Efficacy of diflubenzuron against snakegourd semilooper.

Diflubenzuron, a chitin synthesis inhibitor was tested in the laboratory against freshly laid eggs and those prior to hatching, larvae and pupae of snakegourd semilcoper (Anadevidia peponis). The concentration of 0.002 to 0.1 per cent diflubenzuron inhibited 31.78 to 100.0 and 20.41 to 75.91 per cent egg hatch in both stages of egg development viz., freshly laid eggs and eggs prior to hatching, respectively as against 8.88 and 7.77 per cent in control. The per cent larval mortality in various treatments was ranged from 33.33 to 100.0, 21.66 to 100.0, 20.0 to 100.0 and 6.66 to 93.33, respectively in progressive instars. The affected larvae turned reddish black from normal light green or green colour. The efficacy of diflubenzuron was dependent on age of the larvae at the time of treatment. Pupae formed after the treatment of late instar larvae inhibited deformities such as larval pupal intermediates. Diflubenzuron adversely affected the larval growth and weight. The duration of larval development was also prolonged in treated larvae as compared to control. The per cent adult emergence from the treated pupae was ranged from 0.0 to 100.0 as against 100.0 per cent in control.