RESUMO -Um novo gênero e espécie de grilo falangopsídeo Adelosgryllus rubricephalus é descrito. Ilustrações de espécimes macho e fêmea e a descrição dos escleritos fálicos, assim como os cromossomos e a distribuição geográfica conhecida são relatados. Uma discussão sobre a posição taxonômica desse grilo dentro da família Phalangopsidae é incluída.PALAVRAS-CHAVE: Grylloidea, morfologia, esclerito fálico, cromossomo ABSTRACT -Adelosgryllus rubricephalus, a new genus and species of phalangopsid cricket are described. Illustrations of male and female specimens as well as descriptions of phallic sclerites, chromosomes and geographical known distribution are furnished. A discussion on the species taxonomic status of this cricket within the family is also included.KEY WORDS: Grylloidea, morphology, phallic sclerite, chromosome During the last twenty years few more than twenty specimens of this elusive species were obtained. Some of them were collected as nymphs and completed their development in the laboratory, though some of them died before reaching the adult stage. The species was found throughout a wide brazilian territory, including the states of São Paulo, Paraná and Goiás. A single nymph specimen was observed, but not collected, far north in the Federal University, Campus in Recife, Pernambuco State. They occur in diverse habitats from "cerrado" to forest vegetation and also in urban areas, always close to the ground among leaf litter, sometimes hiding within on under rotten wood or walking in the foliage during day time. With its black body, red head, the first milimeters of the antenna flagellum black, followed by a white segment and finishing dark again, it seems to be mimicring an ant or a wasp.
Material and MethodsMeiotic stages were studied in male testes fixed in Carnoy I followed by acetic aqueous solution 40% treatment during few minutes to separate the cells. Suspension was then centrifugated to aprox. 1200 r/m and the supernatant medium discarded for post fixing of the residues in Carnoy I. The centrifugation and change of fixative was repeated three times and finally the suspended cells were dropped in a hot slide until drying. The staining was done with 1% lactoacetic orcein.
ResultsGeneric Characters. Ocelli absent. Males with tegmen covering approximately half the abdomen (Fig. 1) with Cu 2 vein provided with pars stridens (Fig. 2b). Lateral field of the tegmen with three branching veins (Fig 2b). Mirror divided by two veins. Female tegmina (Fig. 3) in the the majority of specimens as short triangular pads, not touching in the middle line. In some specimens the tegmina are well developed, covering most of the abdomen. In both sexes, wing in general absent, but in some specimens they are fully developed. Legs moderately short. Cephalic tibiae with an oval auditory foramina on the internal face only. Dorsal edge of the hind tibiae armed with four internal and three external movable spines, and without denticles along its whole length. The apical three external spine (Fig. 2c) are smaller than the th...