Microselia prescherae Disney, 2010

Disney, R. H. L., Prescher, S. & Ashmole, N. P., 2010, Scuttle flies (Diptera: Phoridae) of the Canary Islands, Journal of Natural History 44 (3 - 4), pp. 107-218 : 203-205

Microselia prescherae Disney sp. nov.

( Figure 74 )

Material

Holotype female, La Palma: Parc National de la Caldera de Taburiente , Roque de la Cumbrecita, 1377 m, 12–25 August 1999 ( T. Domingo-Quero, MNCNM – 19-150) . Paratypes, three males, one female as holotype, except one male, one female ( CUMZ) .

Etymology

Named after Dr Sabine Prescher for her contribution to this paper.

Male

Frons brown, clearly broader than long, with 90–108 hairs and dense but very fine microsetae. SAs absent. The antials lower on frons than anterolaterals, and about twice as far apart as either is from an AL bristle. Pre-ocellars slightly further apart than either is from a mediolateral bristle, which is very slightly higher on frons. Cheek without bristles but jowl with two. Postpedicels brown, without SPS vesicles, and as Figure 74B . Palps pale dusky yellow, at most a third as broad as postpedicel but almost as long as breadth of latter, with four short bristles. Labrum brown and about twice as wide as a palp. Labella coloured as palps and with only a few short spinules below. Thorax brown. Two notopleural bristles. Scutellum with or without an anterior pair of hairs and a posterior pair of bristles. Abdominal tergites brown with only a few minute hairs ( Figure 74A ). Venter brown, and and seemingly bare at low magnifications, but some microsetae are present ( Figure 74A ). Hypopygium brown, with a pale brown anal tube, and as Figure 74A . Legs brown to yellowish brown. Fore tarsus with posterodorsal hair palisade on segments 1–4 and 5 clearly longer than 4. Mid and hind tarsi with segment 5 a little longer than 4. Hairs below basal half of hind femur slightly longer than those of anteroventral row of outer half. Hind tibia with spinules of apical combs simple. Wings 1.0– 1.1 mm long. Costal index 0.31–0.32. Costal ratios 1.7–2.0: 1. Costal cilia (of section 3) 0.03–0.04 mm long. No hair at base of vein 3. With two axillary bristles, the outer being longer than costal cilia. Sc not reaching R1. Thick veins brownish grey, thin veins 4–6 grey and 7 faint. The tip of vein 4 is strongly deflected rearwards. Membrane lightly tinged grey. Haltere brown.

Female

Head similar to male but postpedicels not quite so wide, so that palps are about twofifths the width of a postpedicel. Otherwise head similar to male. Thorax as male. Abdominal tergites brown, all wider than long and with minute hairs. T6 is broadly divided down the middle. Between T5 and T6 a median structure is evidently that which is associated with the orifice of the duct from a dorsal abdominal gland, although the gland itself was not discerned. Venter brown, and bare below segments 3–5. Sternum of segment 6 with a pair of wedge-shaped small sclerites bearing small hairs and a pair of stronger ones towards the tapered tip at the inner end. Ovipositor segments as Figure 74C,D . Legs similar to male but the fifth tarsal segments on all legs are longer than the fourth and tapered (e.g. segments 3–5 of front tarsus as Figure 74E ). Wing 1.0– 1.1 mm long. Costal index 0.28–0.32. Costal ratios 1.7–2.0: 1. Costal cilia 0.03 mm long. Otherwise it and haltere as male.

Comment

The evidence of at least a vestige of a dorsal abdominal gland, and its position, allows the assignment of this genus to the tribe Gymnophorini ( Disney 2003e) .

Recognition

Three of the four known males have pale straw yellow anal tubes. The fourth and the new species have a largely brown anal tube, but the former has vein 2 fully developed so that vein 3 is clearly forked but M. prescherae has vein 3 essentially unforked, but with a faint basal portion of vein 2 sometimes present. The incomplete or absent vein 2 will immediately distinguish the female from all six known Afrotropical species. Vein 2 tends to be weakly developed or absent in the three European species; but the ovipositor sheath has segment 7 more broadly expanded in M. forsiusi Schmitz and M. rivierae Schmitz , and each side of the rear margin of the sternum of abdominal segment 6 of the latter has a conspicuous transverse row of at least six long bristles. Apart from the differing ovipositors, the female of M. southwoodi Disney has a pair of SA bristles but M. prescherae lacks SAs.

Figures

Figure 74. Microselia prescherae. (A) Left face of male hypopygium. (B) Inner face of male right antenna. (C) Right face of tip of female ovipositor. (D) Left face of female abdominal terminalia (T5–T10, tergite 5 to tergite 10). (E) Segments 3–5 of female front tarsus. Scale bars: 0.1 mm.