Abstract: Objective　To investigate the morphological characteristics of Dermatophagoides farinae at different developmental stages. Methods　The cultured D. farinae was isolated, and the external morphological features of mites at various developmental stages were observed using scanning electron microscopy (SEM), including egg, larva, nymph and adult stages. Results　 The D. farinae egg appeared a long oval shape, and the larval mites had three pairs of legs. The nymph had four pairs of legs and underdeveloped genital pores containing genital setae and anal setae, and adult mites appeared long and oval in shape, with decorative patterns on epidermis, and had four pairs of legs. In male adult mites, remarkable thickening of the leg I and thicker and longer leg III than the leg IV were seen, and ventral genital regions were found between the basal segments of legs III and IV; the anus was surrounded by a circular peri⁃anal ring, with a pair of anal suckers and anal setae within the ring. In the female adult mites, slender legs III and IV with an equal length were seen, and a “λ⁃shape” genital hole was observed on the ventral surface, with a crescent⁃like genital plate in the anterior part, and the anus appeared a longitudinal slit. Conclusion　An SEM observation of the external morphology of D. farinae provides understandings of the morphological characteristics of D. farinae, which is of great significance for the classification and identification.

Key words: Dermatophagoides farinae, Scanning electron microscopy, Morphological characteristic

摘要： 目的　观察粉尘螨（Dermatophagoides farinae）不同发育阶段的形态特征。方法　将纯培养的粉尘螨分离后，应用扫描电子显微镜观察卵、幼螨、若螨、成螨等不同发育阶段外部形态。结果　粉尘螨卵呈长椭圆形。幼螨足3对，若螨足4对，生殖孔不发达，有生殖毛和肛毛。成螨呈长圆形，表皮有细致花纹，足4对；雄成螨足Ⅰ明显加粗，足Ⅲ较足Ⅳ粗长，生殖区位于足Ⅲ、Ⅳ基节间，肛门被一圆形围肛环包围，环内有肛门吸盘和刚毛1对；雌成螨足Ⅲ、Ⅳ较细，长度相等，腹面有1个呈“人”字形的生殖孔，其前端有1个类似月牙形的生殖板，肛门为1个纵形裂缝。结论　对粉尘螨进行扫描电镜观察能够清晰了解其形态结构特征，对粉尘螨分类鉴定具有重要意义。

关键词: 粉尘螨, 扫描电镜, 形态特征