In laboratory bioassays, gravid Culex quinquefasciatus mosquitoes were strongly attracted and or stimulated to oviposit by a habitat-derived chemical cue, 3-methylindole, at several concentrations ranging from 0.01 to 1 microgram/liter in water. At concentrations above 10 micrograms/liter, 3-methylindole became repellent or deterrent. Responses to the known egg raft pheromone, 6-acetoxy-5-hexad...

Cantharidin, the well-known terpenoid compound from the blood of blister beetles (and active principle of Spanish fly), is a feeding deterrent to insects, effective at a concentration of 10(-5) molar.

In a Central Michigan wetland setting, air drawn through a DEET-impregnated screen using an electric fan and projected toward a human subject significantly reduced mosquito orientation by 74%, landing by 75%, and probing by 70%, relative to no applied wind or DEET. The DEET vapor effect was significant as revealed by a statistically significant wind/DEET interaction. The wind speed at the downw...

Callicarpenal (1), a natural terpenoid isolated from American beautyberry (Callicarpa americana), has shown significant repellent activities against mosquitoes, ticks and imported fire ants. Here we report our efficient synthetic approach to this natural product, and preliminary results of the mosquito biting-deterrent effects of callicarpenal as well as its synthetic precursors and related C(8...

We report that an aqueous solution containing 10(-3) M adenosine triphosphate (ATP) and citrate-phosphate-dextrose-adenine (CPDA-1) can effectively replace transfusable human red blood cells in an in vitro Klun and Debboun bioassay system for evaluating chemicals for mosquito feeding-deterrent activity, using either Aedes aegypti or Anopheles stephensi. These species fed with similar avidity th...

Aedes aegypti is responsible for the transmission of dengue, a disease that infects millions of people each year. Although essential oils are well recognized as sources of compounds with repellent and larvicidal activities against the dengue mosquito, much less is known about their oviposition deterrent effects. Commiphora leptophloeos, a tree native to South America, has important pharmacologi...

Oil of the physic nut, Jatropha curcas L. (Malpighiales: Euphorbiaceae), was evaluated in the laboratory for its barrier and repellent activity against the Philippine milk termite Coptotermes vastator Light (Isoptera: Rhinotermitidae). The study showed that J. curcas oil had anti-feeding effect, induced reduction in tunneling activity and increased mortality in C. vastator. Behavior of termites...

Methyl N,N-dimethyl anthranilate (MDA), ethyl anthranilate (EA) and butyl anthranilate (BA) were previously shown to repel Aedes aegypti mosquitoes from landing on human skin. However, the effect of these compounds on the orientation of flying mosquitoes in a choice situation and their effect on mosquito oviposition are not yet known. Here, we used a modified Y-tube olfactometer to test the eff...

Racemic 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine repels blood-feeding arthropods such as mosquitoes, chiggers, and ticks. The compound contains two asymmetric carbon atoms and the racemate consists of four stereoisomers. Quantitative mosquito bioassays using Aedes aegypti (L.) showed that (1S,2'S) and (1R,2'S) configurations were 2.8-3.1 and 1.6-1.8 times more effective, respectively, t...