Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou, 510642, China.
Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou, 510642, China.
Ecotoxicol Environ Saf. 2021 Apr 1;212:111984. doi: 10.1016/j.ecoenv.2021.111984. Epub 2021 Jan 29.
As a natural enemy of green peach aphids, harlequin ladybirds, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), are also indirectly affected by azadirachtin. In this study, we evaluated the effects of ladybird exposure to azadirachtin through azadirachtin-treated aphids. About 2 mg/L azadirachtin treated aphid can deliver the azadirachtin to ladybird larvae in 12 and 24 h. And azadirachtin treatment affected the rate at which fourth instar larvae and adult ladybirds preyed on aphids. Furthermore, the antifeedant effect increased with increasing azadirachtin concentrations. Twelve hours after exposing fourth instar ladybird larvae to aphids treated with 10 mg/L azadirachtin, the antifeedant effect was 47.70%. Twelve hours after exposing adult ladybirds to aphids treated with 2 mg/L azadirachtin, the antifeedant effect was 67.49%. Forty-eight hours after exposing ladybird larvae to azadirachtin-treated aphids, their bodyweights were 8.37 ± 0.044 mg (2 mg/L azadirachtin), 3.70 ± 0.491 mg (10 mg/L azadirachtin), and 2.39 ± 0.129 mg (50 mg/L azadirachtin). Treatment with azadirachtin affected the ability of ladybirds to prey on aphids. The results indicated that the instant attack rate of ladybird larvae and adults and the daily maximum predation rate were reduced by azadirachtin treatment. Superoxide dismutase (SOD), peroxidase (POD), and peroxide (CAT) enzyme activities of ladybirds were affected after feeding on aphids treated with azadirachtin. Azadirachtin has certain antifeedant effects on ladybirds and affects the ability of ladybirds to prey on aphids and the activities of SOD, POD, and CAT enzymes, which results in inhibition of normal body development.
作为桃蚜的天敌，异色瓢虫，Harmonia axyridis Pallas（鞘翅目：瓢虫科）也会受到印楝素的间接影响。在本研究中，我们通过用印楝素处理蚜虫来评估瓢虫暴露于印楝素的影响。大约 2mg/L 的印楝素处理蚜虫可以在 12 和 24 小时内向瓢虫幼虫传递印楝素。并且印楝素处理会影响第四龄幼虫和成虫捕食蚜虫的速度。此外，抗食作用随印楝素浓度的增加而增加。将第四龄幼虫暴露于用 10mg/L 印楝素处理的蚜虫中 12 小时后，抗食作用为 47.70%。将成虫暴露于用 2mg/L 印楝素处理的蚜虫中 12 小时后，抗食作用为 67.49%。将幼虫暴露于印楝素处理的蚜虫中 48 小时后，它们的体重分别为 8.37±0.044mg（2mg/L 印楝素）、3.70±0.491mg（10mg/L 印楝素）和 2.39±0.129mg（50mg/L 印楝素）。用印楝素处理会影响瓢虫捕食蚜虫的能力。结果表明，用印楝素处理会降低瓢虫幼虫和成虫的即时攻击率和日最大捕食率。喂食印楝素处理的蚜虫后，瓢虫的超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化物酶（CAT）酶活性受到影响。印楝素对瓢虫具有一定的抗食作用，并影响瓢虫捕食蚜虫的能力以及 SOD、POD 和 CAT 酶的活性，从而抑制正常的身体发育。
