灰地种蝇[Delia platura(Meigen)],又称种蝇、瓜种蝇,是西瓜播种后至真叶显露前的主要害虫。种子发芽时幼虫自露白处进入,造成种子霉烂不出苗;幼虫蛀食幼苗的根、茎,使植株停止生长或全株枯死,造成缺苗断垄,甚至毁种重播。早春覆膜西瓜是郓城县主要的经济作物,瓜、棉间作套种是 Delia platura (Meigen)], also known as the species of flies, melons and flies, is the main pest after the watermelon is sowed until the real leaves appear. Seed germination larvae enter the white from the Department, resulting in seed mildew does not emerge; larvae eaten seedling roots and stems, so that plants stop growing or whole plant dead, resulting in lack of seedlings broken ridge, and even replanted. Watermelon early spring coating is Tancheng County’s main cash crop, melon, cotton intercropping is