Alimentary canal of fifth instar larvae of Lymantria dispar (Lepidoptera: Erebidae, Lymatriinae)

Abstract

Here, the alimentary canal of fifth instar larvae of the gypsy moth (Lymantria dispar) was re-investigated with light microscopy (LM), and for the first time with laser scanning confocalmicroscopy (LSCM) and scanning electronmicroscopy (SEM). We describe morphological characteristics and provide morphometric data. Well-developed dilator muscles and Malpighian bladders suggest a high capacity for food propulsion, excretion, absorption, and detoxification. The epithelium of the alimentary canal of L. dispar is histologically simple and that of the midgut is composed of columnar, goblet, and regenerative cells. Particular arrangement of the intima of crop with a central ventral region recalling a ladder and numerous folds was detected, indicating the capability for a large increase in volume to store food. Numerous spinules were observed on the cuticular intima of pylorus and spinules of a different type were observed on the pyloric valve, and these might assist in propelling the feces.