Pachycerina stuckenbergi, Davies & Miller, 2009

Davies, Gregory B. P. & Miller, Raymond M., 2009, Revision of Afrotropical Pachycerina Macquart (Diptera: Lauxaniidae), African Invertebrates 50 (2), pp. 295-295 : 317-318

Pachycerina stuckenbergi sp. n.

Figs 23 , 30 , 44

Etymology: Patronym for the late Brian R. Stuckenberg, former Director of the Natal Museum, and pre-eminent dipterist, whose rich collections of Malagasy Diptera greatly enriched the Natal Museum Diptera collection.

Diagnosis: P. stuckenbergi is the only species in Madagascar to have a yellow abdomen with blackish edging to the ventral margins of the tergites. In this feature, P. stuckenbergi recalls P. nigrivittata of the African mainland, but the two can be distinguished on the basis of the male terminalia.A Malagasy endemic, only known from the eastern escarpment.

Description:

Head: Fronto-orbital plates weakly delineated (coloured). Ocellar spot large, not elongated, weakly truncated anteriorly, rounded and weakly tapered posteriorly. Prefrontal spots large, blackish, touching sides of prefrons. Scape and pedicel yellow-orange, postpedicel yellow but proximally brown (around arista base).

Thorax: Striping pattern indistinct on scutum, but appears to have standard subdorsal and sublateral longitudinal orange-brown vittae. Scutellum yellow-orange. Mesopleuron with upper lateral thoracic vitta (not strong). Sternopleuron with lower thoracic vitta in upper third of sclerite. Profemur orange-yellow, dark anterior surface. Protibia black, distally yellow and proximally yellow. Protarsus blackish. Other legs yellow-orange. Wing with costal cell, stigma and marginal cell lightly fumose. Haltere orange to brown.

Abdomen: Yellow, syntergite 1+2 through T5 with thick black edge to ventrolateral margins of tergites. T6 without black edging.

Male terminalia ( Figs 23 , 30 , 44 ): S5 with straight posterior arms and medial spur. T6 with black spots. Surstyli longer than epandrium. Gonopods asymmetric, right gonopod slightly longer, small lateral spinules. Right gonopod with strongly narrowed distal apex with hooked tip (not evident in illustration). Aedeagal apodeme with rounded anterior margin.

Measurements: ơ (n=2), ^(n=2): head length – ơ 0.8, ^0.8; thorax length (incl. scutellum) – ơ 1.9, ^1.9; abdomen length – ơ 1.6, ^1.6; wing length – ơ 3.9, ^3.9.

Holotype: ơ MADAGASCAR: Ranomafana [21°15'S: 47°27'E], 2.viii.1958, F. Keiser ( MHNB).

Other material examined (all MHNB): MADAGASCAR: 3^same data as holotype; 1ơ 3^same locality, 27.vii.1958, F. Keiser; 2ơ 4^same locality, 1–4.x.1958, F. Keiser .

Figures

Figs 23–27. Posterior view of male terminalia: (23) Pachycerina stuckenbergi sp. n.; (24) Pachycerina vaga Adams; (25) Pachycerina crinicornis (Thomson); (26) Pachycerina gabela sp. n.; (27) Pachycerina micropunctata sp. n. Scale bar = 0.8 mm.

Figs 28–33. Dorsal view of male inner genitalia: (28) Pachycerina obscuripennis Lamb; (29) Pachycerina potentilla sp. n.; (30) Pachycerina stuckenbergi sp. n.; (31) Pachycerina atrimela sp. n.; (32) Pachycerina gabela sp. n.; (33) Pachycerina pellocera sp. n. Abbreviation: aed apo – aedeagal apodeme. Scale bar = 0.5 mm.

Figs 39–48. Sternite 5 of male Pachycerina species: (39) P. vaga Adams; (40) P. nigrivittata sp. n.; (41) P. gabela sp. n.; (42) P. atrimela sp. n.; (43) P. pellocera sp. n.; (44) P. stuckenbergi sp. n.; (45) P. crinicornis (Thomson); (46) P. potentilla sp. n.; (47) P.seychellensis Lamb; (48) P. micropunctata sp. n. Abbreviation: post proc – posterior process. Scale bar = 0.5 mm.