烟蚜茧蜂不同释放次数对烟蚜的控制效果

Control Effect of Different Release Times of Aphidius gifuensis Ashmead on Tobacco Aphid

为减少烟草田化学药剂使用,提高烟叶品质等级,采用单因素试验设计,试验因素为放蜂次数,共4次放蜂,设置50目防虫网笼罩的小棚4个,每棚单株接烟蚜量为100头,并放入1块烟蚜茧蜂蜂卡,调查放蜂次数对烟蚜数量、僵蚜数量、虫口减退率的影响,明确最佳放蜂次数。结果表明:随着放蜂次数的增加,1~2次放蜂的单株烟蚜数量持续增加,3~4次放蜂的单株烟蚜量呈先增加后下降趋势,放蜂后第30天,单株烟蚜数量为158.7和146.2头;1~2次放蜂僵蚜数量增长趋势缓慢,3~4次放蜂僵蚜数量增长趋势明显,到放蜂后的第30天,3次放蜂的单株僵蚜数量为290.6头,4次放蜂的单株僵蚜数量为349.8头;在放蜂后的l0 d内,虫口减退率均为负值,放蜂后的第15天,只有1次放蜂处理的虫口减退率变为正值,达到6.8%,之后又重新变为负值;3~4次放蜂的虫口减退均转为正值,最高时分别达到了55.7%和60.8%。试验证明1~2次放蜂对控制烟蚜数量效果差,持效期短,3~4次放蜂能够有效并持久控制烟蚜数量,且虫口减退率明显高于1~2次放蜂。

In order to reduce the use of chemical agents in tobacco field and improve the quality grade of tobacco leaves,the single factor experiment design was adopted in the experiment.The experimental factor was the number of bee release,a total of 4 times.Four greenhouses covered with 50 mesh insect proof nets were set up,and each shed received 100 aphids per plant,and put in one aphid cocoon bee card.The results showed that the number of aphids per plant increased with the increase of the number of wasps released 1-2 times,while the number of aphids per plant increased first and then decreased after 2-3 times.The number of aphids per plant was 158.7 and 146.2 per plant on the 30th day after bee release.The number of dead aphids showed a slow growth trend after 1-2 bee release,while the number of aphids released 3-4 times showed an obvious growth trend.The results showed that the number of dead aphids was 290.6 per plant,and the number of dead aphids was 349.8 per plant after four times of releasing bees;the decline rate of insect population was negative in the 10 d after releasing bees,and only 6.8%in the 15th day after releasing bees,and then turned to negative again;the decline rate of aphids in 3-4 times of releasing bees turned to positive,reaching 55.7%and 60.8%respectively.Therefore,the effect of wasps released 1-2 times on controlling the number of aphids was poor,and the duration was short.Wasps released 3-4 times could effectively and persistently control the number of aphids,and the population decline rate was significantly higher than that of wasps released 1-2 times.