Pheromone trapping of brinjal fruit and shoot borer: Male orientation and spatial distribution

Pheromone trapping is an ecofriendly management of the brinjal shoot and fruit borer Leucinodes orbonalis. In the present study on orientation and distribution of male moths to the sticky arenas in a delta trap were evaluated. One-third of moths trapped were oriented towards the lure source, while the remaining two thirds were found oriented either away from or opposite to the pheromone source. This indicates the predominant tendency of the male moths to escape apparently due to overlapping close range visual or olfactory clues. This pest behaviour could be pursued to ascertain the role of olfactory versus visual stimuli in prompting the moth escape behaviour as basis for minimizing the escapes by altering the trap design suitable. The distribution of the moth catches in the length side of the sticky arena (18.0 x11.0 cm) was found to be more (62%) in the inner half section (closer to the lure source) compared to only about 38% in the outer half. This pattern of greater catches closer to lure source was also evident across the width side. The observed lower catches in sections away from lure source could provide directions to alter the dimensions of the sticky arena.