Study on the population trend of brinjal fruit borer leucinodes orbonalis guen. (lepidoptera: pyralidae) and it’s susceptibility to different insecticides

摘要

Brinjal fruit borer, Leucinodes orbonalis Guen. is the major insect pest of brinjal (eggplant) in South Asia. Larvae bore into the fruit; render it unfit for human consumption. This study reports the seasonal fluctuations and the efficacy of various insecticides against L. orbonalis in a field study conducted in two separate plots under field conditions. To determine the seasonal abundance and population trend of the pest, plants were regularly monitored on weekly basis throughout the cropping season soon after the fruits were formed. L. orbonalis was most persistent throughout the crop growing season. A low infestation (18.66%) of borer was noted in the third week of May, severe infestation (75.50%) in the first week of August, and a high infestation (42.64%) in the last week of September at the end of the crop growing season. Five insecticides from different classes of chemicals were sprayed 3 times at 25 days interval against the borer, which significantly reduced the borer infestation in comparison to the untreated control. However, Ripcord (Cypermethrin) decreased the infestation to a least minimum level than any other insecticide used.