艾美尔球虫防治高原鼠兔实验及对其胚胎发育的影响

Efficacies of coccidian parasites(Protozoa) in control of plateau pika(Ochotona curzoniae) and their effects on embryo development

高原鼠兔是青藏高原地区危害高寒草甸植被的主要有害小哺乳动物。生物控制为有害动物防治的主要发展方向,但存在防治效果见效慢的缺点。艾美尔球虫是高原鼠兔肠道内的主要寄生物,并对宿主具有专一性寄生的特点。为将艾美尔球虫研发成新型的高原鼠兔无公害生物防治制剂,本文测定了球虫毒饵对高原鼠兔致死率并在野外进行了灭鼠实验。结果表明,添加增效剂的300万球虫毒饵在室内可导致63.6%的成年个体死亡,在野外可导致54.9%成体和71.0%幼体死亡。灭鼠后残存高原鼠兔的球虫感染率和感染强度显著大于对照个体,且妊娠雌体的胚胎重较对照显著降低。上述结果说明,艾美尔球虫防治高原鼠兔具有较好的速效性,并能影响残存妊娠雌体的胚胎发育。

The plateau pika（Ochotona curzoniae） has been recorded as one of the serious pests in alpine meadows on the Qinghai-Tibet Plateau.However,biological control,recognized as a primary way in pest control,generally does not display visible effectiveness in the short term.Coccidian parasites are intestinal protozoans,and are currently recognized as the main parasite infecting plateau pika populations.Infection with coccidia seriously impairs the survival of hosts.In order to test whether coccidia could be used for control pikas,we incorporated coccidia into bait and tested its efficacies in both laboratory and field.Our results showed that the bait（containing 300 × 104 oocysts and synergist） led 63.6% adults to die in the laboratory, and 54.9% and 71.0% decreases in numbers of adults and juveniles in field,respectively.In addition,embryo weight was significant lower in the treatment group than that in the control group.Infection rate and infection intensity were significantly higher in treatment plots than those in control plots.Our results suggest that coccidian parasites have good effectiveness in pika control,and it may also influence embryo development of pregnant female infected in the field.