Toxicity and histological architecture of <i>Semecarpus anacardium </i>kernel extract on the foregut of <i>Heliothis armigera </i>

The efficacy of Semecarpus anacardium Linn. kernel extract in chloroform as an antifeedant and stomach poison agent was assessed against Heliothis armigera (Hubner) early fourth instars. Larvae that were fed with food containing different doses of extract showed antifeedant, toxic effects and decreased consumption. The foregut histopathological architecture of larvae fed with S. anacardium kernel extract in chloroform at concentration equal to LD50 value and after 24 and 96 hours of treatment, demonstrates substantial injury to the epithelium layer, including vacuolization in some areas, gut tissue shrinkage, and peritrophic membrane disruption, which leads to the degeneration of goblet, regenerative, and epithelial cells. The height of the columnar epithelium and diameter of lumen were also reduced after 24 hours of exposure. These alterations in the gut had a detrimental effect on the larvae’s ability to digest and absorb food, resulting to a nutritional deficit that may have stunted their development. The findings of this study indicate that S. anacardium kernel extracts in chloroform have a significant stomach poisoning capability against H. armigera larvae, suggesting that this approach could be investigated as an environmentally safe method of integrated pest management.