【摘要】 <正> 本文所述湟水穗螨(Siteroptes huangshuiensis)、青海穗螨(S.chinghaiensis)及燕麦穗螨(S.avenae)为禾谷穗腐病之传布媒介。穗腐病在欧美等地被称作“银顶病”(Silver top)或“白穗病”。此病在青海省部分地区的农田杂草野燕麦(Avena fatua)上发病率很高,并已不同程度地侵染到小麦、青稞及家燕麦(A.sativa)等农作物。关于媒介穗螨的种类记述已更多还原

【Abstract】 Three pyemotid mites, namely Siteroptes chinghaiensis, S. huangshuiensis, and S. avenae, were reared in the laboratory on their associated food fungi and their life cycles, the influences of temperature and humidity on survival and development, and their relationships to the fungi were studied. A temperature about 20℃ and a relative humidity of 70% were found to be suitable for their growth and development. The number of progeny produced by each female decreased at 30℃ and the duration required by them to reach maturity was shortest at 25℃ except S. avenae which seemed to have a wider range of thermal adaptation than, the other two species. The life cycle of S. huangshuiensis was slightly shorter than that of S. chinghaiensis. Lower temperature and higher relative humidity were more favourable for the females to survive. Both the larvae and the adults needed fresh fungi, especially for the transformation into chrysalis of the larvae and for the physogastry of the females. It Was observed that S. chinghaiensis and S. huangshuiensis underwent four developmental stages to complete their life cycles: egg, larva, chrysalis and adult; and nymphal stage was absent. Occasionally the eggs hatched into larvae within the abdomens of the pregnant females, and the result was the rupture of the hysterosoma. Viviparity is highly developed in S. avenae which has only one free living stage, i.e. the imago. All the three species can carry out parthenogenesis and arrhenotoky is the rule. The precentages of parthenogenic females were observed to be 15% in S. huangshuiensis, 20% in S. chinghaiensis, and 5.8% in S. avenae.更多还原