The Australian Sciapodinae (Diptera: Dolichopodidae), with a review of the Oriental and Australasian faunas, and a world conspectus of the subfamily
Abstract
The Sciapodinae (Diptera: Dolichopodidae) of Australia (including Lord Howe, Norfolk, Cocos-Keeling and Christmas Islands) are treated in detail, and 253 species, 208 newly described, are illustrated and keyed. All described Oriental and extralimital Australasian species are critically reviewed, with notes on diagnostic characters, distribution and generic placement, along with many new combinations and synonymies and some keys. Further, the taxonomy of the subfamily is considered at world level, with redefinition and rearrangement of genera and nomenclatural changes for taxa from all regions. The systematic position of the subfamily is discussed and a preliminary phylogenetic analysis presented. The biogeography and natural history of the Australian fauna are treated in detail. Nine new genera are erected, Dytomyia, Negrobovia, Narrabeenia, Abbemyia, Pseudoparentia and Pilbara from Australasia, Mascaromyia and Ethiosciapus from the Afrotropical Region, and Amesorhaga from the Orient. Genera incorrectly referred to the Sciapodinae are discussed.
The Sciapodinae show extensive parallel evolution, and almost all diagnostic generic-level characters have evolved independently many times. Historically, this has led to uncertain generic limits and a complicated nomenclatural history. Genera are redefined on a polythetic basis, no character in isolation necessarily being diagnostic for all members.
Male secondary sexual characters (MSSC) are reviewed. In some species the female phenotype shows weakened expression of MSSC. A model is presented whereby MSSC could be incorporated into the phenotype of both sexes and thereby become 'higher level' taxonomic characters.
The Australian fauna is analysed in detail, with discussions of historical and ecological biogeography. The genera Parentia and Heteropsilopus display classical Bassian distribution patterns and have ties with other southern lands, New Zealand/New Caledonia and India, respectively. The disjunction of Heteropsilopus in Australia and southern India suggests a widespread eastern Gondwanan distribution dating from the lower Cretaceous. No direct relationship with the Neotropics is evident. Australian Nothofagus rainforests are devoid of Sciapodinae, in contrast to such forests in New Zealand. A Torresian fauna of Oriental-Papuan affinity dominates the northern tropics, and has penetrated southwards along the east coast in association with tropical and subtropical rainforest. The major southern limit of Torresian taxa coincides with the southern limit of subtropical rainforest in New South Wales. Lowland Papuan species occur on Cape York Peninsula and across monsoonal northern Australia. In contrast to eastern Australia, the aridity of Western Australia prevented southward movement of tropical elements, and the Southwest maintains only a Bassian fauna. The faunas of Norfolk and Lord Howe Islands are of Australian origin, while those of Christmas and Cocos-Keeling Islands are of Greater Sunda origin.
The faunas of all major zoogeographic regions are reviewed, with emphasis on Australasia and the Orient. Widespread and accidentally introduced species are discussed. Fossil amber Sciapodinae are treated, including new information on Dominican Republic material. The subfamily is most diverse on the Gondwana continents, where it undoubtedly arose. The possible sister group relationship with the predominately Laurasian subfamily Dolichopodinae is discussed. Vicariant distributions between Australia and India, Australia and New Zealand, and Africa and South America support a early Cretaceous origin and radiation for the Sciapodinae.
The tribe Mesorhagini is established with three genera. Amesorhaga n.gen. contains seven Oriental species and is considered the most primitive sciapodine genus. Negrobovia n.gen., from eastern and northern Australia, comprises three species, two of them new. The genus Mesorhaga Schiner is redefined and its distinctive morphology reviewed. The Australian fauna comprises 36 species, 35 new. The tribe Sciapodini is established and with the genera Sciapus Zeller, Mascaromyia n.gen., Helixocerus Lamb, Naufraga Bickel, Dytomyia n.gen., Narrabeenia, n.gen., Pilbara n.gen. and Condylostylus Bigot. Sciapus is greatly restricted in definition and comprises about 65 Holarctic species. The genera Psilopiella Van Duzee, Agastoplax Enderlein, Dactylodiscia Enderlein, Dactylorhipis Enderlein and Placantichir Enderlein are newly placed in synonymy with Sciapus. Many species previously placed in Sciapus are newly referred to other genera. Mascaromyia includes 15 described species from the western Indian Ocean. Helixocerus occurs on Samoa and New Caledonia. Naufraga is known only from New Zealand. Dytomyia is found primarily Australian sclerophyll habitats and comprises five species, four newly described. Narrabeenia is found on the southern Australian coast and comprises two species, one newly described. The genus Pilbara has a single new species, P. octava, from north-western Australia. Condylostylus comprises some 300 species in the Neotropics, Afrotropics and Orient. The New World C. longicornis is recorded from French Polynesia. Neotropical species incorrectly regarded as Chryososma are given new combinations. The Oriental and eastern Palearctic species are keyed. The genus Eurostomerus Bigot, based on a nomen nudum, is made a synonymy of Condylostylus.
The tribe Chrysosmatini is defined and includes ten genera - Parentia Hardy, Pseudoparentia n.gen., Krakatauia Enderlein, Heteropsilopus Bigot, Chrysosoma Guerin-Meneville, Abbemyia, n.gen., Ethiosciapus, n.gen., Plagiozopelma Enderlein, Austrosciapus n.gen. and Amblypsilopus Bigot. Parentia has a temperate distribution in southern Australia, New Zealand and New Caledonia. The Australian fauna, comprising 26 species (21 new), is found mostly in drier habitats. Pseudoparentia, comprises five new species from interior Australia. Krakatauia comprises nine Australian species (8 newly described) in the evulgata, funeralis, alanae and trustorum Groups. The Oriental anthracoides Group is defined. Heteropsilopus comprises three Groups: the trilagatus Group from southern India and Sri Lanka, and the cingulipes and brevicornis Groups with a Bassian distribution in Australia, comprising 17 species, ten newly described. Chrysosoma is redefined. The apical arista, previously used as the key generic character, is shown to have been derived many times within the Sciapodinae. The genus is confined to the Old World tropics and is especially rich in the Australasian and Oriental tropics. The Australian fauna comprises 11 species, two newly described. The genus Megistostylus is placed in synonymy with Chrysosoma, and C. crinicorne replaces M. longicornis as the name for the common Oriental-Australasian species noted for its remarkable male antenna. The Afrotropical Kalocheta Becker is also placed in synonymy with Chrysosoma. The leucopogon and proliciens Groups are rich in Australasia and Sundaland. The common tramp species, C. leucopogon, ranges from eastern Africa to Polynesia, including many isolated islands. The Oriental vittatum Group, the Papuan aeneum, arrogans, lucigena and antennatum Groups, the New Caledonian noumeanum Group, the Pacific lacteimicans Group, and the Afrotropical passiva, senegalense and gemmarium Groups are defined. The genus Abbemyia occurs in Australasia and includes two Australian species, one newly described. Ethiosciapus occurs in Africa and the islands of the western Indian Ocean. Plagiozopelma includes many species previously regarded as Chrysosoma. The genus occurs widely across the Old World tropics but is richest in the Orient. The Australian fauna comprises six species, four newly described. The flavipodex Group occurs across the Orient and Australasia, and includes the widespread P. flavipodex. The alliciens and annotatum Groups are Oriental, the terminiferum and angustifacies Groups Australasian, and the bequaerti Group Afrotropical. The new genus Austrosciapus comprises 42 Australian species, 35 newly described. The proximus Group is eastern Australian, although A. connexus appears to have been introduced to various Pacific islands and Perth, WA, and A. proximus was introduced to New Zealand. The tumidus Group, sarinensis Group, muelleri Group, dendrohalma Group (found on eucalypt trunks), and storeyi Group, all occur in eastern Australia, while the hollowayi Group is known from Western Australia. Amblypsilopus is given new status and includes many species previously regarded as Sciapus. New combinations and synonymies are presented from all zoogeographic regions. The genera Australiola, Labeneura, Sciopolina and Leptorhethum are new synonyms of Amblypsilopus. The genus has 87 Australian species, 78 newly described. The triscuticatus, pallidicornis and flaviappendiculatus Groups are found throughout the tropical Orient and Australasia. The zonatus Group, from Australia and Norfolk and Lord Howe Islands, often has strikingly modified male wings. The argyrodendron, bertiensis, topendensis, cyplus and trogon Groups are northern Australian, while the anomalicornis and glaciunguis, neoplatypus and rimbija Groups occur in Australia and New Guinea. The abruptus Group is found across the Old World tropics.
