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Novel aromatic and aliphatic organic acids, esters and ketones were synthesized and assayed as repellents for ticks. E-7-(cyclohexyl)hept-4-enoic acid (CHEA), E-7-phenylhept-4-enoic acid (PHEA), ethyl E-7-(cyclohexyl)hept-4- enoate (CHEN) and ethyl E-7-phenylhept-4-enoate (PHEN) had repellent activity against the soft tick, Ornithodoros parkeri (Acari: Argasidae) in a two-choice bioassay. PHEN, an aromatic organic ester, was the most active. 2- undecanone, a natural product found in the trichomes of wild tomatoes, was found to mimic our lead chemistry and was active as a repellent at 50 μg/cm². Since this compound is an already known natural botanical with a proven safety record including being approved as a food additive, formulation studies were conducted to optimize its volatility and maximize its repellent activity against ticks and mosquitoes when applied to human skin. Combining undecanone with proprietary emulsions from HOMS LLC, we were able to develop BioUD. BioUD30 and BioUD8 (30 and 8% undecanone, respectively) was a repellent to the American dog tick, Dermacentor variabilis (Acari: Ixodidae), 2.5 h after applications on the skin of human subjects. In field studies in two different habitats (forest and marsh), 99% repellency was found 4.5 h after application to the skin of human subjects for a population of mosquitoes comprised of mixed species. BioUD8 at 6 h after application was better than OFF Botanicals with 10% PMD and equivalent to OFF with 15% DEET. Application of 20 μl BioUD30 silicon (5.88mg undecanone) to 19.63 cm² of cotton fabric repelled on average >90% of D. variabilis ticks in a two-choice bioassay 5 d after application, suggesting that it effectively binds to cotton fabric. The repellent was active on cloth up to 7 d. The submission of BioUD for US EPA registration is expected in early 2006. The product will be marketed by HOMS LLC as a DEET alternative. BioUD will be all natural and non-flammable unlike many DEET products, with the potential of being organically certified. [ABSTRACT FROM AUTHOR]

The use of a non-equilibrium atmospheric pressure plasma discharge (APPD) for controlling insects and mites has only recently been explored. Current research has been successful in showing that a low temperature (37° ± 2°C) discharge can kill arthropods. The mode of action is not understood. Cockroaches exposed to the discharge for 90 s lost significant motor control during the 24 h study, while those exposed only to the helium atmosphere required to operate the DBD (Dielectric Barrier Discharge) returned to normal behavior within 15 min. The oxygen consumption of cockroaches exposed to a 3 min discharge was greater than those only exposed to the helium atmosphere suggesting an increase in metabolic rate. Cockroaches exposed to APPD lost a significantly greater amount of water weight than the control. The cuticular hydrocarbons of citrus mealy bugs were unaffected by the discharge except a reduction in the abundance of n-tritriacontane. In green peach aphids, the trend was toward a reduction in hydrocarbon abundance, although this was not statistically significant for most of the compounds identified by GC-MS. Based on the aberrant behavior of the cockroaches after treatment in the discharge, it appears that the disruption of the nervous or neuromuscular system is a component of the mode of action of APPD. [ABSTRACT FROM AUTHOR]

This paper presents evidence for the efficacy of atmospheric pressure plasma discharge (APPD) in the absence of chemical species and above ambient gas temperature on insect control. The treatment of a model insect system, green peach aphids, was carried out on a plastic surface and tobacco leaves. Both treatments show a reduction in green peach aphid populations, but their mortality on a plastic surface (88% mortality) was significantly higher than that on tobacco leaves (40%) for a 120 s treatment. The reduction in mortality of green peach aphids on leaves is likely from the leaf acting as a lightning rod that is drawing the plasma away from the aphids. For practical applications, the thermal component of the discharge will accompany the plasma treatment to decrease treatment duration. [ABSTRACT FROM AUTHOR]

A consumer version of the feeding disruption bioassay for pesticide resistance detection and species diagnosis (R.M. Roe et al., 2000, US Patent Number 6,060,039) is currently in the commercialization phase of development. The kit measures the potential effectiveness of pesticide treatments against lepidopteran pests, particularly the tobacco budworm (TBW)-cotton bollworm (CBW) complex as it occurs in cotton crops (W.D. Bailey et al. 1998, Crop Prot. 17:591). The kit consists of a specially designed white plastic 16-well plate with recessed hydrateable meal pads containing an insecticide diagnostic dose and a blue feeding indicator. The appearance of blue feces, easily seen on the background of the white plate, is a marker for feeding. Insects that produce blue feces are resistant to the diagnostic dose of the pesticide. The assay kit can be stored at room temperature until needed. The test is performed in 24h on individual neonates or older insects, and the results are read in as little as 4h on groups of insects. Data are presented on a working resistance kit for the TBW and/or the CBW for the following insecticides: Bt, spinosyn, permethrin, indoxacarb and emamectin benzoate. A species diagnosis kit has been designed and field-tested for distinguishing the TBW from the CBW (W.D. Bailey et al, 2001, J. Econ. Entomol. 94:76). Finally, the utility of our new assay approach for other insect species has been demonstrated by the development of a kit for spinosyn in the cabbage looper (R.M. Roe et al., 2002, Proc. Beltwide Cotton Conf., Atlanta, GA). The commercial manufacturer has developed state-of-the-art robotics technology for custom production of resistance and species diagnostic kits, and the basic technologies can be used for routine insect rearing and microtiter plate high throughput screening. Transgenic plant technology will most likely be the major method of control for moth pests in cotton in the future, especially apparent as the result of the next generation of transgenic cotton varieties expressing multiple Bt toxins. Because of this increased dependency, it is critical that we keep up with the latest developments with advances in diagnostic technology for resistance detection. In 2003 we began research to validate the feeding disruption assay for monitoring insect resistance for the next generation transgenic technology. [ABSTRACT FROM AUTHOR]