中国北方越冬代异色瓢虫取食及繁殖力研究

Capacity of Feeding and Fecundity of Overwintering Harmonia axyridis from Northern China

为了明确秋季经自然低温驯化后北方种群越冬代异色瓢虫是否滞育,室内条件下测定了越冬代异色瓢虫吉林和北京种群的取食及繁殖特性。结果表明:试验前对异色瓢虫喂饲豌豆蚜、20%蜂蜜水或清水3 d,两种群各处理每对异色瓢虫在饲喂蚜虫当日即可取食,且随饲喂天数的增加,各处理均保持较高的取食量,试验周期(20 d)内两种群各处理每对异色瓢虫取食蚜虫总量均超过4 000头,种群内各处理逐日取食量和总取食量均无显著差异;连续饲喂20 d,两种群异色瓢虫均可正常繁殖,吉林种群各处理雌虫产卵前期(12.1~12.5 d)均略长于北京种群(11.0~11.4 d),而平均单雌产卵总量(292.6~317.2粒)略低于北京种群(331.9~355.8粒),但均无显著性差异。这可以从生物学角度来判断北方秋季野外采集的越冬代异色瓢虫均未滞育。

In order to determine whether pre-wintering Harmonia axyridis adults experiencing natural cold acclimation in the fall from northern China get into diapause, feeding and reproductive charac- teristics of two populations collected from Jilin and Beijing were investigated under laboratory condi- tions. The results showed that individuals of both populations all fed on cowpea aphids Aphis crac- civora regardless of feeding on aphids, 20% honey solution or water for 3 d prior to experiment. With the feeding days increasing, both populations with various treatments all exhibited high predation on aphids, in which one pair of ladybirds for each population consumed more than 4 000 aphids in 20 d. There was no difference in number of aphids consumed daily and total number consumed with- in the same population with different treatments. Both populations normally reproduced in 20 d with continuous feeding on aphids. The pre-oviposition duration of Jilin population with various treatments （ 12. 1-12. 5 d） was longer than that of Beijing population （ 11.0-11.4 d）, but there was similar total number of eggs laid between Jilin population （292.6-317.2） and Beijing population （331.9- 355.8）. Therefore, it could be concluded based on the biological data that the pre-wintering Harmo-nia axyridis adults experiencing natural cold acclimation in the fall from northern China do not get into diapause.