EVALUATION OF ORGANIC INFUSIONS AND SYNTHETIC COMPOUNDS MEDIATING OVIPOSITION IN AEDES-ALBOPICTUS AND AEDES-AEGYPTI (DIPTERA, CULICIDAE)

Oviposition responses of gravid Aedes albopictus and Ae. aegypti were evaluated to natural organic infusions (hay infusion, larva: rearing w ater, and field-collected larval water) as well as compounds isolated from hay infusion (3-methylindole, 4-methylphenol, 4-ethylphenol, indo le, and phenol) known to elicit oviposition in Culex mosquitoes. In la boratory bioassays, significant oviposition responses were obtained fr om Ae. albopictus, but not from Ae. aegypti, to dilutions of hay infus ion and field water. Oviposition responses of both species were modera te to the synthetic compounds tested in the laboratory (0.01-100 mu g/ liter). Only 3-methylindole (0.1 mu g/liter) and 4-ethylphenol (1.0 mu g/liter) elicited significantly more oviposition by Ac. albopictus th an did well water. Of the synthetic compounds rested with Ae. aegypti, only phenol (1.0 mu g/liter) and 4-ethylphenol (0.1 mu g/liter) elici ted significantly more oviposition than did well water. Significant re pellency or oviposition deterrence for both species occurred in respon se to at least one high concentration of most of the compounds tested. In field cage evaluations, oviposition responses by Ae. albopictus we re strongest to larval water and field water, moderate to hay infusion and 3-methylindole (100 mu liter), and low to well water. A mixture o f five synthetic compounds mimicking hay infusion was no more effectiv e than 3-methylindole alone. For Ae. aegypti, oviposition responses we re greatest to larval water and least to 3-methylindole. In an olfacto meter, gravid females of both species oriented mon to field water than to well water and only Ae. albopictus oriented more to larval water o r hay infusion than well water. In general, gravid Ac. albopictus resp onded more strongly to oviposition stimuli than did Ae. aegypti.