Leia bimaculata (Meigen, 1804)

Polevoi, Alexei & Salmela, Jukka, 2016, New data on poorly known species of the genus Leia Meigen (Diptera, Mycetophilidae) from the Palaearctic region, Zootaxa 4103 (5), pp. 487-500 : 497-499

Variation in the male terminalia of Leia bimaculata (Meigen, 1804)

Leia bimaculata is a common European species, which is variable in body coloration (from almost completely yellow to mostly black) and wing markings (from distinct dark bands to completely clear wing). Male terminalia of this species have been illustrated by several authors. None of the available figures give details of the aedeagal complex structure, but there is always a well visible dorsal projection at the base of the gonostylus ( Plassmann 1973; Hutson et al. 1980; Zaitzev 1994). Considering stable interpretation of the species, we call such specimens "typical". During our study we noticed four specimens from Finland and Russia with small differences in the male terminalia. The most distinctive characters are as follows.

Typical L. bimaculata : lobes of ejaculatory apodeme straight ( Fig. 7 : E), gonostylus with conspicuous dorsal projection at base ( Fig. 7 : A, H–J).

Deviating specimens: lobes of ejaculatory apodeme protruding caudally ( Fig. 7 : G), gonostylus with no trace of dorsal projection at base ( Fig. 7 : K)

Other differences are visible e.g. in the shape of parameres ( Fig. 7 : D–G), but this may depend on the position of terminalia on the slide and the angle of view. Small variation in hypoproct structure ( Fig. 7 : B, C) is observed in both typical and deviating speciemen groups. All deviating specimens have clear wings, while studied typical specimens have wings with distinct (though sometimes quite faint) preapical band. Variable body coloration (from rather narrow dark bands on tergites and mostly yellow thorax, to considerably darkened abdomen and thorax) is observed in both typical and deviating specimen groups. Though differences in the gonostylus and ejaculatory apodeme seem to be stable, we did not feel confident enough to describe this as a new species until additional material is available.

Material examined. Typical specimens: AUSTRIA: 2♂, Igls, Tirol, 900 m, 16.8.1953, J. R. Vockeroth leg. ( CNC, pinned). ITALY: 1♂, Caserta, Campania Prov., 30.4.1844, ( CNC, coll. G. E. Shewell, pinned); 1♂, Bozen, 13.6.1873? ( ZIN, #217, pinned). LITHUANIA: 1♂, Vilnius distr. Karmazinai, 54°49'08,4":24°55'51,9", 19.9– 16.10.2003, rearing from Paxillus involutus (LZM, J.Rimsaite leg., pinned). SLOVAKIA: 1♂, Muranska planina Nat. Park Muran, Hrdzava dolina 26.7.2010, Malaise trap, (JES, J. Ševčík leg. #DIPT-JS-2014-0297); 1♂, Bratislava env., Devinska Kobyla hill, 17.6.1994, Malaise trap (JES, J. Ševčík leg., #DIPT-JS-2014-0298). CZECH REPUBLIC: 1♂, 1♀, Bohemia, Zivohost, near Slapy dam, 22.8.2010, rearing from fungi, ex Lactarius vellereus, (JES, J. Ševčík leg., DIPT-JS-2014-0299). SPAIN: 1♂, Granada, 700 m, 19.7.1960, J. R. Vockeroth leg. ( CNC, pinned). SWEDEN: 2♂, Sm: Ulvsdal, 14.5.– 14.8.2002, Malaise trap, ( IZBE, N. Franc & Co. leg., pinned). UNKNOWN LOCALITY: 1♂, 24.7.1842? ( ZIN, coll. Osten-Sacken, pinned).

Deviating specimens: FINLAND: 2♂, Al: Saltvik, ( ZMH, Frey leg. #3760 and #4016, pinned). RUSSIA: 2♂, Leningrad province, Luga 13– 14.8.1953 ( ZIN, Stackelberg leg., pinned).

Figures

FIGURE 7. Leia bimaculata Meigen, male terminalia. A. ventral view, typical specimens. B, C. hypoproct, typical and deviating specimens. D, F. aedeagal complex, lateral view. E, G. aedeagal complex, ventral view. H – K. gonostylus. (D, E, H – J: typical specimens from Austria, Italy, Lithuania, Spain, Sweden, Czech Republic and Slovakia; C, F, G, K: deviating specimens from Finland and Russia). Scale bars = 0.2 mm. Abbreviations: apo = ejaculatory apodeme, dp = dorsal projection of gonostylus, gst = gonostylus.