The Toxic Effects of Winter Cherry on the Physiology of Cotton Bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

Abstract

Abstract. The cotton bollworm, Helicoverpa armigera (Hübner) is considered as one of the most important pests of vegetables worldwide. Nowadays, alternative safe control measures are usually recommended against various insect pests. We investigated the ethanolic extracts of a medicinal plant fruit called winter cherry Withania somnifera L. (Solanaceae) against third instar larvae of cotton bollworm. The LC50, LC30, and LC10 values were estimated by feeding through larval diet at 1.33, 0.53, and 0.14 (% w/v). Later, the LC30 value (0.53 % w/v) obtained was again treated on third instar larvae to find out its sublethal effects on some important molecules and enzymes. The results showed elevated amount of uric acid and also increased activity in acid phosphatase, aspartate aminotransferase, lactate dehydrogenase, glutathione S-transferase in comparison with the controls (fed artificial diet with ethanol alone). However, decreased activity of alanine aminotransferase, alkaline phosphatase, catalase, acetylcholinesterase, superoxide dismutase, and peroxidase were observed. The midgut histology showed disruption in main midgut epithelial cells as well as other cell types in treated vs controls. Chemical components of the ethanolic extract of winter cherry fruits were also identified using GC-MS where the main components included 5-Hydroxymethylfurfural (51.18 %) and 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl (21.86%). Our results are indicative of a promising natural product that can be regarded as a new source for insect pest control.

Keywords

• extract
• growth and development
• helicoverpa armigera
• toxicity
• whithania somnifera