Study on the ultrastructure of the trichoid sensillum on the antenna of the male pine caterpillar moth, Dendrolimus tabulaeformis Tsia et Liu (Lepidoptera: Lasiocampidae);

Each trichoid sensillum consists of a cuticular hair, three sensory neurons and three auxiliary cells──thecogen, trichogen and tormogen cells which are arranged in concentric array and serve as the envelope of the neurons.

The distribution, shape and functions of spider s mechanoreceptor, structure of the lyriform sensor, electrophysiological characters of sensory neurons, the site of mechanotransduction, initial site of action potential, characters of receptor channel and efferent modulation of sensory neurons have been simply described in this paper, and the questions needed to solve further are involved.