Allometopon conopeum, Owen Lonsdale, 2016

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 20-21

Allometopon conopeum spec. nov.

Figs 40–46

Description. General: ( Figs 41–43 ) Body length approximately 2.7–2.8mm. Arista short plumose. M1+2 ratio 2.5–3.0. First flagellomere slightly enlarged with dorsal margin more pronounced. Female unknown.

Chaetotaxy: Three fronto-orbital setae with anterior seta slightly shorter. Ocellar seta twice length of tubercle. Postvertical seta absent. Interfrontal seta minute. Frons with minute setulae. Distal and anterodorsal margins of first flagellomere with hairs longer than width of arista base. Anterior dorsocentral half length of posterior dorsocentral; closely spaced posteriorly. Acrostichal seta small but well-developed. One small lateral scutellar seta.

Colour: Setae yellow. Head yellow, whitish below level of antenna and light yellow anteriorly on frons; antenna light yellow with first flagellomere white; ocellar tubercle and posterolateral corner of frons brown (encompassing base of vertical setae); back of head with one pair of basally connected stripes radiating from foramen; gena, parafacial and postgena silvery tomentose. Scutum yellow in base colour; anterior margin of scutum brown with one pair of short extensions along dorsocentral rows and one pair of stripe continuing sublaterally along margin of scutum to alar base; postsutural scutum with one pair of thin supra-alar stripes and one pair of broad medial stripes that are ill-defined and barely separated or partially fused medially. Scutellum brown with either small yellow spots at base of apical setae, or large yellow posteromedial spot. Metanotum brownish dorsally on mediotergite and posterodorsally on anatergite. Halter light yellow. Wing very lightly infuscated on distal 1/3 anterior to vein M. Pleuron and legs yellowish-white. Abdomen light yellow with broad dark brown dorsal stripe from tergite 2 to sternite 8; epandrium dark brown with distal margin light yellow.

Variation—Australia: ( Fig 40 ) As described above except as follows: frons yellowish-orange with dark posterolateral spot extending along eye margin to base of posterior fronto-orbital; scutum with complete broad medial stripe that barely touches basal margin, is slightly constricted at transverse suture, and has a small, narrow yellow posteromedial emargination; narrow sublateral brown stripe continues to posterior margin; scutellum brown with narrow yellow posteromedial stripe.

Male terminalia: ( Figs 44–46 ) Sclerites 6–8 weakly differentiated. Cerci ill-defined, nearly fused apically. Surstylus as high as epandrium, subtriangular with apex slightly curved anteriorly and rounded, and posterobasal corner produced; inner surface with clusters of small tubercle-like setae in posterobasal corner, at apex, and along margin of slightly swollen medial to subapical region. Hypandrium with slightly narrowed, dorsally arched arm and broad ventral lobe (slightly produced posteriorly as seen in Sobarocephalinae) with three apical setae. Phallapodeme rod-like and well-developed with shield projecting near base. Pregonite irregular in outline, elongate, ill-defined and with two medial setae. Postgonite lobate with several apical setae. Basiphallus welldeveloped, fused to narrow, projecting epiphallus with swollen, clear apex. Distiphallus with additional sclerotized sheets posteriorly and laterally; ventral section made of two narrow, flat triangular plates that are parallel along inner margin. Paraphallus strongly arched near base, sinuate, mostly clear but with sclerotized base and dorsal margin that is minutely spinulose subbasally.

Etymology: The specific epithet is Latin for “curtain of fine gauze”, a noun in apposition describing the additional sheet-like sections emerging from the distiphallus.

Distribution: Australia (QLD), Papua New Guinea.

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

Paratypes: AUSTRALIA. QLD: 12.435S 143.18E, 11km EnE of Mt. Tozer, 11–16.vii.1986, D.H. Colless, Malaise (1♂, ANIC), N QLD, Gordon Ck., Iron Range 1.5km E Cook’s hut, 12°43′S, 143°19′E, swept in rainforest, 11.v.1981, S.F. McEvey (1♂, ANIC). PAPUA NEW GUINEA. Central Province: nr Eilogo, 8.viii.1981, J.W. Ismay, swept rainforest (1♂, AMSA).

Comments: Allometopon conopeum from Papua New Guinea ( Figs 41–43 ) can be most readily diagnosed by an entirely pale pleuron, an apically yellow scutellum, and the unique scutal pattern—the margin is brown sublaterally from the alar base to the brown anterior margin, and one pair of subrectangular posteromedial stripes that are nearly fused. Australian representatives ( Fig. 40 ) have identical genitalic morphology, but the notal spots have extended to form a complete medial brown stripe with a small yellow posteromedial notch. A similar underlying pattern is seen in A. plicatum ( Philippines) ( Figs 224, 225 ), which also has similar male genitalia (see comments for A. plicatum ).

Figures

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.

FIGURES 224 – 228. Allometopon plicatum spec. nov., holotype; 224: photo, dorsal; 225: same, lateral; 226: external genitalia, left lateral; 227: same, posterior; 228: internal genitalia, left lateral.