This study was conducted to determine how reducing the parasite burden in a definitive host may affect the prevalence in intermediate hosts. Here we used the eyeworm Oxyspirura petrowi and cecal worm Aulonocephalus pennula as model species. Northern bobwhite quail (Colinus virginianus) were provided an anthelmintic medicated feed in wild systems because of convincing evidence that these parasites were suppressing their populations. Eyeworm and cecal worm prevalence were measured in Orthopterans, which act as intermediate hosts, using polymerase chain reaction. Individuals were collected from a control site, a site treated for 2 yr, and a site treated for 5 yr. Orthopteran community composition was significantly different among the sites; however, an interaction between subfamily and site was not significant for the eyeworm. There was a significant reduction in eyeworm-infected Orthopterans on the 5-yr site compared with the other 2, suggesting that treatment of a definitive host may indeed affect the prevalence of eyeworms during other life-cycle stages. There was an interaction between the Orthopteran subfamily and the site for the cecal worm, so results were analyzed within each subfamily. A significant reduction in the prevalence of cecal worms was only found in the Cyrtacanthacridinae subfamily on the 5-yr site when compared with the other sites. However, the greatest prevalence in the Gomphocerinae and Oedipodinae subfamilies across all 3 sites was 4.1%. This indicates an unknown degree of cecal worm host specificity. Therefore, conclusions could not be made through the simple assessment of prevalence.

进行这项研究的目的是确定减少终宿主体内的寄生虫负担如何影响中间宿主的患病率。在这里，我们使用眼虫Oxyspirura petrowi和盲肠蠕虫Aulonocephalus pennula作为模式物种。北方短白鹌鹑（Colinus virginianus）在野生系统中被提供了驱虫药物饲料，因为有令人信服的证据表明这些寄生虫抑制了它们的数量。使用聚合酶链反应测量了作为中间宿主的直翅目动物中眼虫和盲肠虫的患病率。从对照地点、处理2年的地点和处理5年的地点收集个体。直翅类群落组成在不同地点之间存在显着差异；然而，对于眼虫来说，亚科和位点之间的相互作用并不显着。与其他 2 个站点相比，5 年站点上受眼虫感染的直翅目昆虫显着减少，这表明对终宿主的治疗确实可能会影响其他生命周期阶段眼虫的流行。直翅目亚科和盲肠蠕虫的位点之间存在相互作用，因此在每个亚科内分析结果。与其他地点相比，仅在 5 年地点的 Cyrtacanthacridinae 亚科中发现盲肠蠕虫的流行率显着降低。然而，所有 3 个地点的 Gomphocerinae 和 Oedipodinae 亚科的患病率最高为 4.1%。这表明盲肠蠕虫宿主特异性程度未知。因此，不能通过简单的患病率评估得出结论。