BIOCHEMICAL BASIS OF MECHANISMS IN MONOCROTOPHOS-RESISTANT STRAIN OF GREEN-LACE WING (CHRYSOPA SCELESTES), THE EFFECTIVE PREDATOR OF SOFT-BODIED INSECTS

A laboratory-selected monocrotophos-resistant strain of green-lace win e, (Chrysopa scelestes Banks) was biochemically analysed to ascertain the mechanism of resistance. The amount of total lipids, polar and iro n-polar lipids were found more in resistant strain than in susceptible one. On thin liquid chromatography (TLC) separation of polar lipid, N acylphosphatidylethaniolamine (NAPE) was detected in both the strains , but phosphatidyl linositol was lacking in resistant strain. Likewise , separation of non-polar lipid showed the presence of steryl ester an d free fatty acid in resistant strain, whereas absence of free fatty a cid in susceptible strain. The resistant strain showed twice the activ ity of acetylcholine esterase (AchE) than the susceptible one. Hence A chE activity and qualitative as well as quantitative differences in li pid components appears to be responsible for imparting resistance in m onocrotophos in the monocrotophos-resistant strain of Chrysopa scelest es.