ROLE OF SOME ENZYMES IN THE DEGRADATION OF ACYLUREA COMPOUND, DIFLUBENZURON IN LIPAPHIS ERYSIMI (KALT.)

The mustard aphid, Lipaphis erysimi (Kalt.), is a serious pest of Brassica crops in India. The leaf surface treatment of chitin synthesis inhibitor, Diflubenzuron (400 ppm) given to its 2nd instar nymphs (48-52h old) for three time intervals 13, 25, 37h, induced alterations in its enzymatic activity profile. The assessment of the activity of five enzyme systems involved in growth and metabolism revealed that the activity of group transfer enzyme (Glutathione S-transferases), hydrolytic enzyme (Esterases), and oxido-reductase (NADH oxidase) was induced significantly, whereas, the activity of two other oxido-reductase enzymes (NADH dehydrogenase and Glutathione reductase) showed no specific alterations. It was concluded, that Glutathione S-transferases, NADH oxidase and Esterases might be involved in the degradation of Diflubenzuron in L. erysimi.