花椒绵粉蚧寄生性天敌的调查研究

1999—2001年在花椒绵粉蚧Phenacoccus azaleae Kuwana发生严重的山西省盂县对该虫的天敌昆虫进行了详细的调查研究，发现绵粉蚧长索跳小蜂Anagyrus shoenherri (Westwood)、蚜虫跳小蜂Syrphophagus aphidivorus(Mayr)、宽缘金小蜂Pachyneuton sp．、长盾拟金小蜂Eunotus sp．和荆腹拟金小蜂(Gastrancistrus sp．等5种寄生性小蜂类天敌昆虫，其中绵粉蚧长索跳小蜂是优势种，它1a发生2代，成虫出现于4月和6月，对蚧虫越冬期的若虫、春天出蛰的雌性若虫、雌成虫及卵均能寄生。在花椒纯林内对产卵期的蚧虫寄生率为8．7％，在花椒与农作物混种的林地，由于经常喷洒杀虫剂，寄生率只有0．56％。根据该小蜂在白蜡绵粉蚧上的高寄生率，提出从蚧虫多年发生区采集寄生蜂，释放到新发生区的建议。

Investigation on the parasitioids of Phenacoccus azaleae in Chinese prickly-ash

Phenacoccus azaleae Kuwana is a destructive pest attacking Chinese prickly ash in north part of China.Its parasitioids investigated in the forests located in Taihang Mountain areas in Shanxi Province.They are Anagyrus schoenherri (Westwood),Syrphophagus aphidivorus (Mayr),Pachyneuron sp.,Eunotus sp.and Gastrancistrus sp.. Anagyrus schoenherri (Westwood) was the dominan species.It has two generations a year and the adult wasps appears in April and June respectively.It parasites on the nymph,adult and egg of the pest.In the pure forest of Chinese prickly ash the parasitic zation is 8.7%,due to a dense population of the mealybug.In contrast,in the mixed forest of Chinese prickly ash and crops the parasitic zation is only 0.56%,for the spray of pesticides. Meanwhile,a higher parasitic zation was found on other mealybug species,such as Phenacoccus fraxinus Tang and P. pergandei Cockerell by Anagyrus schoenheri.Therefore,a biological control method was suggested which was artificially collecting wasps from the old occurrence places and then releasing them to the new occurrence places.