Sobarocephala nebulosa, Lonsdale, Owen, 2014

Lonsdale, Owen, 2014, Revision of the Old World Sobarocephala (Diptera: Clusiidae), Zootaxa 3760 (2), pp. 211-240 : 226-227

Sobarocephala nebulosa spec. nov.

Figs 30–32

Description. Male. Body length 3.6mm. Arista densely plumose along much of length, becoming sparsely plumose apically. Setae light brown. Ocellar seta thin, half length of postvertical. Presutural intra-alar seta present, slightly longer than surrounding setulae. Two dorsocentral setae. Acrostichal seta present. One lateral scutellar seta. Head yellow with dark brown dorsolateral stripe on outer surface of first flagellomere and ocellar tubercle brown; gena pilose. Holotype in poor condition and notal pattern difficult to discern, but apparently consisting of one pair of apically tapering scutal stripes that attain lateral margin of scutum posteriorly; scutal stripes continue onto lateral corner of scutellum, which is yellow medially; metanotum yellow with katatergite brownish/ochraeous and mediotergite becoming brown towards midline. Pleuron yellow with posterior 2/3 of anepisternum brown, and katatergite, anepimeron and medial stripe on mid coxa ochraeous (possibly an artifact of preservation). Fore legs missing; remaining legs yellow. Distal 2/5 of wing dusky, becoming paler posteriorly. M1+2 ratio 3.6. Abdomen yellow with wide dorsomedial stripe on tergites 2–5 (possibly also tergite 1).

Female. Unknown.

Male terminalia. ( Figs 30–32 ) Perianal region reduced, shifted ventrally between small cerci, which are flanked by broad, lightly sclerotized bands. Setae on cerci short with one slightly longer medial pair. Surstylus slightly shorter than epandrium and half length, with tapered, rounded apex and slight posterobasal swelling; innerdistal surface with cluster of tubercle-like setae. Lateral lobe of hypandrium large, triangular, with two long setae and one short distal floating seta. Pregonite spectral with few minute setae. Postgonite well-developed, with long apical setae. Epiphallus well-developed, arched ventrally. Paraphallus tapered and spinulose with apex weakly sclerotized; thumb absent. Distiphallus split and truncated apically, half length of phallapodeme.

Etymology. The specific epithet is derived from the Latin for “cloudy, indefinite”, referring to the relatively ill-defined colour pattern.

Holotype: LAOS. Vientiane Prov.: Ban Van Eue, 30.vi.1967, Native Collector, Bishop (1♂, BPBM).

Comments. The notal pattern of the Sobarocephala nebulosa holotype, which is partially indistinguishable due to the poor condition of the specimen, appears to differ from most Old World congeners in having one pair of apically tapering scutal stripes that continue onto the lateral margin of the otherwise yellow scutellum. Similar species can be most readily differentiated on the basis of an absence of the presutural intra-alar and prescutellar acrostichal. Of these, S. anonymos is also from Laos, but this species further differs in having an additional small seta in front of the anterior dorsocentral, the pleuron is less extensively pigmented, the surstylus differs in shape, the distiphallus is longer and there is extensive fusion of the basiphallus, epiphallus and basal shield of the distiphallus.

The terminalia of Sobarocephala nebulosa are most characteristic in that the perianal region is largely removed ventrally, restricted to a small opening in between cerci, which are flanked by a broad, weakly sclerotized band. The surstylus is also relatively thin with numerous apical tubercle-like setae and a small posterobasal protuberance. The long, apically truncated distiphallus, spectral pregonite, and weakly sclerotized, but long and tapered paraphallus without a thumb are also diagnostic.

Figures

FIGURES 30 – 32. Sobarocephala nebulosa spec. nov., male genitalia; 30: external, left lateral (annulus not included); 31: external, posterior; 32: hypandrial complex, left lateral. Figs 33 – 35: S. anonymos spec. nov., male genitalia; 33: external, left lateral; 34: external, posterior; 35: hypandrial complex, left lateral. Figs 36 – 38: S. paksana spec. nov., male genitalia; 36: external, left lateral; 37: external, posterior; 38: hypandrial complex, left lateral. Figs 39 – 41: S. insolata spec. nov., male genitalia; 39: external, left lateral; 40: external, posterior; 41: hypandrial complex, left lateral.