FOREGUT MICROSPINES IN 4 FAMILIES OF COCKROACHES (BLATTARIA)

The microspines of the cockroach foregut were investigated in order to determine their fine structure, variation, patterns of distribution, and possible functions. The following were studied: Blaberidae (4 species), Blatellidae (3 species), Blattidae (2 species), and Cryptocercidae (one species). Elongate microspines (over 30 mum), usually several attached to a basal plate. were found in the buccal cavity and anterior and posterior pharynx of blaberids and blattids, whereas moderate (15-20 mum) to short (1-5 mum) miscrospines were found in 2 regions in the blattellid and cryptocercid cockroaches. Short microspines (1-5 mum) individually attached to a basal plate occurred in the esophagus, crop, proventriculus and stomodeal valve regions in all families studied. Microspines appear to be useful in understanding systematics and evolution of cockroaches. The possible role of elongate microspines in retaining food particles during regurgitation behavior is postulated.