Comparative Ultrastructure of the Trifoliate process of some species of Atberigona (Diptera : Muscidae)
M. C. DIKE
Description is given of the ultrastructure of the trifoliate processes of three species of Atherigona, A. albistyla Deeming, J.L, A. dimaculata Stein and A. longifolia Emden. The ultrastructure of the three species is compared with known information on eleven other species. Three groups are identified. The first and simplest group comprises two species, A. dimaculata and A. tomentigera Emden with simple surface microsculpture. The second group is made up of five species: A. albistyla, A. conigera Emden, A. longifolia, A. pallidipleura Deemlng and A. soccata Rondani. In this latter group the lateral lobe of the trifoliate process possesses a dense mat of hairs or: the outer surface and bears rim sensilla but lacks commasets. The third and most structurally complex group consists of A. bedfordi Emden, A. hyalinipennis Emden, A. lineata (Adams), A. matilei Deeming,
A. ponti Deerru.nq, A. secrecauda seguy and A. steeleae Emden. They have the dense mat of halrs, rim sensilla and commasets on the lateral lobe of the process as well as a bilobed hypopygial prominence.