关键词: 毛囊蠕形螨, 皮脂蠕形螨, 形态特征, 活动性

Abstract: Objective To observe dynamic of the morphologic structure and activity of Human Demodex in different stages.Methods The mites are collected by the squeezing method and cellophane tape method,and they are screened by computer with the Motic DM B5 software.Results The morphologic structure and activity of Human Demodex in different stages are checked and described.The development process of Demodex folliculorum and Demodex brevis is similar,the life cycle included egg,larva(three pairs of legs),nymph(four pairs of legs)and adult.During the stage of nymph,Demodex folliculorum has a molting stage,so the nymph stage is divided into protonymph and nymph.And protonymph is shorter than nymph,with blurry coxal follicle.Demodex folliculorum and Demodex brevis have different morphologic structure.The legs and gnathosoma of the mites can move in every stage(except eggs).When the temperature is higher(>20 ℃),the mites move actively,especially the adult.The opisthosoma of Demodex folliculorum and Demodex brevis have biggish difference.And the proctodeum of female Demodex folliculorum is firstly observed and screened under water microscopy.Conclusion The life cycle pattern of Demodex includes the egg,larva,protonymph,nymph,adult.The larva has three pairs of legs,and the nymph(including protonymph)has four pairs of legs.They have different morphologic structure in different stages,so it is easy to identify.The larva,nymph and adult have the ability of activity.The subspecies of Demodex folliculorum and Demodex brevis may exist.