Allometopon phenomena, Owen Lonsdale, 2016

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 50-51

Allometopon phenomena spec. nov.

Figs 212–218

Description. General: ( Figs 212–214 ) Body length 2.6–2.9mm. Arista short plumose. M1+2 ratio 4.6–6.3. First flagellomere slightly enlarged with dorsum produced. Female unknown.

Chaetotaxy: Three fronto-orbital setae, anterior seta 2/3–3/4 length. Ocellar seta thin, slightly longer than tubercle. Postvertical seta minute. Interfrontal seta minute. Frons with minute setulae. First flagellomere past base with hairs longer than width of arista base. Two pairs of vibrissae, posterior pair convergent and appearing fused on distal half. Anterior dorsocentral half length of posterior dorsocentral; closely set posteriorly. Acrostichal seta absent. One small lateral scutellar seta, sometimes with smaller additional seta in front.

Colour: Setae yellow, darker dorsally on abdomen. Head light yellow in ground colour, whitish below frons and foramen; antenna yellowish-white; arista white on basal 2/3; ocellar tubercle dark brown; sometimes posterolateral corner of frons brownish and one pair of very faint brownish stripes evident on back of head; parafacial, gena and postgena silvery tomentose. Scutum brown with venter of postpronotum light yellow, notopleuron and supra-alar region yellowish, confluent with one pair of narrow yellowish postsutural stripes inside supra-alar row that bend inwards at suture ( Fig 213 ); curved stripes sometimes distinct and connected medially along suture ( Fig. 212 ). Scutellum brown, sometimes faintly yellowish at base of apical seta. Katatergite yellow; anatergite brown dorsally; mediotergite brown. Pleuron and legs yellowish-white. Halter yellow. Wing very lightly infuscated, becoming clear posteriorly. Tergites dark brown with lateral margin narrowly yellow; sternite 8 dark brown; dark brown dorsomedial spot on epandrium sometimes present.

Male terminalia: ( Figs 215–218 ) Sternites 6 and 7 narrow, reduced. Cerci divergent, divided, narrow, apically setose. Surstylus over 2/3 height of epandrium and subrectangular with base narrower and apex shallowly rounded; posterobasal corner with small conical spur on outer surface and larger pointed process on inner surface; outer surface bare excluding several marginal and posterodistal setae; several clusters of thickened setae marginally on inner surface, and inner medial surface with whorl of thickened setae (long, short and tubercle-like). Hypandrium band-like with two inner subbasal setae and anterior margin produced as thin sheet. Phallapodeme broad and platelike with transverse carina over apical dome. Pregonite large, irregular, medially setose, mostly membranous. Postgonite twice as long as wide, with several apical and inner medial setae, and inner subapical surface with short row of small closely spaced setae. Basiphallus well-developed, fused to enlarged, arched epiphallus. Distiphallus approximately half length of phallapodeme, narrow and minutely tuberculate. Paraphallus longer than distiphallus, broad and weakly sclerotized with apex tapered and dorsal surface with strip of long spinules.

Etymology: The specific epithet, treated as a noun in apposition, is named after a Dario Argento movie about a young girl who has the ability to communicate with flies.

Distribution: Papua New Guinea.

Holotype: PAPUA NEW GUINEA. East Sepik Province: Kuminibus, near Maprik, 17.xii.1963, D.K. McAlpine (1♂, AMSA).

Material examined: PAPUA NEW GUINEA. East Sepik Province: Imbia, near Maprik, 22.xii.1963, D.K. McAlpine (2♂, AMSA), same collection as holotype (1♂, AMSA; 1♂, CNC).

Comments: Within the Allometopon cavernosium group, A. phenomena and A. tropalis ( Fig. 287 ) are supported as sister-species, most obviously on the basis of multiplicated vibrissae. The former ( Figs 284, 285 ) has several pairs of vibrissae arranged horizontally, and the latter has two pairs, with the posterior pair converging and joining apically. Females are unknown for both species so it is uncertain if this is a sex-restricted character. Other supporting features include the shape of the surstylus, which has a circular whorl of spine-like and tubercle-like setae on the inner surface, and the shape of the postgonite and paraphallus. The underlying notal pattern of both is also similar.

Figures

FIGURES 212 – 218. Allometopon phenomena spec. nov.; 212: paratype male (with complete transverse yellow stripe), photo, dorsal; 213: holotype, photo, dorsal; 214: same, lateral; 215: paratype, external genitalia, left lateral; 216: same, posterior; 217: internal surface surstylus; 218: internal genitalia, left lateral.

FIGURES 284 – 290. Allometopon tropalis Sasakawa, holotype; 284: photo, anterolateral, with detail of vibrissae; 285: same, dorsal; 286: photo, lateral; 287: same, dorsal; 288: paratype, external genitalia, posterior; 289: inner surface of surstylus; 290: internal genitalia, left lateral (from Sasakawa (1974 )).