SEM structure of mandibular sensilla in the carpenter ant, Camponotus compressus (Fabricius) (Formicidae: Hymenoptera) Deepak D. Barsagade # , Dnyaneshwar B. Tembhare and Seema G. Kadu Department of Zoology, RTM Nagpur University, Nagpur India-440033. ( # email: dr_ddbars @ rediffmail. com) Abstract The moutparts in all polymorphic forms of carpenter ant, Camponotus compressus (Fabricius) (Hymenoptera: Formicidae) are adapted for grasping and feeding the prey. The mandibles are unsegmented, strongly sclerotized, large, shovel like, cuticular and powerful structures. The mandibles consist of dorsal sensilla trichoidea DT-I, DT -II and DT-III and on the ventral side VT-I, VT- II and the Sensilla basiconica VB in female and workers, while similar type of sensilla are found in male except sensilla basiconica. Each mandible consists of four incisor and three molar teeth in female and workers while only two incisor teeth are present in male. Keywords: Camponotus compressus, SEM, Mandible, Sensilla. Introduction In most of the ant species, the mouthparts are adapted for grasping and feeding the prey (Snodgrass, 1935; Dumpert, 1972; Richard and Davies, 1987; Chapman, 1982,1998 ). Paul et al. (2002) reported that the receptors of taste are situated in the lower pair of jaws in the ants which distinguish different flavors of sweets and aromatic liquids. Galewski (1971) reported small peg-like sensilla on the dorsal surface of mandible in water beetle, Dytiscus arew. Mayhe-Nunes and Lanziotti (1995, 2002) reported the presence of seven teeth in female and workers while only two in male on the mandibles of ant, Mycetarotes carinatus suggesting sexual dimorphism. In the adult ants the mouth parts are equipped with mechano and chemoreceptors (Gotwald, 1969; Wheeler and Wheeler, 1970; Paul, 2001; Paul et al., 2002).The present work therefore,has been undertaken to explore the surface ultrastruture of mandibles and different types of sensillae present on it in all polymorphic form of the carpenter ant, Componotus compressus. Materials and Methods The carpenter ant, Camponotus compressus colony was excavated from the semidried soil and the mandibles were removed carefully from polymorphs and fixed in 70% alcohol for 12 hours. The dehydrated mandibles were transferred to cold acetone, dried at room temperature, mounted on the carbon coated metallic stubs at different angles and proceeded for platinum coating in the Poloron gold coating automatic unit separately. Finally, the manibles were scanned under Jeol (JSM 6380 A) scanning electron microscope (SEM) at desirable magnification at the Instrumentation Centre of Vishveshvaraya National Institute of Technology (VNIT) Nagpur, India. Results In the carpenter ant, Camponotus compressus the mandibles are unsegmented, strongly sclerotized, large and shovel like cuticular mouth parts bearing strong basal three molar and Halteres, Vol.1, No.2, 2010 53