灭幼脲Ⅲ号对马尾松林昆虫群落多样性的影响研究

１９９５年７月至１９９６年６月在湘中丘陵区马尾松林内用灭幼脲Ⅲ号作的喷药试验结果表明，灭幼脲Ⅲ号不仅直接影响鳞翅目昆虫的物种组成主多样性水平，而且对膜翅目昆虫（主要是蚂蚁）和蜘蛛的物种组成及多样性水平有间接影响。在时间过程中，施药区鳞翅目和直翅目昆虫的多样性水平有一定程度的下降，但下降程度不如对照区大，膜翅目和蜘蛛的多样性水平则有较大程度的上升，因此林内昆虫群落趋于相对稳定。由于药剂对蚜虫种群无影

EFFECTS OF DIMILIN ON THE INSECT COMMUNITY DIVERSITY OF MASSON'S STANDS

The effects of Dimilin on the insect community diversity were studied in masson's pine, Pinus massoniana, stands in the central hill of Hunan Province. The results indicated that the species composition and the diversity degree of Lepidoptera, Orthoptera, Hymenoptera insects and spiders were influenced by Dimilin after its application. The influences on the former two order insects were direct,and those on the Hymenoptera insects and spiders were indirect. In the action of Dimilin, the diversity levels of Lepidoptera and Orthoptera insect of the treatment plot had a certain degree decline, and the diversity degrees of Hymenoptera insect and spider had a large increase, thus insect community in the treatment stand tended to be relatively stable. However, because Dimilin had no direct effect on the population of aphis, this stability of insect community was easily disturbed by the rapid increase of aphis population.