梨园生物群落及其害虫控制机制的研究

The Biotic Communitv in Pear Orchard and Its Pest Control Mechanism

调查表明：梨园常发害虫有１９种、天敌１８种、杂草１５种。梨园地表植物是天敌的良好栖息地，其上天敌种类多、生存时间长，而同梨树共生害虫种类数量少。施用化学农药次数对梨树、梨园草系中害虫、天敌数量均有显著影响。保留梨园地表植物是保护和增强天敌的有效途径。梨园害虫的治理应坚持以冬季管理为基础，保留地表植物，增强天故和合理使用化学农药的综合治理原则。

The investigation showed that there were 19 species of insect pests,18species of natural enemies and 15 species of weeds which usually orcured in pear orchard.There were more variety of natural enemies and less variety of insect pests which harmedpear trees。The numbers of insect pests and natural enemies on pear trees and weeds in pearorchard were influenced by times of pesticids application,Inpear orchard,to retain plant;onthe ground was an effective way for protection and accumulation of natural enen1ies.