Aleochara (Xenochara) suslica, Assing, 2009

Assing, V., 2009, On the taxonomy and zoogeography of some Palaearctic Aleochara species of the subgenera Xenochara M & R and Rheochara M & R (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 59 (1), pp. 33-101 : 57-60

Aleochara (Xenochara) suslica nov. sp. ( Figs 91-104, Map 3)

Type material:

Holotype ♂: " Ukraine - Odessa, shore of Tiligul liman, Kalinivka , suslik hole, 9.IV.2006, A. Gontarenko / Holotypus ♂ Aleochara suslica sp. n., det. V. Assing 2008" (cAss) . Paratypes: 3 ♀♀: same data as holotype (cGon, cAss) ; 3 ♂♂: " Ukraine - Odessa, shore of Tiligul liman, Kalinivka , mouse nest, 13.IV.2005, A. Gontarenko " (cGon, cAss) ; 1 ♂: " Ukraine, Odessa, Korsuncy , suslik hole, 7.IV.1996, leg. A. Gontarenko " (cAss) ; 1 ♂: " Odessa obl., l. bank of Khadzhibey liman, vic. Morozovka [recte: Morozivka ], 17.04.005, leg. Bondarenko D. A. / under stone" (cGon) .

Description:

Body length variable: 4.0-7.0 mm. Habitus as in Fig. 91. Usual coloration (8 type specimens): head, pronotum, and abdomen blackish; elytral disc blackish with reddish posterior margin, or blackish with more or less extensive, weakly delimited reddish spot in posterior portion; legs dark-brown, with the tarsi and sometimes also the tibiae reddish to reddish-brown; antennae blackish-brown. Rarely (one paratype), the legs, antennae, the abdominal apex, and most of the elytral disc may be reddish.

Head 1.10-1.13 times as wide as long; punctation moderately fine and shallow; interstices on average as wide as, or slightly wider than diameter of macropunctures, with micropunctation, but without microsculpture; eyes large and bulging, approximately twice as long as postocular region in dorsal view, or nearly so ( Fig. 92). Antenna similar to that of A. breiti ( Fig. 93).

Pronotum 1.26-1.35 times as wide as long and 1.20-1.40 times as wide as head, larger (in relation to head) in larger than in smaller specimens; widest in or slightly behind the middle; posterior angles weakly marked; punctation more distinct, more defined, and denser than that of head

( Fig. 92); interstices on average approximately as wide as diameter of punctures and without microsculpture.

Elytra 0.75-0.80 times as long as pronotum; posterior margin near posterior angles obliquely truncate, not sinuate ( Fig. 92); punctation well-defined, coarser and denser than that of pronotum; interstices narrower than diameter of punctures, without microsculpture. Legs long and slender; metatarsus approximately as long as metatibia or nearly so; metatarsomere I elongate, distinctly longer than the combined length of II and III, almost as long as the combined length of II-IV.

Abdomen: tergites III-V with moderately deep anterior impressions, tergite VI without anterior impression; anterior impressions of tergites III-V with dense and moderately coarse punctation, remainder of tergal surfaces with sparser punctation; interstices of tergites III-VII without microsculpture ( Fig. 94); posterior margin of tergite VIII weakly and broadly concave ( Fig. 95).

♂: sternite VII with truncate posterior margin, pubescence near posterior margin not conspicuously dense ( Fig. 96); posterior margin of sternite VIII produced posteriorly ( Fig. 97); median lobe of aedeagus with slender ventral process and internal structures of distinctive shape ( Figs 98- 101); apical lobe of paramere short ( Fig. 102).

♀: sternite VIII obtusely pointed posteriorly; spermatheca as in Figs 103-104.

Etymology:

The name (adjective) is derived from the specific epithet of Spermophilus suslicus , in whose burrows most of the type specimens were found.

Comparative notes:

Aleochara suslica is distinguished from the species of the A. cuniculorum group by the more slender and more parallel body shape, the darker average coloration (particularly of the legs, also of the elytra), the longer metatarsomere I, the shape and chaetotaxy of the male sternite VII, the completely different morphology of the aedeagus (shape of the ventral process and internal structures, shorter apical lobe of the paramere), the posteriorly more pointed female sternite VIII, and by the shape of the spermatheca. The species is additionally separated from the syntopic A. gontarenkoi by the sparser and coarser punctation particularly of the pronotum.

Distribution and bionomics:

The known distribution of this species is confined to a few localities near Odessa, Ukraine ( Map 3). The type specimens were collected from burrows of Spermophilus suslicus and from the nest of a mouse of unknown identity. One specimen was found under a stone .

The species of the Aleochara laevigata group

Due to the absence of modern revisions of most Palaearctic Aleochara , as well as the long tradition of identifications based on external characters alone, it was not until NIKITSKY et al. (1998) discovered that what had been treated as A. laevigata was in fact a group of closely related species, which can reliably be distinguished only based on the sexual characters.

The species of the A. laevigata group share the following characters: body of small to moderate size; coloration black, elytra often with a (mostly triangular) reddish spot of more or less variable size; whole body without distinct microsculpture and glossy; legs of moderate length, but tarsi long, metatarsus (almost) as long as metatibia; abdomen, including anterior impressions of tergites III-V, coarsely punctate; male sternites III-VII unmodified; male sternite VIII obtusely produced posteriorly. Species of this group are characterised particularly by the similarly derived, evidently synapomorphic morphology of the spermatheca, as well as by the similar morphology of the median lobe of the aedeagus and its internal structures (shape of apical sclerotised structures, long flagellum). They are distinguished from the externally similar A. cuniculorum and allied species particularly by the distinctly transverse antennomeres V-X, the slightly shorter legs, the coarser punctation of the abdomen, the much less pronounced sexual dimorphism of sternite VIII, the different internal structures of the aedeagus, and the different general shape of the spermatheca.

As far as is currently known, all the species of the A. laevigata group are coprophilous. Below, seven species are attributed to this group: A. laevigata , A. signata , A. lonae , A. accepta , A. grandeguttata , A. brevilaminata , and A. falcata . In view of the external similarity and intraspecific variation, only A. laevigata is (re-)described in detail. The descriptions and diagnoses of the remaining species of this group are restricted to distinguishing characters, particularly the genitalia.