Allometopon flavum Lamb, 1914

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 24

Allometopon flavum Lamb, 1914

Figs 298–301

Allometopon flavum Lamb, 1914: 311 . Melander & Argo 1924: 6 [synonymy]; Frey 1960: 26 [catalogue, World]; Cogan 1980: 636 [catalogue, Afrotropics].

Description [mostly from Lamb (1914)]. General: ( Figs 298–301 ) Holotype in very poor condition; extensively damaged with only thorax, right mid leg and abdomen remaining on minuten; one wing on card. Body length 3.5mm. Arista pubescent. First flagellomere small, circular. M1+2 ratio 2.4. Female unknown.

Chaetotaxy: Four fronto-orbital setae, slightly decreasing in length anteriorly. Ocellar and postvertical setae small. Interfrontal seta “comparatively stout”. Anterior dorsocentral seta appearing to be more than half length of posterior dorsocentral; slightly enlarged seta in front of anterior dorsocentral; dorsocentral setae displaced posteriorly. Two lateral scutellar setae (positioning difficult to ascertain).

Colour: Setae light brown. Entirely yellow with first flagellomere black, arista brown; ocellar tubercle presumably brown. Lamb (1914) notes three brown stripes on thorax, but these may be an artifact created by attachment of underlying muscles; also noted are brownish tarsi, which also appear to be yellow in the examined photo.

Male terminalia: Not dissected.

Distribution: Seychelles.

Holotype: SEYCHELLES. Praslin: Côtes d’Or Estate, 1908 Seychelles Exp., J.S. Gardiner, 1914-537, “ HOLOTYPE Allometopon flavum Lamb , det. J.E. Chainey, 1984” (1♂, BMNH). [Photos examined]

Comments: Allometopon flavum is the only Allometopon known from Seychelles, and still represented solely by the male holotype. While the description and available photographs of the poorly preserved type cannot provide a through description of this species, it appears to be allied to the A. palpale group, specifically, with A. acum ( Fig. 1 ) and A. hybos ( Fig. 120 ), which are yellow species with similarly pale setae and a black first flagellomere. It is nearly inseparable from A. hybos (southeast Asia), and the examination of new material is required to better differentiate the two and describe the male genitalia.

Figures

FIGURES 298 – 306. 298 – 301. Allometopon flavum Lamb, holotype, photos; 298: left lateral; 299: ventral; 300: detail of abdomen; 301: wing. 302 – 304. A. fumipenne Kertész, holotype, photos; 302: head, anterolateral; 303: lateral; 304: detail of terminalia. 305, 306. A. gracile spec. nov., holotype, photos; 305: dorsal; 306: lateral.

FIGURES 1 – 5. Allometopon acum spec. nov.; 1: photo, dorsal; 2: photo, lateral; 3: external male genitalia, left lateral; 4: same, posterior; 5: internal male genitalia, left lateral.

FIGURES 120 – 124. Allometopon hybos Sasakawa, holotype; 120: photo, dorsal; 121: same, lateral; 122: external genitalia, posterior; 123: same, right lateral; 124: internal genitalia, left lateral.