Effect of the chitin synthesis inhibitor triflumuron on the development, viability and reproduction of Aedes aegypti

ABSTRACT

The control of Aedes aegypti is impaired due to the development of resistance to chemical insecticides. Insect Growth Regulators (IGR) exhibit distinct mechanisms of action and are considered potential vector control alternatives. Studies regarding the effects of sublethal IGR doses on the viability of resulting adults will contribute to eval-uating their impact in the field. We analyzed several aspects of Ae. aegypti adults surviving exposure to a partially lethal dose of triflumuron, a chitin synthesis inhibitor. A highly significant difference in the proportion of males and females was noted in the triflumuron-exposed group (65.0 percent males) compared to the controls (50.2 percent males). Triflumuron affected adult longevity, particularly for females; after 16 days, only 29.2 percent of males and 13.8 percent of females were alive, in contrast with 94 percent survival of the control mosquitoes. The locomotor activity was reduced and the blood-feeding ability of the treated females was also affected (90.4 percent and 48.4 percent of the control and triflumuron-exposed females, respectively, successfully ingested blood). Triflumuron-surviving females ingested roughly 30 percent less blood and laid 25 percent fewer eggs than the control females. The treated males and females exhibited a diminished ability to copulate, resulting in less viable eggs.