Abstract：
Currently, only Apis mellifera is used in environmental regulation to evaluate the hazard of pesticides to pollinators. The low representativeness of pollinators and bee diversity in this approach may result in insufficient protection for the wild species. This scenario is intensified in tropical environments, where little is known about the effects of pesticides on solitary bees. We aimed to calculate the medium lethal dose (LD50) and medium lethal concentration (LC50) of the insecticide dimethoate in the Neotropical solitary bee Centris analis, a cavity-nesting, oil-collecting bee distributed from Brazil to Mexico. Males and females of C. analis were exposed orally to dimethoate for 48 h under laboratory conditions. Lethality was assessed every 24 h until 144 h after the beginning of the test. After the LD50 calculation, we compared the value with available LD50 values in the literature of other bee species using the species sensitivity distribution curve. In 48 h of exposure, males showed an LD50 value 1.33 times lower than females (32.78 and 43.84 ng active ingredient/bee, respectively). Centris analis was more sensitive to dimethoate than the model species A. mellifera and the solitary bee from temperate zones, Osmia lignaria. However, on a body weight basis, C. analis and A. mellifera had similar LD50 values. Ours is the first study that calculated an LD50 for a Neotropical solitary bee. Besides, the results are of crucial importance for a better understanding of the effects of pesticides on the tropical bee fauna and will help to improve the risk assessment of pesticides to bees under tropical conditions, giving attention to wild species, which are commonly neglected. Environ Toxicol Chem 2023;42:2758-2767. © 2023 SETAC.
摘要：
目前,环境法规中仅使用Apismellifera物种来评估农药对传粉者的危害。这种方法中传粉者和蜜蜂多样性的代表性低可能导致对野生物种的保护不足。这种情况在热带环境中加剧，对杀虫剂对孤蜂的影响知之甚少。这里,我们的目的是计算新热带单生蜂中杀虫剂乐果的中等致死剂量（LD50）和中等致死浓度（LC50），从巴西分布到墨西哥的一种腔窝采油蜜蜂。将C.analis的雄性和雌性在实验室条件下口服暴露于乐果48小时。每24小时评估致死率,直到测试开始后144小时。计算LD50后，我们使用物种敏感性分布曲线将该值与其他蜜蜂物种文献中可用的LD50进行了比较。在暴露的48小时内，雄性的LD50值比雌性低1.33倍（32.78和43.84nga.i./bee，分别)。C.analis比模型物种A.mellifera和来自温带地区的孤蜂对乐果更敏感，金菊。然而,以体重为基础，C.analis和A.mellifera具有相似的LD50值。这是对新热带孤独蜂的LD50进行计算的第一项研究。此外,这里介绍的结果对于更好地了解农药对热带蜜蜂动物的影响至关重要，并将有助于改善热带条件下农药对蜜蜂的风险评估，注意野生物种，这是通常被忽视的。
