• Dhrishya. V. S
• Binumol. M

Specialist butterflies are specific in their host selection. Leptosia nina (Pieridae), the Psyche butterfly is an insect which feeds on closely related host plants such as plants belongs to Cleomaceae and Capparaceae. The present observation was the ovipositing behaviour of Psyche on Cardamine hirsuta (Brassicaceae). The objective of this work was to identify the plant chemical used by the Pysche for their host plant recognition and also the mechanism responsible for the survival of Psyche’s caterpillar on C. hirsuta. GCMS analysis of methanolic extracts of C. hirsuta was done to identify the plant chemical. The result demonstrates that the glucosinolate serves as the ovipositing stimulant. The glucosinolates are hydrolyzed by the plant enzyme myrosinase. In plant tissues they occur separately. Both are come together only when the plant tissue was damaged. Hydrolysis of glucosinolate by myrosinase result in the generation of harmful isothiocyanate and several other chemical compounds. So, insect specialized on glucosinolate containing plants have to adapt some mechanism to overcome the toxic effect of isothiocyanate. The counteradaptation involves the breakdown of glucosinolate into nitriles instead of isothiocyanate. This deviation is only because of a protein called Nitrile Specifier Protein (NSP) which is specific to Pierid species. This NSP based counteradaptation on glucosinolate demonstrate the mechanism of coevolution of plant and insect herbivore.

Cardamine hirsuta, Glucosinolate, Leptosia nina, Myrosinase, Oviposition, Phytochemicals.

"Chemical behaviour of Leptosia nina in host plant selection and the GCMS analysis of Cardamine hirsuta", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.9, Issue 4, page no.d703-d708, April-2022, Available :http://www.jetir.org/papers/JETIR2204384.pdf

"Chemical behaviour of Leptosia nina in host plant selection and the GCMS analysis of Cardamine hirsuta", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.9, Issue 4, page no. ppd703-d708, April-2022, Available at : http://www.jetir.org/papers/JETIR2204384.pdf