Cephalothoracic nerves of the larva of the castor silk moth, Philosamia ricini Hutt. (Lepidoptera : Saturniidae)

Abstract

Ten pairs of nerves arise from the brain and suboesophageal ganglion. Each of the cephalic nerves originates independently from the brain. The nerve innervating the clypeus and labrum is termed as “Labrofrontal” instead of “clypeolabral”. The labium is innervated by a separate labial nerve. A pair of cervical nerves arises from the posterolateral margins of the suboesophageal ganglion and innervates the prothoracic muscles extending into the head region. Each thoracic ganglion gives off 3 pairs of nerves. The dorsal nerve in the meso- and metathoracic segments originates slightly anterior to the ganglion, and has a forked root with a plexus. Connections between dorsal and transverse nerves are noted.