No abstract

No abstract

No abstract

The effects of hexaflumuron consumption on the mortality of workers of the Western subterranean termite, Reticulitermes hesperus Banks, were observed following various exposures to a substrate treated with 14C-labeled hexaflumuron at 5 g kg(-1). Uptake of hexaflumuron by workers was rapid, peaking at approximately 280 ng hexaflumuron per termite 12 days after exposure. The onset of mortality began at day 8, with cumulative mortality reaching approximately 96% by day 45. Excretion of hexaflumuron from worker termites was rapid following various exposure periods, half-lives ranging from 2.1 to 4.7 days. Trophallaxis among worker termites was efficient, hexaflumuron levels in recipient termites approaching two-thirds of levels present in donor termites feeding continuously on hexaflumuron-treated filter paper. The effect of donor-to-recipient group ratios was negligible on the amounts of hexaflumuron transferred from donors to recipients. In laboratory tests, hexaflumuron diffused from a feeding source within 7 days. The presence of additional food sources appeared to inhibit movement of hexaflumuron. Movement of hexaflumuron by cannibalism and coprophagy occurred, but was significant only when termites were starved. Hexaflumuron also appeared to adversely affect egg development by preventing hatch. Hexaflumuron was readily transferred through termite groups, effectively suppressing laboratory populations of R hesperus. Variable efficacy in field situations employing baiting with hexaflumuron in southern California may be a consequence of sporadic feeding at bait stations, the rapid clearance of hexaflumuron from individual termites, and the difficulties in bait presentation (low foraging activity, poor bait station foraging fidelity) inherent in the foraging characteristics of the Western subterranean termite.

Post-Hurricane Rita mosquito surveillance was carried out in 4 east Texas counties to determine mosquito abundance, species composition, and need for mosquito control. Subsequently, aerial applications of naled (Dibrom) for mosquito control were made by the Air Force Aerial Spray Flight, while continued surveillance documented the efficacy of the applications. Psorophora columbiae was the predominant species in landing counts. Twenty-two mosquito species were represented in light trap collections with Aedes atlanitcus/tormentor, Culex nigripalpus, Ae. vexans, and Ps. columbiae making up 91% of the total. A total of 102,001 ha (252,052 acres) were aerially treated based on high mosquito abundance, exposure of first responders and residents to nuisance biting, and local interruption of electric utilities. A significant 90% decline in mosquito abundance was observed posttreatment.