@article{cave_richardson_chen_watson_roe_2023, title={Acaricidal Biominerals and Mode-of-Action Studies against Adult Blacklegged Ticks, Ixodes scapularis}, volume={11}, ISSN={["2076-2607"]}, url={https://www.mdpi.com/2076-2607/11/8/1906}, DOI={10.3390/microorganisms11081906}, abstractNote={Ticks in the USA are the most important arthropod vector of microbes that cause human and animal disease. The blacklegged tick, Ixodes scapularis, the focus of this study, is able to transmit the bacteria that causes Lyme disease in humans in the USA. The main approach to tick control is the use of chemical acaricides and repellents, but known and potential tick resistance to these chemicals requires the discovery of new methods of control. Volcanic glass, Imergard, was recently developed to mimic the insecticide mode of action of the minerals from diatoms (diatomaceous earth, DE) for the control of malaria mosquitoes in Africa. However, studies on the use of these minerals for tick control are minimal. In a dipping assay, which was put into DE (Celite), the times of 50 and 90% death of adult female I. scapularis were 7.3 and 10.5 h, respectively. Our mimic of DE, Imergard, killed ticks in 6.7 and 11.2 h, respectively. In a choice-mortality assay, ticks moved onto a treated surface of Imergard and died at 11.2 and 15.8 h, respectively. Ticks had greater locomotor activity before death when treated by dipping for both Imergard and Celite versus the no-mineral control. The ticks after making contact with Imergard had the mineral covering most of their body surface shown by scanning electron microscopy with evidence of Imergard inside their respiratory system. Although the assumed mode of action of Imergard and Celite is dehydration, the minerals are not hygroscopic, there was no evidence of cuticle damage, and death occurred in as little as 2 h, suggesting minimal abrasive action of the cuticle. Semi-field and field studies are needed in the future to examine the practical use of Imergard and Celite for tick control, and studies need to examine their effect on tick breathing and respiratory retention of water.}, number={8}, journal={MICROORGANISMS}, author={Cave, Grayson L. and Richardson, Elise A. and Chen, Kaiying and Watson, David W. and Roe, R. Michael}, year={2023}, month={Aug} } @article{luan_mccord_west_cave_travanty_apperson_roe_2023, title={Mosquito Blood Feeding Prevention Using an Extra-Low DC Voltage Charged Cloth}, volume={14}, ISSN={["2075-4450"]}, url={https://doi.org/10.3390/insects14050405}, DOI={10.3390/insects14050405}, abstractNote={Mosquito vector-borne diseases such as malaria and dengue pose a major threat to human health. Personal protection from mosquito blood feeding is mostly by treating clothing with insecticides and the use of repellents on clothing and skin. Here, we developed a low-voltage, mosquito-resistant cloth (MRC) that blocked all blood feeding across the textile and was flexible and breathable. The design was based on mosquito head and proboscis morphometrics, the development of a novel 3-D textile with the outer conductive layers insulated from each other with an inner, non-conductive woven mesh, and the use of a DC (direct current; extra-low-voltage) resistor-capacitor. Blockage of blood feeding was measured using host-seeking Aedes aegypti adult female mosquitoes and whether they could blood feed across the MRC and an artificial membrane. Mosquito blood feeding decreased as voltage increased from 0 to 15 volts. Blood feeding inhibition was 97.8% at 10 volts and 100% inhibition at 15 volts, demonstrating proof of concept. Current flow is minimal since conductance only occurs when the mosquito proboscis simultaneously touches the outside layers of the MRC and is then quickly repelled. Our results demonstrated for the first time the use of a biomimetic, mosquito-repelling technology to prevent blood feeding using extra-low energy consumption.}, number={5}, journal={INSECTS}, author={Luan, Kun and McCord, Marian G. and West, Andre J. and Cave, Grayson and Travanty, Nicholas V. and Apperson, Charles S. and Roe, R. Michael}, year={2023}, month={Apr} } @article{cave_west_mccord_koene_beck_deguenon_luan_roe_2022, title={Novel 3-D Spacer Textiles to Protect Crops from Insect Infestation and That Enhance Plant Growth}, volume={12}, ISSN={["2077-0472"]}, url={https://doi.org/10.3390/agriculture12040498}, DOI={10.3390/agriculture12040498}, abstractNote={Pesticide-free, 3-D, spacer fabrics (Plant Armor Generation (PA Gen) 1 and 2) were investigated for proof-of-concept as an insect barrier to protect plants and improve plant agronomics for organic farming. The time to 50% penetration (TP50) for tobacco thrips, Frankliniella fusca (Hinds) adults in laboratory Petri dish bioassays was 30 and 175 min for PA Gen 1 and 2, respectively, and 12 min for the control (a commercially available, single layer-crop cover, Proteknet). PA Gen 2 was ≥90% resistant to penetration of unfed caterpillar neonates, Helicoverpa zea (Boddie), while the TP50‘s for Gen 1 and Proteknet were 3.1 and 2.35 h, respectively. In small cage studies, PA Gen 2 covered potted cabbage plants were 100% resistant to penetration by these insects through 10 d after which the study was ended. In small field plot studies for 3 summer months, cabbage plants grew approximately twice as fast when covered versus not covered with Gen 1 and Gen 2 without the need for insecticides or herbicides. This was not observed for the control crop cover. Martindale abrasion tests demonstrated Gen 1 and 2 were at least 6- and 1.8-fold more durable than the control crop cover used. Data are also presented on percentage light, water, air, and water vapor penetration across each textile and operational temperatures and humidity for cabbage plants covered and uncovered in small field plots.}, number={4}, journal={AGRICULTURE-BASEL}, publisher={MDPI AG}, author={Cave, Grayson L. and West, Andre J. and McCord, Marian G. and Koene, Bryan and Beck, J. Benjamin and Deguenon, Jean M. and Luan, Kun and Roe, R. Michael}, year={2022}, month={Apr} } @article{deguenon_dhammi_ponnusamy_travanty_cave_lawrie_mott_reisig_kurtz_roe_2021, title={Bacterial Microbiota of Field-Collected Helicoverpa zea (Lepidoptera: Noctuidae) from Transgenic Bt and Non-Bt Cotton}, volume={9}, ISSN={["2076-2607"]}, url={https://www.mdpi.com/2076-2607/9/4/878}, DOI={10.3390/microorganisms9040878}, abstractNote={The bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), is an important agricultural pest in U.S. cotton and is managed using transgenic hybrids that produce insecticidal proteins from the bacterium, Bacillus thuringiensis (Bt). The reduced efficacy against H. zea caterpillars of Bt plants expressing Cry toxins is increasing in the field. In a first step towards understanding Bt cotton–bollworm–microbiota interactions, we investigated the internal bacterial microbiota of second–third stadium H. zea collected in the field from non-Bt versus Bt (WideStrike) cotton in close proximity (in North Carolina, USA). The bacterial populations were analyzed using culture-dependent and -independent molecular approaches. We found that WideStrike samples had a higher bacterial density and diversity per larva than insects collected from non-Bt cotton over two field seasons: 8.42 ± 0.23 and 5.36 ± 0.75 (log10 colony forming units per insect) for WideStrike compared to 6.82 ± 0.20 and 4.30 ± 0.56 for non-Bt cotton for seasons 1 and 2, respectively. Fifteen phyla, 103 families, and 229 genera were identified after performing Illumina sequencing of the 16S rRNA. At the family level, Enterobacteriaceae and Enterococcaceae were the most abundant taxa. The Enterococcaceae family was comprised mostly of Enterococcus species (E. casseliflavus and another Enterococcus sp.). Members of the Enterococcus genus can acidify their environment and can potentially reduce the alkaline activation of some Bt toxins. These findings argue for more research to better understand the role of cotton–bollworm–bacteria interactions and the impact on Bt toxin caterpillar susceptibility.}, number={4}, journal={MICROORGANISMS}, publisher={MDPI AG}, author={Deguenon, Jean M. and Dhammi, Anirudh and Ponnusamy, Loganathan and Travanty, Nicholas V and Cave, Grayson and Lawrie, Roger and Mott, Dan and Reisig, Dominic and Kurtz, Ryan and Roe, R. Michael}, year={2021}, month={Apr} } @article{luan_west_mccord_denhartog_shi_bettermann_li_travanty_mitchell_cave_et al._2021, title={Mosquito-Textile Physics: A Mathematical Roadmap to Insecticide-Free, Bite-Proof Clothing for Everyday Life}, volume={12}, ISSN={2075-4450}, url={http://dx.doi.org/10.3390/insects12070636}, DOI={10.3390/insects12070636}, abstractNote={Garments treated with chemical insecticides are commonly used to prevent mosquito bites. Resistance to insecticides, however, is threatening the efficacy of this technology, and people are increasingly concerned about the potential health impacts of wearing insecticide-treated clothing. Here, we report a mathematical model for fabric barriers that resist bites from Aedes aegypti mosquitoes based on textile physical structure and no insecticides. The model was derived from mosquito morphometrics and analysis of mosquito biting behavior. Woven filter fabrics, precision polypropylene plates, and knitted fabrics were used for model validation. Then, based on the model predictions, prototype knitted textiles and garments were developed that prevented mosquito biting, and comfort testing showed the garments to possess superior thermophysiological properties. Our fabrics provided a three-times greater bite resistance than the insecticide-treated cloth. Our predictive model can be used to develop additional textiles in the future for garments that are highly bite resistant to mosquitoes.}, number={7}, journal={Insects}, publisher={MDPI AG}, author={Luan, Kun and West, Andre J. and McCord, Marian G. and DenHartog, Emiel A. and Shi, Quan and Bettermann, Isa and Li, Jiayin and Travanty, Nicholas V. and Mitchell, Robert D., III and Cave, Grayson L. and et al.}, year={2021}, month={Jul}, pages={636} } @article{chen_deguenon_cave_denning_reiskind_watson_stewart_gittins_zheng_liu_et al._2021, title={New thinking for filth fly control: residual, non-chemical wall spray from volcanic glass}, volume={35}, ISSN={["1365-2915"]}, DOI={10.1111/mve.12521}, abstractNote={Abstract}, number={3}, journal={MEDICAL AND VETERINARY ENTOMOLOGY}, author={Chen, K. and Deguenon, J. M. and Cave, G. and Denning, S. S. and Reiskind, M. H. and Watson, D. W. and Stewart, D. A. and Gittins, D. and Zheng, Y. and Liu, X. and et al.}, year={2021}, month={Sep}, pages={451–461} } @article{halbkat_luan_cave_mccord_roe_denhartog_travanty_apperson_west_2019, title={Fabric infused with a botanical repellent for protection against mosquitoes}, volume={110}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000.2019.1603576}, DOI={10.1080/00405000.2019.1603576}, abstractNote={Abstract 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.}, number={10}, journal={The Journal of The Textile Institute}, publisher={Informa UK Limited}, author={Halbkat, Lilah and Luan, Kun and Cave, Grayson and McCord, Marian and Roe, Michael and DenHartog, Emiel and Travanty, Nicholas J. and Apperson, Charles S. and West, Andre J.}, year={2019}, month={Apr}, pages={1468–1474} } @article{bowman_akialis_cave_barrera_apperson_meshnick_2018, title={Pyrethroid insecticides maintain repellent effect on knock-down resistant populations of Aedes aegypti mosquitoes}, volume={13}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0196410}, abstractNote={Pyrethroid-treated clothing is commonly worn for protection against mosquitoes; pyrethroids are both insecticides and repellents. Pyrethroid resistance has become increasingly common in Aedes aegypti, the vector of dengue, Zika, and other arboviruses, but it is not clear whether resistance is associated with reductions in repellency. In order to determine whether long-lasting permethrin impregnated (LLPI) clothing is protective, we used Aedes aegypti from New Orleans, LA (pyrethroid-sensitive) and San Juan, PR (resistant) to measure both lethality and repellency. PCR and Sanger sequencing were used to confirm resistance status by detecting mutations in the kdr gene at positions 1016 and 1534. Arm-in-cage trials of 100 Aedes aegypti females from both populations were performed for 10 minutes to bare arm or an arm clothed in untreated military camouflage or military camouflage impregnated with deltamethrin, permethrin, or etofenprox. Trials were repeated 4–5 times on different days. Number of landings, number of blood meals, and immediate and 24-hour mortality were recorded. Mortality was extremely low in all trials. Compared to untreated cloth, mosquitoes demonstrated a trend towards a 2%-63% reduction in landings and a statistically significant 78–100% reduction in blood feeding on pyrethroid-treated cloth for most insecticides. Effects were observed in both pyrethroid-sensitive and pyrethroid-resistant mosquito populations. Our data show that kdr mutations are associated with pyrethroid resistance but are likely not the only contributors. Pyrethroids appear to maintain repellent effect against resistant mosquitoes. This finding suggests that even in places where pyrethroid resistance is widespread, permethrin still has a role for use as a repellent on clothing to protect against mosquito bites.}, number={5}, journal={PLOS ONE}, author={Bowman, Natalie M. and Akialis, Kristin and Cave, Grayson and Barrera, Roberto and Apperson, Charles S. and Meshnick, Steven R.}, year={2018}, month={May} } @article{mitchell_zhu_carr_dhammi_cave_sonenshine_roe_2017, title={Infrared light detection by the hailer's organ of adult american dog ticks, Dermacentor variabilis (Ixodida: Ixodidae)}, volume={8}, ISSN={["1877-9603"]}, DOI={10.1016/j.ttbdis.2017.06.001}, abstractNote={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 in the American dog tick showed the AP and Cp but also novel structures not previously 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.}, number={5}, journal={TICKS AND TICK-BORNE DISEASES}, author={Mitchell, Robert D., III and Zhu, Jiwei and Carr, Ann L. and Dhammi, Anirudh and Cave, Grayson and Sonenshine, Daniel E. and Roe, R. Michael}, year={2017}, pages={764–771} }