Histopathological effects of an insect growth regulator, 4-phenoxyphenyl (RS)-2-(2-pyridyloxy) propyl ether (pyriproxyfen), on the larvae of Aedes aegypti

Abstract

Histopathological effects of an insect growth regulator, pyriproxy-fen, on the larvae of Aedes aegypti were studied by treating with concentrations at 1 and 10ppb for 24 and 48hr. At the light microscopic Ievel, vacuolation and inhibition of development of imaginal buds in various grades were seen. Electron microscopy revealed the lack of cuticular formation and vacuolation of epidermal cells. In the midgut and Malpighian tubules, disrupted mitochondria, abundant vacuoles and pooriy-structured cytoplasmie organelles were observed. These findings suggest possible histolysis of the cells induced by pyriproxyfen.