Abai, MR

6th International Congress of DipterologyMaxillary palpal sensilla of the lower Diptera with anemphasis on the intrafamiliar variation within theTipuloidea (Diptera)Petersen, M.J.Department of Entomology, Iowa State University, Ames, IA 50010Email: mp13@iastate.eduScanning electron microscopy was used to examine the externalmorphological structure and variation in composition of the sensillalocated on the apex of the larval maxillary palpus of Tipuloidea genera.The palpal sensilla of other lower Diptera families (Axymyiidae,Blephariceridae, Chironomidae, Ptychopteridae, Scatopsidae, Sciaridae,Simuliidae Tanyderidae, and Trichoceridae) were studied to aid indetermining homologies between individual sensilla. The numbers ofsensilla on each palpus were variable, ranging from 5-14. Fivepredominant sensilla (E 1 , E 2 , A 1 , A 2 , and A 3 ) were observed on allTipuloidea genera and could be homologized with those in other lowerDiptera. The sensilla of the maxillary palpus were typically arranged in asingle cluster for out-group Diptera and for the majority of Tipuloideagenera. The families Scatopsidae and Chironomidae, and the Tipuloideagenera Gonomyia Meigen, Hexatoma Latreille, Pilaria Sintenis, andDicranota Zetterstedt showed a split in the palpal sensilla cluster, onecontaining E 1 and A 1 , and one with E 2 , A 2 , and A 3 . The split in Tipuloideagenera was associated with an elongation or enlargement of the maxillarypalpus and is thought to be an adaptation to predatory feeding behavior.Key Words: Diptera, Tipuloidea, sensory receptors, maxillary palpus,crane fly∗∗∗∗∗∗∗∗∗∗193