Effects of methoprene, a juvenile hormone analogue, on the larval and pupal stages of the yellow fever mosquito, Aedes aegypti

Exposure of early 4th-instar larvae of Aedes aegypti (L.) to the juvenile hormone analogue methoprene (Altosid) significantly increased the concentration of carbohydrates in the haemolymph of late 4th-instar larvae and reduced the haemolymph carbohydrate concentration of 24-h-old pupae relative to controls. Such treatment also effected a decline in haemolymph amino nitrogen levels of the pupal stage and a depletion of haemolymph proteins in late 4th-instar larvae as well as pupae. Two of 9 protein fractions in the haemolymph of larvae were significantly depleted. The data are consistent with the proposition that methoprene elicits neuroendocrinological changes in the target insect.ADDITIONAL ABSTRACT:The addition of 0.1 micro g/l of methoprene (Altosid ZR515) to water containing early fourth-instar larvae of Aedes aegypti caused the haemolymph carbohydrate concentration to increase later in the fourth instar and to decrease in the pupa. In the haemolymph of treated larvae and pupae the protein concentration decreased (with the absence of 2 fractions seen in controls). In the fatbody, glycogen and protein concentrations, glycogen phosphorylase activity and protein synthesis were all reduced. Such changes would be expected if the methoprene upset the neuroendocrine system of the insects.J.E. Hudson.