SENSORY ORGANS ON THE BODY PARTS OF THE BED-BUG CIMEX HEMIPTERUS FABRICIUS (HEMIPTERA, CIMICIDAE) AND THE ANATOMY OF ITS CENTRAL-NERVOUS-SYSTEM

Anatomy of the sensory organs on the prominent body parts of the adult bed-bug Cimex hemipterus (Hemiptera: Cimicidae) and its central nervo us system (CNS) was studied by light, transmission, or scanning electr on microscopy. The distal tips of antenna and rostrum were found to ha ve rich complements of sensilla. The antenna has both olfactory and gu statory sensilla. Olfactory sensilla project to the antennal lobe orga nized in the form of glomeruli, while the 2nd component, presumably fr om gustatory sensilla, projects to the suboesophageal ganglion. The ul trastructure of the sensory pegs on the rostrum of C. hemipterus does not resemble the chemosensilla of adult insects; rather they resemble the larval sensilla of Drosophila melanogaster in the maxillary organ. Earlier we believed this to be a gustatory organ. A few similar sensi lla also occur on the antenna, indicating its multimodal role. Amongst the 3 types of sensory hairs located on legs, there are only a few gu statory hairs (7-10 hairs) on the tibia. The pointed and serrate mecha nosensory hair types occur in abundance; the serrate type are prominen tly present on the lateral surface of the legs. On other parts of the body such as the thorax or abdomen, serrate hairs are most abundant. B oth the distal segment of antenna and rostrum are invested by 2 nerves , where the axon counts of the 2 antennal nerves are 380 and 425, whil e each rostral nerve on average has 205 axons. Abundant clusters of mi crotubules were found in the brain, thoracio-abdominal ganglia, leg-ne rves, and the space between muscles and cuticle. These conspicuous mic rotubule-clusters occur in interaxonal space, mainly glial cells, in t he nervous system. In addition, the glial cells have osmiophilic junct ions amongst themselves. A novel ''hinge and joint'' system, which con trols the cross-section of the food canal and the salivary duct in an inversely related manner, was found in the rostrum of the bed-bug. Cop yright (C) 1996 Published by Elsevier Science Ltd.