Waghorn Tania S, Leathwick D M, Chen L-Y, Gray R A J, Skipp R A
AgResearch Limited, Grasslands Research Centre, Private Bag 11008, Palmerston North, New Zealand.
Vet Parasitol. 2002 Mar 1;104(2):119-29. doi: 10.1016/s0304-4017(01)00629-x.
Biological options for nematode parasite control are being sought, as the long-term efficacy of conventional anthelmintics comes increasingly under threat from drug-resistant parasites. Three biological methods with the potential to reduce pasture contamination by parasitic nematode larvae were examined: (a) killing of larvae developing in dung by nematophagous fungi; (b) removal of dung through earthworm ingestion; (c) burial of dung in soil as might occur through the action of dung beetles. Field trials with the test bio-control agents were carried out in autumn and spring by adding dung from sheep infected with Ostertagia (Teladorsagia) circumcincta to pots of ryegrass/white clover. The factorial treatment structure included five fungal treatments (individual applications of Duddingtonia flagrans, Monacrosporium gephyropagum and Harposporium helicoides, a combination of all the three fungi together and an untreated control), two dung burial treatments (dung buried or deposited on the soil surface) and two earthworm treatments (earthworms present or absent). D. flagrans and H. helicoides, individually or in combination, reduced recovery of infective stage larvae in experiment 1, while only H. helicoides reduced recovery in experiment 2. In both the experiments, dung burial increased the total number of larvae recovered, while the number of infective larvae were reduced by the action of earthworms. Increased recovery following burial, along with the fact that larvae moved rapidly from soil onto herbage, suggests that soil may provide a protective reservoir for infective larvae infesting herbage.
由于传统驱虫药的长期疗效越来越受到抗药寄生虫的威胁，人们正在寻找控制线虫寄生虫的生物方法。研究了三种有可能减少寄生线虫幼虫对牧场污染的生物方法：(a) 食线虫真菌杀死在粪便中发育的幼虫；(b) 通过蚯蚓摄食清除粪便；(c) 粪便可能通过蜣螂的作用埋入土壤。在秋季和春季进行了试验性生物防治剂的田间试验，方法是将感染环纹奥斯特线虫（环形泰勒线虫）的绵羊粪便添加到黑麦草/白三叶花盆中。析因处理结构包括五种真菌处理（分别施用弗氏节丛孢、格氏单顶孢和螺旋哈茨孢，三种真菌组合施用以及未处理对照）、两种粪便掩埋处理（粪便埋入或置于土壤表面）和两种蚯蚓处理（有或无蚯蚓）。在实验1中，弗氏节丛孢和螺旋哈茨孢单独或联合使用可减少感染期幼虫的回收率，而在实验2中只有螺旋哈茨孢可减少回收率。在两个实验中，粪便掩埋增加了回收幼虫的总数，而蚯蚓的作用减少了感染性幼虫的数量。掩埋后回收率增加，以及幼虫迅速从土壤转移到牧草上，这表明土壤可能为侵染牧草的感染性幼虫提供一个保护库。
