新疆麦棉间作布局及麦棉比例与棉田捕食性天敌发生的关系

2008年在新疆莎车县分别比较研究了棉田与麦田间作不同条件下棉田几种主要捕食性天敌发生数量和益害比情况。结果表明：在麦收后前期（6月17日），麦 棉、麦 棉 麦、麦 棉 麦 棉3种布局方式棉田和3种麦棉比例棉田的增益作用要强于全棉棉田，控害效果明显。3种布局方式棉田和3种麦棉比例棉田与全棉棉田的天敌总数、瓢虫类天敌数量和两种益害比差异显著；3种麦棉布局棉田天敌总数分别高出全棉棉田104%、109.4%和113.8%；瓢虫类天敌数量分别高出全棉棉田137.4%、135.3%和173.4%。麦棉布局棉田中，麦 棉 麦 棉镶嵌式布局增益效果最好。麦棉比例1∶5以上、1∶1~1∶5及1∶1以下棉田的天敌总数分别高出全棉棉田79.1%、128.4%和121.2%；瓢虫类天敌数量分别高出全棉棉田108.7%、165.7%和176.2%；3种麦棉比棉田中，1∶1~1∶5的麦棉比例的增益效果最好。麦收后期（7月16日），麦田增益效果减弱，各类棉田天敌害虫发生趋于一致，差异不显著。

Occurrence of predators in different cotton fields in south Xinjiang

Effects of wheat fields on predators, predators/cotton aphids and predators/cotton pest in cotton fields were studied comparatively in Shache, Xinjiang in 2008. The results showed that, compared to single cotton fields, the population of predators increased significantly in cotton/wheat intercropping fields during post harvest period. Significant differences were observed in the number of predators, predators/cotton aphids and predators/cotton pest between the intercropping fields and the cotton fields on June 17. The number of predators in the cotton fields with three wheat cotton layouts and in the cotton fields with three wheat cotton intercropping proportions was higher than that in the cotton fields. Compared to the cotton fields, the number of predators was increased by 104% in wheat cotton intercropping (type I), 109.4% in wheat cotton wheat intercropping (type II), 113.8% in wheat cotton wheat cotton (type III), 79.1% in wheat cotton intercropping proportion one to more five (type i), 128.4% in 1∶1~1∶5 (type ii) and 121.2% in one to less one (type iii); the number of ladybug increased by 137.4 % in type I, 135.3% in type II, 173.4% in type III, 108.7% in type i, 165.7% in type ii and 176.2% in type iii. During late wheat harvest period, no significant differences were found on July 16. The cotton field with the mixed wheat cotton mosaic layout and the cotton field with 1∶1~1∶5 wheat cotton proportions had good effects on predators, predators/cotton aphids and predators/cotton pest.