Nothybidae

McAlpine, David, 2011, Observations on Antennal Morphology in Diptera, with Particular Reference to the Articular Surfaces between Segments 2 and 3 in the Cyclorrhapha, Records of the Australian Museum 63 (2), pp. 113-166 : 149

The Nothybidae and Gobryidae

These two families were referred to the superfamily Diopsoidea by D. McAlpine (1997), and each is only known from its type genus (respectively Nothybus and Gobrya ). They show agreement in many aspects of antennal morphology ( Figs 117–121 ).

The rim of segment 2 is developed into a pair of large hood-like lobes (approximately as in Ephydroidea and other groups), but the distal articular surface, though concave, has no defined cup containing the annular ridge and foramen; the conus is reduced to a low but distinct prominence on the medial side of the foramen, but is obsolete on the lateral side, and as a result the irregularly and asymmetrically developed annular ridge and the foramen face laterally; there are no caesti. Segment 3 ( Figs 117, 118 ) has the strongly produced basal stem bilaterally compressed, and the basal foramen on its medial surface faces medially in Nothybus , ventromedially in Gobrya ; the medial surface of the basal stem has a scabrous zone which extends into the small sub-basal caecum near where the basal stem adjoins the disc of the segment. Segments 4 and 5 of the arista are short but separately sclerotized in Nothybus , absent in Gobrya ; in both groups the arista arises dorsally on segment 3, instead of in the usual dorsolateral position.

Figures

Figures 112–118. (112) Chyliza sp. (Imbia, P.N.G.; fam. Psilidae), left antennal seg. 2, distal view, seg. 3 removed. (113) The same, annular ridge and associated parts within pedicellar cup. (114) Syringogaster sp. (Costa Rica; fam. Syringogastridae), left antennal seg. 2, distal view. (115) Chyliza sp., left antennal seg. 3, medial view. (116) Syringogaster sp. left antennal seg. 3, lateral view. (117) Nothybus decorus de Meijere (fam. Nothybidae), left antennal seg. 3, medial view. (118) Gobrya cyanea (Enderlein) (fam. Gobryidae), the same. a6, antennal seg. 6; as, abraded surface; bf, basal foramen; bs, basal stem; ca, caestus; cu, pedicellar cup; pc, pedicellar cleft; r, dorsal lobes of rim; sbc, sub-basal caecum; sc, sacculus; st, scabrous tongue.

Figures 119–121.Antennae of Nothybidae and Gobryidae.(119) Nothybus decorus de Meijere, left seg.2, distolateral view, seg. 3 removed. (120) Gobrya cyanea (Enderlein), right seg. 2, distolateral view, seg. 3 removed. (121) The same, detail of conus and adjacent parts. bu, pedicellar button; c, medial prominence of reduced conus.