Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, São Paulo, SP, Brazil.
Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
Sci Total Environ. 2024 May 1;923:171526. doi: 10.1016/j.scitotenv.2024.171526. Epub 2024 Mar 7.
Herbicides have been intensively used for weed control, raising concerns about their potentially adverse effects on non-target organisms. Research on the effects of these common agrochemicals on beneficial insects and the ecosystem services they provide (e.g., predation and pollination) is scarce. Therefore, we tested whether a commercial formulation comprising a mixture of mesotrione and atrazine was detrimental to adult females and larvae of the Neotropical predatory social wasp Polistes satan, which is an effective natural enemy of crop pests. Wasps were individually fed syrups contaminated with different concentrations of the herbicide above and below the maximum label rate (MLR = 12 mL/L). Survival was assessed. The locomotor activity, immune response, and midgut morphology of adults as well as the immune response of the larvae were also studied. Herbicide concentrations far above the MLR (12, 40, and 100 times) caused adult mortality, whereas lower concentrations (0.5, 1, and 6 times) did not. Herbicide exposure at 0.5 to 12 times the MLR increased adult activity. Adult exposure at 0.1 or 0.5 times the MLR did not affect melanotic encapsulation of foreign bodies but led to changes in the morphology of the midgut epithelium and peritrophic matrix. In larvae, the ingestion of herbicide at 0.1 or 0.2 times the MLR (corresponding to 9.6 and 19.2 ng of herbicide per individual) did not cause mortality but decreased their melanization-encapsulation response. Increased locomotor activity in herbicide-exposed adults can affect their foraging activity. The altered midgut morphology of adults coupled with the decreased immune response in larvae caused by herbicide exposure at realistic concentrations can increase the susceptibility of wasps to infections. Therefore, herbicides are toxic to predatory wasps.
除草剂被广泛用于杂草防治，这引起了人们对其可能对非靶标生物产生不利影响的关注。关于这些常见农用化学品对有益昆虫及其提供的生态系统服务（如捕食和传粉）的影响的研究很少。因此，我们测试了一种由 mesotrione 和莠去津混合而成的商业制剂对新热带捕食性社会性黄蜂 Polistes satan 的成年雌性和幼虫是否有害，这种黄蜂是作物害虫的有效天敌。黄蜂被单独喂食含有不同浓度除草剂的糖浆，这些浓度高于和低于最大标签率（MLR=12 mL/L）。评估了存活率。还研究了成虫的运动活性、免疫反应和中肠形态以及幼虫的免疫反应。远高于 MLR（12、40 和 100 倍）的除草剂浓度会导致成虫死亡，而较低浓度（0.5、1 和 6 倍）则不会。在 0.5 到 12 倍 MLR 的除草剂暴露下，成虫的活动增加。在 0.1 或 0.5 倍 MLR 的暴露下，成虫的免疫反应没有受到影响，但导致中肠上皮和围食膜的形态发生变化。在幼虫中，在 0.1 或 0.2 倍 MLR 的条件下摄入除草剂（相当于每个个体摄入 0.96 和 1.92 纳克除草剂）不会导致死亡，但会降低其黑化包埋反应。暴露于除草剂的成虫运动活性增加会影响其觅食活动。在现实浓度下，暴露于除草剂会导致成虫中肠形态发生变化，幼虫免疫反应降低，这会增加黄蜂对感染的易感性。因此，除草剂对捕食性黄蜂具有毒性。
