Efficacy of a Linear Furanocoumarin, Xanthotoxin to Manage a Serious Tropical Pest, Spodoptera Litura (Lepidoptera: Noctuidae)
Spodoptera litura (Fabricius), also known as the common cutworm or the tobacco caterpillar is a polyphagous noctuid insect that inflicts heavy damage to a variety of crops in India. Since controlling this serious pest is becoming very challenging using the conventional insecticides, due to development of resistance against a wide variety of insecticides and environmental health issues that has impelled many entomologists to look for ecologically sound methods to control this pest. A linear furanocoumarin, xanthotoxin was tested on this pest under different regimens, viz., (i) 12h Light(+UV-A):12h Dark, (ii) 12h Light:12h Dark, and (iii) 0h Light:24h Dark, to determine the toxicity of this photo toxin LC50, LC90 doses were computed from dose response data. Further, the sterilizing (as a sublethal) dose of xanthotoxin was ascertained against this pest. The present investigations evidently indicated that photoactive plant allelochemicals like xanthotoxin has immense potential in controlling this polyphagous serious pest in a tropical country having immense sunlight exposure throughout the year in an environmentally compatible mode.