【摘要】 本文报道了冬小麦生态系统中小麦、粘虫和粘虫的一种主要天敌——中华星步(虫甲)(Colosomachinense)三个亚系统的模型。同时把三个模型耦联起来进行逐日动态模拟确定了小麦不同生育期和中华星步(虫甲)不同密度下的经济阈值。模拟结果表明:粘虫发生越早,经济阈值越小;在小麦同一个生育期,经济阈值随中华星步(虫甲)密度的增加而提高,但显然不是简单的线性关系,而是随着温度和粘虫密度的变化而变化。根据模拟结果,得到河南驻马店地区亩产500斤以上的小麦在没有中华星步(虫甲)时,用粘粘虫散防治的经济阈值在小麦的不同生育期变动在22—34头/米~2之间,用灭幼脲防治时为每平方米14—23头。如果中华星步(虫甲)每100米~2增加2头,则经济阈值可相应地提高1—3头/米~2。更多还原

【Abstract】 This study includes three models, the plant (wheat)model, the pest(the army-worm) model, and the predator (Calosoma chinense) model. By coupling the plant-pest-predator models and simulating day by day one is able to get the dynamic ET (Table 3) under various developmental stage of winter wheat and various densities of C. chinense. The result of this simulation shows that the earlier the armyworm appears, the smaller the value of ET; under the same developmental stage of wheat, ET increases with the increasing number of predators. Clearly the effect of C. chinense on ET changes as temperature and the number of the armyworm densities changes. In the absence of C. chinense, ET is set at 22-34 pest larvae/m2, which seems to be the right density to control the pest by means of Armyworm powder while by means of Dimilin the ET is set at 14-23 pest larvae /m2 on wheat yield above 250kg per Mu in Zhumadian district of Henan province. When there is an increment of 0.02 predator/m2 the corresponding ET increases 1-3 pest larvae/m2.更多还原