Abstract: Objective To observe the morphological characteristics of live Carpoglyphus lactis at different stages of life cycle and its ultrastructure. Methods The live C. lactis specimens were isolated from longan pulp， and firstly rinsed with double distilled water under a light microscope to make slide preparation by the conventional manner， and then were made into scanning electron microscope （SEM） specimens. The specimens were observed under SEM for the ultrastructure characteristics at different developmental stages including egg， larva， nymph and adult （male and female）. Results The SEM photographs showed that the egg was oval and milky. The larva had three pairs of legs， without genital setae， preanal seta and coxal rod， and there was no trace of genital growth. The nymph had four pairs of legs， genital seta and preanal seta， whereas the genital area was looked still under?developed. The male adult had a conical gnathosoma and a pair of external verticals which were longest setae at the dorsal idiosoma， whereas the other dorsal setae were all short rhabdoid. At the ventral idiosoma， there was an aedoeagus which was like a bent cube， and the top was straight forward. The external sacral setae and post anal were longest setae. The female adult’s genital plates were a composite of plastron and cutex inner root， covering the genital tract， and a hole of anus and a pair of anal setae were located at posterior of idiosoma. Conclusion The morphological characteristics and ultra?structure of C. lactis at different stages of life cycle can be vividly observed under SEM， which provides the morphological bases for further study of the relation between parasitism and disease.

Key words: Carpoglyphus lactis, Scanning electron microscopy, Morphological characteristic, Ultrastructure

摘要： 目的 观察甜果螨生活史不同发育阶段外部形态的超微结构。方法 采集龙眼肉中新鲜甜果螨，置连续变倍光镜下以双蒸水清洗，制备标本置扫描电镜下分别观察卵、幼螨、若螨、成螨外部形态的细微结构。结果 扫描电镜下可见卵呈椭圆形，乳白色；幼螨足3对，生殖毛和肛前毛缺如，无基节杆，无生殖器官生长痕迹；若螨足4对，生殖区发育未完全，有生殖毛和肛前毛。雄成螨颚体圆锥形，躯体背面除一对顶外毛为长刚毛，其余刚毛均为短杆状，腹面生殖区有一弯管阳茎，顶端挺直向前，骶外毛和肛后毛为最长刚毛；雌成螨躯体腹面胸板和足Ⅱ表皮内突愈合成生殖板，覆盖在生殖孔前端，躯体后缘有一肛门孔和一对肛毛。结论 扫描电镜可清晰辨识甜果螨不同发育阶段外部形态超微结构及形态变化，本研究结果为后续阐明甜果螨寄生、致病作用提供了形态学依据。

关键词: 甜果螨, 扫描电镜, 形态特征, 超微结构