Allometopon striatum McAlpine 1960
Creators: name: Owen Lonsdale
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Clusiidae
Allometopon
Allometopon striatum

description: Allometopon striatum McAlpine, 1960
Figs 258–263, 344
Allometopon striatum McAlpine 1960: 87. Pitkin & Evenhuis 1989: 535 [catalogue, Australasia/Pacific].
Description. General: (Figs 258–260) Body length 3.4–4.8mm. Arista short plumose. M1+2 ratio 2.3. Clypeus broad and thick. First flagellomere ovate, slightly expanded dorsally and more obviously enlarged and lobate ventrally.
Chaetotaxy: Three fronto-orbital setae, slightly decreasing in length anteriorly; sometimes with small fourth fronto-orbital anteriorly, up to ½ length of next fronto-orbital. Ocellar seta twice length of tubercle. Postvertical seta small to minute (not larger than ocellar seta). Interfrontal seta minute. Marginal hairs on first flagellomere longer than width of base of arista. Anterior dorsocentral seta half length of posterior dorsocentral (closely set posteriorly). Acrostichal seta well-developed. Anterior lateral scutellar seta small.
Colour—male: Setae brown to yellowish. Head mostly yellow, whitish below antenna; first flagellomere light yellow to whitish below point of pedicel, dark brown above (sometimes anterior margin also light yellow if pigment faded); ocellar tubercle dark brown; clypeus dark yellow in some males; back of head with one pair of dark stripes radiating from foramen sometimes fused basally; gena, parafacial and postgena silvery tomentose. Scutum with pattern relatively variable and usually ill-defined—yellow with lateral ¼ light brown, widening to 1/3 anteriorly (sometimes indistinct), with pigment faded or distinct (as in holotype) and venter of postpronotum whitish; one short, faded (sometimes indistinct), apically split, dark yellow to brownish stripe within dorsocentral rows posteriorly (Fig. 259); if pigment relatively dark, medial scutal stripe sometimes narrow and extending to anterior margin, essentially making scutum light brown with one pair of yellow sublateral stripes not reaching anterior or posterior margins (Fig. 258); scutum sometimes entirely brownish to brown centrally, eliminating yellow markings; if anteromedial margin of scutum more distinctly and widely brownish (i.e. similar to state seen in A. perkinsi), posteromedial stripe always evident. Scutellum brownish, sometimes becoming yellowish anteromedially or only brown dorsomedially. Anatergite and katatergite (sometimes excluding anterior margin or anterior half) brown to light brown; mediotergite yellow. Pleuron and legs light yellow to white. Wing dusky in first and second radial cells, and along wing veins distally. Halter white. Abdominal tergites brown with narrow yellow lateral margin, sternite 8 and epandrium (except venter) dark brown, and cercus and surstylus yellow.
Colour—female: As described for male except as follows: setae brown to dark brown; overall colour more yellow than white; dorsal 1/3 of first flagellomere dark brown; frons sometimes brownish around base of setae; clypeus brown; palpus brown to dark brown apically; abdomen dark brown, paler past tergite 5 and with terminalia yellow, but in some (including holotype) abdomen yellow with tergites 1–4 and central stripe on tergite 5 brown. Holotype female with anterolateral margin of scutum darker, with stripe wider and more well-defined; clypeus and palpus yellow.
Male terminalia: (Figs 261–263) Epandrium relatively long and shallow. Cercus small and rounded. Surstylus over 2/3 length of epandrium, arched posteriorly, and obliquely truncated apically (tubercles present along inner surface of truncated margin); centre bare. Hypandrium broad ventrally, lobe not discreet, with two short laterodistal setae. Phallapodeme well-developed, rod-like. Pregonite long, thin, with apical and distal setulae, and sharply bent medially. Postgonite elongate and curved with apical setae. Basiphallus well-developed. Epiphallus long and broadly arched. Distiphallus 3/5 length of phallapodeme, fused to small, bare paraphallus.
Female terminalia: (Fig. 344) Sternites 6 and 7 slightly longer than wide. Base of ventral receptacle densely spinulose. Spermatheca dark, smooth and cylindrical (apex rounded), with constriction past narrower basal 1/3.
Distribution: Australia (QLD).
Holotype: AUSTRALIA. QLD: N QLD, Kuranda, 19.v.1958, D.K. McAlpine (1♀, AMSA).
Material examined: AUSTRALIA. QLD: N. Qld., Birthday Crk., Paluma, 18.i.1967, D. McAlpine & G. Holloway (3♂ 1♀, AMSA), N QLD, The Crater, near Herberton, 29.i.1972, D.K. McAlpine & G.A. Holloway (10♂, AMSA), 30.i.1972 (1♀, AMSA), 16.xii.1961, D.K. McAlpine (1♂ 2♀, AMSA; 3♂ [same pin], 1♀, CNC), N QLD, Summit, Walter Hill Ra. Cardstone-Ravenshoe Rd., 16.i.1967, McAlpine & Holloway (5♂ 2♀, AMSA), Uhr Ck.—Mulgrave Riv. Junc., 13km SW Gordonvale, swept (rain forest), 26.iv.1980, S.F. McEvey (1♂, ANIC), Cathedral Fig, Dambulla Forest, 6km off Rt. 52, 11.x.2002, A. Freidberg (1♀, TAUI), Curtain Fig Tree, Rt. 52, 2km S, Yungaburra, 11.x.2002, A. Freidberg (1♂, TAUI), Tenison Woods Mtn. nr Mt. Glorious, 27°18′S, 152°45′E, 10.i. 1993, 650m, banana trap, R. van Klinken (1♂, UQIC), Mt. Haig 21km NE by E of Atherton, 18.xi.1981, Malaise Trap, D.H. Colless (1♀, ANIC), The Boulders, Babinda, 10.v.1967, D.H. Colless (1♀, ANIC).
Comments: Allometopon striatum is a relatively pale Australian species usually with the scutum brown laterally and posteromedially. It is most similar to A. infernum (Fig. 125), which can be differentiated on the basis of a more slender surstylus and other less obvious features of the internal genitalia. The surstylus is nearly as high as the epandrium (similar to A. macalpinei; Figs 148–153) with the distal margin slightly flattened, lined with short, stout setae on the inner margin, and angled posteriorly. The pregonite is also narrow and bent medially, and the paraphallus is short, smooth and fused to the distiphallus.
Those few darker specimens with a complete medial scutal stripe resemble Allometopon tetrathrix (Fig. 317), but in that species the yellow scutal stripes reach the posterior margin, the scutellum is yellow with a brown anteromedial spot, there is only one pair of lateral scutellars, four fronto-orbitals, and the base of the halter knob is brownish.
description: Published as part of Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), pp. 1-127 in Zootaxa 4106 (1) on pages 58-60, DOI: 10.11646/zootaxa.4106.1.1, http://zenodo.org/record/258766