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