CUTICULAR STRUCTURES ON THE ANTENNAE OF HYPODERMA-BOVIS DEGEER (DIPTERA, OESTRIDAE) FEMALES

The antennae of Hypoderma bovis (Diptera:Oestridae) females were exami ned using scanning electron microscopy. Each antenna is composed of 3 parts: the scape, the pedicel, and the funiculus, with a large, protru ding arista. Mechanoreceptors are found on the proximal and lateral ma rgins of the scape and pedicel, respectively. Microtrichia, which are presumably non-innervated, are located evenly over both the outer surf ace of the scape and the inner surface of the pedicel. A narrow band o f microtrichia is present proximally on the outer surface of the pedic el. The entire funicular surface is densely covered with microtrichia. Small patches lacking these microtrichia appear as depressions or ''p its'' (8-20 mu m in diameter) on the surface of the funiculus. Olfacto ry sensilla found on the funicular surface include basiconica type 1, basiconica type 2, and trichoid sensilla. The sensilla basiconica comm only occur in pits on the anterodorsal surface of the funiculus. Trich oid sensilla are abundant on the posteroventral surface of the funicul us and do not appear to occur in pits. In addition, clavate and peg se nsilla, whose functions are unknown, are found in low numbers on the f unicular surface. There may be as many as 300 olfactory pits on the an terodorsal surface of each funiculus. These are single-chambered and c ontain 6 or fewer sensilla basiconica. We propose that a relatively hi gh number of pits may be characteristic of flies in Superfamily Oestro idea (as compared with those of Superfamily Muscoidea), but that pit m orphology within the Calyptratae is not Superfamily-specific. Copyrigh t (C) 1996 Elsevier Science Ltd.