4种杀虫剂防治松突圆蚧的野外试验

采用平均虫口数、有虫针束率和危害程度3个指标评价毒死蜱、杀扑磷、噻虫嗪和吡虫啉4种杀虫剂对松突圆蚧的种群及危害动态的影响和野外防治效果。结果表明：4种杀虫剂均可产生有效影响，表现为阶段性显降低松突圆蚧种群数量、有虫针束率和危害程度等指标；其中杀扑磷、毒死蜱和噻虫嗪的的显作用期长(60d以上)，吡虫啉的显作用期短(60d以下)；这种影响主要源于施药后0—60d内杀虫剂对松突圆蚧的有效控制。在毒死蜱、杀扑磷和噻虫嗪作用下，松突圆蚧平均虫口数的校正减退率60d后均高于60％，其余指标则低于50％，但相对较高，可以在生产上使用。

Control effects of 4 kinds of pesticides on Hemiberlesia pitysophila in the fields

Effects of 4 kinds of pesticides including chlorpyrifos, methidathion, thiamethoxam and imidacloprid on population and damage of Hemiberlesia pitysophila were tested by using 3 indexes of average individual amount every pine needle, ratio of needle damaged by the pest and damage degree. The results indicated that 4 kinds of pesticides could significantly depress pest population and its damage degree in certain stage. Among 4 kinds of pesticides, the effective stages of chlorpyrifos, methidathion and thiamethoxam were long(>60 d), and that of imidacloprid was short relatively(<60 d), which were due to effective control of pesticides to the pest in 60 d. Revised depress ratios of 3 indexes of pest population and damage were high under disturbance of chlorpyrifos, methidathion and thiamethoxam, for example, revised depress ratios of average individual amount every pine needle were higher than 60% after 60 d, and revised depress ratios of other 2 indexes disturbed by these 3 kinds of pesticides were higher than those disturbed by imidacloprid, so these pesticides could be used in practice.