fulfils the requirements for a simplified bioassay for early screening of test insect repellents.

Segmentation gene expression patterns in Bactrocera dorsalis and related insects: regulation and shape of blastoderm and larval cuticle.

PubMed

Suksuwan, Worramin; Cai, Xiaoli; Ngernsiri, Lertluk; Baumgartner, Stefan

2017-01-01

The oriental fruit fly, Bactrocera dorsalis, is regarded as a severe pest of fruit production in Asia. Despite its economic importance, only limited information regarding the molecular and developmental biology of this insect is known to date. We provide a detailed analysis of B. dorsalis embryology, as well as the expression patterns of a number of segmentation genes known to act during patterning of Drosophila and compare these to the patterns of other insect families. An anterior shift of the expression of gap genes was detected when compared to Drosophila. This shift was largely restored during the step where the gap genes control expression of the pair-rule genes. We analyzed and compared the shapes of the embryos of insects of different families, B. dorsalis and the blow fly Lucilia sericata with that of the well-characterized Drosophila melanogaster. We found distinct shapes as well as differences in the ratios of the length of the anterior-posterior axis and the dorsal-ventral axis. These features were integrated into a profile of how the expression patterns of the gap gene Krüppel and the pair-rule gene even-skipped were observed along the A-P axis in three insects families. Since significant differences were observed, we discuss how Krüppel controls the even-skipped stripes. Furthermore, we discuss how the position and angles of the segmentation gene stripes differed from other insects. Finally, we analyzed the outcome of the expression patterns of the late acting segment polarity genes in relation to the anlagen of the naked-cuticle and denticle belt area of the B. dorsalis larva.

Compound eyes of insects and crustaceans: Some examples that show there is still a lot of work left to be done.

PubMed

Meyer-Rochow, Victor Benno

2015-03-01

Similarities and differences between the 2 main kinds of compound eye (apposition and superposition) are briefly explained before several promising topics for research on compound eyes are being introduced. Research on the embryology and molecular control of the development of the insect clear-zone eye with superposition optics is one of the suggestions, because almost all of the developmental work on insect eyes in the past has focused on eyes with apposition optics. Age- and habitat-related ultrastructural studies of the retinal organization are another suggestion and the deer cad Lipoptena cervi, which has an aerial phase during which it is winged followed by a several months long parasitic phase during which it is wingless, is mentioned as a candidate species. Sexual dimorphism expressing itself in many species as a difference in eye structure and function provides another promising field for compound eye researchers and so is a focus on compound eye miniaturization in very small insects, especially those that are aquatic and belong to species, in which clear-zone eyes are diagnostic or are tiny insects that are not aquatic, but belong to taxa like the Diptera for instance, in which open rather than closed rhabdoms are the rule. Structures like interommatidial hairs and glands as well as corneal microridges are yet another field that could yield interesting results and in the past has received insufficient consideration. Finally, the dearth of information on distance vision and depth perception is mentioned and a plea is made to examine the photic environment inside the foam shelters of spittle bugs, chrysales of pupae and other structures shielding insects and crustaceans. © 2014 Institute of Zoology, Chinese Academy of Sciences.

Native birds and insects, and introduced honey bees visiting Echium wildpretii (Boraginaceae) in the Canary Islands

NASA Astrophysics Data System (ADS)

Valido, Alfredo; Dupont, Yoko L.; Hansen, Dennis M.

2002-12-01

In this paper, we report observations of flower visitors of the endemic Echium wildpretii in Tenerife, Canary Islands. This plant inhabits the high altitudinal sub-alpine zone, which is characterized by a harsh climate, low species diversity and a short growing season. Echium wildpretii is a monocarpic perennial, producing a 2-3 m column-shaped, red-flowered, nectar-rich inflorescence. Although these floral traits have previously been suggested as being typical of ornithophilous flowers, this is the first study reporting observations of native birds ( Phylloscopus collybita and Serinus canarius) in addition to insects visiting the flowers for nectar. The purposes of this study were firstly to investigate levels of visitation by native birds, native insects, and introduced honey bees. Secondly, we studied the influence of floral display (plant height and number of flowers), nearest neighbours (distance and size) and local vegetation structure on visitation rate. Finally, we discuss the evolution of ornithophily in an otherwise entomophilous plant lineage. We found that the level of bird visitation was relatively high early in the flowering season, but decreased in mid/late season, while the opposite pattern was found for introduced honey bees. For native insects, the frequency of visits was similar in early and late season. Bird visits were correlated with floral display. In the early season, visitation rates of honey bees and the two most common native bee species were correlated with size of the plant or its nearest neighbours, consistent with preference patterns for larger resource patches. Since only insects visit the flowers of other species in the Echium clade, E. wildpretii appears to have evolved from a truly insect-pollinated lineage.

[Estimation of time detection limit for human cytochrome b in females of Lutzomyia evansi].

PubMed

Vergara, José Gabriel; Verbel-Vergara, Daniel; Montesino, Ana Milena; Pérez-Doria, Alveiro; Bejarano, Eduar Elías

2017-03-29

Molecular biology techniques have allowed a better knowledge of sources of blood meals in vector insects. However, the usefulness of these techniques depends on both the quantity of ingested blood and the digestion process in the insect. To identify the time limit for detection of the human cytochrome b (Cyt b) gene in experimentally fed females of Lutzomyia evansi. Eight groups of L. evansi females were fed on human blood and sacrificed at intervals of 24 hours post-ingestion. Total DNA was extracted from each female and a segment of 358 bp of Cyt b was amplified. In order to eliminate false positives, amplification products were subjected to a restriction fragment length polymorphism (RFLP) analysis. The human Cyt b gene segment was detected in 86% (49/57) of the females of L. evansi, from 0 to 168 hours after blood ingestion. In 7% (4/57) of the individuals we amplified insect DNA, while in the remaining 7%, the band of interest was not amplified. We did not find any statistical differences between groups of females sacrificed at different times post-blood meal regarding the amplification of the human Cyt b gene segment or the number of samples amplified. The human Cyt b gene segment was detectable in L. evansi females up to 168 hours after blood ingestion.

Novel in vitro diagnosis of equine allergies using a protein array and mathematical modelling approach: a proof of concept using insect bite hypersensitivity.

PubMed

Marti, E; Wang, X; Jambari, N N; Rhyner, C; Olzhausen, J; Pérez-Barea, J J; Figueredo, G P; Alcocer, M J C

2015-10-15

Insect bite hypersensitivity (IBH) is a seasonal recurrent skin allergy of horses caused by IgE-mediated reactions to allergens present in the saliva of biting insects of the genus Culicoides, and possibly also Simulium and Stomoxys species. In this work we show that protein microarrays containing complex extracts and pure proteins, including recombinant Culicoides allergens, can be used as a powerful technique for the diagnosis of IBH. Besides the obvious advantages such as general profiling and use of few microliters of samples, this microarray technique permits automation and allows the generation of mathematical models with the calculation of individual risk profiles that can support the clinical diagnosis of allergic diseases. After selection of variables on influence on the projection (VIP), the observed values of sensitivity and specificity were 1.0 and 0.967, respectively. This confirms the highly discriminatory power of this approach for IBH and made it possible to attain a robust predictive mathematical model for this disease. It also further demonstrates the specificity of the protein array method on identifying a particular IgE-mediated disease when the sensitising allergen group is known. Copyright © 2015 Elsevier B.V. All rights reserved.

Insect Wing Displacement Measurement Using Digital Holography

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

Aguayo, Daniel D.; Mendoza Santoyo, Fernando; Torre I, Manuel H. de la

2008-04-15

Insects in flight have been studied with optical non destructive techniques with the purpose of using meaningful results in aerodynamics. With the availability of high resolution and large dynamic range CCD sensors the so called interferometric digital holographic technique was used to measure the surface displacement of in flight insect wings, such as butterflies. The wings were illuminated with a continuous wave Verdi laser at 532 nm, and observed with a CCD Pixelfly camera that acquire images at a rate of 11.5 frames per second at a resolution of 1392x1024 pixels and 12 Bit dynamic range. At this frame ratemore » digital holograms of the wings were captured and processed in the usual manner, namely, each individual hologram is Fourier processed in order to find the amplitude and phase corresponding to the digital hologram. The wings displacement is obtained when subtraction between two digital holograms is performed for two different wings position, a feature applied to all consecutive frames recorded. The result of subtracting is seen as a wrapped phase fringe pattern directly related to the wing displacement. The experimental data for different butterfly flying conditions and exposure times are shown as wire mesh plots in a movie of the wings displacement.« less

A new approach to optic disc detection in human retinal images using the firefly algorithm.

PubMed

Rahebi, Javad; Hardalaç, Fırat

2016-03-01

There are various methods and algorithms to detect the optic discs in retinal images. In recent years, much attention has been given to the utilization of the intelligent algorithms. In this paper, we present a new automated method of optic disc detection in human retinal images using the firefly algorithm. The firefly intelligent algorithm is an emerging intelligent algorithm that was inspired by the social behavior of fireflies. The population in this algorithm includes the fireflies, each of which has a specific rate of lighting or fitness. In this method, the insects are compared two by two, and the less attractive insects can be observed to move toward the more attractive insects. Finally, one of the insects is selected as the most attractive, and this insect presents the optimum response to the problem in question. Here, we used the light intensity of the pixels of the retinal image pixels instead of firefly lightings. The movement of these insects due to local fluctuations produces different light intensity values in the images. Because the optic disc is the brightest area in the retinal images, all of the insects move toward brightest area and thus specify the location of the optic disc in the image. The results of implementation show that proposed algorithm could acquire an accuracy rate of 100 % in DRIVE dataset, 95 % in STARE dataset, and 94.38 % in DiaRetDB1 dataset. The results of implementation reveal high capability and accuracy of proposed algorithm in the detection of the optic disc from retinal images. Also, recorded required time for the detection of the optic disc in these images is 2.13 s for DRIVE dataset, 2.81 s for STARE dataset, and 3.52 s for DiaRetDB1 dataset accordingly. These time values are average value.

A Moveable Feast: Insects Moving at the Forest-Crop Interface Are Affected by Crop Phenology and the Amount of Forest in the Landscape.

PubMed

González, Ezequiel; Salvo, Adriana; Defagó, María Teresa; Valladares, Graciela

2016-01-01

Edges have become prevailing habitats, mainly as a result of habitat fragmentation and agricultural expansion. The interchange of functionally relevant organisms like insects occurs through these edges and can influence ecosystem functioning in both crop and non-crop habitats. However, very few studies have focused on the directionality of insect movement through edges, and the role of crop and non-crop amount has been ignored. Using bi-directional flight interception traps we investigated interchange of herbivore, natural enemy, pollinator and detritivore insects between native forest fragments and soybean crops, simultaneously considering movement direction, forest cover in the landscape and crop phenology. In total, 52,173 specimens and 877 morphospecies were collected. We found that, within most functional and taxonomic groups, movement intensity was similar (richness and/or abundance) between directions, whereas a predominantly forest-to-crop movement characterized natural enemies. Insect movement was extensively affected by crop phenology, decreasing during crop senescence, and was enhanced by forest cover particularly at senescence. Mainly the same herbivore species moved to and from the forest, but different natural enemy species predominated in each direction. Finally, our analyses revealed greater forest contribution to natural enemy than to herbivore communities in the crop, fading with distance to the forest in both groups. By showing that larger amounts of forest lead to richer insect interchange, in both directions and in four functional groups, our study suggests that allocation to natural and cultivated habitats at landscape level could influence functioning of both systems. Moreover, natural enemies seemed to benefit more than pests from natural vegetation, with natural enemy spillover from forests likely contributing to pest control in soybean fields. Thus consequences of insect interchange seem to be mostly positive for the agroecosystem, although consequences for the natural system deserve further study.

The evolution of dorsal-ventral patterning mechanisms in insects.

PubMed

Lynch, Jeremy A; Roth, Siegfried

2011-01-15

The gene regulatory network (GRN) underpinning dorsal-ventral (DV) patterning of the Drosophila embryo is among the most thoroughly understood GRNs, making it an ideal system for comparative studies seeking to understand the evolution of development. With the emergence of widely applicable techniques for testing gene function, species with sequenced genomes, and multiple tractable species with diverse developmental modes, a phylogenetically broad and molecularly deep understanding of the evolution of DV axis formation in insects is feasible. Here, we review recent progress made in this field, compare our emerging molecular understanding to classical embryological experiments, and suggest future directions of inquiry.

Managing ammonia emissions from screwworm larval rearing media

USDA-ARS?s Scientific Manuscript database

Mass production, sterilization and release of screwworms (Cochliomyia hominivorax (Coquerel)) that were competitive in the field significantly contributed to the successful application of the sterile insect technique for eradication of screwworms from continental North America. Metabolic byproducts...

Biological properties

Treesearch

Rebecca E. Ibach

2005-01-01

There are numerous biological degradations that wood is exposed to in various environments. Biological damage occurs when a log, sawn product, or final product is not stored, handled, or designed properly. Biological organisms, such as bacteria, mold, stain, decay fungi, insects, and marine borers, depend heavily on temperature and moisture conditions to grow. A higher...

Development of western spruce budworm on Douglas-fir callus tissue.

Treesearch

Roy C. Beckwith; Barry Goldfarb

1991-01-01

The success of feeding and development of western spruce budworm (Choristoneura occidentalis Freeman) on callus tissue of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was determined. Fewer insects died when fed pure callus tissue than when fed on standard diet or callus incorporated into the standard diet. The final...

Development of computer software to analyze entire LANDSAT scenes and to summarize classification results of variable-size polygons

NASA Technical Reports Server (NTRS)

Turner, B. J. (Principal Investigator); Baumer, G. M.; Myers, W. L.; Sykes, S. G.

1981-01-01

The Forest Pest Management Division (FPMD) of the Pennsylvania Bureau of Forestry has the responsibility for conducting annual surveys of the State's forest lands to accurately detect, map, and appraise forest insect infestations. A standardized, timely, and cost-effective method of accurately surveying forests and their condition should enhance the probability of suppressing infestations. The repetitive and synoptic coverage provided by LANDSAT (formerly ERTS) makes such satellite-derived data potentially attractive as a survey medium for monitoring forest insect damage over large areas. Forest Pest Management Division personnel have expressed keen interest in LANDSAT data and have informally cooperated with NASA/Goddard Space Flight Center (GSFC) since 1976 in the development of techniques to facilitate their use. The results of this work indicate that it may be feasible to use LANDSAT digital data to conduct annual surveys of insect defoliation of hardwood forests.

A Bionic Polarization Navigation Sensor and Its Calibration Method.

PubMed

Zhao, Huijie; Xu, Wujian

2016-08-03

The polarization patterns of skylight which arise due to the scattering of sunlight in the atmosphere can be used by many insects for deriving compass information. Inspired by insects' polarized light compass, scientists have developed a new kind of navigation method. One of the key techniques in this method is the polarimetric sensor which is used to acquire direction information from skylight. In this paper, a polarization navigation sensor is proposed which imitates the working principles of the polarization vision systems of insects. We introduce the optical design and mathematical model of the sensor. In addition, a calibration method based on variable substitution and non-linear curve fitting is proposed. The results obtained from the outdoor experiments provide support for the feasibility and precision of the sensor. The sensor's signal processing can be well described using our mathematical model. A relatively high degree of accuracy in polarization measurement can be obtained without any error compensation.

Bioinspired optical sensors for unmanned aerial systems

NASA Astrophysics Data System (ADS)

Chahl, Javaan; Rosser, Kent; Mizutani, Akiko

2011-04-01

Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.

Towards an integrated understanding of gut microbiota using insects as model systems.

PubMed

Pernice, Mathieu; Simpson, Stephen J; Ponton, Fleur

2014-10-01

Metazoans form symbioses with microorganisms that synthesize essential nutritional compounds and increase their efficiency to digest and absorb nutrients. Despite the growing awareness that microbes within the gut play key roles in metabolism, health and development of metazoans, symbiotic relationships within the gut are far from fully understood. Insects, which generally harbor a lower microbial diversity than vertebrates, have recently emerged as potential model systems to study these interactions. In this review, we give a brief overview of the characteristics of the gut microbiota in insects in terms of low diversity but high variability at intra- and interspecific levels and we investigate some of the ecological and methodological factors that might explain such variability. We then emphasize how studies integrating an array of techniques and disciplines have the potential to provide new understanding of the biology of this micro eco-system. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Application of DNA-based methods in forensic entomology.

PubMed

Wells, Jeffrey D; Stevens, Jamie R

2008-01-01

A forensic entomological investigation can benefit from a variety of widely practiced molecular genotyping methods. The most commonly used is DNA-based specimen identification. Other applications include the identification of insect gut contents and the characterization of the population genetic structure of a forensically important insect species. The proper application of these procedures demands that the analyst be technically expert. However, one must also be aware of the extensive list of standards and expectations that many legal systems have developed for forensic DNA analysis. We summarize the DNA techniques that are currently used in, or have been proposed for, forensic entomology and review established genetic analyses from other scientific fields that address questions similar to those in forensic entomology. We describe how accepted standards for forensic DNA practice and method validation are likely to apply to insect evidence used in a death or other forensic entomological investigation.

Transgenic rice expressing Allium sativum leaf agglutinin (ASAL) exhibits high-level resistance against major sap-sucking pests

PubMed Central

Yarasi, Bharathi; Sadumpati, Vijayakumar; Immanni, China Pasalu; Vudem, Dasavantha Reddy; Khareedu, Venkateswara Rao

2008-01-01

Background Rice (Oryza sativa) productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which ~21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal) gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Results Allium sativum leaf lectin gene (asal), coding for mannose binding homodimeric protein (ASAL) from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH). Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. Conclusion In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice plants, bestowed with high entomotoxic effects, imparted appreciable resistance against three major sap-sucking insects. Our results amply demonstrate that transgenic indica rice harbouring asal exhibit surpassing resistance against BPH, GLH and WBPH insects. The prototypic asal transgenic rice lines appear promising for direct commercial cultivation besides serving as a potential genetic resource in recombination breeding. PMID:18854007

Transgenic rice expressing Allium sativum leaf agglutinin (ASAL) exhibits high-level resistance against major sap-sucking pests.

PubMed

Yarasi, Bharathi; Sadumpati, Vijayakumar; Immanni, China Pasalu; Vudem, Dasavantha Reddy; Khareedu, Venkateswara Rao

2008-10-14

Rice (Oryza sativa) productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which approximately 21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal) gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Allium sativum leaf lectin gene (asal), coding for mannose binding homodimeric protein (ASAL) from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH). Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice plants, bestowed with high entomotoxic effects, imparted appreciable resistance against three major sap-sucking insects. Our results amply demonstrate that transgenic indica rice harbouring asal exhibit surpassing resistance against BPH, GLH and WBPH insects. The prototypic asal transgenic rice lines appear promising for direct commercial cultivation besides serving as a potential genetic resource in recombination breeding.

The banana code—natural blend processing in the olfactory circuitry of Drosophila melanogaster

PubMed Central

Schubert, Marco; Hansson, Bill S.; Sachse, Silke

2014-01-01

Odor information is predominantly perceived as complex odor blends. For Drosophila melanogaster one of the most attractive blends is emitted by an over-ripe banana. To analyze how the fly's olfactory system processes natural blends we combined the experimental advantages of gas chromatography and functional imaging (GC-I). In this way, natural banana compounds were presented successively to the fly antenna in close to natural occurring concentrations. This technique allowed us to identify the active odor components, use these compounds as stimuli and measure odor-induced Ca2+ signals in input and output neurons of the Drosophila antennal lobe (AL), the first olfactory neuropil. We demonstrate that mixture interactions of a natural blend are very rare and occur only at the AL output level resulting in a surprisingly linear blend representation. However, the information regarding single components is strongly modulated by the olfactory circuitry within the AL leading to a higher similarity between the representation of individual components and the banana blend. This observed modulation might tune the olfactory system in a way to distinctively categorize odor components and improve the detection of suitable food sources. Functional GC-I thus enables analysis of virtually any unknown natural odorant blend and its components in their relative occurring concentrations and allows characterization of neuronal responses of complete neural assemblies. This technique can be seen as a valuable complementary method to classical GC/electrophysiology techniques, and will be a highly useful tool in future investigations of insect-insect and insect-plant chemical interactions. PMID:24600405

Establishing Research and Management Priorities for Monoecious Hydrilla

DTIC Science & Technology

2014-01-01

strategies. While use of high stocking rates of non-selective sterile grass carp (Ctenopharyngodon idella) has successfully controlled hydrilla in many...discussions of classical biological control agents (e.g. insects that feed specifically on hydrilla) did not yield any promising near-term candidates...possible. Diver- assisted dredging techniques and hand removal techniques were explored on the infestation in the Lake Cayuga inlet; initial results were

Microbiology of processed edible insect products - Results of a preliminary survey.

PubMed

Grabowski, Nils Th; Klein, Günter

2017-02-21

Little is known of the microbiology of processed insect products. The present survey analysed a total of n=38 samples of deep-fried and spiced (Acheta domesticus, Locusta migratoria, and Omphisa fuscidentalis), cooked in soy sauce ("tsukudani"; Oxya yezoensis, Vespula flaviceps, and Bombyx mori), dried (A. domesticus, L. migatoria, Alphitobius diaperinus, Tenebrio molitor, B. mori, Hermetia illucens, and Musca domestica), powdered (H. illucens, T. molitor) and other (incl. deep-frozen B. mori and honeybee pollen) insect products microbiologically (total bacterial count [TBC], Enterobacteriaceae, staphylococci, bacilli, and yeasts and moulds counts, salmonellae, Listeria monocytogenes, and Escherichia coli). Although each product type revealed a microbiological profile of its own, dried and powdered insects ("class I") displayed markedly higher counts than the deep-fried and cooked ones ("class II"). Thresholds between class I and II products were estimated at 4.0 (TBC), 1.0 (Enterobacteriaceae, yeasts and moulds), 2.5 (staphylococci), and 3.0lgcfu/g (bacilli). All samples were negative for salmonellae, L. monocytogenes, E. coli and Stapyhlococcus aureus, but dried and powdered insects, as well as pollen, contained B. cereus, coliforms, Serratia liquefaciens, Listeria ivanovii, Mucor spp., Aspergillus spp., Penicillium spp., and Cryptococcus neoformans. Comparing the results with the hygiene criteria for edible insects proposed by Belgium and the Netherlands, class I products failed to comply with many bacterial count limits despite the absence of classical food pathogens. Therefore, class I products should always be consumed after another heating step as indicated by the manufacturer, until drying techniques are able to ensure lower bacterial counts. Copyright © 2016 Elsevier B.V. All rights reserved.

Paleozoic Nymphal Wing Pads Support Dual Model of Insect Wing Origins.

PubMed

Prokop, Jakub; Pecharová, Martina; Nel, André; Hörnschemeyer, Thomas; Krzemińska, Ewa; Krzemiński, Wiesław; Engel, Michael S

2017-01-23

The appearance of wings in insects, early in their evolution [1], has been one of the more critical innovations contributing to their extraordinary diversity. Despite the conspicuousness and importance of wings, the origin of these structures has been difficult to resolve and represented one of the "abominable mysteries" in evolutionary biology [2]. More than a century of debate has boiled the matter down to two competing alternatives-one of wings representing an extension of the thoracic notum, the other stating that they are appendicular derivations from the lateral body wall. Recently, a dual model has been supported by genomic and developmental data [3-6], representing an amalgamation of elements from both the notal and pleural hypotheses. Here, we reveal crucial information from the wing pad joints of Carboniferous palaeodictyopteran insect nymphs using classical and high-tech techniques. These nymphs had three pairs of wing pads that were medially articulated to the thorax but also broadly contiguous with the notum anteriorly and posteriorly (details unobservable in modern insects), supporting their overall origin from the thoracic notum as well as the expected medial, pleural series of axillary sclerites. Our study provides support for the formation of the insect wing from the thoracic notum as well as the already known pleural elements of the arthropodan leg. These results support the unique, dual model for insect wing origins and the convergent reduction of notal fusion in more derived clades, presumably due to wing rotation during development, and they help to bring resolution to this long-standing debate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolution of insect arylalkylamine N-acetyltransferases: Structural evidence from the yellow fever mosquito, Aedes aegypti

PubMed Central

Han, Qian; Robinson, Howard; Ding, Haizhen; Christensen, Bruce M.; Li, Jianyong

2012-01-01

Arylalkylamine N-acetyltransferase (aaNAT) catalyzes the transacetylation from acetyl-CoA to arylalkylamines. aaNATs are involved in sclerotization and neurotransmitter inactivation in insects. Phyletic distribution analysis confirms three clusters of aaNAT-like sequences in insects: typical insect aaNAT, polyamine NAT-like aaNAT, and mosquito unique putative aaNAT (paaNAT). Here we studied three proteins: aaNAT2, aaNAT5b, and paaNAT7, each from a different cluster. aaNAT2, a protein from the typical insect aaNAT cluster, uses histamine as a substrate as well as the previously identified arylalkylamines. aaNAT5b, a protein from polyamine NAT -like aaNAT cluster, uses hydrazine and histamine as substrates. The crystal structure of aaNAT2 was determined using single-wavelength anomalous dispersion methods, and that of native aaNAT2, aaNAT5b and paaNAT7 was detected using molecular replacement techniques. All three aaNAT structures have a common fold core of GCN5-related N-acetyltransferase superfamily proteins, along with a unique structural feature: helix/helices between β3 and β4 strands. Our data provide a start toward a more comprehensive understanding of the structure–function relationship and physiology of aaNATs from the mosquito Aedes aegypti and serve as a reference for studying the aaNAT family of proteins from other insect species. The structures of three different types of aaNATs may provide targets for designing insecticides for use in mosquito control. PMID:22753468

Is floral specialization an evolutionary dead-end? Pollination system transitions in Ruellia (Acanthaceae).

PubMed

Tripp, Erin A; Manos, Paul S

2008-07-01

Pollination systems frequently reflect adaptations to particular groups of pollinators. Such systems are indicative of evolutionary specialization and have been important in angiosperm diversification. We studied the evolution of pollination systems in the large genus Ruellia. Phylogenetic analyses, morphological ordinations, ancestral state reconstructions, and a character mapping simulation were conducted to reveal key patterns in the direction and lability of floral characters associated with pollination. We found significant floral morphological differences among species that were generally associated with different groups of floral visitors. Floral evolution has been highly labile and also directional. Some specialized systems such as hawkmoth or bat pollination are likely evolutionary dead-ends. In contrast, specialized pollination by hummingbirds is clearly not a dead-end. We found evidence for multiple reverse transitions from presumed ancestral hummingbird pollination to more derived bee or insect pollination. These repeated origins of insect pollination from hummingbird-pollinated ancestors have not evolved without historical baggage. Flowers of insect-pollinated species derived from hummingbird-pollinated ancestors are morphologically more similar to hummingbird flowers than they are to other more distantly related insect-pollinated flowers. Finally, some pollinator switches were concomitant with changes in floral morphology that are associated with those pollinators. These observations are consistent with the hypothesis that some transitions have been adaptive in the evolution of Ruellia.

Towards a sterile insect technique field release of Anopheles arabiensis mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation

PubMed Central

Helinski, Michelle EH; Hassan, Mo'awia M; El-Motasim, Waleed M; Malcolm, Colin A; Knols, Bart GJ; El-Sayed, Badria

2008-01-01

Background The work described in this article forms part of a study to suppress a population of the malaria vector Anopheles arabiensis in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described. Methods Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed. Results Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality (< 6%). Experiments in the field cage showed that mating occurred in high frequencies (i.e. an average of 60% insemination of females after one or two nights of mating), and laboratory reared males (i.e. sixty generations) were able to inseminate wild females at rates comparable to wild males. Based on wing length data, there was no size preference of males for mates. Survival of mosquitoes from the cage, based on recapture after mating, was satisfactory and approximately 60% of the insects were recaptured after one night. Only limited information on male competitiveness was obtained due to problems associated with individual egg laying of small numbers of wild females. Conclusion It is concluded that although conditions are challenging, there are no major obstacles associated with the small-scale irradiation and transportation of insects in the current setting. The field cage is suitable for experiments and studies to test the competitiveness of irradiated males can be pursued. The scaling up of procedures to accommodate much larger numbers of insects needed for a release is the next challenge and recommendations to further implementation of this genetic control strategy are presented. PMID:18439238

Laboratory evaluation on a potential birth control diet for fruit fly sterile insect technique (SIT).

PubMed

Chang, Chiou Ling

2017-08-01

Sterile insect technique (SIT) is one of the most effective fruit fly control technologies. Irradiation has been used to sterilize male fruit flies before release to the field to compete with the wild males for females. Imagine an environmental and cost effective method using a rearing diet that can make insects sterile indefinitely, by feeding for 7days before release. This could replace costly irradiation process. A potential birth control diet was evaluated on fertility, mating, survival, and protein analysis for fruit fly species in Hawaii. Insects were continuously fed an agar diet with lufenuron (LFN) for 7d after emergence and then switched to a control diet to simulate the actual field condition. The influence on egg hatch was dose dependent. With dose of 2-4mg/g in the diet, egg hatch from LFN-fed was almost 100% suppressed for 24 experimental days if adults of Ceratitia capitate (Widemann), Bactrocera dorsalis (Hendel), and B. latifrons (Hendel) continued to feed on LFN diet. B. cucurbitae (Coquillett) was not affected by LFN. However, egg hatch from LFN fed B. latifrons and B. dorsalis were suppressed for at least 2weeks after switching to the control diet at 7d. Egg hatch did not recover >4% up to 24d. Proteome analysis revealed that ABD-4 protein was under expressed by 70-83% on LFN fed females and males of B. latifrons and B. dorsalis while Pbprp2 protein was significantly over expressed by 6-12 fold on LFN fed males only. These two proteins were not expressed in C. capitata and B. cucurbitae. Therefore, this report focused more on B. latifrons and B. dorsalis. This finding suggested a great potential for one alternative to sterilize fruit flies for SIT without irradiation. Published by Elsevier Inc.

Modeling the cost-effectiveness of insect rearing on artificial diets: A test with a tephritid fly used in the sterile insect technique.

PubMed

Pascacio-Villafán, Carlos; Birke, Andrea; Williams, Trevor; Aluja, Martín

2017-01-01

We modeled the cost-effectiveness of rearing Anastrepha ludens, a major fruit fly pest currently mass reared for sterilization and release in pest control programs implementing the sterile insect technique (SIT). An optimization model was generated by combining response surface models of artificial diet cost savings with models of A. ludens pupation, pupal weight, larval development time and adult emergence as a function of mixtures of yeast, a costly ingredient, with corn flour and corncob fractions in the diet. Our model revealed several yeast-reduced mixtures that could be used to prepare diets that were considerably cheaper than a standard diet used for mass rearing. Models predicted a similar production of insects (pupation and adult emergence), with statistically similar pupal weights and larval development times between yeast-reduced diets and the standard mass rearing diet formulation. Annual savings from using the modified diets could be up to 5.9% of the annual cost of yeast, corn flour and corncob fractions used in the standard diet, representing a potential saving of US $27.45 per ton of diet (US $47,496 in the case of the mean annual production of 1,730.29 tons of artificial diet in the Moscafrut mass rearing facility at Metapa, Chiapas, Mexico). Implementation of the yeast-reduced diet on an experimental scale at mass rearing facilities is still required to confirm the suitability of new mixtures of artificial diet for rearing A. ludens for use in SIT. This should include the examination of critical quality control parameters of flies such as adult flight ability, starvation resistance and male sexual competitiveness across various generations. The method used here could be useful for improving the cost-effectiveness of invertebrate or vertebrate mass rearing diets worldwide.

Modeling the cost-effectiveness of insect rearing on artificial diets: A test with a tephritid fly used in the sterile insect technique

PubMed Central

Birke, Andrea; Williams, Trevor; Aluja, Martín

2017-01-01

We modeled the cost-effectiveness of rearing Anastrepha ludens, a major fruit fly pest currently mass reared for sterilization and release in pest control programs implementing the sterile insect technique (SIT). An optimization model was generated by combining response surface models of artificial diet cost savings with models of A. ludens pupation, pupal weight, larval development time and adult emergence as a function of mixtures of yeast, a costly ingredient, with corn flour and corncob fractions in the diet. Our model revealed several yeast-reduced mixtures that could be used to prepare diets that were considerably cheaper than a standard diet used for mass rearing. Models predicted a similar production of insects (pupation and adult emergence), with statistically similar pupal weights and larval development times between yeast-reduced diets and the standard mass rearing diet formulation. Annual savings from using the modified diets could be up to 5.9% of the annual cost of yeast, corn flour and corncob fractions used in the standard diet, representing a potential saving of US $27.45 per ton of diet (US $47,496 in the case of the mean annual production of 1,730.29 tons of artificial diet in the Moscafrut mass rearing facility at Metapa, Chiapas, Mexico). Implementation of the yeast-reduced diet on an experimental scale at mass rearing facilities is still required to confirm the suitability of new mixtures of artificial diet for rearing A. ludens for use in SIT. This should include the examination of critical quality control parameters of flies such as adult flight ability, starvation resistance and male sexual competitiveness across various generations. The method used here could be useful for improving the cost-effectiveness of invertebrate or vertebrate mass rearing diets worldwide. PMID:28257496

Thermal biology, population fluctuations and implications of temperature extremes for the management of two globally significant insect pests.

PubMed

Nyamukondiwa, Casper; Weldon, Christopher W; Chown, Steven L; le Roux, Peter C; Terblanche, John S

2013-12-01

The link between environmental temperature, physiological processes and population fluctuations is a significant aspect of insect pest management. Here, we explore how thermal biology affects the population abundance of two globally significant pest fruit fly species, Ceratitis capitata (medfly) and C. rosa (Natal fruit fly), including irradiated individuals and those expressing a temperature sensitive lethal (tsl) mutation that are used in the sterile insect technique. Results show that upper and lower lethal temperatures are seldom encountered at the field sites, while critical minimum temperatures for activity and lower developmental thresholds are crossed more frequently. Estimates of abundance revealed that C. capitata are active year-round, but abundance declines markedly during winter. Temporal autocorrelation of average fortnightly trap captures and of development time, estimated from an integrated model to calculate available degree days, show similar seasonal lags suggesting that population increases in early spring occur after sufficient degree-days have accumulated. By contrast, population collapses coincide tightly with increasing frequency of low temperature events that fall below critical minimum temperatures for activity. Individuals of C. capitata expressing the tsl mutation show greater critical thermal maxima and greater longevity under field conditions than reference individuals. Taken together, this evidence suggests that low temperatures limit populations in the Western Cape, South Africa and likely do so elsewhere. Increasing temperature extremes and warming climates generally may extend the season over which these species are active, and could increase abundance. The sterile insect technique may prove profitable as climates change given that laboratory-reared tsl flies have an advantage under warmer conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Perspective on the combined use of an independent transgenic sexing and a multifactorial reproductive sterility system to avoid resistance development against transgenic Sterile Insect Technique approaches

PubMed Central

2014-01-01

Background The Sterile Insect Technique (SIT) is an accepted species-specific genetic control approach that acts as an insect birth control measure, which can be improved by biotechnological engineering to facilitate its use and widen its applicability. First transgenic insects carrying a single killing system have already been released in small scale trials. However, to evade resistance development to such transgenic approaches, completely independent ways of transgenic killing should be established and combined. Perspective Most established transgenic sexing and reproductive sterility systems are based on the binary tTA expression system that can be suppressed by adding tetracycline to the food. However, to create 'redundant killing' an additional independent conditional expression system is required. Here we present a perspective on the use of a second food-controllable binary expression system - the inducible Q system - that could be used in combination with site-specific recombinases to generate independent transgenic killing systems. We propose the combination of an already established transgenic embryonic sexing system to meet the SIT requirement of male-only releases based on the repressible tTA system together with a redundant male-specific reproductive sterility system, which is activated by Q-system controlled site-specific recombination and is based on a spermatogenesis-specifically expressed endonuclease acting on several species-specific target sites leading to chromosome shredding. Conclusion A combination of a completely independent transgenic sexing and a redundant reproductive male sterility system, which do not share any active components and mediate the induced lethality by completely independent processes, would meet the 'redundant killing' criteria for suppression of resistance development and could therefore be employed in large scale long-term suppression programs using biotechnologically enhanced SIT. PMID:25471733

The Role of Forest Tent Caterpillar Defoliations and Partial Harvest in the Decline and Death of Sugar Maple

PubMed Central

Hartmann, Henrik; Messier, Christian

2008-01-01

Background and Aims Natural and anthropogenic disturbances can act as stresses on tree vigour. According to Manion's conceptual model of tree disease, the initial vigour of trees decreases as a result of predisposing factors that render these trees more vulnerable to severe inciting stresses, stresses that can then cause final vigour decline and subsequent tree death. This tree disease model was tested in sugar maple (Acer saccharum) by assessing the roles of natural and anthropogenic disturbances in tree decline and death. Methods Radial growth data from 377 sugar maple trees that had undergone both defoliations by insects and partial harvest were used to estimate longitudinal survival probabilities as a proxy for tree vigour. Radial growth rates and survival probabilities were compared among trees subjected to different levels of above- and below-ground disturbances, between periods of defoliation and harvest, and between live and dead trees. Key Results Manion's tree disease model correctly accounts for vigour decline and tree death in sugar maple; tree growth and vigour were negatively affected by a first defoliation, predisposing these trees to death later during the study period due to a second insect outbreak that initiated a final vigour decline. This decline was accelerated by the partial harvest disturbance in 1993. Even the most severe anthropogenic disturbances from partial harvest did not cause, unlike insect defoliation, any growth or vigour declines in live sugar maple. Conclusions Natural disturbances acted as predisposing and inciting stresses in tree sugar maple decline and death. Anthropogenic disturbances from a partial harvest at worst accelerated a decline in trees that were already weakened by predisposing and inciting stresses (i.e. repeated insect defoliations). Favourable climatic conditions just before and after the partial harvest may have alleviated possible negative effects on growth resulting from harvesting. PMID:18660493

Modelling density-dependent resistance in insect-pathogen interactions.

PubMed

White, K A; Wilson, K

1999-10-01

We consider a mathematical model for a host-pathogen interaction where the host population is split into two categories: those susceptible to disease and those resistant to disease. Since the model was motivated by studies on insect populations, we consider a discrete-time model to reflect the discrete generations which are common among insect species. Whether an individual is born susceptible or resistant to disease depends on the local population levels at the start of each generation. In particular, we are interested in the case where the fraction of resistant individuals in the population increases as the total population increases. This may be seen as a positive feedback mechanism since disease is the only population control imposed upon the system. Moreover, it reflects recent experimental observations from noctuid moth-baculovirus interactions that pathogen resistance may increase with larval density. We find that the inclusion of a resistant class can stabilise unstable host-pathogen interactions but there is greatest regulation when the fraction born resistant is density independent. Nonetheless, inclusion of density dependence can still allow intrinsically unstable host-pathogen dynamics to be stabilised provided that this effect is sufficiently small. Moreover, inclusion of density-dependent resistance to disease allows the system to give rise to bistable dynamics in which the final outcome is dictated by the initial conditions for the model system. This has implications for the management of agricultural pests using biocontrol agents-in particular, it is suggested that the propensity for density-dependent resistance be determined prior to such a biocontrol attempt in order to be sure that this will result in the prevention of pest outbreaks, rather than their facilitation. Finally we consider how the cost of resistance to disease affects model outcomes and discover that when there is no cost to resistance, the model predicts stable periodic outbreaks of the insect population. The results are interpreted ecologically and future avenues for research to address the shortfalls in the present model system are discussed. Copyright 1999 Academic Press.

Aggression in Tephritidae Flies: Where, When, Why? Future Directions for Research in Integrated Pest Management.

PubMed

Benelli, Giovanni

2014-12-30

True fruit flies (Diptera: Tephritidae) include over 4000 species, many of which constitute enormous threats to fruit and vegetable production worldwide. A number of Tephritidae are lekking species, forming aggregations in which males fight to defend a small territory where they court females and mate. Male-male contests also occur in non-lekking species, characterized by resource defense polygyny. Tephritidae females display agonistic behavior to maintain single oviposition sites and reduce larval competition for food. Here, how, where, when and why aggressive interactions occur in Tephritidae flies is reviewed. A number of neglected issues deserving further research are highlighted, with a special focus on diel periodicity of aggression, cues evoking aggressive behavior, the role of previous experience on fighting success and the evolution of behavioral lateralization of aggressive displays. In the final section, future directions to exploit this knowledge in Integrated Pest Management, with particular emphasis on enhancement of Sterile Insect Technique and interspecific competitive displacement in the field are suggested.

Aggression in Tephritidae Flies: Where, When, Why? Future Directions for Research in Integrated Pest Management

PubMed Central

Benelli, Giovanni

2014-01-01

True fruit flies (Diptera: Tephritidae) include over 4000 species, many of which constitute enormous threats to fruit and vegetable production worldwide. A number of Tephritidae are lekking species, forming aggregations in which males fight to defend a small territory where they court females and mate. Male-male contests also occur in non-lekking species, characterized by resource defense polygyny. Tephritidae females display agonistic behavior to maintain single oviposition sites and reduce larval competition for food. Here, how, where, when and why aggressive interactions occur in Tephritidae flies is reviewed. A number of neglected issues deserving further research are highlighted, with a special focus on diel periodicity of aggression, cues evoking aggressive behavior, the role of previous experience on fighting success and the evolution of behavioral lateralization of aggressive displays. In the final section, future directions to exploit this knowledge in Integrated Pest Management, with particular emphasis on enhancement of Sterile Insect Technique and interspecific competitive displacement in the field are suggested. PMID:26463064

The extraembryonic serosa protects the insect egg against desiccation

PubMed Central

Jacobs, Chris G. C.; Rezende, Gustavo L.; Lamers, Gerda E. M.; van der Zee, Maurijn

2013-01-01

Insects have been extraordinarily successful in occupying terrestrial habitats, in contrast to their mostly aquatic sister group, the crustaceans. This success is typically attributed to adult traits such as flight, whereas little attention has been paid to adaptation of the egg. An evolutionary novelty of insect eggs is the serosa, an extraembryonic membrane that enfolds the embryo and secretes a cuticle. To experimentally test the protective function of the serosa, we exploit an exceptional possibility to eliminate this membrane by zerknüllt1 RNAi in the beetle Tribolium castaneum. We analyse hatching rates of eggs under a range of humidities and find dramatically decreasing hatching rates with decreasing humidities for serosa-less eggs, but not for control eggs. Furthermore, we show serosal expression of Tc-chitin-synthase1 and demonstrate that its knock-down leads to absence of the serosal cuticle and a reduction in hatching rates at low humidities. These developmental genetic techniques in combination with ecological testing provide experimental evidence for a crucial role of the serosa in desiccation resistance. We propose that the origin of this extraembryonic membrane facilitated the spectacular radiation of insects on land, as did the origin of the amniote egg in the terrestrial invasion of vertebrates. PMID:23782888

Biology Notes.

ERIC Educational Resources Information Center

School Science Review, 1981

1981-01-01

Presents a computer program for analyzing diets, a game designed to supplement a topic on insects, a technique for demonstrating the role of ethene in fruit ripening, an apparatus for removing arthropods from soil samples, activities using cichlids, and an activity on bonds stabilizing protein structure. (JN)

Introductory Laboratory Exercises in Radiobiology

ERIC Educational Resources Information Center

Williams, J. R. Parry; Servant, D. M.

1970-01-01

Describes experiments suitable for introducing use of radioisotopes in biology. Includes demonstrations of tracing food chains, uptake of ions by plants, concentration of elements by insects, tracing photosynthetic reactions, activation analysis of copper, and somatic and genetic effects. Uses autoradiographic and counting techniques. (AL)

The Total Termite.

ERIC Educational Resources Information Center

Prestwich, Glenn D.

1982-01-01

Provides information on collecting and maintaining termites and for using these insects in behavioral studies (trail following, recognition, food choice, reproductive behavior, and behavior in a magnetic field) and termite control experiments (preventive construction techniques, termite repellents, using soil or wood pretreatment, and the bait…

The role of reduced oxygen in the developmental physiology of growth and metamorphosis initiation in Drosophila

USDA-ARS?s Scientific Manuscript database

Rearing oxygen level is known to affect final body size in a variety of insects, but the physiological mechanisms by which oxygen affects size are incompletely understood. In Manduca and Drosophila, the larval size at which metamorphosis is initiated largely determines adult size, and metamorphosis ...

Applicator Training Manual for: Ornamental and Turf Pest Control.

ERIC Educational Resources Information Center

Hartman, John R.; And Others

Contained in this manual are descriptions of the reaction of ornamental plants to diseases caused by fungi, bacteria, and viruses and mycoplasmas. Also described are insects which are associated with ornamentals. Examples of weeds found in ornamental or turf areas, such as crabgrass and chickweed, are described as well. Finally information is…

Chapter 5:Biological Properties of Wood

Treesearch

Rebecca E. Ibach

2013-01-01

There are numerous biological degradations that wood is exposed to in various environments. Biological damage occurs when a log, sawn product, or final product is not stored, handled, or designed properly. Biological organisms such as bacteria, mold, stain, decay fungi, insects, and marine borers depend heavily on temperature and moisture conditions to grow. Figure 5.1...

A Novel Methodology for Improving Plant Pest Surveillance in Vineyards and Crops Using UAV-Based Hyperspectral and Spatial Data

PubMed Central

Vanegas, Fernando; Weiss, John; Gonzalez, Felipe

2018-01-01

Recent advances in remote sensed imagery and geospatial image processing using unmanned aerial vehicles (UAVs) have enabled the rapid and ongoing development of monitoring tools for crop management and the detection/surveillance of insect pests. This paper describes a (UAV) remote sensing-based methodology to increase the efficiency of existing surveillance practices (human inspectors and insect traps) for detecting pest infestations (e.g., grape phylloxera in vineyards). The methodology uses a UAV integrated with advanced digital hyperspectral, multispectral, and RGB sensors. We implemented the methodology for the development of a predictive model for phylloxera detection. In this method, we explore the combination of airborne RGB, multispectral, and hyperspectral imagery with ground-based data at two separate time periods and under different levels of phylloxera infestation. We describe the technology used—the sensors, the UAV, and the flight operations—the processing workflow of the datasets from each imagery type, and the methods for combining multiple airborne with ground-based datasets. Finally, we present relevant results of correlation between the different processed datasets. The objective of this research is to develop a novel methodology for collecting, processing, analysing and integrating multispectral, hyperspectral, ground and spatial data to remote sense different variables in different applications, such as, in this case, plant pest surveillance. The development of such methodology would provide researchers, agronomists, and UAV practitioners reliable data collection protocols and methods to achieve faster processing techniques and integrate multiple sources of data in diverse remote sensing applications. PMID:29342101

Gabor fusion master slave optical coherence tomography

PubMed Central

Cernat, Ramona; Bradu, Adrian; Israelsen, Niels Møller; Bang, Ole; Rivet, Sylvain; Keane, Pearse A.; Heath, David-Garway; Rajendram, Ranjan; Podoleanu, Adrian

2017-01-01

This paper describes the application of the Gabor filtering protocol to a Master/Slave (MS) swept source optical coherence tomography (SS)-OCT system at 1300 nm. The MS-OCT system delivers information from selected depths, a property that allows operation similar to that of a time domain OCT system, where dynamic focusing is possible. The Gabor filtering processing following collection of multiple data from different focus positions is different from that utilized by a conventional swept source OCT system using a Fast Fourier transform (FFT) to produce an A-scan. Instead of selecting the bright parts of A-scans for each focus position, to be placed in a final B-scan image (or in a final volume), and discarding the rest, the MS principle can be employed to advantageously deliver signal from the depths within each focus range only. The MS procedure is illustrated on creating volumes of data of constant transversal resolution from a cucumber and from an insect by repeating data acquisition for 4 different focus positions. In addition, advantage is taken from the tolerance to dispersion of the MS principle that allows automatic compensation for dispersion created by layers above the object of interest. By combining the two techniques, Gabor filtering and Master/Slave, a powerful imaging instrument is demonstrated. The master/slave technique allows simultaneous display of three categories of images in one frame: multiple depth en-face OCT images, two cross-sectional OCT images and a confocal like image obtained by averaging the en-face ones. We also demonstrate the superiority of MS-OCT over its FFT based counterpart when used with a Gabor filtering OCT instrument in terms of the speed of assembling the fused volume. For our case, we show that when more than 4 focus positions are required to produce the final volume, MS is faster than the conventional FFT based procedure. PMID:28270987

The role of Broad in the development of Tribolium castaneum: implications for the evolution of the holometabolous insect pupa.

PubMed

Suzuki, Yuichiro; Truman, James W; Riddiford, Lynn M

2008-02-01

The evolution of complete metamorphosis in insects is a key innovation that has led to the successful diversification of holometabolous insects, yet the origin of the pupa remains an enigma. Here, we analyzed the expression of the pupal specifier gene broad (br), and the effect on br of isoform-specific, double-stranded RNA-mediated silencing, in a basal holometabolous insect, the beetle Tribolium castaneum. All five isoforms are weakly expressed during the penultimate instar and highly expressed during the prepupal period of the final instar. Application of hydroprene, a juvenile hormone analog, during the penultimate instar caused a repeat of the penultimate br expression patterns, and the formation of supernumerary larvae. Use of dsRNA against the br core region, or against a pair of either the br-Z2 or br-Z3 isoform with the br-Z1 or br-Z4 isoform, produced mobile animals with well-differentiated adult-like appendages, but which retained larval-like urogomphi and epidermis. Disruption of either the br-Z2 or the br-Z3 isoform caused the formation of shorter wings. Disruption of both br-Z1 and br-Z4 caused the appearance of pupal traits in the adults, but disruption of br-Z5 had no morphological effect. Our findings show that the br isoform functions are broadly conserved within the Holometabola and suggest that evolution of br isoform expression may have played an important role in the evolution of the pupa in holometabolous insects.

Exploitation of the Medfly Gut Microbiota for the Enhancement of Sterile Insect Technique: Use of Enterobacter sp. in Larval Diet-Based Probiotic Applications

PubMed Central

Papadopoulos, Nikos T.; Abd-Alla, Adly M. M.; Cáceres, Carlos; Bourtzis, Kostas

2015-01-01

The Mediterranean fruit fly (medfly), Ceratitis capitata, is a pest of worldwide substantial economic importance, as well as a Tephritidae model for sterile insect technique (SIT) applications. The latter is partially due to the development and utilization of genetic sexing strains (GSS) for this species, such as the Vienna 8 strain, which is currently used in mass rearing facilities worldwide. Improving the performance of such a strain both in mass rearing facilities and in the field could significantly enhance the efficacy of SIT and reduce operational costs. Recent studies have suggested that the manipulation of gut symbionts can have a significant positive effect on the overall fitness of insect strains. We used culture-based approaches to isolate and characterize gut-associated bacterial species of the Vienna 8 strain under mass rearing conditions. We also exploited one of the isolated bacterial species, Enterobacter sp., as dietary supplement (probiotic) to the larval diet, and we assessed its effects on fitness parameters under the standard operating procedures used in SIT operational programs. Probiotic application of Enterobacter sp. resulted in improvement of both pupal and adult productivity, as well as reduced rearing duration, particularly for males, without affecting pupal weight, sex ratio, male mating competitiveness, flight ability and longevity under starvation. PMID:26325068

Research Advances in the Screwworm Eradication Program over the Past 25 Years

USDA-ARS?s Scientific Manuscript database

Screwworms, Cochliomyia hominivorax (Coquerel) (Calliphoridae: Chrysomyinae), are devastating pests of warm blooded animals that cause significant economic damage to livestock. The successful campaign to eradicate screwworms from continental North America using the sterile insect technique, led by t...

USDA ARS research on the screwworm fly

USDA-ARS?s Scientific Manuscript database

Screwworm myiasis is devastating to warm blooded animals. Eradication of the screwworm from mainland North America using the sterile insect technique is an unprecedented achievement; reinvasion is prevented by maintenance of a barrier at the Panama – Colombia border. Here we update research progress...

Screwworm ecology from field observations to satellite imagery

USDA-ARS?s Scientific Manuscript database

Screwworm fly, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), in its larval stage is a parasite of warm-blooded animals. Screwworm has been successfully eradicated from the United Sates and Central America using the sterile insect technique. Here we present how the field observations o...

Molecular genetics for identification and population studies of screwworms

USDA-ARS?s Scientific Manuscript database

Screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were devastating pests to all warm blooded animals in the United States and the rest of North America. Successful eradication of screwworms was achieved by using the sterile insect technique. Here we discussed the development a...

Transcriptome analysis in cotton boll weevil (Anthonomus grandis) and RNA interference in insect pests.

PubMed

Firmino, Alexandre Augusto Pereira; Fonseca, Fernando Campos de Assis; de Macedo, Leonardo Lima Pepino; Coelho, Roberta Ramos; Antonino de Souza, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

2013-01-01

Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

Transcriptome Analysis in Cotton Boll Weevil (Anthonomus grandis) and RNA Interference in Insect Pests

PubMed Central

Coelho, Roberta Ramos; Antonino de Souza Jr, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas-Jr, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

2013-01-01

Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families’ data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects. PMID:24386449

Explorative study of tropical pitcher plants (Nepenthes sp.) types and insects that trapped inside in Sebangau National Park Palangka Raya Central Kalimantan

NASA Astrophysics Data System (ADS)

Lestariningsih, Nanik; Setyaningsih, Denik

2017-01-01

Pitcher plants (Nepenthes sp.) is a plant with unique shape either of shades of colors, pouch shape and its capability in catching insects. Pitcher plant (Nepenthes sp.) is one of the plants that protected under Law Number. 5 of 1990 about Conservation of Biological Resources and Ecosystem and Government Regulation Number 7/1999 about Preservation of Plants and Animals. Sebangau National Park is one of representative of peat swamp ecosystem and one of some types of pitcher plants (Nepenthes sp.) habitat. This study aimed to determine the types and diversity levels of pitcher plants (Nepenthes sp.) and the trapped insects inside in Sebangau National and to determine the differences of diversity levels of pitcher plants (Nepenthes sp.) and the trapped insects inside in the opened and closed forest in Sebangau National Park. The research type was conducted descriptive qualitative research. The method used survey method with purpossive sampling technique.The result of the study the number of pitcher plants (Nepenthes sp.) obtained in opened forest were three types consist of Nepenthes mirabilis, Nepenthes rafflesiana and Nepenthes gracilis with two types insects trapped inside those were Diptera ordo and Hymenoptera ordo. While the number of pitcher plants (Nepenthes sp.) obtained in closed forest as many as two types consist of Nepenthes ampullaria and Nepenthes rafflesiana with two type insects trapped inside those were Diptera ordo and Hymenoptera ordo. The results of the analysis calculation pitcher plants (Nepenthes sp.) species diversity index in opened and closed forest showed lower category. The diversity in row were 1 and 0,45 with H’ criteria ≤ 1 low diversity. The results of the study of insects trapped inside of pitcher plants (Nepenthes sp.) obtained in opened and closed forest showed low category. The diversity in a row were 0,63 and 0,52 with the criteria of H’ ≤ 1 low diversity.

Novel Epoxy Particulate Composites for Mitigation of Insect Residue Adhesion on Future Aircraft Surfaces

NASA Technical Reports Server (NTRS)

Wohl, Christopher J.; Smith, Joseph G., Jr.; Gardner, John M.; Penner, Ronald K.; Connell, John W.; Siochi, Emilie J.

2014-01-01

Drag is reduced significantly for airflow over surfaces when laminar flow can be maintained over greater chord lengths, the distance from the leading edge of an airfoil.1 However, surface imperfections, such as chipped paint, scratches, and events that change topography on a microscopic scale can introduce airflow instabilities resulting in premature transition to turbulent flow.1 Although many of these surface imperfections can be avoided with proper maintenance, advanced materials, and advanced manufacturing practices, topographical surface anomalies arising during flight from insect impacts cannot be controlled and can influence laminar flow stability. Practical solutions to this operational challenge need to be developed for future aircraft to have full advantage of laminar flow designs that improve fuel efficiency.2 Researchers have investigated various methods to mitigate insect residue adhesion for decades.3 Although several techniques have demonstrated efficacy including mechanical scrapers, active liquid discharge systems, and sacrificial paper coatings, they have not been commercially implemented due to increased manufacturing and operational complexity, environmental impact, and weight penalties. Coatings offer a simple route for passive insect residue adhesion prevention without many of the challenges associated with maintenance of laminar flow.4 In our previous work, we determined that most commercially available materials were not effective at insect residue adhesion.5 We also identified improvements when both surface energy could be controlled by surface modifying agents and the topography could be altered through the use of micron-sized and nanometer-sized filler materials.6 In this work, these general principles were applied to an epoxy system to evaluate the behavior of the surface modifying agent, a fluorinated alkyl ether oligomer, on surface energy and insect residue adhesion properties.

Testing for the Effects and Consequences of Mid Paleogene Climate Change on Insect Herbivory

PubMed Central

Wappler, Torsten; Labandeira, Conrad C.; Rust, Jes; Frankenhäuser, Herbert; Wilde, Volker

2012-01-01

Background The Eocene, a time of fluctuating environmental change and biome evolution, was generally driven by exceptionally warm temperatures. The Messel (47.8 Ma) and Eckfeld (44.3 Ma) deposits offer a rare opportunity to take a census of two, deep-time ecosystems occurring during a greenhouse system. An understanding of the long-term consequences of extreme warming and cooling events during this interval, particularly on angiosperms and insects that dominate terrestrial biodiversity, can provide insights into the biotic consequences of current global climatic warming. Methodology/Principal Findings We compare insect-feeding damage within two middle Eocene fossil floras, Messel and Eckfeld, in Germany. From these small lake deposits, we studied 16,082 angiosperm leaves and scored each specimen for the presence or absence of 89 distinctive and diagnosable insect damage types (DTs), each of which was allocated to a major functional feeding group, including four varieties of external foliage feeding, piercing- and-sucking, leaf mining, galling, seed predation, and oviposition. Methods used for treatment of presence–absence data included general linear models and standard univariate, bivariate and multivariate statistical techniques. Conclusions/Significance Our results show an unexpectedly high diversity and level of insect feeding than comparable, penecontemporaneous floras from North and South America. In addition, we found a higher level of herbivory on evergreen, rather than deciduous taxa at Messel. This pattern is explained by a ca. 2.5-fold increase in atmospheric CO2 that overwhelmed evergreen antiherbivore defenses, subsequently lessened during the more ameliorated levels of Eckfeld times. These patterns reveal important, previously undocumented features of plant-host and insect-herbivore diversification during the European mid Eocene. PMID:22815805

Discovery of a novel mastrevirus and alphasatellite-like circular DNA in dragonflies (Epiprocta) from Puerto Rico.

PubMed

Rosario, Karyna; Padilla-Rodriguez, Marco; Kraberger, Simona; Stainton, Daisy; Martin, Darren P; Breitbart, Mya; Varsani, Arvind

2013-01-01

Geminiviruses have emerged as serious agricultural pathogens. Despite all the species that have been already catalogued, new molecular techniques continue to expand the diversity and geographical ranges of these single-stranded DNA viruses and their associated satellite molecules. Since all geminiviruses are insect-transmitted, examination of insect vector populations through vector-enabled metagenomics (VEM) has been recently used to investigate the diversity of geminiviruses transmitted by a specific vector in a given region. Here we used a more comprehensive adaptation of the VEM approach by surveying small circular DNA viruses found within top insect predators, specifically dragonflies (Epiprocta). This 'predator-enabled' approach is not limited to viral groups transmitted by specific vectors since dragonflies can accumulate the wide range of viruses transmitted by their diverse insect prey. Analysis of six dragonflies collected from an agricultural field in Puerto Rico culminated in the discovery of the first mastrevirus (Dragonfly-associated mastrevirus; DfasMV) and alphasatellite molecule (Dragonfly-associated alphasatellite; Dfas-alphasatellite) from the Caribbean. Since DfasMV and Dfas-alphasatellite are divergent from the limited number of sequences that have been reported from the Americas, this study unequivocally demonstrates that there have been at least two independent past introductions of both mastreviruses and alphasatellites to the New World. Overall, the use of predacious insects as sampling tools can profoundly alter our views of natural plant virus diversity and biogeography by allowing the discovery of novel geminiviruses and associated satellite molecules without a priori knowledge of the types of viruses or insect vectors in a given area. Copyright © 2012 Elsevier B.V. All rights reserved.

A promising biotechnical approach to pest management of Diabrotica virgifera virgifera in Illinois maize fields under kairomonal shielding with the new MSD technique.

PubMed

Hummel, H E; Shaw, J T; Hein, D F

2005-01-01

Environmentally compatible and sustainable plant protection requires novel approaches to pest management characterized by minimal emphasis on toxicants. Classical toxicants traditionally dominated economic entomology for half a century. But worldwide problems with environmental pollution and with increasing resistance levels in all major pesticide classes and in many key insect species including Diabrotica virgifera virgifera (D.v.v.) strongly advocate a rethinking and a change in management paradigms used. Soft, minimally invasive, biological, biotechnical and cultural approaches should replace hard pesticides which are in favor up to now. Fortunately, pheromones, kairomones, plant attractants, better traps, new plant varieties and cultural methods like crop rotation, in short more sophisticated methods are now available as pressure for finding and exploring novel strategies increases. Facing this situation, a new biotechnical approach of population reduction of D.v.v., called "MSD" technique, is introduced. MSD is characterized as an approach combining mass trapping, shielding and deflecting of adult insects along an invisible odor barrier of synthetic kairomone which diminishes the flux of insects across a high capacity trap line baited with kairomone, thus reducing both the population fluctuation and number and its reproductive success within the shielded area. In the case of D.v.v. in Zea mays fields, effects realized by the MSD technique have been measured simultaneously by a number of independent criteria during the summers of 2003 and 2004 at 2 different locations in Illinois maize fields of up to one half hectare size. Results observed are statistically significant and cannot be explained by mass trapping alone. There is also an additional shielding and deflection, in short "diversion" effect whose basic sensory and behavioral mechanisms call for future exploration.

Combining the Sterile Insect Technique with Wolbachia-Based Approaches: II- A Safer Approach to Aedes albopictus Population Suppression Programmes, Designed to Minimize the Consequences of Inadvertent Female Release

PubMed Central

Zhang, Dongjing; Lees, Rosemary Susan; Xi, Zhiyong; Gilles, Jeremie R. L.; Bourtzis, Kostas

2015-01-01

Due to the absence of a perfect method for mosquito sex separation, the combination of the sterile insect technique and the incompatible insect technique is now being considered as a potentially effective method to control Aedes albopictus. In this present study first we examine the minimum pupal irradiation dose required to induce complete sterility in Wolbachia triple-infected (HC), double-infected (GUA) and uninfected (GT) female Ae. albopictus. The HC line is a candidate for Ae. albopictus population suppression programmes, but due to the risk of population replacement which characterizes this triple infected line, the individuals to be released need to be additionally irradiated. After determining the minimum irradiation dose required for complete female sterility, we test whether sterilization is sufficient to prevent invasion of the triple infection from the HC females into double-infected (GUA) populations. Our results indicate that irradiated Ae. albopictus HC, GUA and GT strain females have decreased fecundity and egg hatch rate when irradiated, inversely proportional to the dose, and the complete sterilization of females can be acquired by pupal irradiation with doses above 28 Gy. PCR-based analysis of F1 and F2 progeny indicate that the irradiated HC females, cannot spread the new Wolbachia wPip strain into a small cage GUA population, released at a 1:5 ratio. Considering the above results, we conclude that irradiation can be used to reduce the risk of population replacement caused by an unintentional release of Wolbachia triple-infected Ae. albopictus HC strain females during male release for population suppression. PMID:26252474

Target tracking and 3D trajectory acquisition of cabbage butterfly (P. rapae) based on the KCF-BS algorithm.

PubMed

Guo, Yang-Yang; He, Dong-Jian; Liu, Cong

2018-06-25

Insect behaviour is an important research topic in plant protection. To study insect behaviour accurately, it is necessary to observe and record their flight trajectory quantitatively and precisely in three dimensions (3D). The goal of this research was to analyse frames extracted from videos using Kernelized Correlation Filters (KCF) and Background Subtraction (BS) (KCF-BS) to plot the 3D trajectory of cabbage butterfly (P. rapae). Considering the experimental environment with a wind tunnel, a quadrature binocular vision insect video capture system was designed and applied in this study. The KCF-BS algorithm was used to track the butterfly in video frames and obtain coordinates of the target centroid in two videos. Finally the 3D trajectory was calculated according to the matching relationship in the corresponding frames of two angles in the video. To verify the validity of the KCF-BS algorithm, Compressive Tracking (CT) and Spatio-Temporal Context Learning (STC) algorithms were performed. The results revealed that the KCF-BS tracking algorithm performed more favourably than CT and STC in terms of accuracy and robustness.

High entomotoxicity and mechanism of the fungal GalNAc/Gal-specific Rhizoctonia solani lectin in pest insects.

PubMed

Hamshou, Mohamad; Van Damme, Els J M; Caccia, Silvia; Cappelle, Kaat; Vandenborre, Gianni; Ghesquière, Bart; Gevaert, Kris; Smagghe, Guy

2013-03-01

Whole insect assays where Rhizoctonia solani agglutinin (RSA) was fed to larval stages of the cotton leaf-worm Spodoptera littoralis and the pea aphid Acyrthosiphon pisum demonstrated a high concentration-dependent entomotoxicity, suggesting that this GalNAc/Gal-specific fungal lectin might be a good control agent for different pest insects. RSA at 10 mg/g in the solid diet of 2nd-instar caterpillars caused 84% weight reduction after 8 days with none of the caterpillars reaching the 4th-instar stage. In sucking aphids, 50% mortality was achieved after 3 days with 9 μM of RSA in the liquid diet. Feeding of FITC-labeled RSA to both insect pest species revealed strong lectin binding at the apical/luminal side of the midgut epithelium with the brush border zone, suggesting the insect midgut as a primary insecticide target tissue for RSA. This was also confirmed with cell cultures in vitro, where there was high fluorescence binding at the microvillar zone with primary cultures of larval midgut columnar cells of S. littoralis, and also at the surface with the insect midgut CF-203 cell line without lectin uptake in the midgut cells. In vitro assays using insect midgut CF-203 cells, revealed that RSA was highly toxic with an EC50 of 0.3 μM. Preincubation with GalNAc and saponin indicated that this action of RSA was carbohydrate-binding dependent and happened at the surface of the cells. Intoxicated CF-203 cells showed symptoms of apoptosis as nuclear condensation and DNA fragmentation, and this concurred with an increase of caspase-3/7, -8 and -9 activities. Finally, RSA affinity chromatography of membrane extracts of CF-203 cells followed by LC-MS/MS allowed the identification of 5747 unique peptides, among which four putatively glycosylated membrane proteins that are associated with apoptosis induction, namely Fas-associated factor, Apoptosis-linked gene-2, Neuroglian and CG2076, as potential binding targets for RSA. These data are discussed in relation to the physiological effects of RSA. Copyright © 2012 Elsevier Ltd. All rights reserved.

Death Becomes Them: Bacterial Community Dynamics and Stilbene Antibiotic Production in Cadavers of Galleria mellonella Killed by Heterorhabditis and Photorhabdus spp.

PubMed Central

Wollenberg, Amanda C.; Slough, Greg; Hoinville, Megan E.

2016-01-01

ABSTRACT Insect larvae killed by entomopathogenic nematodes are thought to contain bacterial communities dominated by a single bacterial genus, that of the nematode's bacterial symbiont. In this study, we used next-generation sequencing to profile bacterial community dynamics in greater wax moth (Galleria mellonella) larvae cadavers killed by Heterorhabditis nematodes and their Photorhabdus symbionts. We found that, although Photorhabdus strains did initially displace an Enterococcus-dominated community present in uninfected G. mellonella insect larvae, the cadaver community was not static. Twelve days postinfection, Photorhabdus shared the cadaver with Stenotrophomonas species. Consistent with this result, Stenotrophomonas strains isolated from infected cadavers were resistant to Photorhabdus-mediated toxicity in solid coculture assays. We isolated and characterized a Photorhabdus-produced antibiotic from G. mellonella cadavers, produced it synthetically, and demonstrated that both the natural and synthetic compounds decreased G. mellonella-associated Enterococcus growth, but not Stenotrophomonas growth, in vitro. Finally, we showed that the Stenotrophomonas strains described here negatively affected Photorhabdus growth in vitro. Our results add an important dimension to a broader understanding of Heterorhabditis-Photorhabdus biology and also demonstrate that interspecific bacterial competition likely characterizes even a theoretically monoxenic environment, such as a Heterorhabditis-Photorhabdus-parasitized insect cadaver. IMPORTANCE Understanding, and eventually manipulating, both human and environmental health depends on a complete accounting of the forces that act on and shape microbial communities. One of these underlying forces is hypothesized to be resource competition. A resource that has received little attention in the general microbiological literature, but likely has ecological and evolutionary importance, is dead/decaying multicellular organisms. Metazoan cadavers, including those of insects, are ephemeral and nutrient-rich environments, where resource competition might shape interspecific macrobiotic and microbiotic interactions. This study is the first to use a next-generation sequencing approach to study the community dynamics of bacteria within a model insect cadaver system: insect larvae parasitized by entomopathogenic nematodes and their bacterial symbionts. By integrating bioinformatic, biochemical, and classic in vitro microbiological approaches, we have provided mechanistic insight into how antibiotic-mediated bacterial interactions may shape community dynamics within insect cadavers. PMID:27451445

Antigenic Properties and Diagnostic Potential of Baculovirus-Expressed Infectious Bursal Disease Virus Proteins VPX and VP3

PubMed Central

Martínez-Torrecuadrada, Jorge L.; Lázaro, Beatriz; Rodriguez, José F.; Casal, J. Ignacio

2000-01-01

The routine technique for detecting antibodies specific to infectious bursal disease virus (IBDV) is a serological evaluation by enzyme-linked immunosorbent assay (ELISA) with preparations of whole virions as the antigens. To avoid using complete virus in the standard technique, we have developed two new antigens through the expression of the VPX and VP3 genes in insect cells. VPX and especially VP3 were expressed at high levels in insect cells and simple to purify. The immunogenicity of both proteins was similar to that of the native virus. VPX was able to elicit neutralizing antibodies but VP3 was not. Purified VPX and VP3 were tested in an indirect ELISA with more than 300 chicken sera. There was an excellent correlation between the results of the ELISA using VPX and those of the two commercial kits. VP3 did not perform as well as VPX, and the linear correlation was significantly lower. A comparison with the standard reference technique, seroneutralization, showed that the indirect ELISA was more sensitive. Therefore, VPX-based ELISA is a good alternative to conventional ELISAs that use whole virions. PMID:10882666

Antigenic properties and diagnostic potential of baculovirus-expressed infectious bursal disease virus proteins VPX and VP3.

PubMed

Martínez-Torrecuadrada, J L; Lázaro, B; Rodriguez, J F; Casal, J I

2000-07-01

The routine technique for detecting antibodies specific to infectious bursal disease virus (IBDV) is a serological evaluation by enzyme-linked immunosorbent assay (ELISA) with preparations of whole virions as the antigens. To avoid using complete virus in the standard technique, we have developed two new antigens through the expression of the VPX and VP3 genes in insect cells. VPX and especially VP3 were expressed at high levels in insect cells and simple to purify. The immunogenicity of both proteins was similar to that of the native virus. VPX was able to elicit neutralizing antibodies but VP3 was not. Purified VPX and VP3 were tested in an indirect ELISA with more than 300 chicken sera. There was an excellent correlation between the results of the ELISA using VPX and those of the two commercial kits. VP3 did not perform as well as VPX, and the linear correlation was significantly lower. A comparison with the standard reference technique, seroneutralization, showed that the indirect ELISA was more sensitive. Therefore, VPX-based ELISA is a good alternative to conventional ELISAs that use whole virions.

Semiochemical mediated enhancement of males to complement sterile insect technique in management of the tephritid pest Bactrocera tryoni (Froggatt).

PubMed

Khan, Mohammed Abul Monjur; Manoukis, Nicholas C; Osborne, Terry; Barchia, Idris M; Gurr, Geoff M; Reynolds, Olivia L

2017-10-17

Queensland fruit fly, Bactrocera tryoni (Froggatt), is the most significant pest of Australia's $9 billion horticulture industry. The sterile insect technique (SIT) and cue-lure (a synthetic analogue of raspberry ketone (RK))-based male annihilation technique (MAT) are two of the most effective management tools against this pest. However, combining these two approaches is considered incompatible as MAT kills sterile and 'wild' males indiscriminately. In the present study we tested the effect of pre-release feeding of B. tryoni on RK on their post-release survival and response to MAT in field cages and in a commercial orchard. In both settings, survival was higher for RK supplemented adults compared to control (i.e. RK denied) adults. A lower number of RK supplemented sterile males were recaptured in MAT baited traps in both the field cages and orchard trials compared to RK denied sterile males. The advantage of this novel "male replacement" approach (relatively selective mortality of wild males at lure-baited traps while simultaneously releasing sterile males) is increasing the ratio of sterile to wild males in the field population, with potential for reducing the number of sterile males to be released.

Insecticide ADME for support of early-phase discovery: combining classical and modern techniques.

PubMed

David, Michael D

2017-04-01

The two factors that determine an insecticide's potency are its binding to a target site (intrinsic activity) and the ability of its active form to reach the target site (bioavailability). Bioavailability is dictated by the compound's stability and transport kinetics, which are determined by both physical and biochemical characteristics. At BASF Global Insecticide Research, we characterize bioavailability in early research with an ADME (Absorption, Distribution, Metabolism and Excretion) approach, combining classical and modern techniques. For biochemical assessment of metabolism, we purify native insect enzymes using classical techniques, and recombinantly express individual insect enzymes that are known to be relevant in insecticide metabolism and resistance. For analytical characterization of an experimental insecticide and its metabolites, we conduct classical radiotracer translocation studies when a radiolabel is available. In discovery, where typically no radiolabel has been synthesized, we utilize modern high-resolution mass spectrometry to probe complex systems for the test compounds and its metabolites. By using these combined approaches, we can rapidly compare the ADME properties of sets of new experimental insecticides and aid in the design of structures with an improved potential to advance in the research pipeline. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Detection of an endangered aquatic heteropteran using environmental DNA in a wetland ecosystem

PubMed Central

Katano, Izumi; Sakata, Yusuke; Souma, Rio; Kosuge, Toshihiro; Nagano, Mariko; Ikeda, Kousuke; Yano, Koki; Tojo, Koji

2017-01-01

The use of environmental DNA (eDNA) has recently been employed to evaluate the distribution of various aquatic macroorganisms. Although this technique has been applied to a broad range of taxa, from vertebrates to invertebrates, its application is limited for aquatic insects such as aquatic heteropterans. Nepa hoffmanni (Heteroptera: Nepidae) is a small (approx. 23 mm) aquatic heteropteran that inhabits wetlands, can be difficult to capture and is endangered in Japan. The molecular tool eDNA was used to evaluate the species distribution of N. hoffmanni in comparison to that determined using hand-capturing methods in two regions of Japan. The eDNA of N. hoffmanni was detected at nearly all sites (10 eDNA-detected sites out of 14 sites), including sites where N. hoffmanni was not captured by hand (five eDNA-detected sites out of six captured sites). Thus, this species-specific eDNA technique can be applied to detect small, sparsely distributed heteropterans in wetland ecosystems. In conclusion, eDNA could be a valuable technique for the detection of aquatic insects inhabiting wetland habitats, and could make a significant contribution to providing distribution data necessary to species conservation. PMID:28791177

Active listening for spatial orientation in a complex auditory scene.

PubMed

Moss, Cynthia F; Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

2006-04-01

To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

Active Listening for Spatial Orientation in a Complex Auditory Scene

PubMed Central

Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

2006-01-01

To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal–motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10–20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate “terminal buzz” decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar “strobe groups,” clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal–motor control that directly impacts the signals used for perception. PMID:16509770

Effects of juvenile hormone (JH) analog insecticides on larval development and JH esterase activity in two spodopterans.

PubMed

El-Sheikh, El-Sayed A; Kamita, Shizuo G; Hammock, Bruce D

2016-03-01

Juvenile hormone analog (JHA) insecticides are biological and structural mimics of JH, a key insect developmental hormone. Toxic and anti-developmental effects of the JHA insecticides methoprene, fenoxycarb, and pyriproxyfen were investigated on the larval and pupal stages of Spodoptera littoralis and Spodoptera frugiperda. Bioassays showed that fenoxycarb has the highest toxicity and fastest speed of kill in 2nd instar S. littoralis. All three JHAs affected the development of 6th instar (i.e., final instar) and pupal S. frugiperda. JH esterase (JHE) is a critical enzyme that helps to regulate JH levels during insect development. JHE activity in the last instar S. littoralis and S. frugiperda was 11 and 23 nmol min(-1) ml(-1) hemolymph, respectively. Methoprene and pyriproxyfen showed poor inhibition of JHE activity from these insects, whereas fenoxycarb showed stronger inhibition. The inhibitory activity of fenoxycarb, however, was more than 1000-fold lower than that of OTFP, a highly potent inhibitor of JHEs. Surprisingly, topical application of methoprene, fenoxycarb or pyriproxyfen on 6th instars of S. littoralis and S. frugiperda prevented the dramatic reduction in JHE activity that was found in control insects. Our findings suggest that JHAs may function as JH agonists that play a disruptive role or a hormonal replacement role in S. littoralis and S. frugiperda. Copyright © 2015 Elsevier B.V. All rights reserved.

Screwworms eating living flesh – not just another Halloween tale

USDA-ARS?s Scientific Manuscript database

Screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were devastating pests to all warm blooded animals in the United States and the rest of North America. Successful eradication of screwworms was achieved by using the unique approach called the sterile insect technique. Here we ...

Protein self-marking by ectoparasites: a case study using bed bugs

USDA-ARS?s Scientific Manuscript database

1. The ability to mark individuals is a critical feature of many ecological and evolutionary investigations, including dispersal studies. Insect dispersal is generally investigated using mark-release-recapture techniques, whereby marked individuals are released at a known location and then captured ...

Effect of adult screwworm male size on mating competence

USDA-ARS?s Scientific Manuscript database

Screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were devastating pests in parts of North America and Central America before their eradication by means of the sterile insect technique (SIT). Now, a barrier is maintained to prevent re-entry of screwworms from endemic regions t...

Backpocket: Activities for Nature Study.

ERIC Educational Resources Information Center

Hendry, Ian; And Others

1995-01-01

Leading naturalist-teachers share outdoor learning activities and techniques, including using binoculars as magnifiers, scavenger hunts, games such as "what's it called" and "I spy," insect study, guessing the age of trees by examining the bark, leading bird walks, exploring nature in the community, and enhancing nature hikes…

What happened to screwworms anyway and what are you doing about them now?

USDA-ARS?s Scientific Manuscript database

Myiasis caused by screwworms, Cochliomyia hominivorax (Coquerel), is devastating to warm-blooded animals. Application of the sterile insect technique (SIT) has successfully eradicated screwworms from the U.S., Mexico, Central America and some Caribbean Islands. Annual benefits to livestock producers...

Applicator Training Manual for: Agricultural Animal Pest Control.

ERIC Educational Resources Information Center

Christensen, Christian M.

This manual discusses pesticide safety and environmental considerations, pesticide toxicity, residue potential, pesticide formulations, and application techniques. In addition, descriptions of, and methods for controlling insects and related pests that attack cattle, sheep and goats, swine, horses and other equines, and poultry are given. These…

Terrestrial Ecology Guide.

ERIC Educational Resources Information Center

Morrison, James W., Ed.; Hall, James A., Ed.

This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…

Baculovirus-mediated expression of GPCRs in insect cells.

PubMed

Saarenpää, Tuulia; Jaakola, Veli-Pekka; Goldman, Adrian

2015-01-01

G-protein-coupled receptors (GPCRs) are a large family of seven transmembrane proteins that influence a considerable number of cellular events. For this reason, they are one of the most studied receptor types for their pharmacological and structural properties. Solving the structure of several GPCR receptor types has been possible using almost all expression systems, including Escherichia coli, yeast, mammalian, and insect cells. So far, however, most of the GPCR structures solved have been done using the baculovirus insect cell expression system. The reason for this is mainly due to cost-effectiveness, posttranslational modification efficiency, and overall effortless maintenance. The system has evolved so much that variables starting from vector type, purification tags, cell line, and growth conditions can be varied and optimized countless ways to suit the needs of new constructs. Here, we present the array of techniques that enable the rapid and efficient optimization of expression steps for maximal protein quality and quantity, including our emendations. © 2015 Elsevier Inc. All rights reserved.

Preliminary studies of enhanced contrast radiography in anatomy and embryology of insects with Elettra synchrotron light

NASA Astrophysics Data System (ADS)

Hönnicke, M. G.; Foerster, L. A.; Navarro-Silva, M. A.; Menk, R.-H.; Rigon, L.; Cusatis, C.

2005-08-01

Enhanced contrast X-ray imaging is achieved by exploiting the real part of the refraction index, which is responsible for the phase shifts, in addition to the imaginary part, which is responsible for the absorption. Such techniques are called X-ray phase contrast imaging. An analyzer-based X-ray phase contrast imaging set-up with Diffraction Enhanced Imaging processing (DEI) were used for preliminary studies in anatomy and embryology of insects. Parasitized stinkbug and moth eggs used as control agents of pests in vegetables and adult stinkbugs and mosquitoes ( Aedes aegypti) were used as samples. The experimental setup was mounted in the SYRMEP beamline at ELETTRA. Images were obtained using a high spatial resolution CCD detector (pixel size 14×14 μm 2) coupled with magnifying optics. Analyzer-based X-ray phase contrast images (PCI) and edge detection images show contrast and details not observed with conventional synchrotron radiography and open the possibility for future study in the embryonic development of insects.

Microbial community structure in the gut of the New Zealand insect Auckland tree weta (Hemideina thoracica).

PubMed

Waite, David W; Dsouza, Melissa; Biswas, Kristi; Ward, Darren F; Deines, Peter; Taylor, Michael W

2015-05-01

The endemic New Zealand weta is an enigmatic insect. Although the insect is well known by its distinctive name, considerable size, and morphology, many basic aspects of weta biology remain unknown. Here, we employed cultivation-independent enumeration techniques and rRNA gene sequencing to investigate the gut microbiota of the Auckland tree weta (Hemideina thoracica). Fluorescence in situ hybridisation performed on different sections of the gut revealed a bacterial community of fluctuating density, while rRNA gene-targeted amplicon pyrosequencing revealed the presence of a microbial community containing high bacterial diversity, but an apparent absence of archaea. Bacteria were further studied using full-length 16S rRNA gene sequences, with statistical testing of bacterial community membership against publicly available termite- and cockroach-derived sequences, revealing that the weta gut microbiota is similar to that of cockroaches. These data represent the first analysis of the weta microbiota and provide initial insights into the potential function of these microorganisms.

Learning and discrimination of cuticular hydrocarbons in a social insect

PubMed Central

van Wilgenburg, Ellen; Felden, Antoine; Choe, Dong-Hwan; Sulc, Robert; Luo, Jun; Shea, Kenneth J.; Elgar, Mark A.; Tsutsui, Neil D.

2012-01-01

Social insect cuticular hydrocarbon (CHC) mixtures are among the most complex chemical cues known and are important in nest-mate, caste and species recognition. Despite our growing knowledge of the nature of these cues, we have very little insight into how social insects actually perceive and discriminate among these chemicals. In this study, we use the newly developed technique of differential olfactory conditioning to pure, custom-designed synthetic colony odours to analyse signal discrimination in Argentine ants, Linepithema humile. Our results show that tri-methyl alkanes are more easily learned than single-methyl or straight-chain alkanes. In addition, we reveal that Argentine ants can discriminate between hydrocarbons with different branching patterns and the same chain length, but not always between hydrocarbons with the same branching patterns but different chain length. Our data thus show that biochemical characteristics influence those compounds that ants can discriminate between, and which thus potentially play a role in chemical signalling and nest-mate recognition. PMID:21831880

Identification of lipid fraction constituents from grasshopper (Chorthippus spp.) abdominal secretion with potential activity in wound healing with the use of GC-MS/MS technique.

PubMed

Buszewska-Forajta, Magdalena; Siluk, Danuta; Struck-Lewicka, Wiktoria; Raczak-Gutknecht, Joanna; Markuszewski, Michał J; Kaliszan, Roman

2014-02-01

In recent years biologically active compounds isolated from insects call special interest of drug researchers. According to some Polish etnopharmacological observations, secretion from the grasshopper's abdomen (Orthoptera family) is believed to speed up the process of wound healing. In the present work we focused on determination of main components of the lipid fraction of material from grasshopper abdomen using GC-MS/MS. Samples were qualitatively analyzed using gas chromatography coupled with mass spectrometry. Both liquid-liquid extraction and solid-phase extraction pretreatment methods were used to concentrate and fractionate the compounds from the insect. In the derivatized fractions ca. 350 compounds were identified, including substances of known biological activity. The potential agents affecting wound healing have been indicated. A set of compounds characteristic for all the studied Chorthippus spp., have been identified. Data analysis revealed different lipidomic profiles of grasshoppers depending on the insects origin and collection area. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative proteomics analysis of Spodoptera frugiperda cells during Autographa californica multiple nucleopolyhedrovirus infection.

PubMed

Yu, Qian; Xiong, Youhua; Gao, Hang; Liu, Jianliang; Chen, Zhiqiang; Wang, Qin; Wen, Dongling

2015-08-04

Increasing evidence sugggest that in addition of balculovirus controling insect host, host cells also responds to balculovirus infection. However, compared to existing knowledge on virus gene, host cell responses are relatively poorly understood. In this study, Spodoptera frugiperda (Sf9) cells were infected with Autographa californica multiple nucleopolyhedrovirus (AcMNPV). The protein composition and protein changes of Spodoptera frugiperda (Sf9) cells of different infection stages were analysed by isobaric tag for relative and absolute quantification (iTRAQ) techniques. A total of 4004 Sf9 proteins were identified by iTRAQ and 413 proteins were found as more than 1.5-fold changes in abundance. The 413 proteins were categorised according to GO classification for insects and were categorised into: biological process, molecular function and cellular component. The determination of the protein changes in infected Sf9 cells would help to better understanding of host cell responses and facilitate better design of this virus-host cell interaction in pest insect control and other related fields.

Identification of optimal feedback control rules from micro-quadrotor and insect flight trajectories.

PubMed

Faruque, Imraan A; Muijres, Florian T; Macfarlane, Kenneth M; Kehlenbeck, Andrew; Humbert, J Sean

2018-06-01

This paper presents "optimal identification," a framework for using experimental data to identify the optimality conditions associated with the feedback control law implemented in the measurements. The technique compares closed loop trajectory measurements against a reduced order model of the open loop dynamics, and uses linear matrix inequalities to solve an inverse optimal control problem as a convex optimization that estimates the controller optimality conditions. In this study, the optimal identification technique is applied to two examples, that of a millimeter-scale micro-quadrotor with an engineered controller on board, and the example of a population of freely flying Drosophila hydei maneuvering about forward flight. The micro-quadrotor results show that the performance indices used to design an optimal flight control law for a micro-quadrotor may be recovered from the closed loop simulated flight trajectories, and the Drosophila results indicate that the combined effect of the insect longitudinal flight control sensing and feedback acts principally to regulate pitch rate.

Long-term monitoring of fleshy fruit and hard mast production and seasonal bird distribution at the Savannah River Site, South Carolina.

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

Greenberg, Cathryn, H.; Levey, Douglas J.

2009-06-15

A final report of Fruit and hard mast production in five habitat types at SRS with a comparison of fruit consumption by fledgling versus adult birds at SRS and Relative importance of fruit, seeds, and insects in the diets of overwintering birds at SRS.

Metabolic Complementarity and Genomics of the Dual Bacterial Symbiosis of Sharpshooters

PubMed Central

Wu, Dongying; Daugherty, Sean C; Van Aken, Susan E; Pai, Grace H; Watkins, Kisha L; Khouri, Hoda; Tallon, Luke J; Zaborsky, Jennifer M; Dunbar, Helen E; Tran, Phat L; Moran, Nancy A

2006-01-01

Mutualistic intracellular symbiosis between bacteria and insects is a widespread phenomenon that has contributed to the global success of insects. The symbionts, by provisioning nutrients lacking from diets, allow various insects to occupy or dominate ecological niches that might otherwise be unavailable. One such insect is the glassy-winged sharpshooter (Homalodisca coagulata), which feeds on xylem fluid, a diet exceptionally poor in organic nutrients. Phylogenetic studies based on rRNA have shown two types of bacterial symbionts to be coevolving with sharpshooters: the gamma-proteobacterium Baumannia cicadellinicola and the Bacteroidetes species Sulcia muelleri. We report here the sequencing and analysis of the 686,192–base pair genome of B. cicadellinicola and approximately 150 kilobase pairs of the small genome of S. muelleri, both isolated from H. coagulata. Our study, which to our knowledge is the first genomic analysis of an obligate symbiosis involving multiple partners, suggests striking complementarity in the biosynthetic capabilities of the two symbionts: B. cicadellinicola devotes a substantial portion of its genome to the biosynthesis of vitamins and cofactors required by animals and lacks most amino acid biosynthetic pathways, whereas S. muelleri apparently produces most or all of the essential amino acids needed by its host. This finding, along with other results of our genome analysis, suggests the existence of metabolic codependency among the two unrelated endosymbionts and their insect host. This dual symbiosis provides a model case for studying correlated genome evolution and genome reduction involving multiple organisms in an intimate, obligate mutualistic relationship. In addition, our analysis provides insight for the first time into the differences in symbionts between insects (e.g., aphids) that feed on phloem versus those like H. coagulata that feed on xylem. Finally, the genomes of these two symbionts provide potential targets for controlling plant pathogens such as Xylella fastidiosa, a major agroeconomic problem, for which H. coagulata and other sharpshooters serve as vectors of transmission. PMID:16729848

Transcriptome Analysis of Fat Bodies from Two Brown Planthopper (Nilaparvata lugens) Populations with Different Virulence Levels in Rice

PubMed Central

Chen, Hongdan; Lai, Wenxiang; Fu, Qiang; Lou, Yonggen

2014-01-01

Background The brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. Methodology/Principal Findings In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs) from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. Conclusions/Significance This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies and will be useful in examining the interactions between the fat body and virulence variation in the BPH. PMID:24533099

Transcriptome analysis of fat bodies from two brown planthopper (Nilaparvata lugens) populations with different virulence levels in rice.

PubMed

Yu, Haixin; Ji, Rui; Ye, Wenfeng; Chen, Hongdan; Lai, Wenxiang; Fu, Qiang; Lou, Yonggen

2014-01-01

The brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs) from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies and will be useful in examining the interactions between the fat body and virulence variation in the BPH.

Distribution and Spectroscopy of Green Fluorescent Protein and Acyl-CoA: Cholesterol Acytransferase in Sf21 Insect Cells

NASA Technical Reports Server (NTRS)

Richmond, R. C.; Mahtani, H.; Lu, X.; Chang, T. Y.; Malak, H.; Rose, M. Franklin (Technical Monitor)

2001-01-01

Acyl-CoA: cholesterol acyltransferase (ACAT) is thought to significantly participate in the pathway of cholesterol esterification that underlies the pathology of artherosclerosis. This enzyme is a membrane protein known to be preferentially bound within the endoplasmic reticulum of mammalian cells, from which location it esterifies cholesterol derived from low density lipoprotein. Cultures of insect cells were separately infected with baculovirus containing the gene for green fluroescent protein (GFP) and with baculovirus containing tandem genes for GFP and ACAT. These infected cultures expressed GFP and the fusion protein GCAT, respectively, with maximum expression occurring on the fourth day after infection. Extraction of GFP- and of GCAT-expressing cells with urea and detergent resulted in recovery of fluorescent protein in aqueous solution. Fluorescence spectra at neutral pH were identical for both GFP and GCAT extracts in aqueous solution, indicating unperturbed tertiary structure for the GFP moiety within GCAT. In a cholesterol esterification assay, GCAT demonstrated ACAT activity, but with less efficiency compared to native ACAT. It was hypothesized that the membrane protein ACAT would lead to differences in localization of GCAT compared to GFP within the respective expressing insect cells. The GFP marker directly and also within the fusion protein GCAT was accordingly used as the intracellular probe that was fluorescently analyzed by the new biophotonics technique of hyperspectral imaging. In that technique, fluorescence imaging was obtained from two dimensional arrays of cells, and regions of interest from within those images were then retrospectively analyzed for the emission spectra that comprises the image. Results of hyperspectral imaging of insect cells on day 4 postinfection showed that GCAT was preferentially localized to the cytoplasm of these cells compared to GFP. Furthermore, the emission spectra obtained for the localized GCAT displayed a peak blue shift from 518nm obtained in neutral aqueous solution to 505nm obtained in localized regions within the cells. This blue shift indicates change in the fluorescence coupling of the GFP moiety of GCAT. It is hypothesized that change in tertiary environment of GCAT, coincident with intracellular deposition of GCAT, follows from intracellular trafficking of GCAT leading to membrane interactions with the ACAT moiety, and/or self-assembly of GCAT, that alters the chromophore environment of the GFP moiety of GCAT. These findings introduce a new technique of biophotonic imaging to studies of intracellular protein trafficking and interactions. This technique of hyperspectral imaging could contribute to advancing the emergent field of proteomics. Because of the noninvasive nature of this technique, kinetic processes associated with intracellular protein trafficking, and interactions of proteins within cellular domains, can be considered for investigation within a single cell as well as a cell population.

Computational biomechanics changes our view on insect head evolution.

PubMed

Blanke, Alexander; Watson, Peter J; Holbrey, Richard; Fagan, Michael J

2017-02-08

Despite large-scale molecular attempts, the relationships of the basal winged insect lineages dragonflies, mayflies and neopterans, are still unresolved. Other data sources, such as morphology, suffer from unclear functional dependencies of the structures considered, which might mislead phylogenetic inference. Here, we assess this problem by combining for the first time biomechanics with phylogenetics using two advanced engineering techniques, multibody dynamics analysis and finite-element analysis, to objectively identify functional linkages in insect head structures which have been used traditionally to argue basal winged insect relationships. With a biomechanical model of unprecedented detail, we are able to investigate the mechanics of morphological characters under biologically realistic load, i.e. biting. We show that a range of head characters, mainly ridges, endoskeletal elements and joints, are indeed mechanically linked to each other. An analysis of character state correlation in a morphological data matrix focused on head characters shows highly significant correlation of these mechanically linked structures. Phylogenetic tree reconstruction under different data exclusion schemes based on the correlation analysis unambiguously supports a sistergroup relationship of dragonflies and mayflies. The combination of biomechanics and phylogenetics as it is proposed here could be a promising approach to assess functional dependencies in many organisms to increase our understanding of phenotypic evolution. © 2017 The Author(s).

Artificial diets used in mass production of the New World Screwworm, Cochliomyia hominivorax

USDA-ARS?s Scientific Manuscript database

The New World screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), has been eradicated from North and Central America using the sterile insect technique. This success has been based on mass production of high quality screwworms using artificial diets since 1958. Many diet formulat...

Development of High-Throughput DNA Sequencing Techniques to Improve and Advance Environmental Monitoring and Bioassessment

EPA Pesticide Factsheets

Scientists learn about the health of rivers, streams, lakes, and other aquatic ecosystems by looking at the species that live there. Populations of insects, snails, and worms found in different aquatic ecosystems can indicate overall health in those areas.

Confocal microscopy studies of morphology and apoptosis: ovaries, limbs, embryos and insects

EPA Science Inventory

Confocal laser scanning microscopy (CLSM) is a technique that is capable of generating serial sections of whole-mount tissue and then reassembling the computer-stored images as a virtual 3-dimensional structure. In many ways CLSM offers an alternative to traditional sectioning ap...

Food Processing: Technology and Nutritive Value.

ERIC Educational Resources Information Center

Gerbouin-Rerolle, Pascale

1993-01-01

This booklet examines the principles of food preservation, food preservation techniques, and nutrition-related consequences of food processing. All foodstuffs in their natural state will deteriorate and become unfit for human consumption due to internal factors, such as enzyme activity, or external factors, such as insects, rodents, and…

Ionotropic receptors (IRs): chemosensory ionotropic glutamate receptors in Drosophila and beyond.

PubMed

Rytz, Raphael; Croset, Vincent; Benton, Richard

2013-09-01

Ionotropic Receptors (IRs) are a recently characterized family of olfactory receptors in the fruit fly, Drosophila melanogaster. IRs are not related to insect Odorant Receptors (ORs), but rather have evolved from ionotropic glutamate receptors (iGluRs), a conserved family of synaptic ligand-gated ion channels. Here, we review the expression and function of IRs in Drosophila, highlighting similarities and differences with iGluRs. We also briefly describe the organization of the neuronal circuits in which IRs function, comparing and contrasting them with the sensory pathways expressing ORs. Finally, we summarize the bioinformatic identification and initial characterization of IRs in other species, which imply an evolutionarily conserved role for these receptors in chemosensation in insects and other protostomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

The subtilisin-like protease SBT3 contributes to insect resistance in tomato

PubMed Central

Meyer, Michael; Huttenlocher, Franziska; Cedzich, Anna; Procopio, Susanne; Stroeder, Jasper; Pau-Roblot, Corinne; Lequart-Pillon, Michelle; Pelloux, Jérôme; Stintzi, Annick; Schaller, Andreas

2016-01-01

Subtilisin-like proteases (SBTs) constitute a large family of extracellular plant proteases, the function of which is still largely unknown. In tomato plants, the expression of SBT3 was found to be induced in response to wounding and insect attack in injured leaves but not in healthy systemic tissues. The time course of SBT3 induction resembled that of proteinase inhibitor II and other late wound response genes suggesting a role for SBT3 in herbivore defense. Consistent with such a role, larvae of the specialist herbivore Manduca sexta performed better on transgenic plants silenced for SBT3 expression (SBT3-SI). Supporting a contribution of SBT3 to systemic wound signaling, systemic induction of late wound response genes was attenuated in SBT3-SI plants. The partial loss of insect resistance may thus be explained by a reduction in systemic defense gene expression. Alternatively, SBT3 may play a post-ingestive role in plant defense. Similar to other anti-nutritive proteins, SBT3 was found to be stable and active in the insect’s digestive system, where it may act on unidentified proteins of insect or plant origin. Finally, a reduction in the level of pectin methylesterification that was observed in transgenic plants with altered levels of SBT3 expression suggested an involvement of SBT3 in the regulation of pectin methylesterases (PMEs). While such a role has been described in other systems, PME activity and the degree of pectin methylesterification did not correlate with the level of insect resistance in SBT3-SI and SBT3 overexpressing plants and are thus unrelated to the observed resistance phenotype. PMID:27259555

Characterization of constitutive and putative differentially expressed mRNAs by means of expressed sequence tags, differential display reverse transcriptase-PCR and randomly amplified polymorphic DNA-PCR from the sand fly vector Lutzomyia longipalpis.

PubMed

Ramalho-Ortigão, J M; Temporal, P; de Oliveira , S M; Barbosa, A F; Vilela, M L; Rangel, E F; Brazil, R P; Traub-Cseko, Y M

2001-01-01

Molecular studies of insect disease vectors are of paramount importance for understanding parasite-vector relationship. Advances in this area have led to important findings regarding changes in vectors' physiology upon blood feeding and parasite infection. Mechanisms for interfering with the vectorial capacity of insects responsible for the transmission of diseases such as malaria, Chagas disease and dengue fever are being devised with the ultimate goal of developing transgenic insects. A primary necessity for this goal is information on gene expression and control in the target insect. Our group is investigating molecular aspects of the interaction between Leishmania parasites and Lutzomyia sand flies. As an initial step in our studies we have used random sequencing of cDNA clones from two expression libraries made from head/thorax and abdomen of sugar fed L. longipalpis for the identification of expressed sequence tags (EST). We applied differential display reverse transcriptase-PCR and randomly amplified polymorphic DNA-PCR to characterize differentially expressed mRNA from sugar and blood fed insects, and, in one case, from a L. (V.) braziliensis-infected L. longipalpis. We identified 37 cDNAs that have shown homology to known sequences from GeneBank. Of these, 32 cDNAs code for constitutive proteins such as zinc finger protein, glutamine synthetase, G binding protein, ubiquitin conjugating enzyme. Three are putative differentially expressed cDNAs from blood fed and Leishmania-infected midgut, a chitinase, a V-ATPase and a MAP kinase. Finally, two sequences are homologous to Drosophila melanogaster gene products recently discovered through the Drosophila genome initiative.

Tropical insect diversity: evidence of greater host specialization in seed-feeding weevils.

PubMed

Peguero, Guille; Bonal, Raúl; Sol, Daniel; Muñoz, Alberto; Sork, Victoria L; Espelta, Josep M

2017-08-01

Host specialization has long been hypothesized to explain the extraordinary diversity of phytophagous insects in the tropics. However, addressing this hypothesis has proved challenging because of the risk of over-looking rare interactions, and hence biasing specialization estimations, and the difficulties to separate the diversity component attributable to insect specialization from that related to host diversity. As a result, the host specialization hypothesis lacks empirical support for important phytophagous insect clades. Here, we test the hypothesis in a radiation of seed-feeding insects, acorn weevils (Curculio spp.), sampled in temperate and tropical regions (California and Nicaragua, respectively) with an equivalent pool of oak host species. Using DNA sequences from three low-copy genes, we delimited to species level 778 weevil larvae extracted from host seeds and assessed their phylogenetic relationships by Maximum Likelihood and Bayesian inference. We then reconstructed the oak-weevil food webs and examined differences in alpha, beta and gamma diversity using Hill numbers of effective species. We found a higher alpha, beta and gamma diversity of weevils in Nicaragua compared to California despite similar richness of host species at both local and regional level. By means of Bayesian mixed models, we also found that tropical weevil species were highly specialized both in terms of host range and interaction strength, whereas their temperate congeners had a broader taxonomic and phylogenetic host spectrum. Finally, in Nicaraguan species, larval body size was highly correlated with the size of the acorns infested, as would be expected by a greater host specialization, whereas in California this relationship was absent. Altogether, these lines of evidence support the host specialization hypothesis and suggest contrasting eco-evolutionary dynamics in tropical and temperate regions even in absence of differences in host diversity. © 2017 by the Ecological Society of America.

Shifts in Plant Assemblages Reduce the Richness of Galling Insects Across Edge-Affected Habitats in the Atlantic Forest.

PubMed

Souza, Danielle G; Santos, Jean C; Oliveira, Marcondes A; Tabarelli, Marcelo

2016-10-01

Impacts of habitat loss and fragmentation on specialist herbivores have been rarely addressed. Here we examine the structure of plant and galling insect assemblages in a fragmented landscape of the Atlantic forest to verify a potential impoverishment of these assemblages mediated by edge effects. Saplings and galling insects were recorded once within a 0.1-ha area at habitat level, covering forest interior stands, forest edges, and small fragments. A total of 1,769 saplings from 219 tree species were recorded across all three habitats, with differences in terms of sapling abundance and species richness. Additionally, edge-affected habitats exhibited reduced richness of both host-plant and galling insects at plot and habitat spatial scale. Attack levels also differed among forest types at habitat spatial scale (21.1% of attacked stems in forest interior, 12.4% in small fragments but only 8.5% in forest edges). Plot ordination resulted in three clearly segregated clusters: one formed by forest interior, one by small fragments, and another formed by edge plots. Finally, the indicator species analysis identified seven and one indicator plant species in forest interior and edge-affected habitats, respectively. Consequently, edge effects lead to formation of distinct taxonomic groups and also an impoverished assemblage of plants and galling insects at multiple spatial scales. The results of the present study indicate that fragmentation-related changes in plant assemblages can have a cascade effects on specialist herbivores. Accordingly, hyperfragmented landscapes may not be able to retain an expressive portion of tropical biodiversity. © 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.

Origin and diversification of wings: Insights from a neopteran insect.

PubMed

Medved, Victor; Marden, James H; Fescemyer, Howard W; Der, Joshua P; Liu, Jin; Mahfooz, Najmus; Popadić, Aleksandar

2015-12-29

Winged insects underwent an unparalleled evolutionary radiation, but mechanisms underlying the origin and diversification of wings in basal insects are sparsely known compared with more derived holometabolous insects. In the neopteran species Oncopeltus fasciatus, we manipulated wing specification genes and used RNA-seq to obtain both functional and genomic perspectives. Combined with previous studies, our results suggest the following key steps in wing origin and diversification. First, a set of dorsally derived outgrowths evolved along a number of body segments including the first thoracic segment (T1). Homeotic genes were subsequently co-opted to suppress growth of some dorsal flaps in the thorax and abdomen. In T1 this suppression was accomplished by Sex combs reduced, that when experimentally removed, results in an ectopic T1 flap similar to prothoracic winglets present in fossil hemipteroids and other early insects. Global gene-expression differences in ectopic T1 vs. T2/T3 wings suggest that the transition from flaps to wings required ventrally originating cells, homologous with those in ancestral arthropod gill flaps/epipods, to migrate dorsally and fuse with the dorsal flap tissue thereby bringing new functional gene networks; these presumably enabled the T2/T3 wing's increased size and functionality. Third, "fused" wings became both the wing blade and surrounding regions of the dorsal thorax cuticle, providing tissue for subsequent modifications including wing folding and the fit of folded wings. Finally, Ultrabithorax was co-opted to uncouple the morphology of T2 and T3 wings and to act as a general modifier of hindwings, which in turn governed the subsequent diversification of lineage-specific wing forms.

Pest Management Strategies Against the Coffee Berry Borer (Coleoptera: Curculionidae: Scolytinae).

PubMed

Infante, Francisco

2018-03-22

Coffee ( Coffea arabica and C. canephora) is one of the most widely traded agricultural commodities and the main cash crop in ∼80 tropical countries. Among the factors that limit coffee production, the coffee berry borer, Hypothenemus hampei (Ferrari) has been considered the main insect pest, causing losses of over U.S. $500 million dollars annually. Control of this pest has been hindered by two main factors: the cryptic nature of the insect (i.e., protected inside the coffee berry) and the availability of coffee berries in the field allowing the survival of the pest from one generation to the next. Coffee berry borer control has primarily been based on the use of synthetic insecticides. Management strategies have focused on the use of African parasitoids ( Cephalonomia stephanoderis, Prorops nasuta, and Phymastichus coffea), fungal entomopathogens ( Beauveria bassiana), and insect traps. These approaches have had mixed results. Recent work on the basic biology of the insect has provided novel insights that might be useful in developing novel pest management strategies. For example, the discovery of symbiotic bacteria responsible for caffeine breakdown as part of the coffee berry borer microbiome opens new possibilities for pest management via the disruption of these bacteria. Some chemicals with repellent propieties have been identified, and these have a high potential for field implementation. Finally, the publication of the CBB genome has provided insights on the biology of the insect that will help us to understand why it has been so successful at exploiting the coffee plant. Here I discuss the tools we now have against the CBB and likely control strategies that may be useful in the near future.

Characterization of Am IT, an anti-insect β-toxin isolated from the venom of scorpion Androctonus mauretanicus.

PubMed

Oukkache, Naoual; ElJaoudi, Rachid; Chgoury, Fatima; Rocha, Marisa Teixeira; Sabatier, Jean-Marc

2015-06-25

In the present study, a 'novel' toxin, called Am IT from the venom of scorpion Androctonus mauretanicus is isolated and characterized. A detailed analysis of the action of Am IT on insect axonal sodium currents is reported. Am IT was purified through gel filtration followed by C18 reversed-phase HPLC. Toxicity of Am IT in vivo was assessed on male German cockroach (Blattella germanica) larvae and C57/BL6 mice. Cross-reactivity of Am IT with two β-toxins was evidenced using (125)I-iodinated toxin-based radioimmunoassays with synaptosomal preparations from rat brain. The complete amino acid sequence of Am IT was finally determined by Edman sequencing. Am IT was observed to compete with AaH IT4 purified from the venom of scorpion Androctonus australis in binding assays. It was recognized by an antibody raised against a β-type toxin, which indicated some structural similarity with β-toxins (or related toxin family). The 'novel' toxin exhibited dual activity since it competed with anti-mammal toxins in binding assays as well as showed contracting activity to insect. The toxin competed with radio-labeled β-toxin Css IV by binding to Na(+) channels of rat brain synaptosomes. Analysis of toxin amino acid sequences showed that Am IT shares high structural identity (92%) with AaH IT4. In conclusion, Am IT not only reveals an anti-insect compound properties secreted by 'Old World' scorpions, paralyzing insect larvae by binding to Na(+) channels on larvae's nerve-cell membranes, but also exerts toxic activity in mice, which is similar to anti-mammal toxins from 'New World' scorpions (North and South Americas). Therefore, Am IT appears to be structurally and functionally similar to AaH IT4.

Impairment of leaf photosynthesis after insect herbivory or mechanical injury on common milkweed, Asclepias syriaca.

PubMed

Delaney, K J; Haile, F J; Peterson, R K D; Higley, L G

2008-10-01

Insect herbivory has variable consequences on plant physiology, growth, and reproduction. In some plants, herbivory reduces photosynthetic rate (Pn) activity on remaining tissue of injured leaves. We sought to better understand the influence of leaf injury on Pn of common milkweed, Asclepias syriaca (Asclepiadaceae), leaves. Initially, we tested whether Pn reductions occurred after insect herbivory or mechanical injury. We also (1) examined the duration of photosynthetic recovery, (2) compared mechanical injury with insect herbivory, (3) studied the relationship between leaf Pn with leaf injury intensity, and (4) considered uninjured leaf compensatory Pn responses neighboring an injured leaf. Leaf Pn was significantly reduced on mechanically injured or insect-fed leaves in all reported experiments except one, so some factor(s) (cardiac glycoside induction, reproductive investment, and water stress) likely interacts with leaf injury to influence whether Pn impairment occurs. Milkweed tussock moth larval herbivory, Euchaetes egle L. (Arctiidae), impaired leaf Pn more severely than mechanical injury in one experiment. Duration of Pn impairment lasted > 5 d to indicate high leaf Pn sensitivity to injury, but Pn recovery occurred within 13 d in one experiment. The degree of Pn reduction was more severe from E. egle herbivory than similar levels of mechanical tissue removal. Negative linear relationships characterized leaf Pn with percentage tissue loss from single E. egle-fed leaves and mechanically injured leaves and suggested that the signal to trigger leaf Pn impairment on remaining tissue of an injured leaf was amplified by additional tissue loss. Finally, neighboring uninjured leaves to an E. egle-fed leaf had a small (approximately 10%) degree of compensatory Pn to partly offset tissue loss and injured leaf Pn impairment.

Origin and diversification of wings: Insights from a neopteran insect

PubMed Central

Medved, Victor; Marden, James H.; Fescemyer, Howard W.; Der, Joshua P.; Liu, Jin; Mahfooz, Najmus; Popadić, Aleksandar

2015-01-01

Winged insects underwent an unparalleled evolutionary radiation, but mechanisms underlying the origin and diversification of wings in basal insects are sparsely known compared with more derived holometabolous insects. In the neopteran species Oncopeltus fasciatus, we manipulated wing specification genes and used RNA-seq to obtain both functional and genomic perspectives. Combined with previous studies, our results suggest the following key steps in wing origin and diversification. First, a set of dorsally derived outgrowths evolved along a number of body segments including the first thoracic segment (T1). Homeotic genes were subsequently co-opted to suppress growth of some dorsal flaps in the thorax and abdomen. In T1 this suppression was accomplished by Sex combs reduced, that when experimentally removed, results in an ectopic T1 flap similar to prothoracic winglets present in fossil hemipteroids and other early insects. Global gene-expression differences in ectopic T1 vs. T2/T3 wings suggest that the transition from flaps to wings required ventrally originating cells, homologous with those in ancestral arthropod gill flaps/epipods, to migrate dorsally and fuse with the dorsal flap tissue thereby bringing new functional gene networks; these presumably enabled the T2/T3 wing’s increased size and functionality. Third, “fused” wings became both the wing blade and surrounding regions of the dorsal thorax cuticle, providing tissue for subsequent modifications including wing folding and the fit of folded wings. Finally, Ultrabithorax was co-opted to uncouple the morphology of T2 and T3 wings and to act as a general modifier of hindwings, which in turn governed the subsequent diversification of lineage-specific wing forms. PMID:26668365

From microseconds to seconds and minutes—time computation in insect hearing

PubMed Central

Hartbauer, Manfred; Römer, Heiner

2014-01-01

The computation of time in the auditory system of insects is of relevance at rather different time scales, covering a large range from microseconds to several minutes. At the one end of this range, only a few microseconds of interaural time differences are available for directional hearing, due to the small distance between the ears, usually considered too small to be processed reliably by simple nervous systems. Synapses of interneurons in the afferent auditory pathway are, however, very sensitive to a time difference of only 1–2 ms provided by the latency shift of afferent activity with changing sound direction. At a much larger time scale of several tens of milliseconds to seconds, time processing is important in the context species recognition, but also for those insects where males produce acoustic signals within choruses, and the temporal relationship between song elements strongly deviates from a random distribution. In these situations, some species exhibit a more or less strict phase relationship of song elements, based on phase response properties of their song oscillator. Here we review evidence on how this may influence mate choice decisions. In the same dimension of some tens of milliseconds we find species of katydids with a duetting communication scheme, where one sex only performs phonotaxis to the other sex if the acoustic response falls within a very short time window after its own call. Such time windows show some features unique to insects, and although its neuronal implementation is unknown so far, the similarity with time processing for target range detection in bat echolocation will be discussed. Finally, the time scale being processed must be extended into the range of many minutes, since some acoustic insects produce singing bouts lasting quite long, and female preferences may be based on total signaling time. PMID:24782783

Dickeya dadantii, a Plant Pathogenic Bacterium Producing Cyt-Like Entomotoxins, Causes Septicemia in the Pea Aphid Acyrthosiphon pisum

PubMed Central

Condemine, Guy; Rahbé, Yvan

2012-01-01

Dickeya dadantii (syn. Erwinia chrysanthemi) is a plant pathogenic bacteria that harbours a cluster of four horizontally-transferred, insect-specific toxin genes. It was recently shown to be capable of causing an acute infection in the pea aphid Acyrthosiphon pisum (Insecta: Hemiptera). The infection route of the pathogen, and the role and in vivo expression pattern of these toxins, remain unknown. Using bacterial numeration and immunolocalization, we investigated the kinetics and the pattern of infection of this phytopathogenic bacterium within its insect host. We compared infection by the wild-type strain and by the Cyt toxin-deficient mutant. D. dadantii was found to form dense clusters in many luminal parts of the aphid intestinal tract, including the stomach, from which it invaded internal tissues as early as day 1 post-infection. Septicemia occurred soon after, with the fat body being the main infected tissue, together with numerous early infections of the embryonic chains showing embryonic gut and fat body as the target organs. Generalized septicemia led to insect death when the bacterial load reached about 108 cfu. Some individual aphids regularly escaped infection, indicating an effective partial immune response to this bacteria. Cyt-defective mutants killed insects more slowly but were capable of localisation in any type of tissue. Cyt toxin expression appeared to be restricted to the digestive tract where it probably assisted in crossing over the first cell barrier and, thus, accelerating bacterial diffusion into the aphid haemocel. Finally, the presence of bacteria on the surface of leaves hosting infected aphids indicated that the insects could be vectors of the bacteria. PMID:22292023

Dickeya dadantii, a plant pathogenic bacterium producing Cyt-like entomotoxins, causes septicemia in the pea aphid Acyrthosiphon pisum.

PubMed

Costechareyre, Denis; Balmand, Séverine; Condemine, Guy; Rahbé, Yvan

2012-01-01

Dickeya dadantii (syn. Erwinia chrysanthemi) is a plant pathogenic bacteria that harbours a cluster of four horizontally-transferred, insect-specific toxin genes. It was recently shown to be capable of causing an acute infection in the pea aphid Acyrthosiphon pisum (Insecta: Hemiptera). The infection route of the pathogen, and the role and in vivo expression pattern of these toxins, remain unknown. Using bacterial numeration and immunolocalization, we investigated the kinetics and the pattern of infection of this phytopathogenic bacterium within its insect host. We compared infection by the wild-type strain and by the Cyt toxin-deficient mutant. D. dadantii was found to form dense clusters in many luminal parts of the aphid intestinal tract, including the stomach, from which it invaded internal tissues as early as day 1 post-infection. Septicemia occurred soon after, with the fat body being the main infected tissue, together with numerous early infections of the embryonic chains showing embryonic gut and fat body as the target organs. Generalized septicemia led to insect death when the bacterial load reached about 10(8) cfu. Some individual aphids regularly escaped infection, indicating an effective partial immune response to this bacteria. Cyt-defective mutants killed insects more slowly but were capable of localisation in any type of tissue. Cyt toxin expression appeared to be restricted to the digestive tract where it probably assisted in crossing over the first cell barrier and, thus, accelerating bacterial diffusion into the aphid haemocel. Finally, the presence of bacteria on the surface of leaves hosting infected aphids indicated that the insects could be vectors of the bacteria.

Halyomorpha halys (Hemiptera: Pentatomidae) response to pyramid traps baited with attractive light and pheromonal stimuli

USDA-ARS?s Scientific Manuscript database

Halyomorpha halys is an invasive insect that causes severe economic damage to multiple agricultural commodities. Several monitoring techniques have been developed to monitor H. halys including pheromone and light-baited black pyramid traps. Here, we evaluated the attractiveness of these traps bait...

Chapter 15: Preparations of entomopathogens and diseased specimens for more detailed study using microscopy

USDA-ARS?s Scientific Manuscript database

The science of Insect Pathology encompasses a diverse assemblage of pathogens from a large and varied group of hosts. Microscopy techniques and protocols for these organisms are complex and varied and often require modifications and adaptations of standard procedures. The objective of this chapter...

Research on Screwworms: male-only strains, Cryopreservation and reducing ammonia in mass rearing

USDA-ARS?s Scientific Manuscript database

Screwworm myiasis is devastating to warm blooded animals. The eradication of screwworms from mainland North America using the sterile insect technique (SIT) is an unprecedented achievement; re-invasion is prevented by maintenance of a barrier at the Panama – Colombia border. Several potential advant...

The screwworm eradication program: From an unlikely dream to an outstanding reality

USDA-ARS?s Scientific Manuscript database

The screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), was a devastating pest to all warm blooded animals in the United States and the rest of North America. Successful eradication of the screwworm was achieved by using the unique approach called the sterile insect technique. He...

Nondestructive inspection of nuts for food quality and safety using NIRS (abstract)

USDA-ARS?s Scientific Manuscript database

Mold infection and insect infestation are significant postharvest problems for processors of nuts. Fungal disease causes direct loss of product or reduced value due to the lower-quality grade of the chest-nut lot. In most cases, fungal infection is not detectable using traditional sorting techniques...

INVESTIGATION OF THE PERSISTENCE AND REPLICATION OF NUCLEAR POLYHEDROSIS VIRUSES IN VERTEBRATE AND INSECT CELL CULTURES BY THE USE OF HYBRIDIZATION TECHNIQUES

EPA Science Inventory

The Health Effects Research Laboratory, Research Triangle Park, conducts a coordinaged environmental health research program in toxicology, epidemiology, and clinical studies using human volunteer subjects. These studies address problems in air pollution, non-ionizing radiation, ...

Factors affecting citrus tree absorption of double-stranded ribonucleic acid, and RNAi delivery to psyllids

USDA-ARS?s Scientific Manuscript database

Modern molecular biological techniques allow for the design of molecules of ribonucleic acid capable of disrupting key biological processes of pests and diseases. A major requirement for the practical application of ribonucleic acid interference (RNAi) against insect pests is an efficient entry path...

Progress toward developing trapping techniques for the emerald ash borer

Treesearch

Therese M. Poland; Deborah G. McCullough; Peter dr Groot; Gary Grant; Linda MacDonald; David L. Cappaert

2005-01-01

Since the 2002 discovery of emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in southeastern Michigan and Windsor, Ontario, the distribution of this exotic insect has continued to expand. The primary infestation in Michigan currently includes 13 counties, with small isolated pockets in at least 13 other counties....

Testing Evolutionary Hypotheses in the Classroom with MacClade Software.

ERIC Educational Resources Information Center

Codella, Sylvio G.

2002-01-01

Introduces MacClade which is a Macintosh-based software package that uses the techniques of cladistic analysis to explore evolutionary patterns. Describes a novel and effective exercise that allows undergraduate biology majors to test a hypothesis about behavioral evolution in insects. (Contains 13 references.) (Author/YDS)

Developing attractants and trapping techniques for the emerald ash borer

Treesearch

Therese M. Poland; Peter de Groot; Gary Grant; Linda MacDonald; Deborah G. McCullough

2003-01-01

Shortly after the 2002 discovery of emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in southeastern Michigan and Windsor, Ontario, quarantines regulating the movement of ash logs, firewood, and nursery stock were established to reduce the risk of human-assisted spread of this exotic forest insect pest. Accurate...

Ultraviolet Viewing with a Television Camera.

ERIC Educational Resources Information Center

Eisner, Thomas; And Others

1988-01-01

Reports on a portable video color camera that is fully suited for seeing ultraviolet images and offers some expanded viewing possibilities. Discusses the basic technique, specialized viewing, and the instructional value of this system of viewing reflectance patterns of flowers and insects that are invisible to the unaided eye. (CW)

Influence of holding temperature and irradiation on field performance of mass-reared Thaumatotibia leucotreta (Lepidoptera: Tortricidae)

USDA-ARS?s Scientific Manuscript database

The Sterile Insect Technique (SIT) as an integral component to the area-wide integrated management of the false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), was successfully implemented in the Western Cape region of South Africa and subsequently expanded to citrus are...

Masting characteristics of white oak: implications for management

Treesearch

Marcus A. Lashley; John M. McCord; Cathryn H. Greenberg; Craig A. Harper

2009-01-01

Acorn production is variable from year to year and among species. Weather, insect damage, and genetics are primary causes for variation. Silvicultural techniques have been recommended to improve acorn production; however, those recommendations primarily address variation among red oaks (Quercus rubra). Variability among individual white oaks (Quercus alba) has not been...

Capsules containing entomopathogenic nematodes as a Trojan horse approach to control the western corn rootworm

USDA-ARS?s Scientific Manuscript database

The use of entomopathogenic nematodes in the biological control of soil insect pests is hampered by the costly and inadequate application techniques. As a possible solution we evaluated an encapsulation approach that offers effective application and may possibly attract the pest by adding attractant...

Environmental history impacts gene expression during diapause development in the alfalfa leafcutting bee, Megachile rotundata

USDA-ARS?s Scientific Manuscript database

Our understanding of the mechanisms controlling insect diapause has increased dramatically with the introduction of global gene expression techniques, such as RNAseq. However, little attention has been given to how ecologically relevant field conditions may affect gene expression during diapause dev...

Human Metabolism and Interactions of Deployment-Related Chemicals

DTIC Science & Technology

2003-08-01

with individual test compounds (final concentration, 100 PM), agent pyridostigmine bromide to protect against possible nerve gas NADPH-generating system...an insect repellent (N,N-diethyl-m- toluamide) a nerve gas prophyllactic (pyridostigmine bromide) did not cause the inhibition of trans-permethrin...mechanism of organophosphorus anticholinesterase agents , namely; covalent modification of the active site of the esterases in question. Carbaryl, another

Supporting the Development of Undergraduates' Experimental Design Skills and Investigating their Perceptions of Project Work

ERIC Educational Resources Information Center

MacKenzie, Jane; Ruxton, Graeme

2006-01-01

Project work represents a significant component of most Bioscience degrees. Conscious that students are not necessarily given adequate preparation for their final year project, we have investigated two core elements in the 3rd year of a 4-year Honours programme. One element, an investigative project on aspects of insect biology, has run for…

Morphofunctional Traits and Pollination Mechanisms of Coronilla emerus L. Flowers (Fabaceae)

PubMed Central

Aronne, Giovanna; Giovanetti, Manuela; De Micco, Veronica

2012-01-01

It is accepted that the papilionaceous corolla of the Fabaceae evolved under the selective pressure of bee pollinators. Morphology and function of different parts of Coronilla emerus L. flowers were related to their role in the pollination mechanism. The corolla has a vexillum with red nectar lines, a keel hiding stamens and pistil, and two wing petals fasten to the keel with two notched folds. Pollinators land on the complex of keel and wings, trigger the protrusion of pollen and finally of the stigma from the keel tip. Data on pollen viability and stigma receptivity prove that flowers are proterandrous. The results of hand-pollination experiments confirmed that insects are fundamental to set seed. Interaction with pollinators allows not only the transport of pollen but also the rupture of the stigmatic cuticle, necessary to achieve both allogamy and autogamy. Field observations showed that Hymenoptera, Lepidoptera, and Diptera visited the flowers. Only some of the Hymenoptera landed on the flowers from the front and elicited pollination mechanisms. Most of the insects sucked the nectar from the back without any pollen transfer. Finally, morphological and functional characteristics of C. emerus flowers are discussed in terms of floral larceny and reduction in pollination efficiency. PMID:22666114

Production of Conidia by the Fungus Metarhizium anisopliae Using Solid-State Fermentation.

PubMed

Loera-Corral, Octavio; Porcayo-Loza, Javier; Montesinos-Matias, Roberto; Favela-Torres, Ernesto

2016-01-01

This chapter describes the production of conidia by Metarhizium anisopliae using solid-state fermentation. Before production of conidia, procedures for strains conservation, reactivation, and propagation are essential in order to provide genetic stability of the strains. The strain is conserved in freeze-dried vials and then reactivated through insect inoculation. Rice is used as a substrate for the conidia production in two different bioreactors: plastic bags and tubular bioreactor. The CO2 production in the tubular bioreactors is measured with a respirometer; this system allows calculating indirect growth parameters as lag time (tlag) (25-35 h), maximum rate of CO2 production (rCO2 max) (0.5-0.7 mg/gdm h), specific rate of CO2 production (μ) (0.10-0.15 1/h), and final CO2 production (CO2) (100-120 mg/gdm). Conidial yield per gram of dry substrate (gdm) should be above 1 × 10(9) conidia/gdm after 10 days of incubation. Germination and viability of conidia obtained after 10 days of incubation should be above 80 % and 75 %, respectively. Bioassays using of Tenebrio molitor as a host insect should yield a final mortality above 80 %.

Developmental model of static allometry in holometabolous insects.

PubMed

Shingleton, Alexander W; Mirth, Christen K; Bates, Peter W

2008-08-22

The regulation of static allometry is a fundamental developmental process, yet little is understood of the mechanisms that ensure organs scale correctly across a range of body sizes. Recent studies have revealed the physiological and genetic mechanisms that control nutritional variation in the final body and organ size in holometabolous insects. The implications these mechanisms have for the regulation of static allometry is, however, unknown. Here, we formulate a mathematical description of the nutritional control of body and organ size in Drosophila melanogaster and use it to explore how the developmental regulators of size influence static allometry. The model suggests that the slope of nutritional static allometries, the 'allometric coefficient', is controlled by the relative sensitivity of an organ's growth rate to changes in nutrition, and the relative duration of development when nutrition affects an organ's final size. The model also predicts that, in order to maintain correct scaling, sensitivity to changes in nutrition varies among organs, and within organs through time. We present experimental data that support these predictions. By revealing how specific physiological and genetic regulators of size influence allometry, the model serves to identify developmental processes upon which evolution may act to alter scaling relationships.

Development of transgenic cotton lines expressing Allium sativum agglutinin (ASAL) for enhanced resistance against major sap-sucking pests.

PubMed

Vajhala, Chakravarthy S K; Sadumpati, Vijaya Kumar; Nunna, Hariprasad Rao; Puligundla, Sateesh Kumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

2013-01-01

Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1-2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects.

Development of Transgenic Cotton Lines Expressing Allium sativum Agglutinin (ASAL) for Enhanced Resistance against Major Sap-Sucking Pests

PubMed Central

Nunna, Hariprasad Rao; Puligundla, Sateesh Kumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

2013-01-01

Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1–2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects. PMID:24023750

Make your trappings count: The mathematics of pest insect monitoring. Comment on “Multiscale approach to pest insect monitoring: Random walks, pattern formation, synchronization, and networks” by Petrovskii et al.

NASA Astrophysics Data System (ADS)

Blasius, Bernd

2014-09-01

Since the beginnings of agriculture the production of crops is characterized by an ongoing battle between farmers and pests [1]. Already during biblical times swarms of the desert locust, Schistocerca gregaria, were known as major pest that can devour a field of corn within an hour. Even today, harmful organisms have the potential to threaten food production worldwide. It is estimated that about 37% of all potential crops are destroyed by pests. Harmful insects alone destroy 13%, causing financial losses in the agricultural industry of millions of dollars each year [2-4]. These numbers emphasize the importance of pest insect monitoring as a crucial step of integrated pest management [1]. The main approach to gain information about infestation levels is based on trapping, which leads to the question of how to extrapolate the sparse population counts at singularly disposed traps to a spatial representation of the pest species distribution. In their review Petrovskii et al. provide a mathematical framework to tackle this problem [5]. Their analysis reveals that this seemingly inconspicuous problem gives rise to surprisingly deep mathematical challenges that touch several modern contemporary concepts of statistical physics and complex systems theory. The review does not aim for a collection of numerical recipes to support crop growers in the analysis of their trapping data. Instead the review identifies the relevant biological and physical processes that are involved in pest insect monitoring and it presents the mathematical techniques that are required to capture these processes.

Design and Performance of Insect-Scale Flapping-Wing Vehicles

NASA Astrophysics Data System (ADS)

Whitney, John Peter

Micro-air vehicles (MAVs)---small versions of full-scale aircraft---are the product of a continued path of miniaturization which extends across many fields of engineering. Increasingly, MAVs approach the scale of small birds, and most recently, their sizes have dipped into the realm of hummingbirds and flying insects. However, these non-traditional biologically-inspired designs are without well-established design methods, and manufacturing complex devices at these tiny scales is not feasible using conventional manufacturing methods. This thesis presents a comprehensive investigation of new MAV design and manufacturing methods, as applicable to insect-scale hovering flight. New design methods combine an energy-based accounting of propulsion and aerodynamics with a one degree-of-freedom dynamic flapping model. Important results include analytical expressions for maximum flight endurance and range, and predictions for maximum feasible wing size and body mass. To meet manufacturing constraints, the use of passive wing dynamics to simplify vehicle design and control was investigated; supporting tests included the first synchronized measurements of real-time forces and three-dimensional kinematics generated by insect-scale flapping wings. These experimental methods were then expanded to study optimal wing shapes and high-efficiency flapping kinematics. To support the development of high-fidelity test devices and fully-functional flight hardware, a new class of manufacturing methods was developed, combining elements of rigid-flex printed circuit board fabrication with "pop-up book" folding mechanisms. In addition to their current and future support of insect-scale MAV development, these new manufacturing techniques are likely to prove an essential element to future advances in micro-optomechanics, micro-surgery, and many other fields.

Learning, specialization, efficiency and task allocation in social insects

PubMed Central

Muller, Helene

2009-01-01

One of the most spectacular features of social insect colonies is their division of labor. Although individuals are often totipotent in terms of the labor they might perform, they might persistently work as scouts, fighters, nurses, foragers, undertakers or cleaners with a repetitiveness that might resemble an assembly line worker in a factory. Perhaps because of this apparent analogy, researchers have often assumed a priori that such labor division must be efficient, but empirical proof is scarce. New work on Themnothorax ants shows that there might be no link between an individual's propensity to perform a task, and their efficiency at that task, nor are task specialists more efficient than generalists. Here we argue that learning psychology might provide the missing link between social insect task specialization and efficiency: just like in human societies, efficiency at a job specialty is only partially a result of “talent”, or innate tendency to engage in a job: it is much more a result of perfecting skills with experience, and the extent to which experience can be carried over from one task to the next (transfer), or whether experience at one task might actually impair performance at another (interference). Indeed there is extensive circumstantial evidence that learning is involved in almost any task performed by social insect workers, including food type recognition and handling techniques, but also such seemingly basic tasks as nest building and climate control. New findings on Cerapachys ants indicate that early experience of success at a task might to some extent determine the “profession” an insect worker chooses in later life. PMID:19513269

Genetics and biology of Anastrepha fraterculus: research supporting the use of the sterile insect technique (SIT) to control this pest in Argentina.

PubMed

Cladera, Jorge L; Vilardi, Juan C; Juri, Marianela; Paulin, Laura E; Giardini, M Cecilia; Gómez Cendra, Paula V; Segura, Diego F; Lanzavecchia, Silvia B

2014-01-01

Two species of true fruit flies (taxonomic family Tephritidae) are considered pests of fruit and vegetable production in Argentina: the cosmopolitan Mediterranean fruit fly (Ceratitis capitata Wiedemann) and the new world South American fruit fly (Anastrepha fraterculus Wiedemann). The distribution of these two species in Argentina overlaps north of the capital, Buenos Aires. Regarding the control of these two pests, the varied geographical fruit producing regions in Argentina are in different fly control situations. One part is under a programme using the sterile insect technique (SIT) for the eradication of C. capitata, because A. fraterculus is not present in this area. The application of the SIT to control C. capitata north of the present line with the possibility of A. fraterculus occupying the niche left vacant by C. capitata becomes a cause of much concern. Only initial steps have been taken to investigate the genetics and biology of A. fraterculus. Consequently, only fragmentary information has been recorded in the literature regarding the use of SIT to control this species. For these reasons, the research to develop a SIT protocol to control A. fraterculus is greatly needed. In recent years, research groups have been building a network in Argentina in order to address particular aspects of the development of the SIT for Anastrepha fraterculus. The problems being addressed by these groups include improvement of artificial diets, facilitation of insect mass rearing, radiation doses and conditions for insect sterilisation, basic knowledge supporting the development of males-only strains, reduction of male maturation time to facilitate releases, identification and isolation of chemical communication signals, and a good deal of population genetic studies. This paper is the product of a concerted effort to gather all this knowledge scattered in numerous and often hard-to-access reports and papers and summarize their basic conclusions in a single publication.

Tapping the biotechnological potential of insect microbial symbionts: new insecticidal porphyrins.

PubMed

Martinez, Ana Flávia Canovas; de Almeida, Luís Gustavo; Moraes, Luiz Alberto Beraldo; Cônsoli, Fernando Luís

2017-06-27

The demand for sustainable agricultural practices and the limited progress toward newer and safer chemicals for use in pest control maintain the impetus for research and identification of new natural molecules. Natural molecules are preferable to synthetic organic molecules because they are biodegradable, have low toxicity, are often selective and can be applied at low concentrations. Microbes are one source of natural insecticides, and microbial insect symbionts have attracted attention as a source of new bioactive molecules because these microbes are exposed to various selection pressures in their association with insects. Analytical techniques must be used to isolate and characterize new compounds, and sensitive analytical tools such as mass spectrometry and high-resolution chromatography are required to identify the least-abundant molecules. We used classical fermentation techniques combined with tandem mass spectrometry to prospect for insecticidal substances produced by the ant symbiont Streptomyces caniferus. Crude extracts from this bacterium showed low biological activity (less than 10% mortality) against the larval stage of the fall armyworm Spodoptera frugiperda. Because of the complexity of the crude extract, we used fractionation-guided bioassays to investigate if the low toxicity was related to the relative abundance of the active molecule, leading to the isolation of porphyrins as active molecules. Porphyrins are a class of photoactive molecules with a broad range of bioactivity, including insecticidal. The active fraction, containing a mixture of porphyrins, induced up to 100% larval mortality (LD 50  = 37.7 μg.cm -2 ). Tandem mass-spectrometry analyses provided structural information for two new porphyrin structures. Data on the availability of porphyrins in 67 other crude extracts of ant ectosymbionts were also obtained with ion-monitoring experiments. Insect-associated bacterial symbionts are a rich source of bioactive compounds. Exploring microbial diversity through mass-spectrometry analyses is a useful approach for isolating and identifying new compounds. Our results showed high insecticidal activity of porphyrin compounds. Applications of different experiments in mass spectrometry allowed the characterization of two new porphyrins.

Genetics and biology of Anastrepha fraterculus: research supporting the use of the sterile insect technique (SIT) to control this pest in Argentina

PubMed Central

2014-01-01

Two species of true fruit flies (taxonomic family Tephritidae) are considered pests of fruit and vegetable production in Argentina: the cosmopolitan Mediterranean fruit fly (Ceratitis capitata Wiedemann) and the new world South American fruit fly (Anastrepha fraterculus Wiedemann). The distribution of these two species in Argentina overlaps north of the capital, Buenos Aires. Regarding the control of these two pests, the varied geographical fruit producing regions in Argentina are in different fly control situations. One part is under a programme using the sterile insect technique (SIT) for the eradication of C. capitata, because A. fraterculus is not present in this area. The application of the SIT to control C. capitata north of the present line with the possibility of A. fraterculus occupying the niche left vacant by C. capitata becomes a cause of much concern. Only initial steps have been taken to investigate the genetics and biology of A. fraterculus. Consequently, only fragmentary information has been recorded in the literature regarding the use of SIT to control this species. For these reasons, the research to develop a SIT protocol to control A. fraterculus is greatly needed. In recent years, research groups have been building a network in Argentina in order to address particular aspects of the development of the SIT for Anastrepha fraterculus. The problems being addressed by these groups include improvement of artificial diets, facilitation of insect mass rearing, radiation doses and conditions for insect sterilisation, basic knowledge supporting the development of males-only strains, reduction of male maturation time to facilitate releases, identification and isolation of chemical communication signals, and a good deal of population genetic studies. This paper is the product of a concerted effort to gather all this knowledge scattered in numerous and often hard-to-access reports and papers and summarize their basic conclusions in a single publication. PMID:25471175

A new whole mitochondrial genome qPCR (WMG-qPCR) with SYBR Green® to identify phlebotomine sand fly blood meals.

PubMed

Rodrigues, Ana Caroline Moura; Magalhães, Rafaela Damasceno; Romcy, Kalil Andrade Mubarac; Freitas, Jeferson Lucas Sousa; Melo, Ana Carolina Fonseca Lindoso; Rodon, Fernanda Cristina Macedo; Bevilaqua, Claudia Maria Leal; Melo, Luciana Magalhães

2017-04-30

Phlebotomine sand flies are blood-feeding insects of marked medical and veterinary significance. Investigations on the biology of these insects hold great importance for both ecological and epidemiological purposes. The present work describes a new approach for real-time PCR (qPCR) with SYBR Green ® , named WMG-qPCR, to identify phlebotomine blood meals. The novelty of the assay was to design primers based on the Whole Mitochondrial Genome (WMG) of the potential hosts (human, dog, cat, brown rat and chicken) aiming to amplify through qPCR the regions of mitochondrial DNA (mtDNA) which are less conserved among all species. Initially, the best method for mtDNA extraction to be applied in WMG-qPCR was determined. Afterwards, amplification specificities were accessed by cross-reaction assays with mtDNA samples from all animal species, besides phlebotomine DNA. Finally, the selected primers were also tested for their limit of DNA detection through standard curves constructed by serial dilution of blood DNA obtained for each target animal species. The WMG-qPCR was able to detect as low as 10pL of blood, equivalent to 26, 84, 130, and 320fg DNA of cat, human, dog and rat, respectively. The assay was also capable to amplify as low as 5pL of chicken blood (5pg DNA). In conclusion, WMG-qPCR seems to be a promising tool to identify phlebotomine blood meals, with high species-specificity and sensitivity. Furthermore, as no supplementary techniques are required, this new approach presents minimized costs and simplified technical-training requirements for execution. Copyright © 2017 Elsevier B.V. All rights reserved.

De novo transcriptome sequencing and comparative analysis of midgut tissues of four non-model insects pertaining to Hemiptera, Coleoptera, Diptera and Lepidoptera.

PubMed

Gazara, Rajesh K; Cardoso, Christiane; Bellieny-Rabelo, Daniel; Ferreira, Clélia; Terra, Walter R; Venancio, Thiago M

2017-09-05

Despite the great morphological diversity of insects, there is a regularity in their digestive functions, which is apparently related to their physiology. In the present work we report the de novo midgut transcriptomes of four non-model insects from four distinct orders: Spodoptera frugiperda (Lepidoptera), Musca domestica (Diptera), Tenebrio molitor (Coleoptera) and Dysdercus peruvianus (Hemiptera). We employed a computational strategy to merge assemblies obtained with two different algorithms, which substantially increased the quality of the final transcriptomes. Unigenes were annotated and analyzed using the eggNOG database, which allowed us to assign some level of functional and evolutionary information to 79.7% to 93.1% of the transcriptomes. We found interesting transcriptional patterns, such as: i) the intense use of lysozymes in digestive functions of M. domestica larvae, which are streamlined and adapted to feed on bacteria; ii) the up-regulation of orthologous UDP-glycosyl transferase and cytochrome P450 genes in the whole midguts different species, supporting the existence of an ancient defense frontline to counter xenobiotics; iii) evidence supporting roles for juvenile hormone binding proteins in the midgut physiology, probably as a way to activate genes that help fight anti-nutritional substances (e.g. protease inhibitors). The results presented here shed light on the digestive and structural properties of the digestive systems of these distantly related species. Furthermore, the produced datasets will also be useful for scientists studying these insects. Copyright © 2017. Published by Elsevier B.V.

Gene expression changes governing extreme dehydration tolerance in an Antarctic insect

PubMed Central

Teets, Nicholas M.; Peyton, Justin T.; Colinet, Herve; Renault, David; Kelley, Joanna L.; Kawarasaki, Yuta; Lee, Richard E.; Denlinger, David L.

2012-01-01

Among terrestrial organisms, arthropods are especially susceptible to dehydration, given their small body size and high surface area to volume ratio. This challenge is particularly acute for polar arthropods that face near-constant desiccating conditions, as water is frozen and thus unavailable for much of the year. The molecular mechanisms that govern extreme dehydration tolerance in insects remain largely undefined. In this study, we used RNA sequencing to quantify transcriptional mechanisms of extreme dehydration tolerance in the Antarctic midge, Belgica antarctica, the world’s southernmost insect and only insect endemic to Antarctica. Larvae of B. antarctica are remarkably tolerant of dehydration, surviving losses up to 70% of their body water. Gene expression changes in response to dehydration indicated up-regulation of cellular recycling pathways including the ubiquitin-mediated proteasome and autophagy, with concurrent down-regulation of genes involved in general metabolism and ATP production. Metabolomics results revealed shifts in metabolite pools that correlated closely with changes in gene expression, indicating that coordinated changes in gene expression and metabolism are a critical component of the dehydration response. Finally, using comparative genomics, we compared our gene expression results with a transcriptomic dataset for the Arctic collembolan, Megaphorura arctica. Although B. antarctica and M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods. Whereas several orthologous genes showed similar expression patterns, transcriptional changes were largely species specific, indicating these polar arthropods have developed distinct transcriptional mechanisms to cope with similar desiccating conditions. PMID:23197828

Gene expression changes governing extreme dehydration tolerance in an Antarctic insect.

PubMed

Teets, Nicholas M; Peyton, Justin T; Colinet, Herve; Renault, David; Kelley, Joanna L; Kawarasaki, Yuta; Lee, Richard E; Denlinger, David L

2012-12-11

Among terrestrial organisms, arthropods are especially susceptible to dehydration, given their small body size and high surface area to volume ratio. This challenge is particularly acute for polar arthropods that face near-constant desiccating conditions, as water is frozen and thus unavailable for much of the year. The molecular mechanisms that govern extreme dehydration tolerance in insects remain largely undefined. In this study, we used RNA sequencing to quantify transcriptional mechanisms of extreme dehydration tolerance in the Antarctic midge, Belgica antarctica, the world's southernmost insect and only insect endemic to Antarctica. Larvae of B. antarctica are remarkably tolerant of dehydration, surviving losses up to 70% of their body water. Gene expression changes in response to dehydration indicated up-regulation of cellular recycling pathways including the ubiquitin-mediated proteasome and autophagy, with concurrent down-regulation of genes involved in general metabolism and ATP production. Metabolomics results revealed shifts in metabolite pools that correlated closely with changes in gene expression, indicating that coordinated changes in gene expression and metabolism are a critical component of the dehydration response. Finally, using comparative genomics, we compared our gene expression results with a transcriptomic dataset for the Arctic collembolan, Megaphorura arctica. Although B. antarctica and M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods. Whereas several orthologous genes showed similar expression patterns, transcriptional changes were largely species specific, indicating these polar arthropods have developed distinct transcriptional mechanisms to cope with similar desiccating conditions.

Population genomics of the honey bee reveals strong signatures of positive selection on worker traits.

PubMed

Harpur, Brock A; Kent, Clement F; Molodtsova, Daria; Lebon, Jonathan M D; Alqarni, Abdulaziz S; Owayss, Ayman A; Zayed, Amro

2014-02-18

Most theories used to explain the evolution of eusociality rest upon two key assumptions: mutations affecting the phenotype of sterile workers evolve by positive selection if the resulting traits benefit fertile kin, and that worker traits provide the primary mechanism allowing social insects to adapt to their environment. Despite the common view that positive selection drives phenotypic evolution of workers, we know very little about the prevalence of positive selection acting on the genomes of eusocial insects. We mapped the footprints of positive selection in Apis mellifera through analysis of 40 individual genomes, allowing us to identify thousands of genes and regulatory sequences with signatures of adaptive evolution over multiple timescales. We found Apoidea- and Apis-specific genes to be enriched for signatures of positive selection, indicating that novel genes play a disproportionately large role in adaptive evolution of eusocial insects. Worker-biased proteins have higher signatures of adaptive evolution relative to queen-biased proteins, supporting the view that worker traits are key to adaptation. We also found genes regulating worker division of labor to be enriched for signs of positive selection. Finally, genes associated with worker behavior based on analysis of brain gene expression were highly enriched for adaptive protein and cis-regulatory evolution. Our study highlights the significant contribution of worker phenotypes to adaptive evolution in social insects, and provides a wealth of knowledge on the loci that influence fitness in honey bees.

Toxicity of the mycotoxin fumonisin B1 on the insect Sf9 cell line.

PubMed

Zhang, He; Zhang, Liyang; Diao, Xue; Li, Na; Liu, Chenglan

2017-04-01

Fumonisins are a type of mycotoxin produced by Fusarium spp., mainly F. proliferatum and F. vertieilliodes, and represent a potential hazard to the health of animals and human beings. The toxicity and mechanism of action of fumonisins is ambiguous, and it is unclear whether fumonisins are toxic to insect cells. This study examines the toxicity of fumonisin B 1 (FB 1 ) and its mechanism of action in the Spodoptera frugiperda Sf9 cell line. We found that FB 1 inhibited Sf9 cellular proliferation and arrested cell growth at the G 2 /M phase. Morphological observation showed that FB 1 induced swelling, vacuole formation, and loss of adhesion in Sf9 cells. Flow cytometry analysis showed that FB 1 caused depolarization of the cell membrane potential and hyperpolarization of the mitochondrial membrane potential. To uncover potential genes associated with the molecular mechanisms of FB 1 , 41 differentially expressed genes were identified by transcriptome analyses after FB 1 treatment. These genes are putatively involved in detoxification metabolism, insect hormone regulation, cell apoptosis, and other related processes. Finally, six differentially expressed genes were chosen and validated by quantitative real-time PCR (QRT-PCR). Our test could provide a reference for other kinds of insect cells studies on FB 1 stress. At the same time, our studies try to provide a possible for FB 1 as a precursor compounds of biological insecticide. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Immune Responses of the Animal Hosts of West Nile Virus: A Comparison of Insects, Birds, and Mammals.

PubMed

Ahlers, Laura R H; Goodman, Alan G

2018-01-01

Vector-borne diseases, including arboviruses, pose a serious threat to public health worldwide. Arboviruses of the flavivirus genus, such as Zika virus (ZIKV), dengue virus, yellow fever virus (YFV), and West Nile virus (WNV), are transmitted to humans from insect vectors and can cause serious disease. In 2017, over 2,000 reported cases of WNV virus infection occurred in the United States, with two-thirds of cases classified as neuroinvasive. WNV transmission cycles through two different animal populations: birds and mosquitoes. Mammals, particularly humans and horses, can become infected through mosquito bites and represent dead-end hosts of WNV infection. Because WNV can infect diverse species, research on this arbovirus has investigated the host response in mosquitoes, birds, humans, and horses. With the growing geographical range of the WNV mosquito vector and increased human exposure, improved surveillance and treatment of the infection will enhance public health in areas where WNV is endemic. In this review, we survey the bionomics of mosquito species involved in Nearctic WNV transmission. Subsequently, we describe the known immune response pathways that counter WNV infection in insects, birds, and mammals, as well as the mechanisms known to curb viral infection. Moreover, we discuss the bacterium Wolbachia and its involvement in reducing flavivirus titer in insects. Finally, we highlight the similarities of the known immune pathways and identify potential targets for future studies aimed at improving antiviral therapeutic and vaccination design.

Population genomics of the honey bee reveals strong signatures of positive selection on worker traits

PubMed Central

Harpur, Brock A.; Kent, Clement F.; Molodtsova, Daria; Lebon, Jonathan M. D.; Alqarni, Abdulaziz S.; Owayss, Ayman A.; Zayed, Amro

2014-01-01

Most theories used to explain the evolution of eusociality rest upon two key assumptions: mutations affecting the phenotype of sterile workers evolve by positive selection if the resulting traits benefit fertile kin, and that worker traits provide the primary mechanism allowing social insects to adapt to their environment. Despite the common view that positive selection drives phenotypic evolution of workers, we know very little about the prevalence of positive selection acting on the genomes of eusocial insects. We mapped the footprints of positive selection in Apis mellifera through analysis of 40 individual genomes, allowing us to identify thousands of genes and regulatory sequences with signatures of adaptive evolution over multiple timescales. We found Apoidea- and Apis-specific genes to be enriched for signatures of positive selection, indicating that novel genes play a disproportionately large role in adaptive evolution of eusocial insects. Worker-biased proteins have higher signatures of adaptive evolution relative to queen-biased proteins, supporting the view that worker traits are key to adaptation. We also found genes regulating worker division of labor to be enriched for signs of positive selection. Finally, genes associated with worker behavior based on analysis of brain gene expression were highly enriched for adaptive protein and cis-regulatory evolution. Our study highlights the significant contribution of worker phenotypes to adaptive evolution in social insects, and provides a wealth of knowledge on the loci that influence fitness in honey bees. PMID:24488971

Design, fabrication and testing of hierarchical micro-optical structures and systems

NASA Astrophysics Data System (ADS)

Cannistra, Aaron Thomas

Micro-optical systems are becoming essential components in imaging, sensing, communications, computing, and other applications. Optically based designs are replacing electronic, chemical and mechanical systems for a variety of reasons, including low power consumption, reduced maintenance, and faster operation. However, as the number and variety of applications increases, micro-optical system designs are becoming smaller, more integrated, and more complicated. Micro and nano-optical systems found in nature, such as the imaging systems found in many insects and crustaceans, can have highly integrated optical structures that vary in size by orders of magnitude. These systems incorporate components such as compound lenses, anti-reflective lens surface structuring, spectral filters, and polarization selective elements. For animals, these hybrid optical systems capable of many optical functions in a compact package have been repeatedly selected during the evolutionary process. Understanding the advantages of these designs gives motivation for synthetic optical systems with comparable functionality. However, alternative fabrication methods that deviate from conventional processes are needed to create such systems. Further complicating the issue, the resulting device geometry may not be readily compatible with existing measurement techniques. This dissertation explores several nontraditional fabrication techniques for optical components with hierarchical geometries and measurement techniques to evaluate performance of such components. A micro-transfer molding process is found to produce high-fidelity micro-optical structures and is used to fabricate a spectral filter on a curved surface. By using a custom measurement setup we demonstrate that the spectral filter retains functionality despite the nontraditional geometry. A compound lens is fabricated using similar fabrication techniques and the imaging performance is analyzed. A spray coating technique for photoresist application to curved surfaces combined with interference lithography is also investigated. Using this technique, we generate polarizers on curved surfaces and measure their performance. This work furthers an understanding of how combining multiple optical components affects the performance of each component, the final integrated devices, and leads towards realization of biomimetically inspired imaging systems.

A survival-reproduction trade-off in entomopathogenic nematodes mediated by their bacterial symbionts.

PubMed

Emelianoff, Vanya; Chapuis, Elodie; Le Brun, Nathalie; Chiral, Magali; Moulia, Catherine; Ferdy, Jean-Baptiste

2008-04-01

In this work, we investigate the investment of entomopathogenic Steinernema nematodes (Rhabditidae) in their symbiotic association with Xenorhabdus bacteria (Enterobacteriaceae). Their life cycle comprises two phases: (1) a free stage in the soil, where infective juveniles (IJs) of the nematode carry bacteria in a digestive vesicle and search for insect hosts, and (2) a parasitic stage into the insect where bacterial multiplication, nematode reproduction, and production of new IJs occur. Previous studies clearly showed benefits to the association for the nematode during the parasitic stage, but preliminary data suggest the existence of costs to the association for the nematode in free stage. IJs deprived from their bacteria indeed survive longer than symbiotic ones. Here we show that those bacteria-linked costs and benefits lead to a trade-off between fitness traits of the symbiotic nematodes. Indeed IJs mortality positively correlates with their parasitic success in the insect host for symbiotic IJs and not for aposymbiotic ones. Moreover mortality and parasitic success both positively correlate with the number of bacteria carried per IJ, indicating that the trade-off is induced by symbiosis. Finally, the trade-off intensity depends on parental effects and, more generally, is greater under restrictive environmental conditions.

Selective forces on origin, adaptation and reduction of tympanal ears in insects.

PubMed

Strauß, Johannes; Stumpner, Andreas

2015-01-01

Insect ears evolved many times independently. As a consequence, a striking diversity exists in the location, construction and behavioural implementation of ears. In this review, we first summarise what is known about the evolutionary origin of ears and the presumed precursor organs in the various insect groups. Thereafter, we focus on selective forces for making and keeping an ear: we discuss detecting and localising predators and conspecifics, including establishing new "private" channels for intraspecific communication. More advanced aspects involve judging the distance of conspecifics, or assessing individual quality from songs which makes auditory processing a means for exerting sexual selection on mating partners. We try to identify negative selective forces, mainly in the context of energy expenditure for developing and keeping an ear, but also in conjunction with acoustic communication, which incorporates risks like eavesdropping by predators and parasitoids. We then discuss balancing pressures, which might oppose optimising an ear for a specific task (when it serves different functions, for example). Subsequently, we describe various scenarios that might have led to a reduction or complete loss of ears in evolution. Finally, we describe cases of sex differences in ears and potential reasons for their appearance.

Materials Suitable for preparing Inorganic Nanocasts of butterflies and other insects

NASA Astrophysics Data System (ADS)

Silver, J.; Fern, G. R.; Ireland, T. G.

2015-06-01

Replication of 3D-structures, in particular those that have a periodic modulation of a dielectric material at optical wavelengths and below have proven very difficult to fabricate. The majority of such replication techniques are complex or use moisture sensitive precursors requiring the use of for example a glove box. Here we demonstrate how an air stable supersaturated europium-doped yttrium nitrate phosphor precursor solution has the ability to easily impregnate a structure or produce a cast yielding faithful replicas composed of Y2O:Eu3+ after a final short annealing step. New replicas of Lepidoptera (moth) wing scales using field emission scanning electron microscopy, structures down to 10 nm have been imaged. Moreover as these replicas are made of phosphors, their luminescence in some cases may be modulated by the internal periodic modulation built into their structures. In this work we will discuss more recent results on the use of the phosphors for making nanocasts of moth wing scales and show a range of beautiful pictures to show what the method can achieve.

Butterfly inclusions in Van Schrieck masterpieces. Techniques and optical properties

NASA Astrophysics Data System (ADS)

Berthier, S.; Boulenguez, J.; Menu, M.; Mottin, B.

2008-07-01

Dutch painter Otto Marseus Van Schrieck (1619 1678) is famous for his invention of “sottobosco”. These specific still-life paintings are characterized by the presence of various living organisms (mainly insects and plants) directly on the canvas. We will focus our attention on the painting kept in the museum of Grenoble, France, where a real butterfly is pasted on the canvas. The actual butterfly is a common Nymphalidae, Inachis io, presented in a static position on the dorsal side, without any perspective, compared to the neighboring butterflies. The colors of this butterfly are mainly due to pigments, melanin (black to brown) and ommochromes (yellow, orange, red) often in granules configuration that introduce scattering of light superimposed to the classical selective absorption, except in the ocelli of the hind wings where the blue coloration is due to interferential effects. The nearly perfect refraction index equality between the varnish and the chitin, the main constituent of the butterfly wings, deeply affects its colors. This leads the artist to a final intervention in some parts of the wings, revealed by microscope observation.

Assessing the integrated pest management practices of southeastern US ornamental nursery operations.

PubMed

LeBude, Anthony V; White, Sarah A; Fulcher, Amy F; Frank, Steve; Klingeman Iii, William E; Chong, Juang-Horng; Chappell, Matthew R; Windham, Alan; Braman, Kris; Hale, Frank; Dunwell, Winston; Williams-Woodward, Jean; Ivors, Kelly; Adkins, Craig; Neal, Joe

2012-09-01

The Southern Nursery Integrated Pest Management (SNIPM) working group surveyed ornamental nursery crop growers in the southeastern United States to determine their pest management practices. Respondents answered questions about monitoring practices for insects, diseases and weeds, prevention techniques, intervention decisions, concerns about IPM and educational opportunities. Survey respondents were categorized into three groups based on IPM knowledge and pest management practices adopted. The three groups differed in the use of standardized sampling plans for scouting pests, in monitoring techniques, e.g. sticky cards, phenology and growing degree days, in record-keeping, in the use of spot-spraying and in the number of samples sent to a diagnostic clinic for identification and management recommendation. Stronger emphasis is needed on deliberate scouting techniques and tools to monitor pest populations to provide earlier pest detection and greater flexibility of management options. Most respondents thought that IPM was effective and beneficial for both the environment and employees, but had concerns about the ability of natural enemies to control insect pests, and about the availability and effectiveness of alternatives to chemical controls. Research and field demonstration is needed for selecting appropriate natural enemies for augmentative biological control. Two groups utilized cooperative extension almost exclusively, which would be an avenue for educating those respondents. Copyright © 2012 Society of Chemical Industry.

Consequences of electrical conductivity in an orb spider's capture web

NASA Astrophysics Data System (ADS)

Vollrath, Fritz; Edmonds, Donald

2013-12-01

The glue-coated and wet capture spiral of the orb web of the garden cross spider Araneus diadematus is suspended between the dry silk radial and web frame threads. Here, we experimentally demonstrate that the capture spiral is electrically conductive because of necks of liquid connecting the droplets even if the thread is stretched. We examine how this conductivity of the capture spiral may lead to entrapment of charged airborne particles such as pollen, spray droplets and even insects. We further describe and model how the conducting spiral will also locally distort the Earth's ambient electric field. Finally, we examine the hypothesis that such distortion could be used by potential prey to detect the presence of a web but conclude that any effect would probably be too small to allow an insect to take evasive action.

Identifying Cellular and Molecular Mechanisms for Magnetosensation

PubMed Central

Clites, Benjamin L.; Pierce, Jonathan T.

2017-01-01

Diverse animals ranging from worms and insects to birds and turtles perf orm impressive journeys using the magnetic field of the earth as a cue. Although major cellular and molecular mechanisms for sensing mechanical and chemical cues have been elucidated over the past three decades, the mechanisms that animals use to sense magnetic fields remain largely mysterious. Here we survey progress on the search for magnetosensory neurons and magnetosensitive molecules important for animal behaviors. Emphasis is placed on magnetosensation in insects and birds, as well as on the magnetosensitive neuron pair AFD in the nematode Caenorhabditis elegans. We also review conventional criteria used to define animal magnetoreceptors and suggest how approaches used to identify receptors for other sensory modalities may be adapted for magnetoreceptors. Finally, we discuss prospects for under-utilized and novel approaches to identify the elusive magnetoreceptors in animals. PMID:28772099

The Smart Aerial Release Machine, a Universal System for Applying the Sterile Insect Technique

PubMed Central

Mubarqui, Ruben Leal; Perez, Rene Cano; Kladt, Roberto Angulo; Lopez, Jose Luis Zavala; Parker, Andrew; Seck, Momar Talla; Sall, Baba; Bouyer, Jérémy

2014-01-01

Background Beyond insecticides, alternative methods to control insect pests for agriculture and vectors of diseases are needed. Management strategies involving the mass-release of living control agents have been developed, including genetic control with sterile insects and biological control with parasitoids, for which aerial release of insects is often required. Aerial release in genetic control programmes often involves the use of chilled sterile insects, which can improve dispersal, survival and competitiveness of sterile males. Currently available means of aerially releasing chilled fruit flies are however insufficiently precise to ensure homogeneous distribution at low release rates and no device is available for tsetse. Methodology/Principal Findings Here we present the smart aerial release machine, a new design by the Mubarqui Company, based on the use of vibrating conveyors. The machine is controlled through Bluetooth by a tablet with Android Operating System including a completely automatic guidance and navigation system (MaxNav software). The tablet is also connected to an online relational database facilitating the preparation of flight schedules and automatic storage of flight reports. The new machine was compared with a conveyor release machine in Mexico using two fruit flies species (Anastrepha ludens and Ceratitis capitata) and we obtained better dispersal homogeneity (% of positive traps, p<0.001) for both species and better recapture rates for Anastrepha ludens (p<0.001), especially at low release densities (<1500 per ha). We also demonstrated that the machine can replace paper boxes for aerial release of tsetse in Senegal. Conclusions/Significance This technology limits damages to insects and allows a large range of release rates from 10 flies/km2 for tsetse flies up to 600 000 flies/km2 for fruit flies. The potential of this machine to release other species like mosquitoes is discussed. Plans and operating of the machine are provided to allow its use worldwide. PMID:25036274

The smart aerial release machine, a universal system for applying the sterile insect technique.

PubMed

Leal Mubarqui, Ruben; Perez, Rene Cano; Kladt, Roberto Angulo; Lopez, Jose Luis Zavala; Parker, Andrew; Seck, Momar Talla; Sall, Baba; Bouyer, Jérémy

2014-01-01

Beyond insecticides, alternative methods to control insect pests for agriculture and vectors of diseases are needed. Management strategies involving the mass-release of living control agents have been developed, including genetic control with sterile insects and biological control with parasitoids, for which aerial release of insects is often required. Aerial release in genetic control programmes often involves the use of chilled sterile insects, which can improve dispersal, survival and competitiveness of sterile males. Currently available means of aerially releasing chilled fruit flies are however insufficiently precise to ensure homogeneous distribution at low release rates and no device is available for tsetse. Here we present the smart aerial release machine, a new design by the Mubarqui Company, based on the use of vibrating conveyors. The machine is controlled through Bluetooth by a tablet with Android Operating System including a completely automatic guidance and navigation system (MaxNav software). The tablet is also connected to an online relational database facilitating the preparation of flight schedules and automatic storage of flight reports. The new machine was compared with a conveyor release machine in Mexico using two fruit flies species (Anastrepha ludens and Ceratitis capitata) and we obtained better dispersal homogeneity (% of positive traps, p<0.001) for both species and better recapture rates for Anastrepha ludens (p<0.001), especially at low release densities (<1500 per ha). We also demonstrated that the machine can replace paper boxes for aerial release of tsetse in Senegal. This technology limits damages to insects and allows a large range of release rates from 10 flies/km2 for tsetse flies up to 600,000 flies/km2 for fruit flies. The potential of this machine to release other species like mosquitoes is discussed. Plans and operating of the machine are provided to allow its use worldwide.

Deciphering the preservation of fossil insects: a case study from the Crato Member, Early Cretaceous of Brazil

PubMed Central

Petri, Setembrino; Becker-Kerber, Bruno; Romero, Guilherme Raffaeli; Rizzutto, Marcia de Almeida; Rodrigues, Fabio; Galante, Douglas; da Silva, Tiago Fiorini; Curado, Jessica F.; Rangel, Elidiane Cipriano; Ribeiro, Rafael Parra; Pacheco, Mírian Liza Alves Forancelli

2016-01-01

Exceptionally well-preserved three-dimensional insects with fine details and even labile tissues are ubiquitous in the Crato Member Konservat Lagerstätte (northeastern Brazil). Here we investigate the preservational pathways which yielded such specimens. We employed high resolution techniques (EDXRF, SR-SXS, SEM, EDS, micro Raman, and PIXE) to understand their fossilisation on mineralogical and geochemical grounds. Pseudomorphs of framboidal pyrite, the dominant fossil microfabric, display size variation when comparing cuticle with inner areas or soft tissues, which we interpret as the result of the balance between ion diffusion rates and nucleation rates of pyrite through the originally decaying carcasses. Furthermore, the mineral fabrics are associated with structures that can be the remains of extracellular polymeric substances (EPS). Geochemical data also point to a concentration of Fe, Zn, and Cu in the fossils in comparison to the embedding rock. Therefore, we consider that biofilms of sulphate reducing bacteria (SRB) had a central role in insect decay and mineralisation. Therefore, we shed light on exceptional preservation of fossils by pyritisation in a Cretaceous limestone lacustrine palaeoenvironment. PMID:28028459

Molecular cloning of a cysteine proteinase cDNA from the cotton boll weevil Anthonomus grandis (Coleoptera: Curculionidae).

PubMed

De Oliveira Neto, Osmundo Brilhante; Batista, João Aguiar Nogueira; Rigden, Daniel John; Franco, Octávio Luiz; Fragoso, Rodrigo Rocha; Monteiro, Ana Carolina Santos; Monnerat, Rose Gomes; Grossi-De-Sa, Maria Fátima

2004-06-01

The cotton boll weevil (Anthonomus grandis) causes severe cotton crop losses in North and South America. This report describes the presence of cysteine proteinase activity in the cotton boll weevil. Cysteine proteinase inhibitors from different sources were assayed against total A. grandis proteinases but, unexpectedly, no inhibitor tested was particularly effective. In order to screen for active inhibitors against the boll weevil, a cysteine proteinase cDNA (Agcys1) was isolated from A. grandis larvae using degenerate primers and rapid amplification of cDNA ends (RACE) techniques. Sequence analysis showed significant homologies with other insect cysteine proteinases. Northern blot analysis indicated that the mRNA encoding the proteinase was transcribed mainly in the gut of larvae. No mRNA was detected in neonatal larvae, pupae, or in the gut of the adult insect, suggesting that Agcys1 is an important cysteine proteinase for larvae digestion. The isolated gene will facilitate the search for highly active inhibitors towards boll weevil larvae that may provide a new opportunity to control this important insect pest.

Insecticide resistance and intracellular proteases.

PubMed

Wilkins, Richard M

2017-12-01

Pesticide resistance is an example of evolution in action with mechanisms of resistance arising from mutations or increased expression of intrinsic genes. Intracellular proteases have a key role in maintaining healthy cells and in responding to stressors such as pesticides. Insecticide-resistant insects have constitutively elevated intracellular protease activity compared to corresponding susceptible strains. This increase was shown for some cases originally through biochemical enzyme studies and subsequently putatively by transcriptomics and proteomics methods. Upregulation and expression of proteases have been characterised in resistant strains of some insect species, including mosquitoes. This increase in proteolysis results in more degradation products (amino acids) of intracellular proteins. These may be utilised in the resistant strain to better protect the cell from stress. There are changes in insect intracellular proteases shortly after insecticide exposure, suggesting a role in stress response. The use of protease and proteasome inhibitors or peptide mimetics as synergists with improved application techniques and through protease gene knockdown using RNA interference (possibly expressed in crop plants) may be potential pest management strategies, in situations where elevated intracellular proteases are relevant. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Atomic force microscopy as nano-stethoscope to study living organisms, insects

NASA Astrophysics Data System (ADS)

Sokolov, Igor; Dokukin, Maxim; Guz, Nataliia

2012-02-01

Atomic force microscopy (AFM) is a known method to study various surfaces. Here we report on the use of AFM to study surface oscillations (coming from the work of internal organs) of living organisms, like insects. As an example, ladybird beetles (Hippodamia convergens) measured in different parts of the insect at picometer level. This allows us to record a much broader spectral range of possible surface vibrations (up to several kHz) than the previously studied oscillations due to breathing, heartbeat cycles, coelopulses, etc. (up to 5 -10 Hz). The used here AFM method allows collecting signal from the area as small as ˜100nm2 (0.0001μm2) with an example of noise level of (2±0.2)x10-3 nm r.m.s. at the range of frequencies >50Hz (potentially, up to a MHz). Application of this method to humans is discussed. The method, being a relatively non-invasive technique providing a new type of information, may be useful in developing of what could be called ``nanophysiology.''

Hyperspectral Imaging and Spectroscopy of Fluorescently Coupled Acyl-CoA: Cholesterol Acyltransferase in Insect Cells

NASA Technical Reports Server (NTRS)

Malak, H.; Mahtani, H.; Herman, P.; Vecer, J.; Lu, X.; Chang, T. Y.; Richmond, Robert C.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

A high-performance hyperspectral imaging module with high throughput of light suitable for low-intensity fluorescence microscopic imaging and subsequent analysis, including single-pixel-defined emission spectroscopy, was tested on Sf21 insect cells expressing green fluorescence associated with recombinant green fluorescent protein linked or not with the membrane protein acyl-CoA:cholesterol acyltransferase. The imager utilized the phenomenon of optical activity as a new technique providing information over a spectral range of 220-1400 nm, and was inserted between the microscope and an 8-bit CCD video-rate camera. The resulting fluorescence image did not introduce observable image aberrations. The images provided parallel acquisition of well resolved concurrent spatial and spectral information such that fluorescence associated with green fluorescent protein alone was demonstrated to be diffuse within the Sf21 insect cell, and that green fluorescence associated with the membrane protein was shown to be specifically concentrated within regions of the cell cytoplasm. Emission spectra analyzed from different regions of the fluorescence image showed blue shift specific for the regions of concentration associated with the membrane protein.

Employing in vitro directed molecular evolution for the selection of α-amylase variant inhibitors with activity toward cotton boll weevil enzyme.

PubMed

da Silva, Maria Cristina Mattar; Del Sarto, Rafael Perseghini; Lucena, Wagner Alexandre; Rigden, Daniel John; Teixeira, Fabíola Rodrigues; Bezerra, Caroline de Andrade; Albuquerque, Erika Valéria Saliba; Grossi-de-Sa, Maria Fatima

2013-09-20

Numerous species of insect pests attack cotton plants, out of which the cotton boll weevil (Anthonomus grandis) is the main insect in Brazil and must be controlled to avert large economic losses. Like other insect pests, A. grandis secretes a high level of α-amylases in the midgut lumen, which are required for digestion of carbohydrates. Thus, α-amylase inhibitors (α-AIs) represent a powerful tool to apply in the control of insect pests. Here, we applied DNA shuffling and phage display techniques and obtained a combinatorial library containing 10⁸ α-AI variant forms. From this library, variants were selected exhibiting in vitro affinity for cotton boll weevil α-amylases. Twenty-six variant sequences were cloned into plant expression vectors and expressed in Arabidopsis thaliana. Transformed plant extracts were assayed in vitro to select specific and potent α-amylase inhibitors against boll weevil amylases. While the wild type inhibitors, used to create the shuffled library, did not inhibit the A. grandis α-amylases, three α-AI mutants, named α-AIC3, α-AIA11 and α-AIG4 revealed high inhibitory activities against A. grandis α-amylases in an in vitro assay. In summary, data reported here shown the potential biotechnology of new α-AI variant genes for cotton boll weevil control. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Temperature-dependent sex-reversal by a transformer-2 gene-edited mutation in the spotted wing drosophila, Drosophila suzukii.

PubMed

Li, Jianwei; Handler, Alfred M

2017-09-28

Female to male sex reversal was achieved in an emerging agricultural insect pest, Drosophila suzukii, by creating a temperature-sensitive point mutation in the sex-determination gene, transformer-2 (tra-2), using CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated) homology-directed repair gene-editing. Ds-tra-2 ts2 mutants developed as normal fertile XX and XY adults at permissive temperatures below 20 °C, but at higher restrictive temperatures (26 to 29 °C) chromosomal XX females developed as sterile intersexuals with a predominant male phenotype, while XY males developed with normal morphology, but were sterile. The temperature-dependent function of the Ds-TRA-2 ts2 protein was also evident by the up- and down-regulation of female-specific Ds-Yolk protein 1 (Ds-Yp1) gene expression by temperature shifts during adulthood. This study confirmed the temperature-dependent function of a gene-edited mutation and provides a new method for the more general creation of conditional mutations for functional genomic analysis in insects, and other organisms. Furthermore, it provides a temperature-dependent system for creating sterile male populations useful for enhancing the efficacy of biologically-based programs, such as the sterile insect technique (SIT), to control D. suzukii and other insect pest species of agricultural and medical importance.

Traps and attractants for wood-boring insects in ponderosa pine stands in the Black Hills, South Dakota.

PubMed

Costello, Sheryl L; Negrón, José F; Jacobi, William R

2008-04-01

Recent large-scale wildfires have increased populations of wood-boring insects in the Black Hills of South Dakota. Because little is known about possible impacts of wood-boring insects in the Black Hills, land managers are interested in developing monitoring techniques such as flight trapping with semiochemical baits. Two trap designs and four semiochemical attractants were tested in a recently burned ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in the Black Hills. Modified panel and funnel traps were tested in combination with the attractants, which included a woodborer standard (ethanol and alpha-pinene), standard plus 3-carene, standard plus ipsenol, and standard plus ipsdienol. We found that funnel traps were equally efficient or more efficient in capturing wood-boring insects than modified panel traps. Trap catches of cerambycids increased when we added the Ips spp. pheromone components (ipsenol or ipsdienol) or the host monoterpene (3-carene) to the woodborer standard. During the summers of 2003 and 2004, 18 cerambycid, 14 buprestid, and five siricid species were collected. One species of cerambycid, Monochamus clamator (LeConte), composed 49 and 40% of the 2003 and 2004 trap catches, respectively. Two other cerambycids, Acanthocinus obliquus (LeConte) and Acmaeops proteus (Kirby), also were frequently collected. Flight trap data indicated that some species were present throughout the summer, whereas others were caught only at the beginning or end of the summer.

Radiobiology of Small Hive Beetle (Coleoptera: Nitidulidae) and Prospects for Management Using Sterile Insect Releases.

PubMed

Downey, Danielle; Chun, Stacey; Follett, Peter

2015-06-01

Small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), is considered a serious threat to beekeeping in the Western Hemisphere, Australia, and Europe mainly due to larval feeding on honey, pollen, and brood of the European honeybee, Apis mellifera L. Control methods are limited for this pest. Studies were conducted to provide information on the radiobiology of small hive beetle and determine the potential for sterile insect releases as a control strategy. Adult males and females were equally sensitive to a radiation dose of 80 Gy and died within 5-7 d after treatment. In reciprocal crossing studies, irradiation of females only lowered reproduction to a greater extent than irradiation of males only. For matings between unirradiated males and irradiated females, mean reproduction was reduced by >99% at 45 and 60 Gy compared with controls, and no larvae were produced at 75 Gy. Irradiation of prereproductive adults of both sexes at 45 Gy under low oxygen (1-4%) caused a high level of sterility (>99%) while maintaining moderate survivorship for several weeks, and should suffice for sterile insect releases. Sterile insect technique holds potential for suppressing small hive beetle populations in newly invaded areas and limiting its spread. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

Molecular techniques for detection of confused flour beetle infestations in stored products

USDA-ARS?s Scientific Manuscript database

Tribolium confusum (confused flour beetle) is a stored-product pest which contaminates a wide range of food products, from flour and cereals to spices. The insect reduces food quality and is responsible for large economic losses every year. Although a number of methods for detection of stored-produc...

Improved quality management to enhance the efficacy of the sterile insect technique for lepidopteran pests

USDA-ARS?s Scientific Manuscript database

Lepidoptera are among the most severe pests of food and fibre crops in the world and are mainly controlled using broad spectrum insecticides. This does not lead to sustainable control and farmers are demanding alternative control tools which are both effective and friendly to the environment. The st...

Development of a larval diet for the South American fruit fly Anastrepha fraterculus (Diptera:Tephritidae)

USDA-ARS?s Scientific Manuscript database

Mass-rearing protocols must be developed. In particular, a cost-effective larval diet, to implement the sterile insect technique against Anastrepha fratercculus (Wiedemann). The key elements of this diet are the optimal nutrients and their concentrations, diet supports or bulking agents, and the pH ...

Improving the cost-effectiveness, trade and safety of biological control for agricultural insect pests using nuclear techniques

USDA-ARS?s Scientific Manuscript database

If appropriately applied, biological control offers one of the most promising, environmentally sound, and sustainable control tactics for arthropod pests and weeds for application as part of an integrated pest management (IPM) approach. Public support for biological control as one of the preferred m...

MALDI-TOF mass spectrometry applied to identifying species of insect-pathogenic fungi from the Metarhizium anisopliae complex

USDA-ARS?s Scientific Manuscript database

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has proven to be a powerful tool for taxonomic resolution of microorganisms. In this proof-of-concept study, we assessed the effectiveness of this technique to track the current gene sequence-based phylogenet...

Decision support systems for plant disease and insect management in commercial nurseries in the Midwest: A perspective review

USDA-ARS?s Scientific Manuscript database

Decision-support systems (DDSs) are techniques that help decision makers utilize models to solve problems under complex and uncertain conditions. Predicting conditions that warrant intervention is a key tenet of the concept of integrated pest management (IPM) with the use of expert systems and pest ...

Germline transformation of the olive fruit fly, Bactrocera oleae (Rossi)(Diptera:Tephritidae) with a piggyBac transposon vector

USDA-ARS?s Scientific Manuscript database

The olive fruit fly, Bactrocera oleae, is a highly significant pest in olive growing countries whose control may be enhanced by the use of genetically-modified strains, especially for sterile insect technique programs. To improve and expand this technology, piggyBac-mediated germline transformation ...

Study on Integrated Pest Management for Libraries and Archives.

ERIC Educational Resources Information Center

Parker, Thomas A.

This study addresses the problems caused by the major insect and rodent pests and molds and mildews in libraries and archives; the damage they do to collections; and techniques for their prevention and control. Guidelines are also provided for the development and initiation of an Integrated Pest Management program for facilities housing library…

Guide to testing insecticides on coniferous forest defoliators

Treesearch

Carroll B Jr. Williams; David A. Sharpnack; Liz Maxwell; Patrick J. Shea; Mark D. McGregor

1985-01-01

This report provides a guide to techniques for designing field tests of candidate insecticides, and for carrying out pilot tests and control projects. It describes experimental designs for testing hypotheses, and for sampling trees to estimate insect population densities and percent reduction after treatments. Directions for applying insecticides by aircraft and for...

American beech resistance to Cryptococcus fagisuga

Treesearch

David R. Houston

1983-01-01

American beech trees that were free of beech bark disease in forests long-affected by beech bark disease were challenged with C. fagisuga using the 'foam' technique. Trees were resistant: no insects reached maturity. In Nova Scotia, 12-15 disease-free trees per hectare occurred in the stands examined. Many of these trees occurred in groups...

Imidacloprid in Melon Guttation Fluid: A Mode of Exposure for Pest and Beneficial Organisms

USDA-ARS?s Scientific Manuscript database

ELISA techniques were used to detect imidacloprid in guttation fluid of young cantaloupe plants in Arizona. Imidacloprid was detected at up to 37 µg / ml (ppm) one d after a label rate soil application. These imidacloprid titers exceed reported median oral toxicities for several insect species by ...

The Amateur Zoologist: Explorations and Investigations. Amateur Science Series.

ERIC Educational Resources Information Center

Dykstra, Mary

This book contains over 30 investigations and activities that can be used or adapted for science fair projects. It outlines basic techniques and procedures that can be applied to zoological investigations. Projects and activities described include: finding out how many different kinds of insects and other arthropods live in nearby fields and…

A technique for thermal desorption analyses suitable for thermally-labile, volatile compounds

USDA-ARS?s Scientific Manuscript database

Our group has for some time studied below ground plant produced volatile signals affecting nematode and insect behavior. The research requires repeated sampling of intact plant/soil systems in the lab as well as the field with the help of probes to minimize unwanted effects on the systems we are stu...

Exploring Mosquito Fauna of Majuro Atoll (Republic of Marshall Islands) in the Context of Zika Outbreak.

PubMed

Marie, Jérôme; Perera, Devika; Garstang, Helentina; Bossin, Herve C; Bourtzis, Kostas

2018-04-09

First autochthonous Zika clinical case was reported in the Republic of Marshall Islands (RMI) on Majuro Atoll in February 2016. An entomological survey of mosquito larvae and adult populations was carried out in four areas of Majuro, the most populated atoll of RMI encompassing different habitats (forest, rural, or urban) including some with confirmed clinical Zika cases to evaluate which mosquito species could be involved in the Zika transmission. A total of 2,367 immature and adult mosquito specimens were collected and identified to the species level. In total, five mosquito species were detected, Aedes aegypti (Linnaeus), Aedes albopictus (Skuse), Aedes marshallensis (Stone and Bohart), Culex quinquefasciatus (Say), and Culex annulirostris (Skuse) (Diptera: Culicidae), a first record for RMI. The most abundant species was Ae. aegypti presumed to be the main vector of Zika virus followed by Ae. albopictus. Improved management of breeding containers through better public awareness and community engagement, mosquito surveillance and innovative mosquito control strategies using the sterile insect technique (SIT) and/or the incompatible insect technique (IIT) could help prevent outbreaks of arboviruses in the RMI.

Services of DNA barcoding in different fields.

PubMed

Muhammad Tahir, Hafiz; Akhtar, Samreen

2016-11-01

DNA barcoding is a new master key for species identification and has greatly accelerated the pace of species discovery. In this novel and cost-effective technique, a short DNA sequence from a standard region of mitochondrial "CO1" gene called "barcode" is used. At present, researchers all over the world are utilizing this powerful tool for investigating biodiversity, differentiating cryptic species, testing food authenticity, identifying parasites, vectors, insect pests, and predators, monitoring of illegal trade of animals and their products, and identifying forensically important insects. In addition, this technique can potentially be used to monitor quality of drinking water, quickly identify the indicator species of lakes, rivers, and streams, identify species with harmful attributes or medicinal properties, monitor smuggling of endangered plants and animals and their products, and disease investigations. Despite non-favorable criticism from a few researchers, DNA barcoding has achieved immense popularity in the scientific community, especially among biologists. The present review provides an overview of DNA barcoding and its practical applications. The limitation, future prospective and main informative platforms for DNA barcoding have also been discussed.

Protection of Grain Products from Sitophilus oryzae (L.) Contamination by Anti-Insect Pest Repellent Sachet Containing Allyl Mercaptan Microcapsule.

PubMed

Chang, Yoonjee; Lee, Soo-Hyun; Na, Ja Hyun; Chang, Pahn-Shick; Han, Jaejoon

2017-11-01

The purpose of this study was to develop an anti-insect pest repellent sachet to prevent Sitophilus oryzae (L.) (Coleoptera: Curculionidae) contamination in grain packaging. The anti-insect pest activities of essential oils (EOs) from garlic (Allium Sativum), ginger (Zingiber Officinalis), black pepper (Piper nigrum), onion (Allium cepa), and fennel (Foeniculum vulgare) as well as major compounds (allyl disulfide, AD; allyl mercaptan, AM) isolated from of garlic and onion (AD and AM) were measured against S. oryzae. The results revealed that garlic EO, onion EO, AD, and AM showed strong fumigant insecticidal activities. Among these, AM showed the highest acetylcholinesterase (AChE) inhibition rate, indicating that the fumigation insecticidal efficacy of AM is related with its AChE inhibition ability. Subsequently, the microcapsules were produced with a high efficiency (80.02%) by using AM as a core material and rice flour as a wall material. Finally, sachet composed of rice flour microcapsule containing 2% AM (RAM) was produced. Repellent assay was performed to measure anti-insect pest ability of the RAM sachet, showed remarkable repelling effect within 48 h both in the presence or absence of attractant. In a release profile of RAM sachet, it was expected to last over 20 mo during the distribution period of brown rice. Moreover, RAM sachet showed no undesirable changes to the sensory properties of the rice both before and after cooking. Taken together, these results suggest that the newly developed RAM sachet could be used as a packaging material to protect grain products from S. oryzae contamination. The rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), causes damages to stored products and its contamination in grain products has become a major problem in cereal market. To preserve brown rice, an anti-insect pest repellent sachet containing 2% allyl mercaptan was newly developed and it showed remarkable repellent abilities against S. oryzae. It could be used as an active food packaging system to protect grain products from insect pest contamination. © 2017 Institute of Food Technologists®.

A protocol for analysing thermal stress in insects using infrared thermography.

PubMed

Gallego, Belén; Verdú, José R; Carrascal, Luis M; Lobo, Jorge M

2016-02-01

The study of insect responses to thermal stress has involved a variety of protocols and methodologies that hamper the ability to compare results between studies. For that reason, the development of a protocol to standardize thermal assays is necessary. In this sense, infrared thermography solves some of the problems allowing us to take continuous temperature measurements without handling the individuals, an important fact in cold-blooded organisms like insects. Here, we present a working protocol based on infrared thermography to estimate both cold and heat thermal stress in insects. We analyse both the change in the body temperature of individuals and their behavioural response. In addition, we used partial least squares regression for the statistical analysis of our data, a technique that solves the problem of having a large number of variables and few individuals, allowing us to work with rare or endemic species. To test our protocol, we chose two species of congeneric, narrowly distributed dung beetles that are endemic to the southeastern part of the Iberian Peninsula. With our protocol we have obtained five variables in the response to cold and twelve in the response to heat. With this methodology we discriminate between the two flightless species of Jekelius through their thermal response. In response to cold, Jekelius hernandezi showed a higher rate of cooling and reached higher temperatures of stupor and haemolymph freezing than Jekelius punctatolineatus. Both species displayed similar thermoregulation ranges before reaching lethal body temperature with heat stress. Overall, we have demonstrated that infrared thermography is a suitable method to assess insect thermal responses with a high degree of sensitivity, allowing for the discrimination between closely related species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Harnessing mosquito-Wolbachia symbiosis for vector and disease control.

PubMed

Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

2014-04-01

Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

Culturing and Characterization of Gut Symbiont Burkholderia spp. from the Southern Chinch Bug, Blissus insularis (Hemiptera: Blissidae)

PubMed Central

Buss, Eileen A.; Boucias, Drion G.

2016-01-01

ABSTRACT The phloem-feeding Southern chinch bug, Blissus insularis, harbors a high density of the exocellular bacterial symbiont Burkholderia in the lumen of specialized midgut crypts. Here we developed an organ culture method that initially involved incubating the B. insularis crypts in osmotically balanced insect cell culture medium. This approach enabled the crypt-inhabiting Burkholderia spp. to make a transition to an in vitro environment and to be subsequently cultured in standard bacteriological media. Examinations using ribotyping and BOX-PCR fingerprinting techniques demonstrated that most in vitro-produced bacterial cultures were identical to their crypt-inhabiting Burkholderia counterparts. Genomic and physiological analyses of gut-symbiotic Burkholderia spp. that were isolated individually from two separate B. insularis laboratory colonies revealed that the majority of individual insects harbored a single Burkholderia ribotype in their midgut crypts, resulting in a diverse Burkholderia community within each colony. The diversity was also exhibited by the phenotypic and genotypic characteristics of these Burkholderia cultures. Access to cultures of crypt-inhabiting bacteria provides an opportunity to investigate the interaction between symbiotic Burkholderia spp. and the B. insularis host. Furthermore, the culturing method provides an alternative strategy for establishing in vitro cultures of other fastidious insect-associated bacterial symbionts. IMPORTANCE An organ culture method was developed to establish in vitro cultures of a fastidious Burkholderia symbiont associated with the midgut crypts of the Southern chinch bug, Blissus insularis. The identities of the resulting cultures were confirmed using the genomic and physiological features of Burkholderia cultures isolated from B. insularis crypts, showing that host insects maintained the diversity of Burkholderia spp. over multiple generations. The availability of characterized gut-symbiotic Burkholderia cultures provides a resource for genetic manipulation of these bacteria and for examination of the mechanisms underlying insect-bacterium symbiosis. PMID:27016568

Sampling techniques for thrips (Thysanoptera: Thripidae) in preflowering tomato.

PubMed

Joost, P Houston; Riley, David G

2004-08-01

Sampling techniques for thrips (Thysanoptera: Thripidae) were compared in preflowering tomato plants at the Coastal Plain Experiment Station in Tifton, GA, in 2000 and 2003, to determine the most effective method of determining abundance of thrips on tomato foliage early in the growing season. Three relative sampling techniques, including a standard insect aspirator, a 946-ml beat cup, and an insect vacuum device, were compared for accuracy to an absolute method and to themselves for precision and efficiency of sampling thrips. Thrips counts of all relative sampling methods were highly correlated (R > 0.92) to the absolute method. The aspirator method was the most accurate compared with the absolute sample according to regression analysis in 2000. In 2003, all sampling methods were considered accurate according to Dunnett's test, but thrips numbers were lower and sample variation was greater than in 2000. In 2000, the beat cup method had the lowest relative variation (RV) or best precision, at 1 and 8 d after transplant (DAT). Only the beat cup method had RV values <25 for all sampling dates. In 2003, the beat cup method had the lowest RV value at 15 and 21 DAT. The beat cup method also was the most efficient method for all sample dates in both years. Frankliniella fusca (Pergande) was the most abundant thrips species on the foliage of preflowering tomato in both years of study at this location. Overall, the best thrips sampling technique tested was the beat cup method in terms of precision and sampling efficiency.

Combining the Sterile Insect Technique with the Incompatible Insect Technique: III-Robust Mating Competitiveness of Irradiated Triple Wolbachia-Infected Aedes albopictus Males under Semi-Field Conditions.

PubMed

Zhang, Dongjing; Lees, Rosemary Susan; Xi, Zhiyong; Bourtzis, Kostas; Gilles, Jeremie R L

2016-01-01

Combination of the sterile insect technique with the incompatible insect technique is considered to be a safe approach to control Aedes albopictus populations in the absence of an accurate and scalable sex separation system or genetic sexing strain. Our previous study has shown that the triple Wolbachia-infected Ae. albopictus strain (wAlbA, wAlbB and wPip) was suitable for mass rearing and females could be completely sterilized as pupae with a radiation dose of at least 28 Gy. However, whether this radiation dose can influence the mating competitiveness of the triple infected males was still unknown. In this study we aimed to evaluate the effects of irradiation on the male mating competitiveness of the triple infected strain under laboratory and semi-field conditions. The results herein indicate that irradiation with a lower, female-sterilizing dose has no negative impact on the longevity of triple infected males while a reduced lifespan was observed in the wild type males (wAlbA and wAlbB) irradiated with a higher male-sterilizing dose, in small cages. At different sterile: fertile release ratios in small cages, triple-infected males induced 39.8, 81.6 and 87.8% sterility in a wild type female population at 1:1, 5:1 and 10:1 release ratios, respectively, relative to a fertile control population. Similarly, irradiated triple infected males induced 31.3, 70.5 and 89.3% sterility at 1:1, 5:1 and 10:1 release ratios, respectively, again relative to the fertile control. Under semi-field conditions at a 5:1 release ratio, relative to wild type males, the mean male mating competitiveness index of 28 Gy irradiated triple-infected males was significantly higher than 35 Gy irradiated wild type males, while triple infected males showed no difference in mean mating competitiveness to either irradiated triple-infected or irradiated wild type males. An unexpected difference was also observed in the relative male mating competitiveness of the triple infected strain after irradiation at 28 Gy dose in small vs large cages, with a higher male mating competitiveness index calculated from results of experiments in the large cages. Based on these results, we consider that the male mating performance of the triple infected strain after irradiation at 28 Gy, a dose required for complete female sterility and the avoidance of population replacement, is approximately equal to that of the wild type males under semi-field conditions. Though field evaluation is required, this suggests that the triple infected strain is suitable for irradiation and release as part of a combined SIT-IIT approach to Ae. albopictus control.

Combining the Sterile Insect Technique with the Incompatible Insect Technique: III-Robust Mating Competitiveness of Irradiated Triple Wolbachia-Infected Aedes albopictus Males under Semi-Field Conditions

PubMed Central

Zhang, Dongjing; Lees, Rosemary Susan; Xi, Zhiyong; Bourtzis, Kostas; Gilles, Jeremie R. L.

2016-01-01

Combination of the sterile insect technique with the incompatible insect technique is considered to be a safe approach to control Aedes albopictus populations in the absence of an accurate and scalable sex separation system or genetic sexing strain. Our previous study has shown that the triple Wolbachia-infected Ae. albopictus strain (wAlbA, wAlbB and wPip) was suitable for mass rearing and females could be completely sterilized as pupae with a radiation dose of at least 28 Gy. However, whether this radiation dose can influence the mating competitiveness of the triple infected males was still unknown. In this study we aimed to evaluate the effects of irradiation on the male mating competitiveness of the triple infected strain under laboratory and semi-field conditions. The results herein indicate that irradiation with a lower, female-sterilizing dose has no negative impact on the longevity of triple infected males while a reduced lifespan was observed in the wild type males (wAlbA and wAlbB) irradiated with a higher male-sterilizing dose, in small cages. At different sterile: fertile release ratios in small cages, triple-infected males induced 39.8, 81.6 and 87.8% sterility in a wild type female population at 1:1, 5:1 and 10:1 release ratios, respectively, relative to a fertile control population. Similarly, irradiated triple infected males induced 31.3, 70.5 and 89.3% sterility at 1:1, 5:1 and 10:1 release ratios, respectively, again relative to the fertile control. Under semi-field conditions at a 5:1 release ratio, relative to wild type males, the mean male mating competitiveness index of 28 Gy irradiated triple-infected males was significantly higher than 35 Gy irradiated wild type males, while triple infected males showed no difference in mean mating competitiveness to either irradiated triple-infected or irradiated wild type males. An unexpected difference was also observed in the relative male mating competitiveness of the triple infected strain after irradiation at 28 Gy dose in small vs large cages, with a higher male mating competitiveness index calculated from results of experiments in the large cages. Based on these results, we consider that the male mating performance of the triple infected strain after irradiation at 28 Gy, a dose required for complete female sterility and the avoidance of population replacement, is approximately equal to that of the wild type males under semi-field conditions. Though field evaluation is required, this suggests that the triple infected strain is suitable for irradiation and release as part of a combined SIT-IIT approach to Ae. albopictus control. PMID:26990981

Monitoring gypsy moth defoliation by applying change detection techniques to Landsat imagery

NASA Technical Reports Server (NTRS)

Williams, D. L.; Stauffer, M. L.

1978-01-01

The overall objective of a research effort at NASA's Goddard Space Flight Center is to develop and evaluate digital image processing techniques that will facilitate the assessment of the intensity and spatial distribution of forest insect damage in Northeastern U.S. forests using remotely sensed data from Landsats 1, 2 and C. Automated change detection techniques are presently being investigated as a method of isolating the areas of change in the forest canopy resulting from pest outbreaks. In order to follow the change detection approach, Landsat scene correction and overlay capabilities are utilized to provide multispectral/multitemporal image files of 'defoliation' and 'nondefoliation' forest stand conditions.

Slanted joint axes of the stick insect antenna: an adaptation to tactile acuity

NASA Astrophysics Data System (ADS)

Mujagic, Samir; Krause, André F.; Dürr, Volker

2007-04-01

Like many flightless, obligatory walking insects, the stick insect Carausius morosus makes intensive use of active antennal movements for tactile near range exploration and orientation. The antennal joints of C. morosus have a peculiar oblique and non-orthogonal joint axis arrangement. Moreover, this arrangement is known to differ from that in crickets (Ensifera), locusts (Caelifera) and cockroaches (Blattodea), all of which have an orthogonal joint axis arrangement. Our hypothesis was that the situation found in C. morosus represents an important evolutionary trait of the order of stick and leaf insects (Phasmatodea). If this was true, it should be common to other species of the Phasmatodea. The objective of this comparative study was to resolve this question. We have measured the joint axis orientation of the head scape and scape pedicel joints along with other parameters that affect the tactile efficiency of the antenna. The obtained result was a complete kinematic description of the antenna. This was used to determine the size and location of kinematic out-of-reach zones, which are indicators of tactile acuity. We show that the oblique and non-orthogonal arrangement is common to eight species from six sub-families indicating that it is a synapomorphic character of the Euphasmatodea. This character can improve tactile acuity compared to the situation in crickets, locusts and cockroaches. Finally, because molecular data of a recent study indicate that the Phasmatodea may have evolved as flightless, obligatory walkers, we argue that the antennal joint axis arrangement of the Euphasmatodea reflects an evolutionary adaptation to tactile near range exploration during terrestrial locomotion.

Are the metabolomic responses to folivory of closely related plant species linked to macroevolutionary and plant-folivore coevolutionary processes?

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

Rivas-Ubach, Albert; Hódar, José A.; Sardans, Jordi

The debate whether the coevolution of plants and insects or macroevolutionary processes (phylogeny) is the main driver determining the arsenal of molecular defensive compounds of plants remains unresolved. Attacks by herbivorous insects affect not only the composition of defensive compounds in plants but the entire metabolome (the set of molecular metabolites), including defensive compounds. Metabolomes are the final products of genotypes and are directly affected by macroevolutionary processes, so closely related species should have similar metabolomic compositions and may respond in similar ways to attacks by folivores. We analyzed the elemental compositions and metabolomes of needles from Pinus pinaster, P.more » nigra and P. sylvestris to determine if these closely related Pinus species with different coevolutionary histories with the caterpillars of the processionary moth respond similarly to attacks by this lepidopteran. All pines had different metabolomes and metabolic responses to herbivorous attack. The metabolomic variation among the pine species and the responses to folivory reflected their macroevolutionary relationships, with P. pinaster having the most divergent metabolome. The concentrations of phenolic metabolites were generally not higher in the attacked trees, which had lower concentrations of terpenes, suggesting that herbivores avoid individuals with high concentrations of terpenes. Our results suggest that macroevolutionary history plays important roles in the metabolomic responses of these pine species to folivory, but plant-insect coevolution probably constrains those responses. Combinations of different evolutionary factors and trade-offs are likely responsible for the different responses of each species to folivory, which is not necessarily exclusively linked to plant-insect coevolution.« less

A Challenge for Micro and Mini UAV: The Sensor Problem

DTIC Science & Technology

2005-05-01

pressure airspeed sensors on one single circuit board (Figure 8). Figure 8: Autopilot. The Quadcopter The fourth and final MAV is a quad-copter with...UNCLASSIFIED/UNLIMITED Figure 9: Quadcopter MAV. Figure 10: Loopshaping Diagram. The IMU contains 3 MEMS gyros. These form the rotational sensors Gx...flapping wings) and even by insects (vibrating wings). Once in operation, they will be extremely discrete, making it very difficult to distinct

The Seven Challenges for Transitioning into a Bio-based Circular Economy in the Agri-food Sector.

PubMed

Borrello, Massimiliano; Lombardi, Alessia; Pascucci, Stefano; Cembalo, Luigi

2016-01-01

Closed-loop agri-food supply chains have a high potential to reduce environmental and economic costs resulting from food waste disposal. This paper illustrates an alternative to the traditional supply chain of bread based on the principles of a circular economy. Six circular interactions among seven actors (grain farmers, bread producers, retailers, compostable packaging manufacturers, insect breeders, livestock farmers, consumers) of the circular filière are created in order to achieve the goal of "zero waste". In the model, two radical technological innovations are considered: insects used as animal feed and polylactic acid compostable packaging. The main challenges for the implementation of the new supply chain are identified. Finally, some recent patents related to bread sustainable production, investigated in the current paper, are considered. Recommendations are given to academics and practitioners interested in the bio-based circular economy model approach for transforming agri-food supply chains.

Neuropeptide imaging on an LTQ with vMALDI source: The complete `all-in-one' peptidome analysis

NASA Astrophysics Data System (ADS)

Verhaert, Peter D.; Conaway, Maria C. Prieto; Pekar, Tonya M.; Miller, Ken

2007-02-01

Direct tissue imaging was performed on dissected insect tissue using a MALDI ion trap to visualize endogenous neuropeptides. Coupling tissue imaging to tandem MSn allows for the identification of previously known species and the ability to identify new ones by de novo sequencing, as searchable databases for insects are sparse. Direct tissue imaging is an attractive technique for the study of neuropeptides as minimal sample preparation is required prior to mass spectrometry. We successfully identified neuropeptides present in the corpora cardiaca and allata of Acheta domesticus (the house cricket). Diagnostic fragments at low m/z were used to distinguish between lipids and neuropeptides. The distribution of peptides appears to be more differentially localized than that of phospholipids, which seem to be more evenly distributed within the tissue.

Geographic variation in bacterial communities associated with the red turpentine beetle (Coleoptera: Curculionidae)

Treesearch

Aaron S. Adams; Sandye M. Adams; Cameron R. Currie; Nancy E. Gillette; Kenneth F. Raffa

2010-01-01

Bacterial communities are known to play important roles in insect life histories, yet their consistency or variation across populations is poorly understood. Bacteria associated with the bark beetle Dendroctonus valens LeConte from eight populations, ranging from Wisconsin to Oregon, were evaluated and compared. We used the culture-independent technique of denaturing...

Comparative rearing parameters for bisexual and genetic sexing strains of Zeugodacus cucurbitae and Bactrocera dorsalis (Diptera: Tephritidae) on an artificial diet

USDA-ARS?s Scientific Manuscript database

The Sterile Insect Technique (SIT) is an important component of area wide programs to control invading or established populations of pestiferous tephritids. The SIT involves the production, sterilization, and release of large numbers of the target species, with the goal of obtaining sterile male x w...

Distribution and persistence of sterile screwworms (Diptera: Calliphoridae) released at the Panama-Colombia border

USDA-ARS?s Scientific Manuscript database

The sterile insect technique is currently used by the Comisión Panamá - Estados Unidos para la Erradicación y Prevención del Gusano Barrenador del Ganado (COPEG) to maintain a barrier at the border between Panama and Colombia that prevents screwworms, Cochliomyia hominivorax (Coquerel), from South A...

Development of neuropeptide analogs capable of traversing the integument: A case study using diapause hormone analogs in Helicoverpa zea

USDA-ARS?s Scientific Manuscript database

Diapause hormone and its analogs terminate pupal diapause in H. zea when injected, but if such agents are to be used as effective diapause disruptors it will be essential to develop simple techniques for administering active compounds that can exert their effect by penetrating the insect epidermis. ...

Anoxia-conditioning hormesis alters the relationship between irradiation doses for survival and sterility in the cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae)

USDA-ARS?s Scientific Manuscript database

One of the most important components of a Sterile Insect Technique (SIT) program is appropriate irradiation dose. Knowing the organismal dose-response enables the selection of a dose that induces the highest level of sterility while preserving the sexual competitiveness and quality of the sterile in...

Development of liquid larval diet with modified rearing system for Bactrocera dorsalis (Hendel) (Diptera:Tephritidae) for the application of sterile insect technique

USDA-ARS?s Scientific Manuscript database

A liquid larval diet and its rearing system have been developed for mass rearing of Bactrocera dorsalis (Hendel) in Hawaii. Rearing facility in Institute of Food and Radiation Biology, Atomic Energy Research Establishment, Dhaka, Bangladesh, modified protein source from brewer's yeast to a combinat...

Employing immunomarkers to track dispersal and trophic relationships of piercing-sucking predator, Podisus maculiventris (Hemiptera: Pentatomidae)

USDA-ARS?s Scientific Manuscript database

Proteins such as rabbit IgG and chicken IgY are markers that are easy to apply and analyze on insects for monitoring dispersal and/or pest consumption, but current application techniques are less effective in research for the large guild of piercing-sucking predators used in biocontrol. To address t...

Horticultural technique for rearing and redistribution of the sessile biological control agent, Rhizaspidiotus donacis on its host plant, Arundo donax

USDA-ARS?s Scientific Manuscript database

Arundo donax, giant reed, is an invasive weed in the riparian habitats of the Rio Grande Basin. A biological control program using specialist insects from the native range in Mediterranean Europe, including the arundo scale, Rhizaspidiotus donacis, has been implemented. The arundo scale is a sessile...

Developing Sterile Insect Technique (SIT) as a tool Mosquito Control Districts can use for integrated Aedes aegypti control

USDA-ARS?s Scientific Manuscript database

Uncontrolled populations of Aedes aegypti pose a significant public health-risk to humans as a vector of dangerous arboviruses in most of the tropical and much of the temperate regions of the world. Aedes aegypti are difficult to control because they exploit abundant artificial containers around ho...

Influence of methoprene and dietary protein on maturation and sexual performance of sterile, Anastrepha ludens (Diptera: Tephritidae)

USDA-ARS?s Scientific Manuscript database

Juvenile hormone levels and adult diet have important effects on the attractiveness and competitiveness of the male Anastrepha ludens (Loew) (Mexican fruit fly). Since the success of the sterile insect technique requires the release of males that can compete in the wild, these effects are very impor...

Mating compatibility and competitiveness between wild and laboratory strains of Eldana saccharina (Lepidoptera: Pyralidae) after radiation treatment

USDA-ARS?s Scientific Manuscript database

The efficacy of the sterile insect technique (SIT) applied as part of area-wide integrated pest management (AW-IPM) programmes depends on the efficient transfer of sperm carrying dominant lethal mutations from sterile males to wild females. The success or failure of this strategy is therefore critic...

Feasibility of Using a Caribbean Strain of the New World Screwworm for SIT Campaigns in Brazil

USDA-ARS?s Scientific Manuscript database

The New World Screwworm (NWS) is one of the most damaging parasites of livestock in South America with annual losses of millions of dollars. Recently, Mercado Común del Sur countries demonstrated interest for the control of this pest by the Sterile Insect Technique (SIT). A pilot-project was conduct...

Cryopreservation of embryos of the Mediterranean fruit fly Ceratitis capitata Vienna 8 Genetic Sexing Strain

USDA-ARS?s Scientific Manuscript database

The Mediterranean fruit fly, Ceratitis capitata, is one of the most serious pests of fruit crops world-wide. During the last decades, area-wide pest management (AW-IPM) approaches with a sterile insect technique (SIT) component have been used to control populations of this pest in an effective and e...

Classification and spatial analysis of eastern hemlock health using remote sensing and GIS

Treesearch

Laurent R. Bonneau; Kathleen S. Shields; Daniel L. Civco; David R. Mikus

2000-01-01

Over the past decade hemlock stands in southern Connecticut have undergone significant decline coincident with the arrival in 1985 of an exotic insect pest, the hemlock woolly adelgid (Adelges tsugae Annand). The objective of this study was to evaluate image enhancement techniques for rating the health of hemlocks at the landscape level using...

The Virtual Genetics Lab II: Improvements to a Freely Available Software Simulation of Genetics

ERIC Educational Resources Information Center

White, Brian T.

2012-01-01

The Virtual Genetics Lab II (VGLII) is an improved version of the highly successful genetics simulation software, the Virtual Genetics Lab (VGL). The software allows students to use the techniques of genetic analysis to design crosses and interpret data to solve realistic genetics problems involving a hypothetical diploid insect. This is a brief…

A Bio-inspired Collision Avoidance Model Based on Spatial Information Derived from Motion Detectors Leads to Common Routes

PubMed Central

Bertrand, Olivier J. N.; Lindemann, Jens P.; Egelhaaf, Martin

2015-01-01

Avoiding collisions is one of the most basic needs of any mobile agent, both biological and technical, when searching around or aiming toward a goal. We propose a model of collision avoidance inspired by behavioral experiments on insects and by properties of optic flow on a spherical eye experienced during translation, and test the interaction of this model with goal-driven behavior. Insects, such as flies and bees, actively separate the rotational and translational optic flow components via behavior, i.e. by employing a saccadic strategy of flight and gaze control. Optic flow experienced during translation, i.e. during intersaccadic phases, contains information on the depth-structure of the environment, but this information is entangled with that on self-motion. Here, we propose a simple model to extract the depth structure from translational optic flow by using local properties of a spherical eye. On this basis, a motion direction of the agent is computed that ensures collision avoidance. Flying insects are thought to measure optic flow by correlation-type elementary motion detectors. Their responses depend, in addition to velocity, on the texture and contrast of objects and, thus, do not measure the velocity of objects veridically. Therefore, we initially used geometrically determined optic flow as input to a collision avoidance algorithm to show that depth information inferred from optic flow is sufficient to account for collision avoidance under closed-loop conditions. Then, the collision avoidance algorithm was tested with bio-inspired correlation-type elementary motion detectors in its input. Even then, the algorithm led successfully to collision avoidance and, in addition, replicated the characteristics of collision avoidance behavior of insects. Finally, the collision avoidance algorithm was combined with a goal direction and tested in cluttered environments. The simulated agent then showed goal-directed behavior reminiscent of components of the navigation behavior of insects. PMID:26583771

The effect of within-instar development on tracheal diameter and hypoxia-inducible factors α and β in the tobacco hornworm, Manduca sexta.

PubMed

Lundquist, Taylor A; Kittilson, Jeffrey D; Ahsan, Rubina; Greenlee, Kendra J

2017-12-12

As insects grow within an instar, body mass increases, often more than doubling. The increase in mass causes an increase in metabolic rate and hence oxygen demand. However, the insect tracheal system is hypothesized to increase only after molting and may be compressed as tissues grow within an instar. The increase in oxygen demand in the face of a potentially fixed or decreasing supply could result in hypoxia as insects near the end of an instar. To test these hypotheses, we first used synchrotron X-ray imaging to determine how diameters of large tracheae change within an instar and after molting to the next instar in the tobacco hornworm, Manduca sexta. Large tracheae did not increase in diameter within the first, second, third, and fourth instars, but increased upon molting. To determine if insects are hypoxic at the end of instars, we used the presence of hypoxia-inducible factors (HIFs) as an index. HIF-α and HIF-β dimerize in hypoxia and act as a transcription factor that turns on genes that will increase oxygen delivery. We sequenced both of these genes and measured their mRNA levels at the beginning and end of each larval instar. Finally, we obtained an antibody to HIF-α and measured protein expression during the same time. Both mRNA and protein levels of HIFs were increased at the end of most instars. These data support the hypothesis that some insects may experience hypoxia at the end of an instar, which could be a signal for molting. As caterpillars grow within an instar, major tracheae do not increase in size, while metabolic demand increases. At the same life stages, caterpillars increased expression of hypoxia inducible factors, suggesting that they become hypoxic near the end of an instar. Copyright © 2017 Elsevier Ltd. All rights reserved.

Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus.

PubMed

Lan, Hanhong; Chen, Hongyan; Liu, Yuyan; Jiang, Chaoyang; Mao, Qianzhuo; Jia, Dongsheng; Chen, Qian; Wei, Taiyun

2016-01-15

Numerous viruses are transmitted in a persistent manner by insect vectors. Persistent viruses establish their initial infection in the midgut epithelium, from where they disseminate to the midgut visceral muscles. Although propagation of viruses in insect vectors can be controlled by the small interfering RNA (siRNA) antiviral pathway, whether the siRNA pathway can control viral dissemination from the midgut epithelium is unknown. Infection by a rice virus (Southern rice black streaked dwarf virus [SRBSDV]) of its incompetent vector (the small brown planthopper [SBPH]) is restricted to the midgut epithelium. Here, we show that the siRNA pathway is triggered by SRBSDV infection in continuously cultured cells derived from the SBPH and in the midgut of the intact insect. Knockdown of the expression of the core component Dicer-2 of the siRNA pathway by RNA interference strongly increased the ability of SRBSDV to propagate in continuously cultured SBPH cells and in the midgut epithelium, allowing viral titers in the midgut epithelium to reach the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/μg of midgut RNA) needed for viral dissemination into the SBPH midgut muscles. Our results thus represent the first elucidation of the threshold for viral dissemination from the insect midgut epithelium. Silencing of Dicer-2 further facilitated the transmission of SRBSDV into rice plants by SBPHs. Taken together, our results reveal the new finding that the siRNA pathway can control the initial infection of the insect midgut epithelium by a virus, which finally affects the competence of the virus's vector. Many viral pathogens that cause significant global health and agricultural problems are transmitted via insect vectors. The first bottleneck in viral infection, the midgut epithelium, is a principal determinant of the ability of an insect species to transmit a virus. Southern rice black streaked dwarf virus (SRBSDV) is restricted exclusively to the midgut epithelium of an incompetent vector, the small brown planthopper (SBPH). Here, we show that silencing of the core component Dicer-2 of the small interfering RNA (siRNA) pathway increases viral titers in the midgut epithelium past the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/μg of midgut RNA) for viral dissemination into the midgut muscles and then into the salivary glands, allowing the SBPH to become a competent vector of SRBSDV. This result is the first evidence that the siRNA antiviral pathway has a direct role in the control of viral dissemination from the midgut epithelium and that it affects the competence of the virus's vector. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus

PubMed Central

Lan, Hanhong; Chen, Hongyan; Liu, Yuyan; Jiang, Chaoyang; Mao, Qianzhuo; Jia, Dongsheng; Chen, Qian

2015-01-01

ABSTRACT Numerous viruses are transmitted in a persistent manner by insect vectors. Persistent viruses establish their initial infection in the midgut epithelium, from where they disseminate to the midgut visceral muscles. Although propagation of viruses in insect vectors can be controlled by the small interfering RNA (siRNA) antiviral pathway, whether the siRNA pathway can control viral dissemination from the midgut epithelium is unknown. Infection by a rice virus (Southern rice black streaked dwarf virus [SRBSDV]) of its incompetent vector (the small brown planthopper [SBPH]) is restricted to the midgut epithelium. Here, we show that the siRNA pathway is triggered by SRBSDV infection in continuously cultured cells derived from the SBPH and in the midgut of the intact insect. Knockdown of the expression of the core component Dicer-2 of the siRNA pathway by RNA interference strongly increased the ability of SRBSDV to propagate in continuously cultured SBPH cells and in the midgut epithelium, allowing viral titers in the midgut epithelium to reach the threshold (1.99 × 109 copies of the SRBSDV P10 gene/μg of midgut RNA) needed for viral dissemination into the SBPH midgut muscles. Our results thus represent the first elucidation of the threshold for viral dissemination from the insect midgut epithelium. Silencing of Dicer-2 further facilitated the transmission of SRBSDV into rice plants by SBPHs. Taken together, our results reveal the new finding that the siRNA pathway can control the initial infection of the insect midgut epithelium by a virus, which finally affects the competence of the virus's vector. IMPORTANCE Many viral pathogens that cause significant global health and agricultural problems are transmitted via insect vectors. The first bottleneck in viral infection, the midgut epithelium, is a principal determinant of the ability of an insect species to transmit a virus. Southern rice black streaked dwarf virus (SRBSDV) is restricted exclusively to the midgut epithelium of an incompetent vector, the small brown planthopper (SBPH). Here, we show that silencing of the core component Dicer-2 of the small interfering RNA (siRNA) pathway increases viral titers in the midgut epithelium past the threshold (1.99 × 109 copies of the SRBSDV P10 gene/μg of midgut RNA) for viral dissemination into the midgut muscles and then into the salivary glands, allowing the SBPH to become a competent vector of SRBSDV. This result is the first evidence that the siRNA antiviral pathway has a direct role in the control of viral dissemination from the midgut epithelium and that it affects the competence of the virus's vector. PMID:26537672

Characterization of a venom gland-associated rhabdovirus in the parasitoid wasp Diachasmimorpha longicaudata.

PubMed

Simmonds, Tyler J; Carrillo, Daniel; Burke, Gaelen R

2016-01-01

Parasitoid wasps reproduce by laying their eggs on or inside of a host insect, which triggers a defense response in the host insect that kills the developing wasp. To counteract the host's lethal response, some parasitoid wasps are associated with symbiotic viruses that alter host metabolism and development to promote successful development of the wasp embryo. These symbiotic viruses display a number of characteristics that differ from those of pathogenic viruses, but are poorly understood with the exception of one group, the polydnaviruses. Here, we characterize the genome of a non-polydnavirus associated with parasitoid wasps, Diachasmimorpha longicaudata rhabdovirus (DlRhV), and assess its role as a potential mutualistic virus. Our results show that the DlRhV genome contains six open reading frames (ORFs). Three ORFs show sequence homology to known viral genes and one ORF encodes a previously identified protein, called parasitism-specific protein 24 (PSP24), that has been hypothesized to play a role in promoting successful parasitism by D. longicaudata. We constructed a phylogeny that shows that DlRhV is most closely related to other insect-infecting rhabdoviruses. Finally, we report that DlRhV infection does not occur in all populations of D. longicaudata, and is not required for successful parasitism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of an entomopathogenic bacterium, Serratia sp. ANU101, and its hemolytic activity.

PubMed

Kim, Yonggyun; Kim, Keunseob; Seo, Jiae; Shrestha, Sony; Kim, Hosanna H; Nalini, Madanagopal; Yi, Youngkeun

2009-03-01

Four different bacterial colonies were isolated from an old stock of an entomopathogenic nematode, Steinernema monticolum. They all showed entomopathogenicity to final instar larvae of beet armyworm, Spodoptera exigua, by hemocoelic injection. However, they varied in colony form, susceptibility to antibiotics, and postmortem change of the infected host insects. Biolog microbial identification and 16S rDNA sequence analyses indicate that these are four different species classified into different bacterial genera. owing to high entomopathogenicity and a cadaver color of infected insect host, Serratia sp. was selected as a main symbiotic bacterial species and analyzed for its pathogenicity. Although no virulence of Serratia sp. was detected at oral administration, the bacteria gave significant synergistic pathogenicity to fifth instar S. exigua when it was treated along with a spore-forming entomopathogenic bacterium, Bacillus thuringiensis. The synergistic effect was explained by an immunosuppressive effect of Serratia sp. by its high cytotoxic effect on hemocytes of S. exigua, because Serratia sp. caused septicemia of S. exigua when the bacterial cells were injected into S. exigua hemocoel. The cytotoxic factor(s) was present in the culture medium because the sterilized culture broth possessed high potency in the cytotoxicity, which was specific to granular cells and plasmatocytes, two main immune-associated hemocytes in insects.

Pollination systems involving floral mimicry of fruit: aspects of their ecology and evolution.

PubMed

Goodrich, Katherine R; Jürgens, Andreas

2018-01-01

Floral mimicry of nonfloral resources is found across many angiosperm families, with mimicry of varied models including carrion, dung, fungi, insects and fruit. These systems provide excellent models to investigate the role of visual and olfactory cues for the ecology and evolution of plant-animal interactions. Interestingly, floral mimicry of fruit is least documented in the literature, although ripe or rotting fruits play an important role as a food or brood site in many insect groups such as Diptera, Hymenoptera and Coleoptera, and frugivorous vertebrates such as bats and birds. In ecosystems where fruit represents a frequent, reliable resource (e.g. tropical forests), this form of floral mimicry could represent a common mimicry class with specialization possible along multiple axes such as fruit of different species, stages of ripeness and microbial colonization. In this review, we summarize current research on floral mimicry of fruit. We place this review in the context of floral mimicry of a broader spectrum of nonfloral resources, and we discuss conceptual frameworks of mimicry vs generalized food deception or pre-existing sensory bias. Finally, we briefly review the specificity and complexity of fruit-insect ecological interactions, and we summarize important considerations and questions for moving forward in this field. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

The insect central complex as model for heterochronic brain development-background, concepts, and tools.

PubMed

Koniszewski, Nikolaus Dieter Bernhard; Kollmann, Martin; Bigham, Mahdiyeh; Farnworth, Max; He, Bicheng; Büscher, Marita; Hütteroth, Wolf; Binzer, Marlene; Schachtner, Joachim; Bucher, Gregor

2016-06-01

The adult insect brain is composed of neuropils present in most taxa. However, the relative size, shape, and developmental timing differ between species. This diversity of adult insect brain morphology has been extensively described while the genetic mechanisms of brain development are studied predominantly in Drosophila melanogaster. However, it has remained enigmatic what cellular and genetic mechanisms underlie the evolution of neuropil diversity or heterochronic development. In this perspective paper, we propose a novel approach to study these questions. We suggest using genome editing to mark homologous neural cells in the fly D. melanogaster, the beetle Tribolium castaneum, and the Mediterranean field cricket Gryllus bimaculatus to investigate developmental differences leading to brain diversification. One interesting aspect is the heterochrony observed in central complex development. Ancestrally, the central complex is formed during embryogenesis (as in Gryllus) but in Drosophila, it arises during late larval and metamorphic stages. In Tribolium, it forms partially during embryogenesis. Finally, we present tools for brain research in Tribolium including 3D reconstruction and immunohistochemistry data of first instar brains and the generation of transgenic brain imaging lines. Further, we characterize reporter lines labeling the mushroom bodies and reflecting the expression of the neuroblast marker gene Tc-asense, respectively.

A Model Framework to Estimate Impact and Cost of Genetics-Based Sterile Insect Methods for Dengue Vector Control

PubMed Central

Alphey, Nina; Alphey, Luke; Bonsall, Michael B.

2011-01-01

Vector-borne diseases impose enormous health and economic burdens and additional methods to control vector populations are clearly needed. The Sterile Insect Technique (SIT) has been successful against agricultural pests, but is not in large-scale use for suppressing or eliminating mosquito populations. Genetic RIDL technology (Release of Insects carrying a Dominant Lethal) is a proposed modification that involves releasing insects that are homozygous for a repressible dominant lethal genetic construct rather than being sterilized by irradiation, and could potentially overcome some technical difficulties with the conventional SIT technology. Using the arboviral disease dengue as an example, we combine vector population dynamics and epidemiological models to explore the effect of a program of RIDL releases on disease transmission. We use these to derive a preliminary estimate of the potential cost-effectiveness of vector control by applying estimates of the costs of SIT. We predict that this genetic control strategy could eliminate dengue rapidly from a human community, and at lower expense (approximately US$ 2∼30 per case averted) than the direct and indirect costs of disease (mean US$ 86–190 per case of dengue). The theoretical framework has wider potential use; by appropriately adapting or replacing each component of the framework (entomological, epidemiological, vector control bio-economics and health economics), it could be applied to other vector-borne diseases or vector control strategies and extended to include other health interventions. PMID:21998654

Morphometric evidence for a possible role of Rhodnius prolixus from palm trees in house re-infestation in the State of Barinas (Venezuela).

PubMed

Feliciangeli, M Dora; Sanchez-Martin, Maria; Marrero, Rosalba; Davies, Clive; Dujardin, Jean-Pierre

2007-02-01

The main vector of Chagas disease in Venezuela is Rhodnius prolixus. Specimens of Rhodnius sp., identified elsewhere as R. prolixus by molecular tools, were collected in Barinas State (Venezuela) before insecticide application, and compared by morphometric techniques with post-spraying, re-infesting insects after control. Geometric morphometry was applied, allowing separate analyses of shape and size. The idea of a single species sharing silvatic and domestic/peri-domestic ecotopes was supported, suggesting new evolutionary scenarios for the controversial R. prolixus origins. The same data allowed to understand the possible mechanisms of villages re-infestation after a control campaign, either recolonization by local recovery of survivors or re-infestation by external migrants. Both mechanisms were apparent. Although shape properties could distinguish very close subpopulations such as insects from houses and insects from peri-domestic shelters, they were unable to identify the insects from palm trees as a distinct subpopulation. This strongly suggested that human environment could receive immigrants from palm trees. The pattern of size variation supported the hypothesis of a one-way exchange from silvatic to human environments, but did not support the reverse movement. Thus, morphometric data indicated that a silvatic population of the local vector is probably responsible for re-infesting villages after insecticide application, and they also pointed to the existence of re-infestation by local recovery of survivors. According to this interpretation, new epidemiological scenarios must be considered to improve Chagas disease control in Venezuela.

Respiratory strategy is a major determinant of [3H]water and [14C]chlorpyrifos uptake in aquatic insects

USGS Publications Warehouse

Buchwalter, D.B.; Jenkins, J.J.; Curtis, L.R.

2002-01-01

Despite the extensive use of aquatic insects to evaluate freshwater ecosystem health, little is known about the underlying factors that result in sensitivity differences between taxa. Organismal characteristics (respiratory strategy and body size) were used to explore the rates of [3H]H2O and [14)C]chlorpyrifos accumulation in aquatic insects. Ten aquatic insect taxa, including ephemeropteran, trichopteran, dipteran, hemipteran, and coleopteran species, were exposed to [14C]chlorpyrifos (240 ng??L-1) and [3H]H2O for up to 12 h. Because exchange epithelial surfaces on the)integument are permeable to water, [3H]H2O was used as a quantitative surrogate for exposed cellular surface area.) [14C]Chlorpyrifos uptake rates were highly correlated with water permeability in all 10 taxa tested and largely covaried with body size and respiratory strategy. Rates were highest among smaller organisms on a per-weight basis and in taxa with relatively large external cellular surfaces such as gills. Air-breathing taxa were significantly less permeable to both [3)HH20 and [14C)C]chlorpyrifos. A method for labeling exposed epithelial surfaces with a fluorescent dye was developed. This technique allowed discrimination between exchange epithelium and barrier tissue on the integument. Fluorescent dye distributions on the body surface provided a rapid method for estimating exposed epithelium consistent with [3H]H2O and [14)C]chlorpyrifos accumulation.

Interrogating an insect society

PubMed Central

Gadagkar, Raghavendra

2009-01-01

Insect societies such as those of ants, bees, and wasps consist of 1 or a small number of fertile queens and a large number of sterile or nearly sterile workers. While the queens engage in laying eggs, workers perform all other tasks such as nest building, acquisition and processing of food, and brood care. How do such societies function in a coordinated and efficient manner? What are the rules that individuals follow? How are these rules made and enforced? These questions are of obvious interest to us as fellow social animals but how do we interrogate an insect society and seek answers to these questions? In this article I will describe my research that was designed to seek answers from an insect society to a series of questions of obvious interest to us. I have chosen the Indian paper wasp Ropalidia marginata for this purpose, a species that is abundantly distributed in peninsular India and serves as an excellent model system. An important feature of this species is that queens and workers are morphologically identical and physiologically nearly so. How then does an individual become a queen? How does the queen suppress worker reproduction? How does the queen regulate the nonreproductive activities of the workers? What is the function of aggression shown by different individuals? How and when is the queen's heir decided? I will show how such questions can indeed be investigated and will emphasize the need for a whole range of different techniques of observation and experimentation. PMID:19487678

Molecular Diet Analysis of Two African Free-Tailed Bats (Molossidae) Using High Throughput Sequencing

PubMed Central

Bohmann, Kristine; Monadjem, Ara; Lehmkuhl Noer, Christina; Rasmussen, Morten; Zeale, Matt R. K.; Clare, Elizabeth; Jones, Gareth; Willerslev, Eske; Gilbert, M. Thomas P.

2011-01-01

Given the diversity of prey consumed by insectivorous bats, it is difficult to discern the composition of their diet using morphological or conventional PCR-based analyses of their faeces. We demonstrate the use of a powerful alternate tool, the use of the Roche FLX sequencing platform to deep-sequence uniquely 5′ tagged insect-generic barcode cytochrome c oxidase I (COI) fragments, that were PCR amplified from faecal pellets of two free-tailed bat species Chaerephon pumilus and Mops condylurus (family: Molossidae). Although the analyses were challenged by the paucity of southern African insect COI sequences in the GenBank and BOLD databases, similarity to existing collections allowed the preliminary identification of 25 prey families from six orders of insects within the diet of C. pumilus, and 24 families from seven orders within the diet of M. condylurus. Insects identified to families within the orders Lepidoptera and Diptera were widely present among the faecal samples analysed. The two families that were observed most frequently were Noctuidae and Nymphalidae (Lepidoptera). Species-level analysis of the data was accomplished using novel bioinformatics techniques for the identification of molecular operational taxonomic units (MOTU). Based on these analyses, our data provide little evidence of resource partitioning between sympatric M. condylurus and C. pumilus in the Simunye region of Swaziland at the time of year when the samples were collected, although as more complete databases against which to compare the sequences are generated this may have to be re-evaluated. PMID:21731749

Applied radiation physics: The use of x-rays for the structural characterization of aqueous emulsions and the development of new insect sterilization protocols

NASA Astrophysics Data System (ADS)

Brar, Ramaninder K.

X-rays have great potential of applications in a wide variety of fields. This dissertation presents the use of x-rays for the structural characterization of aqueous emulsions and for insect sterilization. The stabilization of hydrophobic colloids, such as oil droplets, in water has attracted scientist for a variety of scientific, pharmaceutical and industrial applications. Several studies have been done to understand the stability of oil-in-water emulsions. The work of Pashley and his coworkers has demonstrated that the removal of dissolved gasses from water enhances the dispersion of hydrophobic oil in water and these surfactant-free emulsions do not lose their stability when the previously removed gasses are reintroduced. However, very little is known about the structure and stability of these emulsions over time or even to what extent they form. The formation of a stable emulsion in the complete absence of a surfactant could provide an alternative approach to a physiologically safe drug carrier. In this dissertation we demonstrate the formation of stabilized surfactant-free degassed emulsions of hydrocarbons - hexane, heptane and octane and silicone oil in ultra-pure water. The enhancement of dispersion of oil droplets by degassing was large for highly hydrophobic silicone oil. Turbidity measurements and small angle x-ray scattering results show that the uniformly dispersed oil droplets weakly aggregate over a period of several hours. Gentle perturbation re-generates the dispersion to nearly initial conditions. The control of insect species for the protection of crops, livestock, and prevention of disease, such as dengue fever and malaria, is a high priority in today's global economy. Sterile Insect Technique (SIT), a method of insect extermination without the use of pesticides, has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipterans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. To improve mosquito SIT, we have developed new radiation protocols for insect sterilization using long wavelength x-rays. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males' longevity as well as on the efficacy of sterilization while employing a substantially lower dose.

Analysis of amino acids in nectar from pitchers of Sarracenia purpurea (Sarraceniaceae).

PubMed

Dress, W; Newell, S; Nastase, A; Ford, J

1997-12-01

Sarracenia purpurea L. (northern pitcher plant) is an insectivorous plant with extrafloral nectar that attracts insects to a water-filled pitfall trap. We identified and quantified the amino acids in extrafloral nectar produced by pitchers of S. purpurea. Nectar samples were collected from 32 pitchers using a wick-sampling technique. Samples were analyzed for amino acids with reverse-phase high-performance liquid chromatography with phenylisothiocyanate derivatization. Detectable amounts of amino acids were found in each of the 32 nectar samples tested. Mean number of amino acids in a nectar sample was 9 (SD = 2.2). No amino acid was detected in all 32 samples. Mean amount of amino acids in a nectar sample (i.e., amount per wick) was 351.4 ng (SD = 113.2). Nine amino acids occurred in 20 of the 32 samples (aspartic acid, cysteine, glutamic acid, glycine, histidine, hydroxyproline, methionine, serine, valine) averaging 263.4 ng (SD = 94.9), and accounting for ~75% of the total amino acid content. Nectar production may constitute a significant cost of carnivory since the nectar contains amino acids. However, some insects prefer nectar with amino acids and presence of amino acids may increase visitation and capture of insect prey.

Effects of gamma irradiation on the midgut ultrastructure of Glossina palpalis subspecies

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

Stiles, J.K.; Molyneux, D.H.; Wallbanks, K.R.

1989-05-01

In the sterile insect technique, insects are sterilized prior to release in areas where they are pests. The sterile males compete for and with fertile wild individuals for mates, thus reducing the population's reproductive rate. Tsetse fly (Glossina spp.) populations have been eradicated after release of laboratory-bred flies sterilized by gamma irradiation. However, no studies exist on radiation-induced damage to the midgut morphology and function of the radiation-sterilized insects. After G. palpalis palpalis and G. p. gambiensis were subjected to 130 Gy gamma radiation, their midgut damage and recovery were monitored by electron microscopy. The first sign of damage wasmore » atrophy and loss of the microvillous border from epithelial cells. The rate of cell degeneration increased, with young as well as old cells being affected and cellular debris filling the ectoperitrophic space. Muscle cells were destroyed, patches of basal lamina were left bare, intracellular virus- and rickettsia-like organisms became more frequent, and many replacement cells became unusually large. Partial recovery occurred from the 10th day postirradiation. Such changes in midgut ultrastructure and the corresponding inhibition of functions may increase the susceptibility of the fly to trypanosome infection.« less

A Non-lethal water-based removal-reapplication technique for behavioral analysis of cuticular compounds of ants.

PubMed

Roux, Olivier; Martin, Jean-Michel; Ghomsi, Nathan Tene; Dejean, Alain

2009-08-01

Interspecific relationships among insects are often mediated by chemical cues, including non-volatile cuticular compounds. Most of these compounds are hydrocarbons that necessitate the use of solvents for their extraction, identification, and manipulation during behavioral assays. The toxicity of these solvents often precludes the removal and reapplication of hydrocarbons from and to live insects. As a consequence, dummies often are used in behavioral assays, but their passivity can bias the behavior of the responding insects. To overcome these limitations, we propose a method where cuticular compounds are extracted from live ants by placing them into glass vials half-filled with tepid water (ca. 34 degrees C) and vigorously shaking the vials to form an emulsion whose supernatant can be analyzed and/or reapplied to other ants. We demonstrate that cuticular compounds can be extracted from workers of the red fire ant, Solenopsis saevissima, and reapplied to the cuticle of workers from a sympatric species, Camponotus blandus (both Hymenoptera: Formicidae), while keeping the ants alive. Gas chromatographic-mass spectrometric analysis and behavioral assays were used to confirm the successful transfer of the behaviorally active compounds.

Dissecting the variance-covariance structure in insect physiology: the multivariate association between metabolism and morphology in the nymphs of the sand cricket (Gryllus firmus).

PubMed

Nespolo, Roberto F; Castañeda, Luis E; Roff, Derek A

2005-08-01

Energy metabolism in animals has been largely studied in relation to exogenous sources of variation. However, because they give insight into the relationship between whole metabolism and lower organizational levels such as organs and tissues, examination of endogenous determinants of metabolism other than body mass is itself very important. We studied the multivariate association of body parts and several aspects of energy metabolism in an insect, the nymphs of the sand cricket, Gryllus firmus. By using a variety of both univariate and multivariate techniques, we explored the resultant variance-covariance matrix to build a path diagram with latent variables. After controlling for body mass, we found a significant canonical correlation between metabolism and morphology. According to the factor loadings and path coefficients, the most important contributions of morphology to the correlation were thorax and abdomen size measures, whereas the most important metabolic contribution was resting metabolism. Activity metabolism was mostly explained by body mass rather than body parts, which could be a result of resting rates being chronic consequences of the functioning of the metabolic machinery that the insect must maintain.

A Chromosome-Scale Assembly of the Bactrocera cucurbitae Genome Provides Insight to the Genetic Basis of white pupae

PubMed Central

Sim, Sheina B.; Geib, Scott M.

2017-01-01

Genetic sexing strains (GSS) used in sterile insect technique (SIT) programs are textbook examples of how classical Mendelian genetics can be directly implemented in the management of agricultural insect pests. Although the foundation of traditionally developed GSS are single locus, autosomal recessive traits, their genetic basis are largely unknown. With the advent of modern genomic techniques, the genetic basis of sexing traits in GSS can now be further investigated. This study is the first of its kind to integrate traditional genetic techniques with emerging genomics to characterize a GSS using the tephritid fruit fly pest Bactrocera cucurbitae as a model. These techniques include whole-genome sequencing, the development of a mapping population and linkage map, and quantitative trait analysis. The experiment designed to map the genetic sexing trait in B. cucurbitae, white pupae (wp), also enabled the generation of a chromosome-scale genome assembly by integrating the linkage map with the assembly. Quantitative trait loci analysis revealed SNP loci near position 42 MB on chromosome 3 to be tightly linked to wp. Gene annotation and synteny analysis show a near perfect relationship between chromosomes in B. cucurbitae and Muller elements A–E in Drosophila melanogaster. This chromosome-scale genome assembly is complete, has high contiguity, was generated using a minimal input DNA, and will be used to further characterize the genetic mechanisms underlying wp. Knowledge of the genetic basis of genetic sexing traits can be used to improve SIT in this species and expand it to other economically important Diptera. PMID:28450369

Increasing evidence that bats actively forage at wind turbines

PubMed Central

Foo, Cecily F.; Bennett, Victoria J.; Korstian, Jennifer M.; Schildt, Alison J.; Williams, Dean A.

2017-01-01

Although the ultimate causes of high bat fatalities at wind farms are not well understood, several lines of evidence suggest that bats are attracted to wind turbines. One hypothesis is that bats would be attracted to turbines as a foraging resource if the insects that bats prey upon are commonly present on and around the turbine towers. To investigate the role that foraging activity may play in bat fatalities, we conducted a series of surveys at a wind farm in the southern Great Plains of the US from 2011–2016. From acoustic monitoring we recorded foraging activity, including feeding buzzes indicative of prey capture, in the immediate vicinity of turbine towers from all six bat species known to be present at this site. From insect surveys we found Lepidoptera, Coleoptera, and Orthoptera in consistently high proportions over several years suggesting that food resources for bats were consistently available at wind turbines. We used DNA barcoding techniques to assess bat diet composition of (1) stomach contents from 47 eastern red bat (Lasiurus borealis) and 24 hoary bat (Lasiurus cinereus) carcasses collected in fatality searches, and (2) fecal pellets from 23 eastern red bats that were found on turbine towers, transformers, and tower doors. We found that the majority of the eastern red bat and hoary bat stomachs, the two bat species most commonly found in fatality searches at this site, were full or partially full, indicating that the bats were likely killed while foraging. Although Lepidoptera and Orthoptera dominated the diets of these two bat species, both consumed a range of prey items with individual bats having from one to six insect species in their stomachs at the time of death. The prey items identified from eastern red bat fecal pellets showed similar results. A comparison of the turbine insect community to the diet analysis results revealed that the most abundant insects at wind turbines, including terrestrial insects such as crickets and several important crop pests, were also commonly eaten by eastern red and hoary bats. Collectively, these findings suggest that bats are actively foraging around wind turbines and that measures to minimize bat fatalities should be broadly implemented at wind facilities. PMID:29114441

Increasing evidence that bats actively forage at wind turbines.

PubMed

Foo, Cecily F; Bennett, Victoria J; Hale, Amanda M; Korstian, Jennifer M; Schildt, Alison J; Williams, Dean A

2017-01-01

Although the ultimate causes of high bat fatalities at wind farms are not well understood, several lines of evidence suggest that bats are attracted to wind turbines. One hypothesis is that bats would be attracted to turbines as a foraging resource if the insects that bats prey upon are commonly present on and around the turbine towers. To investigate the role that foraging activity may play in bat fatalities, we conducted a series of surveys at a wind farm in the southern Great Plains of the US from 2011-2016. From acoustic monitoring we recorded foraging activity, including feeding buzzes indicative of prey capture, in the immediate vicinity of turbine towers from all six bat species known to be present at this site. From insect surveys we found Lepidoptera, Coleoptera, and Orthoptera in consistently high proportions over several years suggesting that food resources for bats were consistently available at wind turbines. We used DNA barcoding techniques to assess bat diet composition of (1) stomach contents from 47 eastern red bat ( Lasiurus borealis ) and 24 hoary bat ( Lasiurus cinereus ) carcasses collected in fatality searches, and (2) fecal pellets from 23 eastern red bats that were found on turbine towers, transformers, and tower doors. We found that the majority of the eastern red bat and hoary bat stomachs, the two bat species most commonly found in fatality searches at this site, were full or partially full, indicating that the bats were likely killed while foraging. Although Lepidoptera and Orthoptera dominated the diets of these two bat species, both consumed a range of prey items with individual bats having from one to six insect species in their stomachs at the time of death. The prey items identified from eastern red bat fecal pellets showed similar results. A comparison of the turbine insect community to the diet analysis results revealed that the most abundant insects at wind turbines, including terrestrial insects such as crickets and several important crop pests, were also commonly eaten by eastern red and hoary bats. Collectively, these findings suggest that bats are actively foraging around wind turbines and that measures to minimize bat fatalities should be broadly implemented at wind facilities.

SEM characterization of anatomical variation in chitin organization in insect and arthropod cuticles.

PubMed

Chandran, Rakkiyappan; Williams, Lee; Hung, Albert; Nowlin, Kyle; LaJeunesse, Dennis

2016-03-01

The cuticles of insects and arthropods have some of the most diverse material properties observed in nature, so much so that it is difficult to imagine that all cutciles are primarily composed of the same two materials: a fibrous chitin network and a matrix composed of cuticle proteins. Various factors contribute to the mechanical and optical properties of an insect or arthropod cuticle including the thickness and composition. In this paper, we also identified another factor that may contribute to the optical, surface, and mechanical properties of a cuticle, i.e. the organization of chitin nanofibers and chitin fiber bundles. Self-assembled chitin nanofibers serve as the foundation for all higher order chitin structures in the cuticles of insects and other arthropods via interactions with structural cuticle proteins. Using a technique that enables the characterization of chitin organization in the cuticle of intact insects and arthropod exoskeletons, we demonstrate a structure/function correlation of chitin organization with larger scale anatomical structures. The chitin scaffolds in cuticles display an extraordinarily diverse set of morphologies that may reflect specific mechanical or physical properties. After removal of the proteinaceous and mineral matrix of a cuticle, we observe using SEM diverse nanoscale and micro scale organization of in-situ chitin in the wing, head, eye, leg, and dorsal and ventral thoracic regions of the periodical cicada Magicicada septendecim and in other insects and arthropods. The organization of chitin also appears to have a significant role in the organization of nanoscale surface structures. While microscale bristles and hairs have long been known to be chitin based materials formed as cellular extensions, we have found a nanostructured layer of chitin in the cuticle of the wing of the dog day annual cicada Tibicen tibicens, which may be the scaffold for the nanocone arrays found on the wing. We also use this process to examine the chitin organizations in the fruit fly, Drosophila melanogaster, and the Atlantic brown shrimp, Farfantepenaeus aztecus. Interestingly many of the homologous anatomical structures from diverse arthropods exhibit similar patterns of chitin organization suggesting that a common set of parameters, govern chitin organization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Techniques of fisheries management: water quality assessment with stream insects

Treesearch

A. Dennis Lemly

2000-01-01

Nutrient enrichment of streams is a long-standing problem that continues to have substantial local and regional consequences. For example, water quality of streams in the southern Appalachian Mountains of the U.S. can be seriously degraded by organic nutrients leached from animal wastes if cattle or other livestock are allowed to graze in the riparian zone. Local...

Basrah Modern Slaughterhouse, Basrah, Iraq

DTIC Science & Technology

2010-04-27

pigs (for pork) goats (for chevon) fowl (chickens, turkeys, and ducks for poultry meat ) Slaughtering animals poses significant public health...techniques result in the unnecessary loss of meat and meat by- products. Slaughtering facilities are frequently contaminated and may not be protected...from dogs, rodents, and insects. Meat products coming from such conditions are often deteriorated due to bacterial infection or contamination, which

F1 Sterile insect technique: a novel approach for risk assessment of Episimus unguiculus (Lepidoptera: Tortricidae), a candidate biological control agent of Schinus terebinthifolus in the Continental USA

USDA-ARS?s Scientific Manuscript database

Federal regulations mandate that researchers in the field of classical weed biological control follow the precautionary principle when proposing the release of an organism that can affect our environment. However, the host range observed in traditional laboratory cage experiments typically is broad...

Menuing and Scrolling as Alternative Information Management Techniques

DTIC Science & Technology

1988-02-01

Reef Inhabitant Angelfish Parrotfish[ Cardinalfish Scorpionfish INSECT Carnivorous r Cicada Killer Lacewing LFlea Mosquito Herbivorous r Chinch Bug...Ayt -Ave 20 0 Bow f in 20 4 Bunt ing 20 1 1 0 Carrion Beetle 20 7 5 2 C avy 20 0 0 Chamoi s 20 i 1 0 Chinch Bug 20 4 2 Cicada Kilter 20 4 3 1 Earwig

Root zone chemical ecology: new techniques for below grounf sampling and mass spectrometric analyses of volatile semiochemicals

USDA-ARS?s Scientific Manuscript database

The ban of methyl bromide as a soil fumigant has led to an urgent need to develop novel methods of control of soil-dwelling pests. The use of semiochemicals for below-ground insect and nematode control is one such novel avenue of research. New technologies to study semiochemically mediated below-g...

Effect of Parasitoid: Host Ratio and Parasitoid and Host Group Size on Fitness of Spathius galinae (Hymenoptera: Braconidae), a Parasitoid of Emerald Ash Borer (Coleoptera: Buprestidae): Implications for Mass-Rearing

USDA-ARS?s Scientific Manuscript database

Producing insect natural enemies in laboratories or insectaries for biological pest control is often expensive, and developing cost-effective rearing techniques is a goal of many biological control programs. Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a recently described...

Challenging Science and Literacy Activities for K-9 Students - The Cricket Chronicles: Student Edition

ERIC Educational Resources Information Center

Matthews, Catherine E.

2006-01-01

This is an extensive integrated unit of study focused on that common and familiar insect-the cricket. In this edition, students are provided with more than 30 activities on crickets, which will help them learn science content and skills including: (1) Taxonomy; (2) Anatomy; (3) Ecology; (4) Mark and recapture techniques for estimating population…