Study on Wax Secretion and Wax-Secreting System of Mulberry Pest Paurocephala sauteri Enderlein (Hemiptera: Psyllidae)

Abstract

Paurocephala sauteri Enderlein is one of the most important pests of mulberry trees in the tropical and subtropical regions of China. This species by penetrating the veins on the back of leaves and buds of mulberry trees, nymphs and female adults can secrete wax, these wax accumulated on the mulberry leaves significantly affects photosynthesis and silkworm cultivation. Therefore, this study aimed to understand the wax-secreting system and characteristics of wax secretion, expecting a potential strategy to control the species population. The main findings were as follows: scanning electron microscopy revealed that the nymphs and female adults secrete wax in long tubes with spherical ends, and male adults secrete honeydew. Additionally, the wax-secreting system of the nymphs and female adults differ, the nymph owned a bending moon-shaped wax-secreting system, the wax-secreting system first instar nymph consisted of one circle of rectangular, depressed cell, whereas the wax-secreting system of second to fifth instar nymph made up of one circle of rectangular, depressed cell and one circle of round, depressed cell. There were a certain number of white pores inside of this depressed cell. Wax filaments produced by these pores are converted into a dense, tight and hollow the wax tube. Gas chromatography/mass spectrometer showed that the main constituents of P. sauteri wax are hydrocarbons. The wax tube as a water conservation pool during the P. sauteri developmental process. This physiological feature may be a key point for a potential strategy to control P. sauteri, even other secreting insects.