关键词: 白蜡虫, 蜡腺, 泌蜡, 性二型性, 生态学意义

Abstract: 【Aim】 To observe the structural characteristics of wax glands on sexual dimorphic Ericerus pela, and explore the ecological adaptability significance of wax secretion of females and males.【Methods】 The distribution of different developmental stages of E. pela on host plants and their wax secretion characteristics were investigated in the field, the structure of their wax glands and wax filament morphology were observed under an electron microscope in the laboratory, and the cuticular thickness of females and males was compared by using paraffin section, the differences in wax secretion and chitin synthesis between females and males were analyzed based on transcriptome data and analysis of the rules of wax secretion and cuticle thickening. 【Results】Six types of wax glands were found on the body surface of E. pela. Among them, the quadrilocular pores were unique to the 1st instar male nymphs, the decalocular glands were unique to the female adults, and the 2nd instar male nymphs were covered with tubular ducts, which are the main wax-producing organs of males. Quinquelocular pores, stigmatic glands and anal glands were found on E. pela at all developmental stages. Males have more types and quantities of wax glands while the cuticle of female nymphs was nearly 35% thicker than that of male nymphs. The fatty acyl-CoA reductase gene far, a key gene involved in wax synthesis showed higher expression levels in male adults than in female adults, while the chitin synthase gene cs, a key gene involved in chitin synthesis exhibited higher expression levels in female adults than in male adults. 【Conclusion】There is a significant difference in wax secretion between E. pela females and males. The type and quantity of wax glands are related to the different ecological adaptation strategies between two sexes. Sciophilous male nymphs secrete a layer of wax filaments to protect the process of complete metamorphosis. Heliophilous female nymphs hardly secrete any wax, they adapt to the environment by a thickened cuticle, the wax secreted by females may assist breathing, prevent honeydew from flowing back, and protect their body from pathogen invading, protect eggs from predators, prevent egg masses from sticking to each other, and reduce the impacts of external forces on eggs.

Key words: Ericerus pela, wax glands, wax secretion, sexual dimorphism, ecological significance