The potential attractant or repellent effects of different water types on oviposition in Aedes aegypti L. (Dipt., Culicidae)

The selection of oviposition sites by the yellow-fever mosquito, Aedes aegypti , was studied in the laboratory. The repellent or attractant effects of salinity and the presence of bacteria in water collected from a local community on the Brazilian coast were investigated. Water contaminated with bacteria (waste water and lagoon water) elicited significantly more oviposition than distilled water. Oviposition decreased with an increase in salinity, with almost no oviposition above 12%. The salinity tolerance of A. aegypti larvae was investigated by measuring their mortality in response to salt concentrations ranging from 10 to 15%. The LD50 of salt for A. aegypti larvae was around 13%

Captura de Rhynchophorus palmarum L. (Coleoptera: curculionidae) em armadilhas iscadas com o feromônio de agregação e compostos voláteis de frutos do abacaxi Trap catches of Rhynchophorus palmarum L. (Coleoptera: curculionidae) baited with its aggregation pheromone and volatile compounds from pineapple

O objetivo deste trabalho foi determinar os índices de captura de Rhynchophorus palmarum em armadilhas iscadas com o feromônio de agregação, 6-metil-2(E)-hepten-4-ol (rincoforol), associado a toletes de cana-de-açúcar, a pedaços de frutos do abacaxi e a seis compostos voláteis isolados de frutos do abacaxi. Os compostos voláteis do abacaxi são caracterizados por uma mistura de ésteres metílicos e etílicos, sendo o octanoato de metila e o octanoato de etila os mais abundantes. As armadilhas iscadas com o rincoforol associado a toletes de cana-de-açúcar e as iscas com rincoforol associado a pedaços de abacaxi não apresentaram diferenças significativas no número de besouros capturados. No entanto, ambas apresentaram índices de captura superiores àquelas em que o rincoforol foi utilizado em associação com voláteis do abacaxi. Não se observaram efeitos significativos do local e época de captura, nem no número de machos e de fêmeas capturados.<br>The aim of this work was to investigate the capture of Rhynchophorus palmarum in traps baited with its aggregation pheromone, 6-methyl-2(E)-hepten-4-ol (rhynchophorol), in association with sugar cane, pieces of pineapple fruit, and six volatile compounds from pineapple. A mixture of methyl and ethyl esters, being methyl octanoate and ethyl octanoate the most abundant, characterizes the volatile compounds from pineapple fruits. Traps baited with rhynchophorol in association with sugar cane and those baited with rhynchophorol in association with pieces of pineapple, showed no significant differences in the number of trapped weevils. However, both traps caught significantly more weevils, than those baited with rhynchophorol in association with pineapple volatiles. There were no significant effects from place and time or in the number of male and female weevils trapped