Abstract：
Anthelmintic residues in livestock dung can adversely affect beneficial organisms. Targeted selective treatment (TST) of a reduced proportion of livestock with anthelmintics can slow resistance development in gastrointestinal nematodes by providing residue-free dung which could also benefit non-target organisms. We tested effects of TST on survival and reproduction of the dung beetle Onthophagus taurus (Scarabaeidae) in a factorial glasshouse experiment (Experimental treatments: five TST levels, 0.00, 0.25, 0.50, 0.75, 1.00 x four ivermectin concentrations, 125, 250, 375, 500 ppb). Each mesocosm comprised a 60 L bin containing sand, four dung pats and six pairs of adult beetles (F0 generation). No effects of TST level and ivermectin concentration on mortality of F0 adults after one week were observed. F0 adult brood ball production was affected by TST level, particularly at high ivermectin concentrations. Brood ball production increased as more untreated pats became available, with greater increases at higher ivermectin concentrations. We tested for evidence of a reported attraction of dung beetles to ivermectin-treated dung using a novel glitter-marker to trace the origin of dung used in brood balls. Where mesocosms contained both dung types, the proportion of brood balls created from untreated dung showed no statistical difference from the null expectation based on untreated dung availability in the mesocosm. Emergence of F1 adults was affected by the increase in TST, with this effect dependent on concentration. Treatments with concentrations of 250-500 ppb had the lowest emergence rates (ca. 5-20 % in mesocosms where all dung pats were treated) but emergence rates increased with TST level, reaching 68-88 % emergence where no dung pats were treated with ivermectin. Ivermectin-induced mortality occurred predominantly at egg and first instar stages. TST can provide refuges for dung beetles offering a strategy for livestock producers to maintain livestock welfare whilst benefiting from ecosystem services provided by important insects.
摘要：
牲畜粪便中的驱虫药残留物会对有益生物产生不利影响。用驱虫药减少的家畜的靶向选择性治疗（TST）可以通过提供无残留的粪便来减缓胃肠线虫的抗性发展，这也可以使非目标生物受益。我们在阶乘温室实验中测试了TST对粪甲虫金牛（Scarabaeidae）的存活和繁殖的影响（实验处理：五个TST水平，0.00、0.25、0.50、0.75、1.00x四种伊维菌素浓度，125、250、375、500ppb)。每个中观世界都包括一个60升的装有沙子的垃圾箱，四个粪便拍子和六对成年甲虫（F0代）。一周后，未观察到TST水平和伊维菌素浓度对F0成人死亡率的影响。F0成年育鸟球产量受TST水平影响，特别是在高伊维菌素浓度下。随着更多未经处理的拍子可用，育肉球的产量增加，在更高的伊维菌素浓度下增加更多。我们使用一种新颖的闪光标记物追踪育儿球中使用的粪便的起源，测试了据报道的粪便甲虫对伊维菌素处理过的粪便的吸引力的证据。在中间宇宙包含两种粪便的地方，未经处理的粪便产生的育卵球的比例与基于中观未处理的粪便可用性的零预期没有统计学差异。F1成年人的出现受到TST增加的影响，这种效果取决于浓度。浓度为250-500ppb的处理具有最低的出苗率（约在所有粪便都经过治疗的中观中，有5-20％），但出苗率随TST水平而增加，在没有用伊维菌素治疗粪便的情况下，出现率达到68-88％。伊维菌素诱导的死亡率主要发生在卵和第一龄阶段。TST可以为粪甲虫提供避难所，为牲畜生产者提供战略，以维持牲畜福利，同时受益于重要昆虫提供的生态系统服务。
