Strongylophthalmyia albisternum Evenhuis

Evenhuis, Neal L., 2016, World review of the genus Strongylophthalmyia Heller (Diptera: Strongylophthalmyiidae). Part I: Introduction, morphology, species groups, and review of the Strongylophthalmyia punctata subgroup, Zootaxa 4189 (2), pp. 201-243 : 210

Strongylophthalmyia albisternum Evenhuis , n. sp.

( Figs. 10 , 62 )

Diagnosis. Easily separated from the congeners in this subgroup by non-sclerotized sternites resulting in white abdominal sternites I–II and sometimes III. Other species may have these abdominal segments predominantly white, but there is always a brownish sclerotization of the sternites.

Description. Lengths. Ƌ: body, 3.4–4.1 mm; wing, 2.8–3.0 mm. Male. Head: globular; frons shining black, brown above antennae, yellow above ptilinal suture; face gray; gena gray, silvery pollinose, row of short black hairs ventrally; occiput black, brown posteroventrally; clypeus thin, brown; palpus ( Fig. 10 ) linear-ellipsoid, length four times width, slightly bowed with flared round apex, yellowish white with black apicodorsally, with row of stiff black hairs ventrally, becoming longer and thicker apically; proboscis brown.

Antenna: scape and pedicel yellow; flagellomere subrhomboid, rounded apically, longer than wide, yellow with brown apicolaterally, clothed with white hairs, with long, slender, slightly sinuous dorsal process densely clothed with white hairs, 1.5 times length of flagellomere; arista subequal in length to dorsal process, styliform, bare. Thorax: shining; mesonotum and scutellum shining black, sparsely clothed with short hair-like setulae; propleuron yellow, katepisternum brown, remaining pleura black; anepisternum with tuft of silvery white hairs medially, a few minute white hairs along prealar suture.

Wing: hyaline; vein R2+3 nearly straight, ending in costa beyond level of crossvein dm-cu; crossvein r-m before middle of cell dm; veins R4+5 and M1+2 parallel distally; halter white.

Legs: coxae white; fore coxa with 3 long yellowish white hairs; fore femur ( Fig. 62 ) yellowish white, white apically, dorsally with 6 short black thorn-like spicules, basalmost pair in close approximation; mid femur yellow; hind femur yellow, brown apically; fore tibia white; mid and hind tibiae brown basally, white apically; tarsi white.

Abdomen: tergites I–II yellowish to tan, weakly sclerotized medially and laterally; tergites III–VI dark brown, with short sparse brown hairs, these hairs longest on tergites V–VI; sternites I–III not sclerotized, membranous and white-colored; sternites IV–VI brown.

Male genitalia. Not dissected; epandrium and surstylus shining black, with white hairs; cerci light brow, narrow basally, flared and rounded apically, with long white hairs dorsally, shorter black hairs apically and ventrally.

Female. Unknown.

Material examined. Holotype ♂ (pinned) and three ♂ paratypes (preserved in ethanol) from THAILAND: Chiang Mai Province : Chiang Mai, Botanical Gardens , QSBG, 18.8955°N, 98.8636°E, 11–25 Jul 2013, M. Hauser ( QSBG) . Holotype and paratypes in QSBG.

Distribution. Thailand.

Etymology. This species is named for the white non-sclerotized basal abdominal sternites, sclerotized brownish in the other species of the cluster of species in the S. punctata subgroup possessing a small pleural tuft of anepisternal hairs.

Figures

FIGURES 10 – 17. Male Strongylophthalmyia palpus, left lateral view. 10. S. albisternum, n. sp.; 11. S. borneensis, n. sp.; 12. S. caestus, n. sp.; 13. S. federeri, n. sp.; 14. S. hauseri, n. sp.; 15. S. nigripalpis, n. sp.; 16. S. punctata Hennig; 17. S. thailandica, n. sp..

FIGURES 62 – 69. Male Strongylophthalmyia, fore femur, left lateral view. 62. S. albisternum, n. sp.; 63. S. borneensis, n. sp.; 64. S. hauseri, n. sp.; 65. S. immaculata Hennig, arrow points to tight thorn-like cluster of setae; 66. S. indochinensis, n. sp.; 67. S. inundans, n. sp.; 68. S. lowi, n. sp., arrow points to ventral cluster of setae; 69. S. malayensis, n. sp., arrow points to tight thorn-like cluster of setae.