Plumbagin and azadirachtin deplete hemolymph ecdysteroid levels and alter the activity profiles of two lysosomal enzymes in the fat body of Helicoverpa armigera (Lepidoptera : Noctuidae)
A. Josephrajkumar et Subrahmanyam, B",srinivasan, Plumbagin and azadirachtin deplete hemolymph ecdysteroid levels and alter the activity profiles of two lysosomal enzymes in the fat body of Helicoverpa armigera (Lepidoptera : Noctuidae), EUR J ENTOM, 96(4), 1999, pp. 347-353
The profile of hemolymph ecdysteroid was studied in the gram pod borer, Hel
icoverpa armigera, during larval-pupal transformation. The changes closely
correspond to the developmental events occurring at metamorphosis. Two inse
ct growth regulators, plumbagin and azadirachtin, significantly depleted th
e content and altered the profile of ecdysteroids at crucial stages, when a
pplied at ED50 doses. The activity profiles of two fat body lysosomal enzym
es, acid phosphatase and beta-galactosidase, were also significantly affect
ed by the insect growth regulators. It is suggested that plumbagin and azad
irachtin treatments primarily modify the ecdysteroid titer, which in turn l
eads to changes in lysosomal enzyme activity causing overt morphological ab
normalities during the metamorphic molt.