亦称潜水甲虫或真水生甲虫。鞘翅目，龙虱科。在我国主要产于广东、广西、海南、福建和湖南、湖北等省区。成、幼虫都生活在静水或流水中，少数见于卤水或温泉内，均能捕食软体动物、昆虫、蝌蚪或小鱼。幼虫尤其贪食。成虫有趋光性。
学名：predaceous diving beetle
英文名：lice
This species belongs to the family of Dytiscidae,order of coleoptera,also known as diving beetle.Mainly distributed in Guangdong, Guangxi, Hainan, Fujian and Hunan, Hubei and other provinces of China.Adult and larvae still live in running water, a few found in brine or hot springs.They can prey on mollusks, insects, tadpoles or small fish.Larvae are particularly bulimia and adult has phototaxis.