Megaselia seychellesensis, Disney, R. Henry L., 2006

Disney, R. Henry L., 2006, Nine new species of Megaselia Rondani (Diptera: Phoridae) from the Seychelles, Zootaxa 1210, pp. 1-25 : 19-21

Megaselia seychellesensis sp. nov.

(Figs 31–33)

In the keys of Beyer (1965) the male of this species runs to triplet 23 on page 50. It fits none of the three options due to the combination of the mesopleuron having hairs and a differentiated bristle and the costal index exceeding 0.43. Two species running to the same triplet are the omitted: M. latinervis (Collin) , which is distinguished by is conspicuously broadened vein 3 (Rs), and the subsequently described M. morani Disney , which has a conspicuous ventral bulge of the mid femur. It belongs to a group of subsequently described species ( Disney, 2004b), most of which have a shorter costal index, but the same modification of the mid femur distinguishes them from the species covered by the subsequent couplets in Beyer’s key.

Etymology

The name refers to the type locality.

Male

Frons brown, with 48–90 hairs, dense but very fine microsetae and with bristles arranged as in Fig. 32. SAs robust and about equal. Cheek with 2–4 bristles and jowl with 2 longer ones. Postpedicels subglobose, brown, without SPS vesicles. Palps pale straw yellow, with 5 bristles (the most apical being the longest) and 4–6 hairs. Labrum at most as pale as palps and about half as wide as postpedicel. Labella as pale and with only a few short spinules below. Thorax brown, being paler on sides. Mesopleuron with 3–6 hairs and a small bristle (subequal to posterior notopleural bristle). 3 notopleural bristles and no cleft in front of these. Scutellum with an anterior pair of hairs (shorter than hairs at rear of scutum) and a posterior pair of bristles. Abdominal tergites brown with the hairs at rear of T6 a little longer than rest (Fig. 33). Venter straw yellow lightly tinged grey, and with hairs below segments 3–6. Hypopygium brown, but anal tube paler and narrow left lobe of hypandrium straw yellow, and as Fig. 33. Right lobe of hypandrium vestigial. Seemingly without rectal papillae. Legs mainly straw yellow apart from brown patch on mid coxa and outer third of hind femur and dorsal edge of hind femur, which are tinged brown. Sometimes the brown is more extensive on these parts of the hind leg. Fore tarsus with posterodorsal hair palisade on segments 1–4. Dorsal hair palisade of mid tibia extends almost 0.6–0.7x length. Hairs below basal half of hind femur about as long as those of anteroventral row of outer half. Hind tibia with 12–17 differentiated, but fine, posterodorsal hairs. Spinules of apical combs simple. Wings 0.9–1.1 mm long. Costal index 0.44–0.49. Costal ratios 2.4–3.2: 1.3–2.8: 1. Costal cilia (of section 3) 0.05–0.07 mm long. No hair at base of vein 3. With 2–3 (usually 2) axillary bristles, the outermost being longer than costal cilia. Sc not reaching R1. Veins brown, but 7 very pale. Membrane tinged brownish grey. Haltere brown.

Putative female

Frons similar to male. Labrum 0.7x wider than diameter of postpedicel. Otherwise head similar to male. Thorax as male. Abdominal tergites brown. T6–T7 as Fig. 31. Venter greyish brown, and with hairs below segments 3–6. Sternite 7 a smaller version of T7. Posterolateral lobes at rear of sternum 8 not developed apart from three bristles on position of each. Cerci whitish grey and almost circular, being about as long as broad. Seemingly without rectal papillae. Furca not evident. Dufour’s crop mechanism pale and situated well forward in the thorax. Legs similar to male. Wing as male except Costal ratios 3.6: 2.0–2.1: 1. Otherwise it and haltere as male.

Material

HOLOTYPE male, Seychelles, Lantana, Lantana North, marsh edge/open ground, Malaise trap, 30 July­1 August 2000, J. Gerlach ( CUMZ, 8­123). Paratypes, 2 males, as holotype (8–122, 126); 4 males, Silhouette Island, Jardin Marron (guavas), 5–10 July 2000, J. Gerlach ( CUMZ, 8­98, 99, 142). Putative female of this species, Mt Dauban, in pitcher of Nepenthes pervillei , 11 August 2000, J. Gerlach ( CUMZ, 8­100).