西宁地区苜蓿蚜生物学特性的研究

Studies on the Biological Characteristics of Black Bean Aphid (Aphis craccivora Koch)in Xining

苜蓿蚜在西宁1年发生10～14代,主要为害蚕豆,以卵在蜀葵、酸模、苦苣菜等杂草根茎处或地表干枯的草籽荚壳上越冬.翌年4月温度达10～12℃开始孵化.每雌平均产蚜量为30头,15℃左右完成一代需8～10天,20℃左右只需3～4天.取食为害季节无翅胎生雌蚜平均存活7天左右.孪斑瓢虫和蚜茧蜂是其主要天敌.

Black bean aphid (Aphis craccivora Koch) has 10 to 14 generations in a year,mainly damages to the top parts of broad bean (Vicia faba L. ),and overwinters as eggs on the hollyhock (Althaea rosea ), curly dock (Rumex crispus L. ) , field sowthistle (Sonchus brachyotus DC. )and other plants . In the spring (April) eggs will hatch when temperature reaches 10 to 12 ℃. Each female aphid commonly produces 30 young on the broad bean. One generation needs 8 to 10 days to complete development at 15 ℃ , 3 to 4 days at 20 ℃. Wingless ovoviviparous females can survive about 7 days on the bean. Twin spot ladybird (Coccinella geminopuncatata Liu) and aphidivorous braconid (Ephedrus sp. )are important natural enemies to black bean aphid.