The influence of ant-visiting Kerria yunnanensis on populations of Holcocera pulverea in lac plantation

Key Words：ant，lac insect，interspecific relationship

Abstract：       The effects of visits by ants to Kerria yunnanensis Ou et Hong on populations of its predator Holcocera pulverea Meyr, and the commercial impact and population dynamic of H. pulverea, were investigated in the presence and absence of ants in lac plantations in Yayi region, Mojiang County, Yunnan Province, China. The results show that the commercial impact of H. pulverea on lac production was high and increased monthly, but that this was slightly reduced in the presence of ants. The presence of ants significantly reduced populations of H. pulverea (︱t︱=2.764, df=356, P＜0.01) by interfering with oviposition, destroying their eggs and physically attacking eggs and larvae. These effects occurred mainly during the larval stage of K. yunnanensis. However, the presence of ants had no significant effect on the monthly increase of H. pulverea populations after K. yunnanensis had reached the adult stage (︱t︱=0.970, df=161, P＞0.05), probably because ants could no longer encounter H. pulvera who by this time live beneath the lac. There were significant differences in the behavioral responses of ants and H. pulvera when these species encounter each other χ²=4.781, df=1, P＜0.05); ants prey on H. pulvera. Ants and K. yunnanensis have a symbiotic relationship and visits by ants to lac insects may reduce commercial damage to lac crops by reducing numbers of H. pulverea.