Megaselia limpachensis, R. Henry L. Disney & Sabine Prescher, 2015

R. Henry L. Disney & Sabine Prescher, 2015, Three new species of Megaselia Rondani, 1856 (Diptera, Phoridae) from Switzerland, Mitteilungen der Schweizerischen Entomologischen Gesellschaft 88, pp. 295-306 : 297-300

Megaselia limpachensis sp. n.

( Figs 1–9)

In the key to the males of the British species (Disney 1989) this species runs to couplet 126, lead 2to M. unguicularis (Wood, 1909) , which it closely resembles. It is distinguished by its paler abdominal venter, the proctiger hairs being longer and more robust than those on cerci, by the anterior ocellus being at least as large as the posterior pair (the anterior ocellus of M. unguicularis is distinctly smaller than the posterior ocelli). In addition it has posterodorsal hair palisades on the segments 1– 4of the front tarsus (as opposed to 1–5 in M. unguicularis ). For Palaearctic species not yet recorded from the British Isles, in the key to the species of Abteilung V (Schmitz &Delage 1974) it runs to couplet 6, lead 1to M. divergens (Malloch, 1912) or couplet 28, lead 1to M. involuta (Wood, 1910) . The shorter wing (0.9–1.0 mm) and costal index (0.33) distinguishes M. divergens .The epandrium has fewer more robust hairs in M. involuta , as well as posterodorsal hair palisades on all five segments of the front tarsus and whose basitarsus has some hairs reduced to small spinules.

Other European species not recorded from the British Isles will run to the same couplet. This couplet is expanded below to include the new species and those most resembling it. Other species have alonger anal tube and/or bristles not hairs on the epandrium

Description.Male: Frons brown and as in Fig. 1, with very fine microtrichia absent from most of frons (the lower supra-antennal bristle is absent on the right side and the upper SA is displaced forwards. The left side displays the correct positions of these bristles). Cheek with 4bristles and jowl with two that are longer. Postpedicel ( Fig. 2) lacks subcutaneous pit sensilla (SPS vesicles). Palps as in Fig. 2. Proboscis as in Fig. 3, the labella with only afew short spinules below. Thorax brown. Three notopleural bristles and no cleft in front of these. Mesopleuron with 8–9 hairs. Scutellum with an anterior pair of small hairs and a posterior pair of bristles. Abdominal tergites brown with hairs that are clearly longest posterolaterally on T6 ( Figs 4 &5). Venter gray ( Fig. 4), and with hairs on segments 3–6. Hypopygium as in Figs 4&5, with hypandrial lobes vestigial. Coxae to tibiae of legs brown but those of front legs only lightly tinged and all tarsi pale. Fore tarsus ( Fig. 6) with posterodorsal hair palisades on segments 1–4. Dorsal hair palisade of mid tibia extends almost half its length ( Fig. 7). Hairs below basal half of hind femur shorter than those of anteroventral row of outer half ( Fig. 8). Hind tibia with 14–16 differentiat- ed posterodorsal hairs and spinules of apical combs simple. Wings ( Fig. 9) 1.46 mm long. Costal index 0.40. Costal ratios 4.6–4.7:0.9:1. Costal cilia (of section 3) 0.12 mm long. Avery small hair at base of vein 3. With 2axillary bristles, the outer being 0.12 mm long. Sc not quite reaching R1. Haltere brown.

Material: HOLOTYPE male, Switzerland, Limpach [BE], 14 May 1987, Peter Duelli (6, GiE (2), CUMZ, 19-137).

Etymology:Named after the type locality.

Expanded couplet 126 of Disney (1989. Figs D89-XXX refer to figures in this publication

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126 Scutellum with an anterior pair of small hairs and aposterior pair of bristles .............................................................................................................. 126A

— Scutellum with 4bristles that are about the same length. (The anterior spur of the hind tibia is about 0.8 times as long as the ventral spur). The length of the epandrium is far greater than its height. The brown vestigial hypan- drial lobes are very broad ............................................... aristica (Schmitz)

126A Anal tube clearly shorter than dorsal length of epandrium. (Costal cilia more than 0.10 mm long) .............................................................................. 126B

— Anal tube about as long as epandrium or longer ................................. 126C

126B Wing membrane dusky (clearly evident when viewed with the naked eye against awhite background). With at least 3axillary bristles. The hairs at tip of proctiger clearly weaker than hairs of cerci (Fig. D89 366) .................... .................................................................................... unguicularis (Wood)

— Wing membrane only lightly tinged grey. With only 2axillary bristles. Hairs at tip of proctiger clearly stronger than hairs of cerci ( Fig. 5) ...................... ........................................................................................ limpachensis sp. n.

126C Palps yellow ......................................................................................... 126D

— Palps brown. (Costa more than two fifths of length. Hypopygium as in Figs 10–12) ............................................................................... digitalis Schmitz

126D Anal tube about as long as dorsal face of epandrium or slightly shorter

............................................................................................................... 126E

— Anal tube clearly longer than epandrium ( Fig. 14). (Hairs below basal half of hind femur shorter than AV hairs of outer half ........................................ ................................................................... lavoursensis Disney &Withers

126E Hypopygium as in Fig. 15, the hairs of proctiger being about as strong as those of cerci. Costal cilia of section 3at most 0.10 mm long ..................... ............................................................................... subcarpalis (Lundbeck)

— Hypopygium as Fig. D89-367 the hairs of proctiger being longer and more robust than hairs of cerci. Costal cilia of section 3at least 0.13 mm long ... .......................................................................................... feshiensis Disney