Megaselia sororbata Disney, 2011

Disney, R. Henry L., Ševčík, Jan & Cb, Cambridge, 2011, A new species of fungus breeding Megaselia (Diptera: Phoridae) from Indonesia, Acta Entomologica Musei Nationalis Pragae 51 (1), pp. 211-215 : 212-214

Megaselia sororbata Disney sp. nov.

( Figs. 1 –4)

Type material. HOLOTYPE: J, INDONESIA, North Sulawesi, Minahasa, Tomohon env., 950 m, 01.32370°N, 124.86163°E, reared from sporophore of Rigidoporus microporus (Sw.) Overeem ( Polyporales , Meripilaceae ), 25 January 2010, J. Ševčík (coll. University of Cambridge, Museum of Zoology – 8-164). PARATYPES: 2 JJ, 2 ♀♀ as holotype (coll. University of Cambridge, Museum of Zoology).

Description. Male. Frons brown, clearly broader than long, with 80–88 hairs and dense but very fine microtrichia. Lower pair of supra-antennal bristles (SAs) robust but clearly shorter than upper pair. The antials lower on frons than anterolaterals and about as far from upper SAs as either is from an AL bristle. Pre-ocellars and at most as far apart as upper SAs but further apart than either is from a mediolateral bristle, which is very slightly higher on frons. Cheek with 4 bristles and jowl with 2 that are longer and more robust. The subglobose postpedicels brown and without SPS vesicles. Palps ( Fig. 3 ) yellow, at most a third as broad as postpedicel wide as diameter of postpedicel and the width of the combined labella as wide or slightly wider than labrum. Thorax as male. Abdominal tergites brown. T5–T7 and terminalia as Fig. 4, the cerci being vestigial, and ventrally with a pair of pale, apical, tapered but slightly curved outwards spinules. Venter brown, and with hairs below segments 3–6. Sternite 7 at most three quarters as long as T7, tapered anteriorly and with 4–5 hairs in posterior quarter. Furca not evident. Dufour’s crop mechanism pale, about 1.8 times as long as its greatest width, and rounded behind. Legs similar to male. Wing as male except 1.3 mm long. Costal index 0.39–0.42. Costal ratios 1.4–1.6: 1. Otherwise it and haltere as male.

Etymology. Named after it being a sister species of Megaselia orbata Borgmeier, 1967 (see below).

Affinities. In the keys to the species of Group VIII of BORGMEIER (1967) the males readily run to couplet 3, lead 1, to M. orbata . This species is only known from males from Queensland, Australia. The male of the new species is immediately distinguished by the vestigial posterior lobes of the hypandrium compared with well developed lobes of M. orbata and the distal margins of the labella of the proboscis being more steeply inclined rearwards compared with M. orbata (cf. Figs. 1 and 2 with Figs. 8 and 9 in DISNEY (2008b)).

Remarks. The host fungus was collected on the stem of live bamboo ( Fig. 5 ) in a mixed secondary forest on the volcano Mt. Mahawu. Several unnamed species of Limoniidae , Cecidomyiidae , Ceratopogonidae , Psychodidae , Drosophilidae , Muscidae (Diptera) and two unnamed species of parasitic Hymenoptera were reared from the same sample.

Figures

Figs. 1–3. Megaselia sororbata Disney sp. nov., male. 1 – right face of epandrium and hypandrium; 2 – left face of hypopygium; 3 – proboscis and left palp from above. Scale bars = 0.1 mm.

Figs. 5–6. Habitat (5) and host fungus (6) of Megaselia sororbata Disney sp. nov. (photo by P. Kočárek and J. Ševčík).