论文部分内容阅读
比利时专家确定,瓢虫是对付绿蚜虫的天敌,去年春季将3万3千只瓢虫放入布鲁塞尔公园和市周围的森林,半年后发现,树
Belgian experts have determined that ladybugs are natural enemies of green aphids. Last spring, 33,000 ladybugs were placed in the parks and surrounding forests of Brussels, and six months later it was discovered that trees