Redescription of the genus Diopsosoma Malloch (Diptera, Periscelididae)

Abstract

RESUMO.Redescrição do gênero Diopsosoma Malloch (Diptera, Periscelididae). Diopsosoma Malloch, 1932 e sua única espécie conhecida, D. primum Malloch, 1932 são redescritos. O gênero, embora facilmente reconhecível pela cabeça projetada lateralmente em pedúnculos oculares, é praticamente desconhecido. Por isso, apresenta-se sua redescrição em conjunto com breves redescrições de Periscelididae e da subfamília Periscelidinae. Chave para os gêneros de Periscelididae e fotomontagem do holótipo, talvez o único exemplar preservado da espécie, são fornecidas.PALAVRAS-CHAVE. Diopsosoma primum; Diptera; Neotropical; Periscelididae.ABSTRACT. Diopsosoma Malloch, 1932 and its only included species, D. primum Malloch, 1932 are redescribed. While the genus is remarkable and easily recognized by its laterally elongate head that is produced into eyestalks, it is otherwise virtually unknown. To bring attention to this extraordinary fly we redescribe it within the context of brief descriptions of the family Periscelididae and subfamily Periscelidinae. We also provide an annotated key to the described genera of Periscelididae and a photographic montage of the holotype, which is perhaps the only preserved specimen of this genus and species.

A revision of the genus Planinasus Cresson (Diptera, Periscelididae)

“… Baptista and Mathis (1994) questioned the monophyly of Stenomicrinae and presented evidence that Planinasus might be more closely related to Periscelidinae . Griffiths (1972) considered Diopsosoma Malloch (see also Mathis and Rung 2004 ) and the small Neotropical genus Somatia Schiner (tentatively in a separate subfamily, the Somatiinae ) to belong in the Periscelididae . Although Mathis and Papp (1992) and Grimaldi and Mathis (1993) questioned the placement of Diopsosoma in the Periscelididae , Mathis and Rung (2004) presented five synapomorphies that confirm its inclusion.…”

“… Griffiths (1972) considered Diopsosoma Malloch (see also Mathis and Rung 2004 ) and the small Neotropical genus Somatia Schiner (tentatively in a separate subfamily, the Somatiinae ) to belong in the Periscelididae . Although Mathis and Papp (1992) and Grimaldi and Mathis (1993) questioned the placement of Diopsosoma in the Periscelididae , Mathis and Rung (2004) presented five synapomorphies that confirm its inclusion. Mathis (1993) considered Somatia as closely related to the Psilidae ( Diopsoinea ), while D. K. McAlpine (1997) treated Somatiidae (monotypic) as incertae sedis .…”

Survey of the families Anthomyzidae, Aulacigastridae, Odoniidae, Periscelididae, and Trichoceridae (Insecta: Diptera)

“…Hyaline or infusate wing, absent costal break and incomplete subcostas, costal vein reaching the vein or not M1, dm cell with a shallow longitudinal fold (Periscelidinae), cup cell generally present and well-developed or reduced CuA2 vein; middle tibia with an apicoventral bristle; male pre-abdomen composed of six segments, symmetrical or asymmetrical post-abdomen, developed or inconspicuous surstyle, articulated or fused with epandrium, cerci weakly sclerotized; Female abdomen with 2 tergite and sternites, seven separate or fused, forming a complete ring. The main characteristic of the family is a pedicel similar to a hood with a dorsal slit, however, this characteristic also occurs in Neurochaetidae and other genera of Acalyptratae [41][42][43].…”

Hennig’s orphans revisited: Testing morphological hypotheses in the “Opomyzoidea” (Diptera: Schizophora)

“…Genera have been transferred between these two families and sometimes transferred to seemingly distantly-related groups. Periscelididae sensu stricto (containing Diopsosoma Malloch, Marbenia Malloch, Neoscutops Malloch, Parascutops Mathis and Papp, Periscelis Loew, and Scutops Coquillett), and Aulacigastridae sensu stricto (containing Aulacigaster Macquart and Curiosimusca Rung, Mathis, and Papp) are generally recognized as monophyletic units supported by a handful of putative synapomorphies (see Mathis and Rung, 2004;Rung et al, 2005). The debate has largely centered on the position of Stenomicra Coquillett, Cyamops Melander, and Planinasus Cresson, comprising the subfamily Stenomicrinae (Mathis and Papp, 1992;Mathis, in press).…”

“…Neminidae, dubbed ''nobody flies" by their discoverer (Latin nemo = ''nobody"; McAlpine, 1983McAlpine, , 1998, are now known from southern Africa, Australia, and New Guinea, but have been very rarely collected, and nothing is known about their biology. Although easily recognized by the laterally elongate head produced into eyestalks (Mathis and Rung, 2004), the bizarre periscelidid genus Diopsosoma, with only one included species, D. primum Malloch, is still known only from the type series collected in Peru in 1931 (Mathis and Rung, 2004). Some opomyzoid taxa are restricted to very specific microhabitats (such as sap fluxes of wounded trees or phytotelmata on specific plant species) and are thus infrequently encountered.…”