Abstract:

 【Aim】 To observe the external morphology and ultrastructure characteristics of Lardoglyphus konoi at different developmental stages. 【Methods】 Based on the individual samples of different developmental stages of L. konoi cultured in the laboratory, the external morphology and ultrastructure of various developmental stages of L. konoi, including egg, larva, nymph and adult, were observed under scanning electron microscope (SEM). 【Results】 The egg of L. konoi is oval. The larva has three pairs of legs, but has no genital organs, genital setae and anal setae. The nymph has four pairs of legs, and the genital area, genital setae and anal setae still look under-developed. The hypopus has a tapering front end and a round and pear-shaped rear end. Sucker plate appears in the end idiosoma, and there are 13 suckers on the sucker plate with 2-2-4-5 distribution. The chelicera of adult mite is slender, scissor-like, and there are several small teeth on its fixed digit and movable digit. The external vertical seta (ve) is about half the length of the internal vertical seta (vi), and situated at the same horizon as the internal vertical seta. Tarsus end of the 3rd leg in the male adult is replaced by two thick, blunt teeth. At the ventral idiosoma, there is a genital region and an anal region with a pair of anal suckers. All legs in the female adult have forked claws. The ventral gonopore is a longitudinal crack. The anus does not reach the posterior margin of idiosoma. 【Conclusion】 The external morphology and ultrastructure of L. konoi at different developmental stages are observed by SEM, and the morphological characteristics of the mite are understood in more details, providing a theoretical basis for further study of its taxonomy and biology.

Key words: Lardoglyphus konoi, developmental stage, morphological characteristics, ultrastructure, scanning electron microscopy