Nueroendocrine complex of Jamaicana flava (Caudell) (Orthoptera : Tettigoniidae)

Abstract

The anatomy and histology of the neuroendocrine complex of adult Jamaicana flava have been studied by means of intra-vitam injection of methylene blue followed by dissection, and by the examination of sections, cut serially, which have been stained with either paraldehyde fuchsin or chrome haematoxylin phloxine. A detailed illustration of the nerve pathways within the system is presented. The stomatogastric nervous system comprises a frontal ganglion, hypocerebral ganglion, and paired ingluvial ganglia. Nerve pathways link this system to the brain, retrocerebral glands and to the musculature of the foregut and head. Two fine nerves leave each frontal connective, FCN 1 and FCN 2. The former divides into an inner nerve, which joins with its counterpart from the opposite side, and an outer nerve which joins with a fine branch of the median nerve and supplies the dilator muscles of the cibarium and the posterior retractor muscles of the labrum. FCN 2 innervates the dorsal dilator muscles of the pharynx and the retractor muscles of the labrum. The median nerve leaves the anterior margin of the frontal ganglion and innervates the clypeus, epipharynx, and the anterior retractor muscles of the labrum. A single pair of pharyngeal nerves leaves the frontal ganglion and these ramify over the surface of the gut, forming a complex network. Numerous fine nerves were observed linking the recurrent nerve and the dorsal musculature of the pharynx. Three cell types were observed in the pars intercerebralis medialis of the brain, of which one was recognised as being neurosecretory. Neurosecretory ‘A’ material, present in these cells, was also found in the NCC 1 and the anterior storage lobe of the corpora cardiaca. Nerve fibres were observed linking the corpora cardiaca to the hypocerebral ganglion. Neurosecretory material was never observed in the hypocerebral ganglion, the recurrent nerve or the oesophageal nerves. However, stainable material was present in the large neurones of the frontal ganglion. The corpora allata are connected to the corpora cardiaca by a pair of nerves, NCA 1 and to the suboesophageal ganglion by another pair NCA 2. Neurosecretory material was not observed in either the glands or their associated nerves. Similarities and differences between the neuroendocrine complex of Jamaica flava and that of other species are discussed.