Allometopon palpale Frey, 1928

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 48-49

Allometopon palpale Frey, 1928

Figs 247, 248, 339, 341

Allometopon palpalis Frey, 1928: 107 . Sasakawa 1977: 236 [catalogue, Orient]. Allometopon palpale, Frey, 1960: 21 .

Description. General: (Figs 247, 248) Body length 4.5mm. Arista short plumose. M1+2 ratio 3.2. First flagellomere small, ovate. Clypeus relatively broad and thick. Male unknown.

Chaetotaxy: Three fronto-orbital setae (increasingly shorter anteriorly). Ocellar seta approximately twice length of tubercle. Postvertical seta as long as tubercle. Interfrontal seta slightly longer than tubercle. Anterior dorsocentral seta half length of posterior dorsocentral; closely set posteriorly. Acrostichal seta not much longer than surrounding setulae. Two long lateral scutellar setae.

Colour: Setae yellow. Head mostly yellow; ocellar tubercle brown; gena and anterior margin of postgena silvery tomentose; distal 1/3 of palpus black. Thorax and legs yellow, fore tarsus apparently brownish-orange in non-type (possibly artifact of preservation). Wing clear. Abdomen yellow with tergites 2–7 brown.

Female terminalia: ( Figs 339, 341 ) Sternite 6 slightly wider than long. Sternite 7 almost entirely absent; venter entirely recessed and membranous, with only basal pair of sensory setulae remaining. Sides of tergite 7 touching subbasally behind level of spiracles (enclosed in tergite); one pair of long, thin spines posteriorly. Segment 8 long, well sclerotized, bare, and with numerous longitudinal wrinkles; setose sternite small, narrow and distal.Spermatheca dark, spherical; duct approximately three times length of spermatheca with base tapered. Ventral receptacle narrow with long neck that has minute transverse wrinkles on distal 2/3; apical sac small, narrow, and without evident flagellum.

Distribution: Philippines, Malaysia (Sabah).

Holotype: PHILIPPINES. Samar, Catbalogan, iv.1915 (1♀, MZHF).

Additional material examined: MALAYSIA. Sabah: N. Borneo, Bettotan nr. Sandakan, 24.vii.1937, Ex. F.M.S. Museum, B.M. 1955-354 (1♀, BMNH).

Comments: Allometopon palpale and A. sensitivum (Fig. 245) are highly similar in morphology and known from very few specimens. Closer examination of these two species should be made following the collection of males to better delimit boundaries and clarify within-species variation, and determine whether the two are actually conspecific.

Figures

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.