梨树主要害虫越冬虫口密度调查为了掌握梨树害虫的发生量，制订有效的防治措施，在害虫越冬期调查其越冬虫口密度是非常必要的。通过实践我们总结出一套简单、可靠的调查方法，现介绍如下。１、梨大食心虫及梨食芽蛾梨大食心虫越冬幼虫转芽前，结合修剪，在梨园中按对角线... Pear tree pests overwintering population density survey In order to grasp the occurrence of pear pests, develop effective control measures, pest overwintering investigation of its population density of overwintering insect is very necessary. Through practice, we conclude a simple and reliable survey method, which is introduced below. 1, pear large bore worms and pears eat buds moths large borer overwintering larvae before the shoot, combined with pruning, in the pear by diagonal ...