Abstract: 【Aim】 Carsidara limbata is an insect pest that seriously damages Firmiana simplex. Observation and identification of the ultra-morphology of waxy secretions and waxy glands in C. limbata nymphs of different instars would provide a theoretical basis for the future studies on its growth and development. 【Methods】 The nymphal instars of C. limbata were determined by morphological characteristics, and the ultrastructure of waxy secretions and waxy glands in nymphs of different instars were observed using stereomicroscope and scanning electron microscopy (SEM). 【Results】 Waxy glands of C. limbata nymphs are divided into two types: one is wax-secreting pore, appearing on the integument since the 3rd instar nymph; the other is regular or irregular circular porous gland, rarely distributed in the 1st instar nymph. The gland amounts and types in late instar nymphs were more than those in early instars. Waxy secretions can be divided into four types, i.e., filamentous wax filament, hollow C-shaped wax filament, spring crimp wax filament, and hollow long wax filament. In addition, there is a circumferential hole ring at the end of the abdomen, and micro-thorn and various types of setae are distributed all over the dorsal and ventral surface of abdomen. 【Conclusion】 C. limbata nymph has four types of waxy secretions and two types of waxy glands. Their types and distribution are different among different nymphal instars. This study provides a reference for the study of waxy organs in Carsidaridae.

Key words: Carsidara limbate, nymph, waxy glands, waxy secretions, ultrastructure