Myllaena mutabilis, Assing, 2018

Assing, Volker, 2018, On some Myllaena species in the East Mediterranean and Caucasus regions (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 50 (2), pp. 1015-1032 : 1018-1023

Myllaena mutabilis nov.sp. ( Figs 8-19 , Map 1 )

T y p e m a t e r i a l: Holotype ♀: " GREECE: Corfu [19], Kilada Ropa , Gavrolimni 39°39'28''N, 19°48'06''E, 75 m, lake shore, sifted, 5.VI.2017, V. Assing / Holotypus ♀ Myllaena mutabilis sp. n., det. V. Assing 2018" (cAss) . Paratypes: 12♂♂, 9♀♀: same data as holotype (cAss) ; 3 exs. [2 teneral]: same data as holotype, but leg. Schülke ( MNB) ; 3♂♂, 95 exs. [many teneral]: " GREECE: Corfu [9a], Kilada Ropa , 39°40-41'N, 19°47-48'E, 70 m, car-net, 2.VI.2017, leg. Schülke & Assing " (cAss, cFel, MNB) ; 15 exs.: same data, but " 31.V.2017 ... [KOR17-09]" ( MNB) ; 36 exs.: same data, but " 5.VI.2017 ... [KOR17-09b]" ( MNB) ; 2 exs.: " Greece, S Kérkyra, NW Zigos , 39°44'N, 19°48'E, 280-310 m, stream valley, decid. forest, arable land, fallows, car-net, 3.VI.2017, leg. Schülke & Assing [KOR17-17]" ( MNB) .

E t y m o l o g y: The specific epithet (Latin, adjective: variable) alludes to the remarkably variable body size.

D e s c r i p t i o n: Body length 2.4-3.7 mm; length of forebody 1.2-1.5 mm. Forebody as in Fig. 8 . Coloration: forebody blackish-brown to blackish with the pronotal margins (especially the lateral margins) usually diffusely paler, partly also the posterior margins of the elytra paler; abdomen blackish with the posterior margins of segments III- VII and the posterior portion of segment VIII reddish to brown; legs yellow to reddishyellow; antennae dark-brown to blackish-brown with antennomere I yellow and antennomere XI often pale-brown.

Other external characters similar to those of M. intermedia and M. graeca .

♂: tergite VIII ( Fig. 9 ) oblong, posterior margin acutely pointed; sternite VIII ( Fig. 10 ) oblong and with strongly convex posterior margin; median lobe of aedeagus ( Figs 11-13 ) approximately 0.45 mm long, with long and slender bisinuate (lateral view) ventral process.

♀: tergite VIII ( Fig. 14 ) oblong, posterior margin of similar shape as that of male; posterior margin of sternite VIII truncate in the middle ( Fig. 15 ); spermatheca small, shaped as in Figs 16-19.

C o m p a r a t i v e n o t e s: As can be inferred from the highly similar external and secondary sexual characters and particularly from the practically identical morphology of the aedeagus, M. mutabilis is closely allied to M. graeca . Although M. mutabilis is of darker average coloration, a reliable separation from M. graeca is possible only based on the completely different shape of the spermatheca.

Myllaena graeca and M. mutabilis evidently belong to a group of species that is represented in the East Mediterranean by at least four species with a highly similar aedeagus. In the course of the present study, specimens of additional undescribed species belonging to this group from the Pelopónnisos (one male), Ikaría (one male), Bolu (one male), and Antalya (one female) were studied.

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Myllaena mutabilis is currently known only from the Greek island Corfu ( Map 1 ). As can be inferred from the fact that numerous specimens were collected with a car-net, the species is an active flyer and most likely more widespread at least in the southern Balkans.

The specimens from the type locality were collected at the shore of a lake by sifting grass and debris in reed. The vast majority of the type specimens was collected with a car-net on a forest track passing lakes and wetland. Three specimens from the type locality and numerous specimens collected on the wing are teneral.

Figures

Map 1: Distributions of Myllaena graeca (based on revised records) (circles), M. mutabilis (triangles), and M. cretica (star).

Figs 8-19: Myllaena mutabilis: (8) forebody; (9) male tergite VIII; (10) male sternite VIII; (11-13) median lobe of aedeagus in lateral and in ventral view; (14) female tergite VIII; (15) female sternite VIII; (16-19) spermatheca. Scale bars: 8: 0.5 mm; 9-10, 14-15: 0.2 mm; 11-13, 16-19: 0.1 mm.