1Division of Lac Production, Indian Lac Research Institute, Namkum, Ranchi-834 010, Bihar (India).
2Division of Transfer of Technology, Indian Lac Research Institute, Namkum, Ranchi-834 010, Bihar (India).
Diflubenzuron (Dimilin 25 WP) was evaluated against the larvae of Eublemma amabilis Moore, a highly destructive lepidopterous predator of lac insect, Kerria tacca (Kerr.). Five concentrations ranged from 0.0125 to 0.2%. Two different methods of application, viz, oral and topical exhibited larvicidal action and ecdysial failure, adversely affecting survival and resulted in the production of non-viable larval-pupal and pupal-adult intermediates. Per cent mortality varied from 56.67 to 93.3 and 46.67 to 90.00 in oral and topical treatments, respectively. The proportion of larval mortality due to ecdysial failure increased with the increase in concentration, while at lower concentrations significantly more larvae died due to direct larvicidal action than due to malformation in both the treatments. Also, lac colonies sprayed with 0.05% diflubenzuron suppressed cent per cent population of E. amabilir, when the predator eggs were released on these treated colonies. The survival of lac insect was not affected.
