在黄橙橙的油菜花盛开的季节,人们常常可以看到一种色彩艳丽的小甲虫,背着瓢形的盔甲,上面匀称地镶嵌着七个小黑点,十分逗人喜爱,这种小昆虫叫“七星瓢虫”,孩子们又叫它“花大姐”。因为它具有捕食棉蚜的特殊本领,一天能吃掉上百头棉蚜,使棉苗常常“死而复生”,因此,贫下中农又叫它为“棉大夫”。一九七四年,山西省永济县三娄寺公杜卿头学校的生物防治小组一成立,就与“棉大夫”交上了朋友。从此,这个组的同学们每年都要搞人工助迁,于五月下旬,把苜蓿地和小麦地里的瓢虫,捉来放到棉田中,防治棉蚜虫。几年来,有一千多亩棉田经他们放瓢治蚜,提高了产量,降低了成本。贫下中农十分欢迎,称他们是“棉田的警卫兵”。 In the yellow-orange rapeseed season, people often see a colorful small beetle, carrying a scoop-shaped armor, symmetrically embedded in the above seven black spots, very cute, this small Insects called “Seven Star Ladybug”, the children called it “Flower Sister.” Because it has the special ability of predation on cotton aphids, it can eat up to a hundred cotton aphids a day so that the cotton seedlings often “die and revive.” Therefore, the poor and middle-aged peasants also call it the “cotton doctor.” In 1974, the biological control team of Duqingtou School, San Lou Temple, Yongji County, Shanxi Province, was established as a friend with the “Cotton Doctor”. Since then, students in this group have been making artificial relocation every year. In late May, ladybugs in alfalfa fields and wheat fields were caught in cotton fields to control cotton aphids. Over the past few years, more than 1,000 acres of cotton fields have been scooping their aphids to increase production and reduce costs. Poor middle peasants are very welcome, saying they are “cotton guards.”