日本松干蚧捕食天敌数量变化的研究

在日本松干蚧显露若虫、雌成虫和卵囊发生期，树枝上捕食天敌是数量是树干上捕食天敌 １．１８倍。在１龄若虫发生期，树干上天敌的数量是树上的１．１０倍。树上同时有日本松干蚧和松大蚜发生时，蚧虫天敌增加了２．９８倍，主要是捕食蚧虫的贤惠义增多了。异色标虫是两种昆虫的主要捕食者，但较多造反蚜虫刻瓢虫、蒙古光瓢虫、华鹿瓢虫主要捕食蚧虫，崦隐斑瓢虫主要捕食蚜主。

RESEARCH ON POPULATION VARIATION OF NATURAL PREYERS OF MATSUCOCCUS MATSUMURAE

In the life cycle of pinebast scale Matsucoccus matsumurae , the populations of its natural preyers varies as follows: when the pinebast scale appears as nymphs (female imago and egg sac), the numbers of preyers on the tree branches are larger than those on the tree trunks, but things are quite different when it appears as a nymph in the first stage. When there is a simultaneous occurrence of the scale and the pine aphid, the population of the preyers increases considerably, mostly due to the increased number of the two pests, and are more inclined to prey on the pine aphids. Ladybugs Sticholotis punctus Crotch, Exochomus monol Baovsky and Sospita chinensis Molsant prey on the scales, while the ladybugs Ballia obscurosignata Liu prey mainly on the phids.