Bat community response to insect abundance in relation to rice phenology in Peninsular Malaysia

Bats provide us with important ecosystem services including insect population controllers in agricultural areas. Studies on bats and insect abundance in Malaysian rice fields are still lacking. Two harp traps and two mist nets were used to trap bats at the Gunung Keriang while a light trap was used to sample insects in the rice field area at three identified sites. A total of 2499 bats from 27 species were captured and for insect abundance a total of 161,539 individuals from 11 orders were captured. Rhinolophus pusillus was recorded as the dominant bat species in all seasons. In the dry season, the dominant insect pest was Chilo polychrysus (Stem borer) and in the wet season, Nilaparvata lugens (Brown planthopper) the dominant insect pest species. Insects from the Order Coleoptera (the dominant insect Order in dry season) may be eaten by bats that have a larger body size and that have a strong bite force. Due to high food availability and insect abundance, the peak time of bat foraging activity is the same as the peak time of insect emergence. We found that there is a significant relationship between bat activity with temperature and rainfall, but not with insect abundance. This study further highlights the importance of bats in regulating the insect pests population naturally in the rice field area.