Anatomical study of the alimentary canal of Xylosandrus germanus

Key Words：Xylosandrus germanus, alimentary canal, anatomy, proventriculus, gastric caeca

Abstract：     The anatomy of the alimentary canal of Xylosandrus germanus (Blandford) was described with the aid of stereo and scanning electron microscope. The results showed that the alimentary canal of X. germanus was composed of foregut, midgut and hindgut. The adult's proventriculus that composed of 8 proventricular plates was lanternshaped. Each plate was composed of anterior plate and posterior plate; the former was short and simple, while the later was long, and composed of declivity, masticatory brush and stopping bristles. The gastric caeca were located in the posterior region of midgut, being tubeshaped and sacshaped. The adults had a pair of tubeshaped and a pair of sacshaped gastric caecae, while the larvae had a pair of tubeshaped and three to five pairs of sacshaped gastric caecae. There were six Malpighian tubules which were arranged in one group of four and another of two. The six Malpighian tubules and the hindgut wall constituted the cryptonephridial system. The adult could be identified by a pair of tubeshaped and a pair of sacshaped gastric caecae in the alimentary canal.