Effects of Carbaryl and γ-BHC on the Histology of Midgut and Digestive Enzyme Profiles in the Third Instar Larvae of Fruit-sucking Moth, Othreis materna (Linn.) (Lepidoptera: Noctuidae)


Abstract: The effects of LC50 dose of carbaryl and gamma benzene hexachloride (γ-BHC) on midgut histopathology and midgut enzyme activities in the third instar larvae of fruit-sucking moth, Othreis materna (L.) were studied. The sub-lethal doses of carbaryl and \gamma-BHC caused initially hypersecretory activity in the midgut epithelial cells leading to deposition of numerous secretory vesicles in the extraperitrophic space, clumping of chromatin matter, and regression and vacuolization of the columnar cells, but later on they were recovered within 24 h. Activities of the midgut digestive enzymes (amylase, invertase, lipase, and protease) were significantly affected. Carbaryl enhanced (P < 0.05) the amylase, invertase, lipase, and protease activities initially up to 4 h and 6 h of treatment, but after 24 h of treatment, amylase and invertase activities resumed while an inhibitory effect was observed on lipase and protease activities. \gamma-BHC did not affect the amylase and protease activities up to 4 h but later on it significantly (P < 0.05) enhanced their activities up to 6 h and 12 h, respectively. Thereafter it fell without showing any sign of recovery. \gamma-BHC enhanced (P < 0.05) invertase and lipase activities but they fell after 4 h treatment.

Keywords: Othreis materna, midgut histopathology, digestive enzymes, pesticides

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