Atherimorpha White

Kerr, Peter H., 2010, 2592, Zootaxa 2592, pp. 1-133 : 82-84

Genus Atherimorpha White

Figs. 7–8, 46–47, 71, 92, 118, 129, 139.

Atherimorpha White 1915: 41 . Type species Atherimorpha vernalis White 1915 , by monotypy.

Bicalcar Lindner 1923: 4 . Type species Chrysopila obscuripennis (Loew) 1873 , by monotypy [misidentification = Atherimorpha ].

Therevirhagio Lindner 1925: 20 . Type species Therevirhagio setosiradiatus Lindner 1925 , by monotypy.

Philippoleptis Malloch 1931: 276 (as subgenus). Type species Leptis praefica Philippi 1865 , by original designation.

Aritherimorpha Nagatomi 1982a: 44 (lapsus).

Neorhagio Lindner 1924: 75 . Type species Leptis setosa Philippi 1865 , by monotypy. New Synonymy.

Diagnosis. The distinctive form of the antenna may provide evidence for the monophyly of the species of Atherimorpha . While the first flagellomere may vary in shape (from subglobose to onion-shaped to conical) and the total number of flagellomeres may also vary (3 to 7), the first flagellomere is always enlarged compared to the other flagellomeres, which are narrow and rod-like in form. Species of the genus Atherimorpha are small to moderately sized (4.4 to 11.4 mm) flies of coloration that varies from entirely gray or black and gray (as all Australian members of this genus) to brown, brown and yellow, entirely yellow, or orangish. Eyes in male holoptic or dichoptic, laterotergite setose, tibial spur formula 0:2:2, macrochaetae present on hind tibiae, and M 3 present.

Atherimorpha are very Rhagio -like in form and behavior, but can be distinguished from this genus by the antenna, which has 3–7 flagellomeres, and by having two-segmented palpus. Species of Atherimorpha are most similar to Arthroteles in the form of the antenna, but differ in that the first flagellomere is larger in comparison to the other flagellomeres and the remaining flagellomeres are narrower. Atherimorpha species may be distinguished immediately from Arthroteles by their short, fleshy proboscis. Atherimorpha are distributed in South America, South Africa, and Australia. Among these faunas, South America is the richest in terms of species number and morphological form and color, although many remain undescribed.

Description. Head. Clypeus bulbous. Scape approximately same size as pedicel or clearly larger than pedicel (as in A. albohirta and A. praefica ). Flagellomeres 3 to 7; first flagellomere clearly larger than other flagellomeres, round in cross section or laterally compressed; round, conical, subglobose to globose, or fusiform; terminal flagellomere more elongate than other cylindrical flagellomeres. Eyes inconspicuously setulose; in female, dichoptic; in male, holoptic or dichoptic, not flattened dorsally, ommatidia evenly distributed, of equal size. Labella with pseudotracheae, longer or shorter than palpus. Theca short and stout, lateral theca sclerites adjacent and touching, but mostly separated. Palpus two-segmented; distal segment longer than proximal segment. Stipes surrounded by membrane above theca, directed posteriorly. Cardo not swollen. Lacinia shorter than palpus, tip not serrated. Mandibles absent. Cibarial pump long, clearly not as wide as long. Cornu shorter than cibarial pump. Pharyngeal pump narrow along most of length, mostly flat along its length, approximately same length as cibarial pump.

Thorax. Mesonotum with vittae. Dorsocentral bristles present or absent. Anepisternum bare. Laterotergite setose, in row(s), mostly on ventral half (katatergite). Postspiracular scale absent. Proscutellum absent. Subscutellum not enlarged nor lengthened; inconspicuous. Wing hyaline or lightly to darkly infuscate; without markings. Pterostigma present or absent. Lower calypter reduced. Upper calypter well developed, with reduced curvature, width more than twice length. Costa extends to wing tip (between R 4 and R 5). Humeral crossvein well developed. Sc-r crossvein weakly developed, positioned distal to h by less than length of h, by approximate length of h, or by more than length of h. Dorsal side of R 1 setulose, ventral side with or without setulae. Other wing veins and cells variously setulose or bare. R 2+3 sinuous, apical third of R 2+3 ultimately bends anteriorly slightly, toward wing tip. Length of R 2+3 longer than R 5, but less than twice as long. Base of R 4 –R 5 fork proximal or directly above distal end of cell dm. R 4 at base strongly curved or angled, nearly straight apically. R 4 and R 5 contain wing tip. R 5 aligned with R 4+5. R 5 clearly longer than R 4+5 (r-m to R 4 origin). Origin of CuA 1 at cell bm. M 3 present. Cell m 3 parallel-sided at margin. CuA 2 greater than 2/3 length of posterior vein of cell bm. Alula with narrow or broad curvature, rounded evenly. Anal lobe well developed. Cell cu p open or closed. Halter knob between 1/2–2/3 length of stem. Tibial spur formula 0:2:2. Hind coxal tubercle absent. Hind tibial macrochaetae enlarged. First hind metatarsus of male not swollen. Postmetacoxal bridge absent.

Abdomen. Terminal abdominal segments 5–10 evenly tapered from segments 1–4. In female, tergite 7 about as long as wide, intersegmental membrane between segments 7 and 8 especially long, sternite 8 length wider than long or as wide as long (triangular, ovoid, or nearly square). Male terminalia with epandrium simple, not containing hypandrium ventrally. Epandrium usually wider than long (longer than wide in A. albohirta and A. praefica ), strongly notched anteriorly. Tergite 10 absent. Hypoproct margins entire, setose. Cercus base held underneath epandrium. Cerci directly adjacent to one another, separation distance one quarter width of cercus or less, held horizontal or at angle in relation to rest of abdomen; in posterior view, flat. Hypandrium separated from gonocoxites by complete suture. Gonocoxite with sinuous dorsal ridge, leading to gonocoxal apodeme. Gonocoxal apodemes short or long enough to reach anterior margin of hypandrium. Sperm sac bulbous, with shallowly paired swellings ventrally. Lateral ejaculatory processes present, not part of sperm sac posteriorly. Ejaculatory apodeme moderately long, reaching anterior margin of hypandrium, laterally compressed. Aedeagal tines absent. Endoaedeagal process present. Female terminalia with three spermathecae, swollen, not sclerotized. Spermathecal ducts no more than three times length of sternite 9, not inflated at base of spermathecae. Spermathecal duct accessory glands absent. Spermathecal ducts near junction thickened, but not sclerotized, without surface furrows. Spermathecal duct junction thickened. Common spermathecal duct thickened, subequal in length to longest diameter of genital chamber. Genital chamber oval, moderately sized. Accessory gland posterior to genital chamber inconspicuous, easily overlooked even after staining. Sternite 9 anterior end pointed, posterior end with broad lateral extensions that meet medially, in vertical plane. Tergite 10 entire. Sternite 10 roughly rectangular, posterior half below first cercal segment. Cercus two-segmented. First segment of cercus not elongate, with ventral process. Ventral lobes of first segment of cercus not curving ventrally towards one another to form ring. Basal cercal segment adjacent dorsally. Second cercal segment not elongated. Cercus with apical sensory pits.

Larva. Unknown.

Biology. In South America, Atherimorpha is principally associated with Nothofagus -dominated woodlands, although a few species of Atherimorpha are found in arid and scrubby habitats to the north of Santiago and in Brazil where Nothofagus does not occur ( Malloch 1932b). In Australia, Atherimorpha species may inhabit dense scrub and or wet montane forests (sometimes in association with an Australian species of Nothofagus ). Few notes are available on the biology of South African Atherimorpha , but records show that they are also mostly collected in mountainous regions. In all habitats, it appears that Atherimorpha species gravitate towards small, slow moving streams, which presumably provide moist soil substrate for their larval development.

Atherimorpha is distributed in a typical Gondwanan fashion, found in Australia, Patagonia, and South Africa.

Literature. A revision of the African fauna, including a key to species, is given by Nagatomi & Nagatomi (1990c). Malloch (1932b) gives a key to the Neotropical species. Paramonov (1962) treats the Australian species and provides a key.

Notes. The original concept of Neorhagio Lindner has remained unresolved because the specimen that Lindner identified as Leptis setosa Philippi , the type species he designated for the genus, is lost. However, I concur with J. R. Malloch (1932b: 206) who determined on the basis of his own knowledge of the Chilean fauna and on the basis of Philippi’s original descriptions, that all of Philippi’s species described in the genus Leptis belong to Atherimorpha . A specimen in the AMNH collection bears on old determination label reading Atherimorpha setosa Philippi. “Angol – Chile, 12 Ocbre 1933, J Salazar / Atherimorpha setosa Phil. / USNMENT00025130.” I designate this specimen as the neotype of Leptis setosa Philippi , in the interests of a stable taxonomy. This species is a junior synonym of Atherimorpha praefica Philippi , new synonymy.