抄録
Effects of native ladybird females of Harmonia axyridis Pallas and Coccinella septempunctata L. on oviposition behavior of the exotic species, Adalia bipunctata (L.), were assessed by pairing females of the exotic species with conspecific or heterospecific females. Pairs of females were provided with aphids in excess for 30 days, during which time there were no significant differences in weight, rates of mortality, or selections of sites for oviposition among the treatments. However, females of A. bipunctata laid significantly fewer eggs over the 30-day experimental period when paired with females of H. axyridis or C. septempunctata than when paired with conspecifics, even though aphids were abundantly available in all three cases. The number of eggs laid by a female of A. bipunctata paired with conspecifics gradually declined over the 30-day experimental period, while egg production declined especially rapidly during the second ten-day period when females were paired with females of H. axyridis and C. septempunctata. Thus, egg production by females of the exotic species was reduced in the presence of the native ladybirds.
