【摘要】 本文根据Gerrard阈限密度法,对57组调查资料进行分析,建立了锈螨的经济预测模型: m=1.7479[-1n（1-P）]^1.3994式中m为虫口密度,P为有虫叶率。更多还原

【Abstract】 According to Gerrard’s threshold density method,the total population density of the adult and nymph of citrus rust mites （phyllocoples obleivorus Ashmead） on citrus was estimated based on sampling data during 1991～ 1992. The model of Gerrard was determined: m = l. 7479[—In（l—P）]^1.3994 where m is the density of citrus rust mite,and P is the frequency of leaf with this pest.更多还原