水稻苗期稻茎毛眼水蝇经济阈值的研究

接虫试验表明，水稻苗期每丛稻茎毛眼水蝇卵数（Ｘ_１）、为害株数（Ｘ_２）与产量损失（Ｙ）的关系符合下列方程：Ｙ＝－７．３１＋３．０１６ｘ１±２．１５，ｒ＝０．９８０４；Ｙ＝－６．７＋３．５３ｘ２±２．１９，ｒ＝０．９８０２。早稻产量损失的主要原因是受害后千粒重和实粒数减少；晚稻为千粒重下降。根据当前的稻谷价格、防治费用等，导出水稻苗期稻茎毛眼蝇的经济阈值为每丛４．６粒卵或３．７４株受害。经大田验证，与实际基本相符

Economic Threshold of Hydrellia sasakii at Seedling Stage of Rice

Field experiment indicated that the relationships between the yield loss (Y) of rice and the egg density of Hydrellia sasakii (x₁) and the damaged plants (x₂) at the seedling stage of rice fit the follow equations: Y=-7.31+3.016x₁±2.15, r=0.9804; Y=-6.7+3.53x₂±2.19, r=0.9802 The main reasons of yield loss were that the 1000 grain weight and fertile grain on early rice and 1000 grain weight on late rice were reduced respectively According to the presentprice of rough rice and control cost, the economic thresholds of Hydrellia sasakii were 4.6 eggs or 3.74 damaged plants per cluster, which were approved by the tests in the field