Entomology Faculty Research and Publications

Permanent URI for this collection


Recent Submissions

Now showing 1 - 20 of 152
  • ItemOpen Access
    Supplementary videos associated with “An electropenetrography waveform library for the study of probing and ingestion behaviors in Culex tarsalis”
    (2023-04-14) Cooper, Anastasia M. W.; Jameson, Samuel B.; Pickens, Victoria; Osborne, Cameron; Backus, Elaine A.; Silver, Kristopher; Mitzel, Dana N.
    Electropenetrography (EPG) is a technique used to indirectly visualize and quantify unseen mouthpart movements that occur inside opaque host tissues when an insect or arthropod bites (i.e., probes). To use this technique on a specific insect, the electrical signals (called waveforms) generated during probing must first be characterized and correlated with insect behaviors. To this end, we characterized the waveforms generated by Culex tarsalis mosquitoes feeding on human hands and made video recordings of the insects during EPG. The findings from this investigation are published as “An electropenetrograpy waveform library for the study of probing and ingestion behaviors in Culex tarsalis.” This manuscript references supplementary videos containing highlights from the video recordings to show specific behaviors that occur during each waveform, which are archived here.
  • ItemOpen Access
    Serosurvey of human antibodies recognizing Aedes aegypti D7 salivary proteins in Colombia
    (2018-05-18) Londono-Renteria, Berlin L.; Shakeri, Heman; Rozo-Lopez, Paula; Conway, Michael J.; Duggan, Natasha; Jaberi-Douraki, Majid; Colpitts, Tonya M.
    Background: Dengue is one of the most geographically significant mosquito-borne viral diseases transmitted by Aedes mosquitoes. During blood feeding, the mosquito deposits salivary proteins that induce antibody responses. These can be related to the intensity of exposure to bites. Some mosquito salivary proteins, such as D7 proteins, are known as potent allergens. The antibody response to D7 proteins can be used as a marker to evaluate the risk of exposure and disease transmission, and provide critical information for understanding the dynamics of vector-host interactions. Methods: The study was conducted at the Los Patios Hospital, Cucuta, Norte de Santander, Colombia. A total of 63 participants were enrolled in the study. Participants were categorized into three disease status groups, age groups, and socioeconomic strata. The level of IgG antibodies against D7 Aedes proteins was determined by ELISA. We used a statistical approach to determine if there is an association between antibody levels and factors such as age, living conditions, and dengue virus infection. Results: We found that IgG antibodies against D7 proteins were higher in non-DENV infected individuals in comparison to DENV-infected participants. Also, age factor showed a significant positive correlation with IgG antibodies against D7 proteins, and the living conditions (socioeconomic stratification), in people ages 20 years or older, are a statistically significant factor in the variability of IgG antibodies against D7 proteins. Conclusions: This pilot study represents the first approximation to elucidate any correlation between the antibody response against mosquito D7 salivary proteins and its correlation with age, living conditions and dengue virus infection in a dengue endemic area.
  • ItemOpen Access
    A taxonomic revision of the subfamily Tillinae Leach sensu lato (Coleoptera, Cleridae) in the New World
    (2017-12-07) Burke, Alan; Zolnerowich, Gregory; gregz; burkea; Zolnerowich, Gregory
    The subfamily Tillinae Leach is represented by 12 genera in the New World. In this study, eight of these genera are revised. A diagnosis and redescription of the species of Araeodontia Barr, Barrotillus Rifkind, Bogcia Barr, Cylidrus Latreille, Cymatoderella Barr, Lecontella Wolcott & Chapin, Monophylla Spinola, and Onychotillus Chapin are presented. Bogcia oaxacae Barr is designated as a junior synonym of Bogcia disjuncta Barr. One species, Cymatodera striatopunctata Chevrolat, is transferred to Lecontella. The following species are redescribed: Araeodontia isabellae (Wolcott), A. marginalis Barr, A. peninsularis (Schaeffer), Barrotillus kropotkini Rifkind, Bogcia disjuncta Barr, Cylidrus abdominalis Klug, Cymatoderella collaris (Spinola), C. morula Rifkind, C. patagoniae (Knull), Lecontella brunnea (Spinola), L. gnara Wolcott, L. striatopunctata (Chevrolat), Monophylla californica (Fall), M. pallipes Schaeffer, M. terminata (Say), Onychotillus vittatus Chapin, and O. cubana De Zayas. Transcriptions of the original descriptions of Araeodontia picipennis Barr, Bostrichoclerus bicornis Van Dyke and Monophylla cinctipennis (Chevrolat) are given. Cymatodera Gray, with approximately 130 described species, is excluded from this study due to the number of species involved. The genera Neocallotillus Burke and Callotillus Wolcott are also excluded here since these groups have been recently revised elsewhere. Collection data are provided for all species revised. Updated distribution maps are presented. Keys to New World genera and species are given and taxonomic characters of relevant importance are provided and discussed.
  • ItemOpen Access
    Efficacy of controlled atmosphere treatments to manage arthropod pests of dry-cured hams
    (2016-09-02) Hasan, Md. Mahbub; Aikins, Michael J.; Schilling, W.; Phillips, Thomas W.; twp1; Phillips, Thomas W.
    Research here explored the use of controlled atmospheres (CA) for managing arthropod pests that infest dry-cured hams. Experiments were conducted with low oxygen (O2) achieved with low pressure under a vacuum, high carbon dioxide (CO2), and ozone (O3). Results showed that both low O2 and high CO2 levels required exposures up to 144 h to kill 100% of all stages of red-legged ham beetle, Necrobia rufipes (De Geer) (Coleoptera: Cleridae) and ham mite Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) at 23 °C. In addition, both low O2 and high CO2 had no significant mortality against the ham beetle and ham mites at short exposures ranging from 12 to 48 h. Ham beetles were more tolerant than ham mites to an atmosphere of 75.1% CO2 and low pressure of 25 mm Hg, which imposed an atmosphere estimated at 0.9% O2. Both low O2 and high CO2 trials indicated that the egg stages of both species were more tolerant than other stages tested, but N. rufipes eggs and pupae were more susceptible than larvae and adults to high concentration ozone treatments. The results indicate that O3 has potential to control ham beetles and ham mites, particularly at ≈166 ppm in just a 24 h exposure period, but O3 is known from other work to have poor penetration ability, thus it may be more difficult to apply effectively than low O2 or high CO2. would be. CA treatment for arthropod pests of dry-cured hams show promise as components of integrated pest management programs after methyl bromide is no longer available for use. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
  • ItemOpen Access
    Helicoidal Organization of Chitin in the Cuticle of the Migratory Locust Requires the Function of the Chitin Deacetylase2 Enzyme (LmCDA2)
    (2016-09-07) Yu, R. R.; Liu, W. M.; Li, D. Q.; Zhao, X. M.; Ding, G. W.; Zhang, M.; Ma, E.; Zhu, Kun Y.; Li, S.; Moussian, B.; Zhang, J. Z.; kzhu; Zhu, Kun Y.
    In the three-dimensional extracellular matrix of the insect cuticle, horizontally aligned microfibrils composed of the polysaccharide chitin and associated proteins are stacked either parallel to each other or helicoidally. The underlying molecular mechanisms that implement differential chitin organization are largely unknown. To learn more about cuticle organization, we sought to study the role of chitin deacetylases (CDA) in this process. In the body cuticle of nymphs of the migratory locust Locusta migratoria, helicoidal chitin organization is changed to an organization with unidirectional microfibril orientation when LmCDA2 expression is knocked down by RNA interference. In addition, the buCDA2-deficient cuticle is less compact suggesting that LmCDA2 is needed for chitin packaging. Animals with reduced LmCDA2 activity die at molting, underlining that correct chitin organization is essential for survival. Interestingly, we find that LmCDA2 localizes only to the initially produced chitin microfibrils that constitute the apical site of the chitin stack. Based on our data, we hypothesize that LmCDA2-mediated chitin deacetylation at the beginning of chitin production is a decisive reaction that triggers helicoidal arrangement of subsequently assembled chitin-protein microfibrils.
  • ItemOpen Access
    Comparisons of Transcriptional Profiles of Gut Genes between Cry1Ab-Resistant and Susceptible Strains of Ostrinia nubilalis Revealed Genes Possibly Related to the Adaptation of Resistant Larvae to Transgenic Cry1Ab Corn
    (2017-01-30) Yao, Jianxiu; Zhu, Y. C.; Lu, N. Y.; Buschman, Lawrent L.; Zhu, Kun Y.; kzhu; Zhu, Kun Y.
    A microarray developed on the basis of 2895 unique transcripts from larval gut was used to compare gut gene expression profiles between a laboratory-selected Cry1Ab-resistant (R) strain and its isoline susceptible (S) strain of the European corn borer (Ostrinia nubilalis) after the larvae were fed the leaves of transgenic corn (MON810) expressing Cry1Ab or its non-transgenic isoline for 6 h. We revealed 398 gut genes differentially expressed (i.e., either up- or down-regulated genes with expression ratio 2.0) in S-strain, but only 264 gut genes differentially expressed in R-strain after being fed transgenic corn leaves. Although the percentages of down-regulated genes among the total number of differentially expressed genes (50% in S-strain and 45% in R-strain) were similar between the R- and S-strains, the expression ratios of down-regulated genes were much higher in S-strain than in R-strain. We revealed that 17 and 9 significantly up- or down-regulated gut genes from S and R-strain, respectively, including serine proteases and aminopeptidases. These genes may be associated with Cry1Ab toxicity by degradation, binding, and cellular defense. Overall, our study suggests enhanced adaptation of Cry1Ab-resistant larvae on transgenic Cry1Ab corn as revealed by lower number and lower ratios of differentially expressed genes in R-strain than in S-strain of O. nubilalis.
  • ItemOpen Access
    Divergence of the diapause transcriptome in apple maggot flies: winter regulation and post-winter transcriptional repression
    (2016-08-31) Meyers, P. J.; Powell, T. H. Q.; Walden, K. K. O.; Schieferecke, Adam J.; Feder, J. L.; Hahn, D. A.; Robertson, H. M.; Berlocher, S. H.; Ragland, Gregory J.; gragland; Ragland, Gregory J.
    The duration of dormancy regulates seasonal timing in many organisms and may be modulated by day length and temperature. Though photoperiodic modulation has been well studied, temperature modulation of dormancy has received less attention. Here, we leverage genetic variation in diapause in the apple maggot fly, Rhagoletis pomonella, to test whether gene expression during winter or following spring warming regulates diapause duration. We used RNAseq to compare transcript abundance during and after simulated winter between an apple-infesting population and a hawthorn-infesting population where the apple population ends pupal diapause earlier than the hawthorn-infesting population. Marked differences in transcription between the two populations during winter suggests that the 'early' apple population is developmentally advanced compared with the 'late' hawthorn population prior to spring warming, with transcripts participating in growth and developmental processes relatively up-regulated in apple pupae during the winter cold period. Thus, regulatory differences during winter ultimately drive phenological differences that manifest themselves in the following summer. Expression and polymorphism analysis identify candidate genes in the Wnt and insulin signaling pathways that contribute to population differences in seasonality. Both populations remained in diapause and displayed a pattern of up-and then down-regulation (or vice versa) of growth-related transcripts following warming, consistent with transcriptional repression. The ability to repress growth stimulated by permissive temperatures is likely critical to avoid mismatched phenology and excessive metabolic demand. Compared with diapause studies in other insects, our results suggest some overlap in candidate genes/pathways, though the timing and direction of changes in transcription are likely species specific.
  • ItemOpen Access
    Combination of methoprene and controlled aeration to manage insects in stored wheat
    (2017-06-17) Liu, S. S.; Arthur, F. H.; Vangundy, D.; Phillips, Thomas W.; twp1; Phillips, Thomas W.
    A commercial formulation of the insect growth regulator methoprene was applied to wheat stored in small bins either alone or in combination with controlled aeration of the bins, to lower grain temperature for insect pest management of stored wheat. Grain temperatures were monitored and modified by a computer-controlled thermocouple system that also activated the aeration system at programmed set-points to move cool ambient air through the grain mass to lower grain temperature. Results from sampling insect populations in experimental storage bins along with laboratory mortality bioassays of insects placed on wheat taken from the bins over the course of the storage period showed that methoprene was very effective in controlling infestation by the externally-feeding stored grain insects Plodia interpunctella (Hübner), the Indian meal moth Tribolium castaneum (Herbst), the red flour beetle, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, and also for the internal-feeding pest Rhyzopertha dominica(Fauvel), the lesser grain borer. Methoprene did not give good control of the internal-feeding pest Sitophilus oryzae (L.), the rice weevil. Aeration alone was somewhat effective in suppressing insect population development, while methoprene alone or when combined with aeration greatly enhanced insect control. Commercial grain grading for industry quality standards at the end of the storage period confirmed the impact of insect suppression on maintaining high quality of the stored wheat. This field experiment shows that methoprene combined with aeration to cool grain can be effective for pest management of stored wheat in the southern plains of the United States of America. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
  • ItemOpen Access
    LmCYP4G102: An oenocyte-specific cytochrome P450 gene required for cuticular waterproofing in the migratory locust, Locusta migratoria
    (2016-07-22) Yu, Z. T.; Zhang, X. Y.; Wang, Y. W.; Moussian, B.; Zhu, Kun Y.; Li, S.; Ma, E. B.; Zhang, J. Z.; kzhu; Zhu, Kun Y.
    Cytochrome P450 superfamily proteins play important roles in detoxification of xenobiotics and during physiological and developmental processes. To contribute to our understanding of this large gene family in insects, we have investigated the function of the cytochrome P450 gene LmCYP4G102 in the migratory locust Locusta migratoria. Suppression of LmCYP4G102 expression by RNA interference (RNAi) does not interfere with moulting but causes rapid loss of body weight - probably due to massive loss of water, and death soon after moulting. Accordingly, maintaining these animals at 90% relative humidity prevented lethality. Consistently, RNAi against LmCYP4G102 provoked a decrease in the content of cuticular alkanes, which as an important fraction of cuticular hydrocarbons have been shown to confer desiccation resistance. In addition, the cuticle of LmCYP4G102- knockdown locusts was fragile and easier deformable than in control animals. Presumably, this phenotype is due to decreased amounts of cuticular water that is reported to modulate cuticle mechanics. Interestingly, LmCYP4G102 was not expressed in the epidermis that produces the cuticle but in the sub-epdiermal hepatocyte-like oenocytes. Together, our results suggest that the oenocyte-specific LmCYP4G102 plays a critical role in the synthesis of cuticular hydrocarbons, which are important for cuticle waterproofing and mechanical stability in L. migratoria
  • ItemOpen Access
    Populations of Stored Product Mite Tyrophagus putrescentiae Differ in Their Bacterial Communities
    Erban, T.; Klimov, P. B.; Smrz, J.; Phillips, Thomas W.; Nesvorna, M.; Kopecky, J.; Hubert, J.; twp1; Phillips, Thomas W.
    Background: Tyrophagus putrescentiae colonizes different human-related habitats and feeds on various post harvest foods. The microbiota acquired by these mites can influence the nutritional plasticity in different populations. We compared the bacterial communities of five populations of T putrescentiae and one mixed population of T putrescentiae and T fanetzhangorum collected from different habitats. Material: The bacterial communities of the six mite populations from different habitats and diets were compared by Sanger sequencing of cloned 16S rRNA obtained from amplification with universal eubacterial primers and using bacterial taxon-specific primers on the samples of adults/juveniles or eggs. Microscopic techniques were used to localize bacteria in food boli and mite bodies. The morphological determination of the mite populations was confirmed by analyses of CO1 and ITS fragment genes. Results: The following symbiotic bacteria were found in compared mite populations: Wolbachia (two populations), Cardiniurn (five populations), Bartonella-like (five populations), Blattabacteriurn-like symbiont (three populations), and Solitalea-like (six populations). From 35 identified OTUs97, only Solitalea was identified in all populations. The next most frequent and abundant sequences were Bacillus, Moraxella, Staphylococcus, Kocuria, and Microbacteriurn. We suggest that some bacterial species may occasionally be ingested with food. The bacteriocytes were observed in some individuals in all mite populations. Bacteria were not visualized in food boli by staining, but bacteria were found by histological means in ovaria of Wolbachia infested populations. Conclusion: The presence of Blattabacterium-like, Cardinium, Wolbachia, and Solitalea like in the eggs of T putrescentiae indicates mother to offspring (vertical) transmission. Results of this study indicate that diet and habitats influence not only the ingested bacteria but also the symbiotic bacteria of T putrescentiae.
  • ItemOpen Access
    Taxonomic revision of the New World genus Callotillus Wolcott (Cleridae, Tillinae), with the description of the new genus Neocallotillus, and an illustrated key of identification to species
    (2016-09-15) Burke, Alan F.; Zolnerowich, Gregory; gregz
    The New World checkered beetle genus Callotillus Wolcott, 1911 is revised and the new genus Neocallotillus established. The subspecies Callotillus elegans vafer Wolcott is synonymized with the nominal subspecies, C. elegans elegans (Erichson), which is transferred to, and designated as the type species of Neocallotillus gen. n. as Neocallotillus elegans (Erichson, 1847), comb. n. Two additional species are transferred from Callotillus to the new genus: Neocallotillus intricatus (Wolcott & Dybas, 1947), comb. n. and N. crusoe (Wolcott, 1923), comb. n., the latter tentatively and based on Wolcott’s original description. Callotillus is now composed of two species: C. eburneocinctus Wolcott, 1911 and C. bahamensis Vaurie, 1952. All abovementioned species except N. crusoe are diagnosed and redescribed. In the absence of reference material of Neocallotillus crusoe, Wolcott’s original description is transcribed. An illustrated key to species is provided. Characters of taxonomic relevance are illustrated and discussed. Updated distribution maps and locality data for all specimens examined are presented.
  • ItemOpen Access
    Multiple functions of Na/K-ATPase in dopamine-induced salivation of the Blacklegged tick, Ixodes scapularis
    (2016-02-10) Kim, Donghun; Urban, Joshua; Boyle, Daniel L.; Park, Yoonseong; ypark; dboyle
    Control of salivary secretion in ticks involves autocrine dopamine activating two dopamine receptors: D1 and Invertebrate-specific D1-like dopamine receptors. In this study, we investigated Na/K-ATPase as an important component of the secretory process. Immunoreactivity for Na/K-ATPase revealed basal infolding of lamellate cells in type-I, abluminal interstitial (epithelial) cells in type-II, and labyrinth-like infolding structures opening towards the lumen in type-III acini. Ouabain (10 mu mol l(-1)), a specific inhibitor of Na/K-ATPase, abolished dopamine-induced salivary secretion by suppressing fluid transport in type III acini. At 1 mu mol l(-1), ouabain, the secreted saliva was hyperosmotic. This suggests that ouabain also inhibits an ion resorptive function of Na/K-ATPase in the type I acini. Dopamine/ouabain were not involved in activation of protein secretion, while dopamine-induced saliva contained constitutively basal level of protein. We hypothesize that the dopamine-dependent primary saliva formation, mediated by Na/K-ATPase in type III and type II acini, is followed by a dopamine-independent resorptive function of Na/K-ATPase in type I acini located in the proximal end of the salivary duct.
  • ItemOpen Access
    Ligand selectivity in tachykinin and natalisin neuropeptidergic systems of the honey bee parasitic mite Varroa destructor
    (2016-01-28) Jiang, H.; Kim, D.; Dobesh, S.; Evans, J. D.; Nachman, R. J.; Kaczmarek, K.; Zabrocki, J.; Park, Yoonseong; ypark
    The varroa mite, Varroa destructor, is a devastating ectoparasite of the honey bees Apis mellifera and A. cerana. Control of these mites in beehives is a challenge in part due to the lack of toxic agents that are specific to mites and not to the host honey bee. In searching for a specific toxic target of varroa mites, we investigated two closely related neuropeptidergic systems, tachykinin-related peptide (TRP) and natalisin (NTL), and their respective receptors. Honey bees lack both NTL and the NTL receptor in their genome sequences, providing the rationale for investigating these receptors to understand their specificities to various ligands. We characterized the receptors for NTL and TRP of V. destructor (VdNTL-R and VdTRP-R, respectively) and for TRP of A. mellifera (AmTRP-R) in a heterologous reporter assay system to determine the activities of various ligands including TRP/NTL peptides and peptidomimetics. Although we found that AmTRP-R is highly promiscuous, activated by various ligands including two VdNTL peptides when a total of 36 ligands were tested, we serendipitously found that peptides carrying the C-terminal motif-FWxxRamide are highly specific to VdTRP-R. This motif can serve as a seed sequence for designing a VdTRP-R-specific agonist.
  • ItemOpen Access
    Virulent Diuraphis noxia Aphids Over-Express Calcium Signaling Proteins to Overcome Defenses of Aphid-Resistant Wheat Plants
    (2016-01-27) Sinha, Deepak K.; Chandran, Predeesh; Timm, Alicia E.; Aguirre-Rojas, Lina; Smith, C. Michael; cmsmith
    The Russian wheat aphid, Diuraphis noxia, an invasive phytotoxic pest of wheat, Triticum aestivum, and barley, Hordeum vulgare, causes huge economic losses in Africa, South America, and North America. Most acceptable and ecologically beneficial aphid management strategies include selection and breeding of D. noxia-resistant varieties, and numerous D. noxia resistance genes have been identified in T. aestivum and H. vulgare. North American D. noxia biotype 1 is avirulent to T. aestivum varieties possessing Dn4 or Dn7 genes, while biotype 2 is virulent to Dn4 and avirulent to Dn7. The current investigation utilized next-generation RNAseq technology to reveal that biotype 2 over expresses proteins involved in calcium signaling, which activates phosphoinositide (PI) metabolism. Calcium signaling proteins comprised 36% of all transcripts identified in the two D. noxia biotypes. Depending on plant resistance gene-aphid biotype interaction, additional transcript groups included those involved in tissue growth; defense and stress response; zinc ion and related cofactor binding; and apoptosis. Activation of enzymes involved in PI metabolism by D. noxia biotype 2 aphids allows depletion of plant calcium that normally blocks aphid feeding sites in phloem sieve elements and enables successful, continuous feeding on plants resistant to avirulent biotype 1. Inhibition of the key enzyme phospholipase C significantly reduced biotype 2 salivation into phloem and phloem sap ingestion.
  • ItemOpen Access
    Genomic insights into the Ixodes scapularis tick vector of Lyme disease
    (2016-02-09) Gulia-Nuss, M.; Nuss, A. B.; Meyer, J. M.; Sonenshine, D. E.; Roe, R. M.; Waterhouse, R. M.; Sattelle, D. B.; de la Fuente, J.; Ribeiro, J. M.; Megy, K.; Thimmapuram, J.; Miller, J. R.; Walenz, B. P.; Park, Yoonseong; ypark
    Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing similar to 57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent.
  • ItemOpen Access
    Sorted gene genealogies and species- specific nonsynonymous substitutions point to putative postmating prezygotic isolation genes in Allonemobius crickets
    (2016-02-15) Noh, S.; Marshall, Jeremy L.; cricket
    In the Allonemobius socius complex of crickets reproductive isolation is primarily accomplished via postmating prezygotic barriers. We tested seven protein-coding genes expressed in the male ejaculate for patterns of evolution consistent with a putative role as postmating prezygotic isolation genes. Our recently diverged species generally lacked sequence variation. As a result, omega-based tests were only mildly successful. Some of our genes showed evidence of elevated omega values on the internal branches of gene trees. In a couple of genes, these internal branches coincided with both species branching events of the species tree, between A. fasciatus and the other two species, and between A. socius and A. sp. nov. Tex. In comparison, more successful approaches were those that took advantage of the varying degrees of lineage sorting and allele sharing among our young species. These approaches were particularly powerful within the contact zone. Among the genes we tested we found genes with genealogies that indicated relatively advanced degrees of lineage sorting across both allopatric and contact zone alleles. Within a contact zone between two members of the species complex, only a subset of genes maintained allelic segregation despite evidence of ongoing gene flow in other genes. The overlap in these analyses was arginine kinase (AK) and apolipoprotein A-1 binding protein (APBP). These genes represent two of the first examples of sperm maturation, capacitation, and motility proteins with fixed non-synonymous substitutions between species-specific alleles that may lead to postmating prezygotic isolation. Both genes express ejaculate proteins transferred to females during copulation and were previously identified through comparative proteomics. We discuss the potential function of these genes in the context of the specific postmating prezygotic isolation phenotype among, our species, namely conspecific sperm precedence and the superior ability of conspecific males to induce oviposition in females.
  • ItemOpen Access
    Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia
    Barhoumi, W.; Fares, W.; Cherni, S.; Derbali, M.; Dachraoui, K.; Chelbi, I.; Ramalho-Ortigao, Marcelo; Beier, J. C.; Zhioua, E.; mortigao
    The current spread of zoonotic visceral leishmaniasis (ZVL) throughout arid areas of Central Tunisia is a major public health concern. The main objective of this study is to investigate whether the development of irrigation in arid bio-geographical areas in Central Tunisia have led to the establishment of a stable cycle involving sand flies of the subgenus Larroussius and Leishmania infantum, and subsequently to the emergence of ZVL. Sand flies were collected from the village of Saddaguia, a highly irrigated zone located within an arid bio-geographical area of Central Tunisia by using modified Centers for Diseases Control (CDC) light traps. Morphological keys were used to identify sand flies. Collected sand flies were pooled with up to 30 specimens per pool according to date and tested by nested Polymerase Chain Reaction (PCR) DNA sequencing from positive pools was used to identify Leishmania spp. A total of 4915 sand flies (2422 females and 2493 males) were collected from Saddaguia in September and in October 2014. Morphological identification confirmed sand flies of the subgenus Larroussius to be predominant. PCR analysis followed by DNA sequencing indicated that 15 pools were infected with L. infantum yielding an overall infection rate of 0.6%. The majority of the infected pools were of sand fly species belonging to subgenus Larroussius. Intense irrigation applied to the arid bio-geographical areas in Central Tunisia is at the origin of the development of an environment capable of sustaining important populations of sand flies of the subgenus Larroussius. This has led to the establishment of stable transmission cycles of L. infantum and subsequently to the emergence of ZVL.
  • ItemOpen Access
    Oviposition by female plodia interpunctella (Lepidoptera: Pyralidae): Description and time budget analysis of behaviors in laboratory studies
    (2016-01-22) Sambaraju, K. R.; Donelson, S. L.; Bozic, J.; Phillips, Thomas W.; twp1
    The oviposition behavior of the Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), a major insect pest of durable stored foods, was studied in small experimental arenas under laboratory conditions using videography, and a time budget analysis of its behaviors was documented. Resting gravid females typically became active shortly after the start of the scotophase. The characteristic behaviors exhibited by mated females prior to oviposition included antennal movement, grooming of antennae and mouth parts using the forelegs, walking or flying, and abdomen bending and dragging. Pre-oviposition behaviors such as antennal grooming and walking or flying were observed to alternate several times before females commenced the abdominal dragging behavior that preceded egg laying. Eggs were laid singly or sometimes in groups, either freely or stuck to food material. Gravid females showed little or no movement during the photophase; however, they actively flew and oviposited during the scotophase. Females allocated only a small portion of their time to oviposition while the rest of the time was spent away from food. Females oviposited on food material by making repeated visits, predominantly during the first four hours of the scotophase. Visits and time spent on food declined as the scotophase advanced. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
  • ItemOpen Access
    Insecticide-Mediated Up-Regulation of Cytochrome P450 Genes in the Red Flour Beetle (Tribolium castaneum)
    (2015-01-19) Liang, X.; Xiao, D.; He, Y. P.; Yao, J. X.; Zhu, G. N.; Zhu, Kun Y.; kzhu
  • ItemOpen Access
    Diagnostic Molecular Markers for Phosphine Resistance in US Populations of Tribolium castaneum and Rhyzopertha dominica
    (2015-03-31) Chen, Zhaorigetu; Schlipalius, D.; Opit, G.; Bhadriraju, Subramanyam; Phillips, Thomas W.; jorigtoo; twp1; sbhadrir