Source: NORTH CAROLINA STATE UNIV submitted to NRP
CONTROL OF ARTHROPOD PESTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1010623
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2016
Project End Date
Sep 30, 2021
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695
Performing Department
Entomology
Non Technical Summary
This project is to study the basic biology of insect and tick pests and how pesticides and evironmental chemicals affect human heath. Thebasic understanding is aimed at developing products to control these pests. Although the basic research will advance our core knowledge of biology from behavior to how genes are regulated in the cell nucleus, the objective also is to develop practical information and products to improve the human condition in the near term. This will be acheived through partnerships with private industry driven by expertise created from the basic research andnew technology developed by the program and licensed to industry. Products being developed include the first, non insecticidal shampoo for the control of head lice eggs, larvae and adults; a non-DEET, all natural insect and tick repellent more effective than DEET; a more confortable bed net for Africa to control the spread of malaria; new textiles to be used for all types of clothing which is mosquito, tick, chigger and fly bite proof; a natural replacement for methyl bromide for fumigation and to replace methyl bromide which is damaging the ozone layer of the earth; phone Apps to help the public deal with pest problems; new building materials which control insect pests; andproviding information about the potential health risks associated with exposure to environmental chemicals.
Animal Health Component
40%
Research Effort Categories
Basic
30%
Applied
40%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
72131101000100%
Knowledge Area
721 - Insects and Other Pests Affecting Humans;

Subject Of Investigation
3110 - Insects;

Field Of Science
1000 - Biochemistry and biophysics;
Goals / Objectives
Major goals of the project are (i) to study the basic function of pest arthropods and model arthropod systems and from the understanding of these systems, development new methods for the management of their populations and reducing the impact of their pest status and (ii) to better understand the impact of arthropod control systems and enviornmental chemicals in general on animal and human health. The pest empahsis is in three areas: agriculture, urban and medical-vet entomology. The main focus of enviornmental chemicals is their direct impact on human systems with other animals models of secondary importance. My program is interested in moving basic kowledge from the laboratory to "store shelves"; so an active technology transfer effort involving intellectual property disclosures, filing of patents, engaging existing companies, supporting new start-up companies, and working with technology from private industry is anticipated as a continuation of my existing efforts to provide practical pest solutions. I will also be engaged in cross-displinary and highly collaborative research to achieve these goals.
Project Methods
Studies of basic function will concentrate on a global molecular approach including the study of the organism genome, gene expression(using RNAseq and qPCR), epigenetics (especially focused on lncRNA and microRNA), bacteria and viral genomics, knockouts and using high-throughput sequencing to characterize organism-arthropod pest-plant-microbiome relationships. Applications in synthetic, analytical and formulation chemistry will be used to develop new products like arthropod repellents, a methyl bromide replacment, head lice shampoo, etc. Applications in material sciences and textile structure and manufacturing along with modeling will be used in the development of new types of nets, clothing and building materials. Studies of insect genetics, behavior and microbiomes coupled with bioassay will be usedto understand and assess the potential for insect evolution of resistance to GMOs.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Scientific community, pesticide industry, and general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training for Ph.D. students, visiting scholars and techncians in entomology and same in Wilson College of Textiles and College of Natural Resources. How have the results been disseminated to communities of interest?Published scientific paper, made presentations at scientific meetings, patent filings published, patents granted, NCSU startup companies formed, products advertised in retail stores and on the internet, and interactions with industry and investors. What do you plan to do during the next reporting period to accomplish the goals?No plans to change our current research and development approaches.

Impacts
What was accomplished under these goals? Evolved resistance to genetically modified crops including economically important products such as cotton, corn, soybeans and many others has become rapidly and globally widespread over the last 20 years. There are now examples of important agricultural pests of crops expressing Bt (Bacillus thuringiensis) bacterial proteins (Cry1Ac, Cry1F, Cry2Ac) that have evolved resistance to these Bt-toxins. Increases in resistance have been reported with each field season in recent years to Cry1Ac in Helicoverpa zea. RNA-seq is a method to quantitatively measure total gene expression in an organism. This method was used to measure differences in global gene expression between a Bt susceptible and a Bt-resistant strain of bollworm, where the differences in susceptibility to Cry1Ac +Cry1F toxin was 100-fold. We found gene expression differences that would be expected based on our current understanding of Bt mode of action and Bt resistance, including increased expression of proteases and reduced expression of Bt-interacting receptors in Bt-resistant bollworms. We have also found additional expression differences between the two strains of bollworm in genes that have not previously been thoroughly investigated, non-coding and immune system associated genes. This suggests that there are multiple different mechanisms influencing the development of Bt-resistance in addition to potential previously unrecognized pathways of resistance in this agricultural pest species. Also, it is important to consider how investigations into the genetic mechanisms of Bt-resistance will aide in understanding how resistance develops, and this could also provide better monitoring tools for resistance. Ideally this knowledge can then be applied to reduce the vulnerability of novel and next-generation integrated pest management technologies to pest resistance. Human exposure to environmental chemicals both individually and in combination occurs frequently world wide most often with unknown consequences. Use of molecular approaches to aide in the assessment of risk involved in chemical exposure is a growing field in toxicology. We examined the impact of two environmental chemicals used in and around homes, the insect repellent DEET (N,N-diethyl-m-toluamide) and the phenylpyrazole insecticide fipronil (fluocyanobenpyrazole) on transcript levels of enzymes potentially involved in xenobiotic metabolism and on long non-coding RNAs (lncRNAs). Primary human hepatocytes were treated with these two chemicals both individually and in combination. Using RNA-Seq, we found that 10 major enzyme categories involved in phase 1 and phase 2 xenobiotic metabolism were significantly (α = 0.05) up- and down-regulated (i.e., 100 μM DEET-19 transcripts, 89% up and 11% down; 10 μM fipronil-52 transcripts, 53% up and 47% down; and 100 μM DEET +10 μM fipronil-69 transcripts, 43% up and 57% down). The altered genes were then mapped to the human genome and their proximity (within 1,000,000 bp) to lncRNAs examined. Unique proximities were discovered between altered lncRNA and altered P450s (CYP) and other enzymes (DEET, 2 CYP; Fipronil, 6 CYP and 15 other; and DEET + fipronil, 7 CYP and 21 other). Many of the altered P450 transcripts were in multiple clusters in the genome with proximal altered lncRNAs, suggesting a regulator function for the lncRNA. At the gene level there was high percent identity for lncRNAs near P450 clusters, but this relationship was not found at the transcript level. The role of these altered lncRNAs associated with xenobiotic induction, human diseases and chemical mixtures is discussed. Malaria is the deadliest mosquito-borne disease and kills predominantly people in sub-Saharan Africa (SSA). The now widespread mosquito resistance to pyrethroids, with rapidly growing resistance to other insecticide classes recommended by the World Health Organization (WHO), may overturn the successes gained in mosquito control in recent years. It is of utmost importance to search for new, inexpensive, and safe alternatives, with new modes of action, that might improve the efficacy of current insecticides. The efficacy of a novel mechanical insecticidal mineral derived from volcanic rock, ImergardTMWP, was investigated to determine its efficacy as a stand-alone residual wall spray and as a mixture with deltamethrin (K-Othrine® Polyzone) in experimental huts in Cove, Benin. The evaluation was conducted with susceptible (Kisumu) and wild-type Anopheles gambiae (s.l.). Deltamethrin applied alone demonstrated 40-45% mortality (at 72 h post-exposure) during the first four months, which declined to 25% at six months for wild An. gambiae from Cove. ImergardTMWP alone and mixed with deltamethrin, under the same assay conditions, produced 79-82% and 73-81% mortality, respectively, during the same six-month period. ImergardTMWP met the 80% WHO bio-efficacy threshold for residual activity for the first five months with 78% residual activity at six months. ImergardTMWP can be used as a mixture with chemical insecticides or as a stand-alone pesticide for mosquito control in Africa. Mosquito-borne malaria kills 429,000 people each year with the problem being acute in sub-Saharan Africa. The successes gained with long-lasting pyrethroid-treated bednets are now in jeopardy because of wide-spread, pyrethroid resistance in mosquitoes. Using crowd modeling theory normalized for standard bednet architecture, we were able to design an attract-trap-kill technology for mosquitoes that does not require insecticides. Using three-dimensional polyester knitting and heat fixation, trap funnels were developed with high capture efficacy with no egression under worst-case laboratory conditions. Field testing in Africa in WHO huts with Gen1-3 T (trap)-Nets validated our model, and as predicted, Gen3 had the highest efficacy with a 4.3-fold greater trap-kill rate with no deterrence or repellency compared to Permanet 2.0, the most common bednet in Africa. A T-Net population model was developed based on field data to predict community-level mosquito control compared to a pyrethroid bednet. This model showed the Gen3 non-insecticidal T-Net under field conditions in Africa against pyrethroid resistant mosquitoes was 12.7-fold more efficacious than single chemical, pyrethroid-treated net. Patent was granted on non-inseciticidal, bite resistant textiles and garments where textile structure is used to prevent mosquito biting. This technology is licensed to a NCSU start up company.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Lawrie, R., J. M. Deguenon, R. D. Mitchell III, L. Ponnusamy, D. Reisig, A. Del Pozo-Valdivia, R. M. Roe and R. W. Kurtz. 2020. Global mechanisms of Bt resistance in the cotton bollworm, Helicopverpa zea: the expected and unexpected. Proceedings of the 2020 Beltwide Cotton Conferences, Austin, TX, Jan. 8-10, 2020. Cotton Council, Memphis, TN. Pp. 207-218.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Lawrie, R. D., R. D. Mitchell III, A. Dhammi, A. Wallace, E. Hodgson and R. M. Roe. 2020. Role of long non-coding RNA in DEET- and fipronil-mediated alteration of transcripts associated with Phase I and Phase II xenobiotic metabolism in human primary hepatocytes. Pestic. Biochem. Physiol. 167:104607. Doi.org/10.1016/j.pestbp.2020.104607.
  • Type: Other Status: Published Year Published: 2020 Citation: McCord, M. G., R. M. Roe, C. S. Apperson, A. J. West and E. A. DenHartog. 2020. Insect barrier textile liner system. US Patent Application Publication Pub. No.: US 2020/0048801 A1. Pub. Date: Feb. 13, 2020.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Deguenon, J. M., R. Azondekon, F. R. Agossa, G. G. Padonou, R. Anagonou, J. Ahoga, B. Ndombidje, B. Akinro, D. A. Stewart, B. Wang, D. Gittins, L. Tiomirov, C. S. Apperson, M. G. McCord, M. C. Akogbeto and R. M. Roe. 2020. ImergardTMWP: a non-chemical alternative for an indoor residual spray, effective against pyrethroid-resistant Anopheles gambiae (s.l.) in Africa. Insects. 11,322; doi: 10.3390/insects11050322.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Mouhamadou, C. S., K. Luan, B. K. Fodjo, A. J. West, M. G. McCord, C. S. Apperson and R. M. Roe. 2020. Development of an insecticide-free trapping bednet to control mosquitoes and manage resistance in malaria vector control: A new way of thinking. 2020, 11, 732; doi:10.3390/insects11110732.
  • Type: Other Status: Published Year Published: 2020 Citation: West, A. J., M. G. McCord, C. S. Apperson, R. M. Roe and E. A. DenHartog. 2020. Non-chemical, mosquito bite-resistant garments. US Patent No.: US 10,694,793 B2. Date of Patent: June 30, 2020.


Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Scientific community, pesticide indurstry, and general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training for Ph.D. students, visiting scholars and techncians in entomology. How have the results been disseminated to communities of interest?Published scientific paper, made presentations at scientific meetings, patent filings published, NCSU startup companies formed, products advertised in retail stores and on the internet, and interactions with industry and investors. What do you plan to do during the next reporting period to accomplish the goals?No plans to change our current research and development approaches.

Impacts
What was accomplished under these goals? Mosquito resistant apparel has become increasingly sought-after due to the rise in vector-borne illnesses such as the Zika Virus, Malaria, and Dengue Fever. Botanical insect repellents have been introduced to the market for consumers that desire a natural solution involving no pesticides or added chemicals. Fabric swatches consisting of 80% nylon and 20% elastane were separately treated with an organic repellent using a patented nonwoven vessel. The fabrics were then tested for effectiveness in repelling the mosquito Aedes aegypti using an arm-in-cage assay, the most commonly used method for mosquito repellents. The repellents were also evaluated and rated by study participants according to their preference for the appeal of the scent. The treatment method is user-friendly, enabling consumers to treat their clothing with an organic insect repellent as opposed to applying a synthetic chemical to their clothing and skin. The infused fabrics showed to be effective at repelling mosquitoes for up to 8 h after repellent infusion. Insecticide resistance in caterpillars has been attributed to many environmental and genomic changes, but the role of the microbiome in insects in comparison has barely been explored. In recent years, several studies suggest the microbiome might affect insect susceptibility to insecticides. The microbiome of an organism also can be affected by a number of variables including the insect's diet and potentially the introduction of transgenes into crop plants in which caterpillars feed. Often insects from the field are bioassayed using highly enriched artificial diet containing antimicrobial agents that might affect insecticide susceptibility tests. We report ongoing studies over two field seasons on the microbial diversity in the bollworm, Helicoverpa zea, collected from the field from non-Bt and WideStrike cotton. In years 2 and 3, the internal cultivable bacteria were higher in 2nd to 3rd stadium bollworms from WideStrike versus non-Bt cotton, even when the plants were grown in the field just a few rows apart. Amplification of the bacterial V3 region of the 16S rRNA gene suggested differences in bacteria diversity between WideStrike versus non-Bt cotton-collected bollworms, although additional work is needed to understand reduced PCR product amplification and a low number of OTUs in our Illumina sequencing work. Potential reasons for the differences in the bollworm microbiome between WideStrike and non-Bt cotton are discussed. Our findings argue for more research to understand the interactions between the bollworm and plant microbiomes and the impact of cotton variety and transfer to artificial diets on Bt susceptibility. The black blow fly, Phormia regina (Meigen) (Diptera: calliphoridae) is one of the most abundant carrion flies in North America. Calliphorids are important in agriculture and animal production, veterinary sciences, forensics and medical entomology. While the role of flies in the epidemiology of human and animal diseases is an active area of research, little is known about the microorganisms associated with these insects. We examined the diversity of wild-caught black blow fly endogenous (internal body) and exogenous (external body) microbial communities using 16S rRNA gene sequencing. Overall, 27 phyla, 171 families and 533 genera were detected, and diversity was significantly higher (P < 0.05) on external body surfaces. At the genus level, Dysgonomonas, Ignatzschineria, Acinetobacter, Vagococcus, Myroides, and Wohlfahrtiimonas were predominant. Cloning and sequencing of nearly full-length fragments of the 16S rRNA gene showed that some of the species identified are known to be pathogenic to humans, animals, and plants. Myroides odoratimimus and Acinetobacter radioresistens are wellknown, multi-drug resistant bacteria. these results provide a snapshot of the microbial communities harbored by adult black blow flies and call for more comprehensive studies to better characterize the role these flies may play in the transmission of pathogenic microorganisms. Filth flies live in close proximity to humans and livestock and transmit pathogens. Current control relies on chemical insecticides, and flies can develop resistance to these insecticides. The public is also interested in natural and safer insecticides. Therefore, alternative pesticides compatible with the synanthropic nature of flies are needed. Four plant aliphatic methyl ketones were evaluated for control of adult house flies, Musca domestica L., blow flies, Cochliomyia macellaria (F.), and gray flesh flies, Sarcophaga bullata (Parker). In sealed petri dish assays, 2-heptanone, 2-octanone, 2-nonanone, and 2-undecanone exhibited fumigant activity against house flies with 24-h LC50s of 6.9, 7.5, 8.0, and 9.2µg/cm3, respectively. Further research focused on undecanone (a U.S. EPA-registered biopesticide). When tested in larger enclosures at 1.7, 2.3, and 2.8µg/cm3, undecanone provided 60.4, 82.2, and 94.4% house fly mortality; 56.9, 75.6, and 92.5% flesh fly mortality; and 62.1, 84.5, and 97.9% blow fly mortality, respectively, after a 2-h exposure. In a two-choice behavioral assay with 194.6µg/ cm2 of the test compound on the treatment versus an untreated surface of the same area, the overall mean repellencies for blow flies were 84.7% for undecanone versus 87.6% for N,N-diethyl-meta-toluamide (DEET). For house flies, mean repellencies were 80.7% for undecanone and 84.9% for DEET. The house fly topical LD50 for undecanone was 58.1µg per fly. Undecanoone was far less expensive for filth fly control than the gold standard for insect fumigation, methyl bromide. See patent pending abstracts for details of new inventions.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Roe, R. M., J. M. Deguenon, N. V. Travanty, A. Dhammi, L. Ponnusamy, D. Mott, D. Reisig and R. W. Kurtz. 2019. Caterpillar microbiome in non-Bt versus WideStrike cotton. In Proceedings, 2019 Beltwide Cotton Conferences, New Orleans, LA, Jan. 8-10, 2019. Cotton Council, Memphis, TN. Pp. 505-516.
  • Type: Other Status: Published Year Published: 2019 Citation: Halbkata, L. , K. Luana , G. Cave, M. McCord, M. Roe, E. DenHartog, N. J. Travanty, C. S. Apperson and A. J. West. 2019. Fabric infused with a botanical repellent for protection against mosquitoes. J. Textile Sci. doi.org/10.1080/00405000.2019.1603576. 7 pp.
  • Type: Other Status: Published Year Published: 2019 Citation: West, A. J., M. G. McCord, R. M. Roe, J. B. Davis and J. Zhu. 2019. 3D Spacer textiles for crop protection and insect control. Pub. No.: US2019/0230920 A1, Aug. 1, 2019. Appl. No. 16/258,574.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Deguenon, J. M., N. Travanty, J. Zhu, A. Carr, S. Denning, M. H. Reiskind, D. W. Watson, R. M. Roe and L. Ponnusamy. 2019. Exogenous and endogenous microbiomes of wild-caught Phormia regina (Diptera: Calliphoridae) flies from a suburban farm by 16S rRNA gene sequencing. Sci. Reports 9:20365
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Deguenon, J. M., J. Zhu, S. Denning, M. H. Reiskind, D. W. Watson and R. M. Roe. 2019. Control of filth flies, Cochliomyia macellaria (Diptera: Calliphoridae), Musca domestica (Diptera: Muscidae), and Sarcophaga bullata (Diptera: Sarcophagidae), using novel plant-derived methyl ketones. J. Med. Entomol. 56: 17041714.
  • Type: Other Status: Published Year Published: 2019 Citation: Roe, R. M. 2019. Methods and composition for killing of insect pest eggs. Pub. No.: US 2019/0166830 A1, Jun. 6, 2019. Appl. No.: 16/321,126. PCT No.: PCT/US2017/045064.
  • Type: Other Status: Published Year Published: 2019 Citation: Roe, R. M., S. Watson and H. Beach. 2019. Insect and tick repellent formulations and methods of use thereof. Intl. Publ. No.: WO 2019/133675 A1, July 4, 2019. Intl. Appl. No.: PCT/US20 18/067625.


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Scientific community, industry interested in developing products for insect and tick control, and the general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Research training was provided for Ph.D. students in entomology and toxicology, postdoctoral researchers, technicians and visiting scholars from other countries. How have the results been disseminated to communities of interest?Presentations at scientific meetings, scientific publications, patents, licensing and by advertisements made by companies with our products now on the market. Also, there are two NCSU startup companies formed from technology developed in my project; these companies have interactions with many different companies in the process of product development. What do you plan to do during the next reporting period to accomplish the goals?No changes from previous two years expected for next year. The program in its current form has many clearly defined successes in terms of publications, patents filed by NCSU, license agreements, startup companies, products in the market place for worldwide distribution, grant funding and Ph.D. student training.

Impacts
What was accomplished under these goals? Scrub typhus is a mites-borne rickettsiosis caused by the obligate intracellular Gram-negative bacterium Orientia tsutsugamushi. The disease is potentially life threatening and is prevalent in tropical Asia, islands of the western Pacific Ocean and northern Australia where an estimated one million cases occur annually. Orientia tsutsugamushi is transmitted by the bite of larval mites in the genus Leptotrombidium. In the present study, the composition of the microbiome in larvae, deutonymphs and adult males and females from laboratory colonies of L. imphalum that were infected as well as uninfected with O. tsutsugamushi were investigated by high-throughput sequencing of the bacterial 16S rRNA gene. Notably, the bacterial microbiomes of infected adult females were dominated by sequences of O. tsutsugamushi and an unidentified species of Amoebophilaceae, which together comprised 98.2% of bacterial sequences. To improve the taxonomic resolution of the Amoebophilaceae OTU a nearly full length sequence of the 16S rRNA gene was amplified, cloned, and Sanger sequenced. Infected female mites had 89 to 92% nucleotide identity with the Amoebophilaceae family, indicating that the bacterium was likely to be a species of a novel genus. The species composition of bacterial communities varied between mite life stages regardless of their infection status. Uninfected adults exhibited greater species diversity than adults infected with O. tsutsugamushi. In the infected colony, the rate of filial infection with Orientia was less than 100%. Larval and male mites that were PCR-negative for Orientia contained low numbers of sequences of Amoebophilaceae (0.01 and 0.06%, respectively) in their taxonomic profiles, suggesting that a mutualistic relationship exists between the novel species of Amoebophilaceae and O. tsutsugamushi. Our study findings provide the basis for further research to determine the influence of the novel Amoebophilaceae specieson the bacterial microbiome and on vector susceptibility to and transovarial transmission of O. tsutsugamushi. Tobacco thrips, Frankliniella fusca (Hinds), are a serious threat to cotton production in the United States; their host range is not limited to cotton and they have the ability to feed on a variety of other host plants of economic importance. Their small size, cryptic color, and multiple reproductive strategies are among several other factors that make tobacco thrips extremely difficult to detect and manage. They are also a competent vector for Tomato Spotted Wilt Virus (TSWV), a destructive virus that destroys the plant material it infects and contributes to reduced leaf area, reduced plant height, loss of apical dominance, and wilting. While TSWV is not found in cotton, it infects many closely related plant species. F. fusca have developed resistance to some of the commonly used and best chemical insecticides implemented for their control. There are also concerns about deregistration of chemical insecticides like neonicotinoids that are currently used in their control. In our current work, the mechanical insecticide Celite® 610 (DEadzone), a 100% natural diatomaceous earth (DE) formulation, was evaluated as a foliar spray in the field on cotton for tobacco thrips control; it was as effective as Orthene®, an organophosphate chemical insecticide commonly referred to as acephate. Celite® 610 (DEadzone) provides an alternative mode of action to control tobacco thrips than currently available chemical insecticides and has a number of additional advantages. It has a non-toxic mode of action, is fast acting and persistent, active at high humidity, has no restrictions for field reentry after an application, and is applicable to organic farming. Our studies also showed Celite® 610 in a tank mix could enhance the insecticidal activity of Orthene®, potentially reducing the amount of chemical needed for thrips control. Celite® 610 as a powder in these studies readily mixed with water and was applied as a mist using standard spray equipment.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Ponnusamy, L., A. C. Willcox, R. M. Roe, S. A. Davidson, P. Linsuwanon, A. L. Schuster, A. L. Richard, S. R. Meshnick and C. S. Apperson. 2018. Bacterial microbiome of the chigger Leptotrombidium imphalum varies by life state and infection with the scrub typhus pathogen Orientia tsutsugamushi. PLOSone 13:e0208327.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Zhu, J., A. Dhammi, J. B. van Kretschmar, E. L. Vargo, C. S. Apperson and R. M. Roe. 2018. Novel use of aliphatic n-methyl ketones as a fumigant and alternative to methyl bromide for insect control. Pest. Manag. Sci. 74:648-657.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Mitchell III, R. D., D. W. Mott, A. Dhammi, D. D. Reisig, R. M. Roe, and D. Stewart. 2018. Field evaluation of a new thrips control agent for cotton: a mechanical insecticide. In Proceedings, 2018 Beltwide Cotton Conferences, San Antonio, TX, Jan. 3-5, 2018. Cotton Council, Memphis, TN. Pp. 786-795.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Scientific community, the US military, private industry interested in development of new products for insect and tick control, and the general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Provided training to Ph.D. students, Postdoctoral Researchers, Technicians, and Visiting Scholars from US and other countries. How have the results been disseminated to communities of interest?By presentations in scientific meetings, published journal articiles, patents, and licensiing to companies. What do you plan to do during the next reporting period to accomplish the goals?There is no expected change in our effort in research, technology development and training different from this reporting period (see this report for details of my activity).

Impacts
What was accomplished under these goals? Selected accomplishments (too many to provide all): Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1Gbp 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 re?ects accumulation of repetitive DNA, new lineages of retrotransposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing 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. The Haller's organ (HO), unique to ticks and mites, is found only on the first tarsus of the front pair of legs. The organ has an unusual morphology consisting of an anterior pit (AP) with protruding sensilla and a posterior capsule (Cp). The current thinking is that the HO's main function is chemosensation analogous to the insect antennae, but the functionality of its atypical structure (exclusive to the Acari) is unexplained. We provide the first evidence that the HO allows the American dog tick, Dermacentor variabilis, to respond to infrared (IR) light. Unfed D. variabilis adults with their HOs present were positively phototactic to IR. However, when the HOs were removed, no IR response was detected. Ticks in these experiments were also attracted to white light with and without the HOs, but were only positively phototactic to white light when the ocelli (primitive eyes) were unobstructed. Covering the eyes did not prevent IR attraction. A putative TRPA1 receptor was characterized from a D. variabilis-specific HO transcriptome we constructed. This receptor was homologous to transient receptor potential cation channel, subfamily A, member 1 (TRPA1) from the pit organ of the pit viper, python, and boa families of snakes, the only receptor identified so far for IR detection. HO scanning electron microscopy (SEM) studies inthe American dog tickshowedthe AP and Cpbutalso novel structures notpreviously described; the potential role of these structures in IR detection is discussed. The ability of ticks to use IR for host finding is consistent with their obligatory hematophagy and has practical applications in tick trapping and the development of new repellents. New paradigms for human health risk assessment of environmental chemicals emphasize the use of molecular methods and human-derived cell lines. In this study, we examined the effects of the insect repellent DEET (N,N-diethyl-m-toluamide) and the phenylpyrazole insecticide fippronil on transcript levels in primary human hepatocytes. These chemicals were tested individually and as a mixture. RNA-Seq showed that 100 μM DEET signifcantly increased transcript levels (α = 0.05) for 108 genes and lowered transcript levels for 64 genes and fipronil at 10 μM increased the levels of 2246 transcripts and decreased the levels for 1428 transcripts. Fipronil was 21-times more effective than DEET in eliciting changes, even though the treatment concentration was 10-fold lower for fipronil versus DEET. The mixture of DEET and fipronil produced a more than additive effect (levels increased for 3017 transcripts and decreased for 2087 transcripts). The transcripts affected for all chemical treatments were classified by GO analysis and mapped to chromosomes. The overall treatment responses, specific pathways, and individual transcripts affected were discussed at different levels of fold-change. Changes found in transcript levels in response to treatments will require further research to understand their importance in overall cellular, organ, and organismic function. Fumigants like phosphine, methyl bromide and sulfuryl fluoride are highly effective for the control of structural, storage and agricultural arthropod pests. Unfortunately, many of these synthetic compounds are highly toxic to people, many pests have developed resistance to these compounds and methyl bromide, the 'gold standard' for fumigants, was de-registered because of its contribution to depletion of the stratospheric ozone layer. Alternative fumigant chemistry is needed. Several plant species produce n-aliphatic methyl ketones to prevent plant herbivory. To examine the use of methyl ketones as a fumigant, structure-mortality studies were conducted using the red imported fire ant, Solenopsis invicta Buren, as a model. A new easy-to-use, inexpensive and disposable bioassay system was developed for this study. The LC50 values for heptanone, octanone, nonanone and undecanone were 4.27, 5.11, 5.26 and 8.21 micrograms/cm3 of ambient air, respectively. Although heptanone, octanone and nonanone were more effective than undecanone, subsequent research was conducted with 2-undecanone because this compound already has US Environmental Protection Agency (EPA) registration as a biopesticide. In dose-response field studies,12.4mL of undecanone injected into mounds was the lowest application rate that produced no ant activity in the mound with no re-establishment of ants. Reagent grade undecanone was more cost effective than methyl bromide for fire ants, adult German cockroaches and tobacco budworm eggs, but slightly more expensive for adult flour beetles. Insecticide resistance in insects has been attributed to many factors, namely target site modification, penetration, sequestration, metabolism, excretion and behavior. But the role of the microbiome present in insects in resistance is barely explored. In recent years, several studies suggest the microbiome might affect insect susceptibility to pesticides. The microbiome of an organism also can be affected by a number of variables including the insect's diet (often artificially produced) and food plants. Often insects from the field are bioassayed using artificial diet which contain antimicrobial inhibitors. In this study, changes in microbial diversity in the cotton bollworm, Helicoverpa zea, were investigated from conventional and WideStrike field cotton and which were also transferred to the laboratory on artificial diet. Microbial diversity was analyzed by the Tryptic Soy Agar (TSA) plate drop count method and by denaturing gradient gel electrophoresis (DGGE) after amplification of the bacterial V3 region of the 16S rRNA gene. The TSA analysis shows a lower number of culturable bacteria when field collected bollworms from conventional cotton were reared for 48 h on regular artificial diet (with a microbial inhibitor, methyl paraben (MPB)) as compared to bollworms collected directly from conventional cotton. The bacteria count was higher when they were reared on MPB free diet. There also were more culturable bacteria in bollworms from WideStrike as compared to conventional cotton. The DGGE studies show that the transfer of bollworms from conventional cotton to artificial diet with or without MPB changes the make-up of the bacterial community. Also the bollworms from WideStrike had a higher microbial diversity as compared to conventional cotton. These preliminary findings need further replication but at least argue for more research to understand the interactions between the bollworm and plant microbiomes and the impact of cotton variety and transfer to artificial diets on Bt susceptibility, including the use of high throughput sequencing to better characterize the bacterial communities.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Monika Gulia-Nuss et al. 2016. Genomic insights into the Ixodes scapulais tick vector of Lyme disease. Nature Comm. 7:10507.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Carr, A. L. and M. Roe. 2016. Acrine attractants: chemoreception, bioassay, chemistry and control. Pestic. Biochem. Physiol. 131:60-79.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Carr, A. L., D. E. Sonenshine, J. B. Strider Jr. and R. M. Roe. 2016. Evidence of female sex pheromones and characterization of the cuticular lipids of unfed, adult male versus female blacklegged ticks, Ixodes scapularis. Exp. Appl. Acarol. 68:519-538.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Zhu, J., S. M. Khalil, R. D. Mitchell, B. W. Bissinger, N. Egekwu, D. E. Sonenshine and R. M. Roe. 2016. Mevalonate-farnesal biosynthesis in ticks: comparative synganglion transcriptomics and a new perspective. Plos One 11:e0141084.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Carr, A. L., R. D. Mitchell III, A. Dhammi, B. W. Bissinger, D. E. Sonenshine and R. M. Roe. 2017. Tick Hallers organ, a new paradigm for arthropod olfaction: how ticks differ from insects. Intl. J. Mol. Sci. 18:1563.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mitchell III, R. D., J. Zhu, A. L. Carr, A. Dhammi, G. Cave, D. E. Sonenshine and R. M. Roe. 2017. Infrared light detection by the Hallers organ of adult American dog ticks, Dermacentor variabilis (Ixodida: Ixodidae). Ticks Tick-borne Diseases 8:764-771.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Roe, R. M., A. Dhammi, J. Zhu, D. Reisig and R. W. Kurtz. 2016. Multiple mechanisms for caterpillar resistance to BT: Dont forget our history. In Proceedings, 2016 Beltwide Cotton Conferences, New Orleans, LA, Jan. 5-7, 2016. Cotton Council, Memphis, TN. Pp. 849-857.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Zhu, J., A. Dhammi, R. M. Roe and D. Stewart. 1016. Novel mechanical pesticides for tobacco thrips, Frankliniela fusca, control in cotton. In Proceedings, 2016 Beltwide Cotton Conferences, New Orleans, LA, Jan. 5-7, 2016. Cotton Council, Memphis, TN. Pp. 704-712.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Dhammi, A., L. Ponnusamy, J. Zhu, G. Cave, R. M. Roe and R. W. Kurtz. 2017. Caterpillars, cotton pest protection and insect bioassay: dont forget the microbiome. In Proceedings, 2017 Beltwide Cotton Conferences, Dallas, TX, Jan. 4-6, 2017. Cotton Council, Memphis, TN. Pp. 771-774.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mitchell III, R. D., A. D. Wallace, E. Hodgson and R. M. Roe. 2017. Differential expression profile of lncRNAs from primary human hepatocytes following DEET and Fipronil exposure. Intl. J. Molec. Sci. 18:2104.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Dhammi, A., J. B. van Krestchmar, L. Ponnusamy, J. S. Bacheler, D. D. Reisig, A. Herbert, A. I. Del Pozo-Valdivia and R. M. Roe. 2016. Biology, pest status, microbiome and control of kudzu bug (Hemiptera: Heteroptera: Plataspidae): a new invasive pest in the U.S. Int. J. Mol. Sci. 17:1570.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Mitchell III, R. D., A. Dhammi, A. Wallace, E. Hodgson and R. M. Roe. 2016. Impact of environmental chemicals on the transcriptome of primary human hepatocytes: potential for health effects. J. Biochem. Mol. Tox. 30:375-395.