Allometopon perkinsi McAlpine, 1960

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 49-50

Allometopon perkinsi McAlpine, 1960

Figs 205–211 , 342

Allometopon perkinsi McAlpine 1960: 86 . Pitkin & Evenhuis 1989: 535 [catalogue, Australasia/Pacific].

Description. General: ( Figs 205–208 ) Body length 2.5–2.9mm. Arista sparsely short plumose, nearly pubescent. Female clypeus narrow, not enlarged. M1+2 ratio 4.5–6.0. First flagellomere enlarged, slightly reniform with venter more lobate.

Chaetotaxy: Three fronto-orbital setae, anterior seta half length. Ocellar seta well-developed, nearly as long as anterior fronto-orbital. Postvertical seta absent. Interfrontal seta thin, small. First flagellomere along margin with hairs longer than width of base of arista. Two or three dorsocentral setae closely set posteriorly; second dorsocentral ½–3/5 length of posterior dorsocentral, third 3/5 length of second when present. Acrostichal seta welldeveloped. Sometimes two lateral scutellar setae with anterior seta smaller; anterior seta sometimes absent from one or both sides.

Colour—male: Setae light brown, darker on abdomen. Head partially yellow in ground colour, light yellow to white below antenna; first flagellomere white, outer surface light brown to brown above point of pedicel with anterior margin paler, inner surface with only dorsum and sometimes base darker; frons dark yellow or with slight brown tint posteromedially; ocellar tubercle dark brown; gena and postgena silvery tomentose; back of head dark brown above foramen, sometimes with dorsomedial region brown to partly yellow, or entire dorsal region yellow with one pair of dark to faded lateral stripes. Scutum yellow with anterior and posterior margins (sometimes lateral 1/3) dark brown; posterior margin sometimes thinly brown, fully enclosing central yellow spot. Scutellum dark brown, sometimes with yellow anteromedial spot with that is small or much larger and conspicuous. Metanotun dark brown with mediotergite and/or anterior margin of katatergite sometimes yellow. Pleuron and legs light yellow. Wing very lightly clouded, becoming slightly darker on distal 1/3 towards costa, with darker infuscation around R2+3. Halter white. Abdomen dark brown with tergite 1 yellow and surstylus and cercus light yellow.

Colour—female: As described for male except as follows: darker in colouration overall; setae brown to dark brown; first flagellomere dark brown above point of pedicel; frons darker yellow to brownish posteriorly and with brown region around base of vertical setae; mouthparts, face and venter of gena dark yellow; anepimeron and anepisternum dark brown with dorsal margin of anepisternum yellow, but sclerites sometimes paler with margins more widely yellow; abdomen dark brown with segment 10 and cercus light yellow.

Male terminalia: ( Figs 209–211 ) Annulus well-developed with spiracle free from sclerite. Cerci enlarged, half length of epandrium, pointed and joined on basal half. Surstylus approximately 2/3 length of epandrium, sparsely setulose, appearing narrow on basal 2/3 when viewed laterally because face angled posteriorly, and with distal margin very wide, tuberculate and obliquely angled. Ventral lobe of hypandrium small with one minute seta; arm long and arched. Phallapodeme rod-like, well-developed with head relatively narrow. Pregonite large, weakly sclerotized and with scattered medial setulae. Postgonite very longand narrow with apical and subapical setae. Basiphallus well-developed. Epiphallus heavily sclerotized and shifted anteriorly. Distiphallus 1/3 length of phallapodeme. Paraphallus broad, blunt and spinulose apically.

Female terminalia: ( Fig. 342 ) Spermathecae subovate with base constricted, dark, with shallow bumps over surface and minute clear pits basally; base slightly invaginated, enclosing abruptly narrowed apex of duct. Spermathecae asymmetrical; smaller spermatheca with short, slightly narrowed base and pits restricted to basal third; larger spermatheca with narrower, longer basal section bearing smaller pits; larger spermatheca split in all dissections, apparently with very thin membranous cover (i.e. possibly not an artifact of dissection).

Distribution: Australia (NSW, QLD).

Holotype: AUSTRALIA. QLD: Lamington National Park, 25.x.1955, F.A. Perkins (1♂, QMBA).

Material examined: AUSTRALIA. NSW: Upper Allyn River, 14.ii.1968, D.H. Colless (1♀, ANIC), Woombye, nr. Nambour, 11–16.x.1965, D.H. Colless (1♀, ANIC), ‘Swans Crossing’, Kerewong S.F., approx.. 12km WNW Wauchope, 24.x.1993, G.&B. Williams, ex rainforest (1♂, AMSA), Wilson R. Reserve, 5.ix.1981, B.J. Day (1♂, AMSA), 15km N of Lowanna, 30: 04.33S, 152: 52.84E, site 64CM, 20.iii.1993, swept, McEvey & Leask (3♂, AMSA), native fruit (1♂, AMSA), Richmond Range, AMG 472700 6816900, site 54AG, 4.xii.1991, swept, SF McEvey (1♀, AMSA), QLD: Tamborine Mt., 16.ii.1980, E.M. Exley (1♂, UQIC), L. Barrine Q., Atherton Tab., 2300′, Harvard exp., Darlington, 18.iv.1932 (2♂♂, MCZ), 19.iv.1932 (1♂, MCZ), SE QLD, Mt. Glorious, Rainforest Circuit tr., 24.x.2002 /20, 27.20S / 152.46E, rainforest, Merz, Foldvari & McNeil / 20 (1♂, MHNG), Tamborine Mts., Eagle Heights, Palm Grove, 26.x.2002 /25, 27.56S / 153.12E, rainforest, B. Merz & M. Foldvari (1♂, MHNG), Binna Burra, Lamington Nat. Pk., 31.i.1961, D.K. McAlpine (1♂, AMSA), Monto District, Bulburin, site 1, 24˚31′S, 151˚29′E, 540m, ex Malaise trap, 22.iii.1973, D. Milledge (1♂, AMSA), Monto District, Bulburin (Austral), site 3, 24˚34′S, 151˚29′E, 580m, 21.iii.1975, D.K. McAlpine (3♀, AMSA), Bunya Mtns, 8.ii.1961, D.K. McAlpine (1♂, AMSA), Broken River, Eungella, 10.xii.1961, D.K. McAlpine (1♀, AMSA), Austral forest via Bulburin, site 3, 24˚34′S, 151˚29′E, 20.iii.1975, D.K. McAlpine (1♀, AMSA).

Comments: The notal pattern of Allometopon perkinsi is characteristic, with a large yellow central region on the scutum bordered by a brown stripe along the anterior and lateral margins, but rarely posteriorly, where the yellow spot sometimes extends onto the brown scutellum. The ocellar seta in this species is also as long as the anterior fronto-orbital, some specimens also have a long seta in front of the second dorsocentral, and the postvertical is absent (present in other Australian species except for A. conopeum ( Fig. 40 )). The male terminalia are diagnostic in having elongate, pointed cerci, a long surstylus that is flattened front-to-back on the basal 2/3, a short distiphallus and a paraphallus that is broad and minutely spinulose apically.

Figures

FIGURES 205 – 211. Allometopon perkinsi McAlpine, non-type male; 205: photo, head, dorsal; 206: same, anterior; 207: photo, dorsal; 208: same, lateral; 209: external genitalia, left lateral; 210: same, posterior; 211: internal genitalia, left lateral.

FIGURES 339 – 346. Allometopon female genitalia; 339: A. palpale Frey, external; 340: A. malayensis Sasakawa, internal; 341: A. palpale, internal; 342: A. perkinsi McAlpine, internal; 343: A. philomela spec. nov., paratype, internal; 344: A. striatum McAlpine, internal; 345: A. tetrathrix spec. nov., holotype, internal; 346: A. thrinacos Sasakawa, internal.

FIGURES 40 – 46. Allometopon conopeum spec. nov.; 40: Australian male, photo, dorsal; 41: PNG paratype male (AMSA), photo, dorsal; 42: holotype, photo, dorsal; 43: same, lateral; 44: holotype external genitalia, left lateral; 45: same, posterior; 46: internal genitalia, left lateral.