Abstract:  【Aim】 To observe the morphological changes of the live Caloglyphus berlesei and the ultra-structure under scanning electron microscope (SEM) at different developmental stages. 【Methods】 C. berlesei specimens were isolated from the bed feedsduff in an Eupolyphaga sinensis breeding farm, and rinsed with double distilled water. One portion of the isolations were used for slide preparation in the conventional manner and immediately observed under light microscope, and the other was fixed with 2.5% glutaraldehyde solution and washed once again with 75% alcohol. By critical-point drying, the specimens were observed under SEM for the ultrastructure characteristics at different developmental stages including egg, larva, nymph and adult. 【Results】 Morphological variations of C. berlesei, including its legs, setae, external genitalia and accessories, are clearly identified under SEM. The larva has three pairs of legs, without leaf-like setae, yet its coxal rod is well-developed. By nymphal stage, four pairs of legs and the 4th dorsal seta arise, whereas the genital area looks still under-developed. At hypopus, the claws and tarsules are well-built, and leaf-like setae, setae of tibia and setae of genu are seen. One pair of suckers and setas are located on both sides of the genital plates which are ossified obviously. There are 4 pairs of suckers, single sucker and 2 pairs of round-like bulge in sucker plate. The genital sense organ of adults exhibits itself with cordiform external aspect and typical ossification texture, wherease the male is dissimilar with the female regarding seta number on the genital sense organ. 【Conclusion】 Description of the morphology and ultrastructure of C. berlesei provides important information for the taxonomy and further study of its life history as well as basis for controlling the allergic disorders due to infection of this pest.

Key words: Caloglyphus berlesei, morphology, ultrastructure, hypopus, sucker plate, scanning electron microscopy (SEM)