Laboratory Study on Some Potential Histological Changes Induced by the Toxicity of a Mixed Insecticide (spinetoram + methoxyfenozide) on The Spiny Bollworm, Earias insulana

Abstract

Ashraf, F.A., M.A. Kandil and M.A.M. Shalaby. 2023. Laboratory Study on Some Potential Histological Changes Induced by the Toxicity of a Mixed Insecticide (spinetoram + methoxyfenozide) on The Spiny Bollworm, Earias insulana. Arab Journal of Plant Protection, 41(4): 437-443. https://doi.org/10.22268/AJPP-41.4.437443 The present laboratory study was conducted using the larvae of spiny bollworm, Earias insulana (Boisd.) (Lepidoptera: Nolidae) to observe the correlation between the toxicity effect and the potential histopathological changes induced by feeding with LC50 of the pesticideUphold (36% SC), a commercial insecticide mixture formulation of two active ingredients [spinetoram 6% + methoxyfenozide 30% (w/v)]. The microscopic observations showed morphological variations in the midgut and fat body that indicated a defect in the performance of their functions. The treated larvae showed modifications in the midgut tissues vs the control sections, whereas the epithelial cells seamed without any distinct stratification and had malformed morphology along the midgut. The peritrophic membrane lining loss was evident. The abdominal fat body of the treated larvae appeared in densely spread lobes, accumulating and occupying an enormous portion of the abdominal cavity. Its cellular components were characterized by their large size compared to the untreated ones. The results obtained indicated that the tested mixed insecticide gained its properties from its active ingredients. The findings herein indicated that chronic exposure to the applied insecticide could be considered stressful conditions affecting different aspects of fat body functions needed for late vital activities. That effect could be viewed as a possible disruptive impact on the detoxification mechanism and biosynthetic-fat body functions required during the advanced stages ofthe development and maturation of the treated larvae. Keywords: Spinetoram, Methoxyfinozide, Spiny bollworm, Earias insulana, Midgut, Fat body