Microdota Mulsant & Rey

Klimaszewski, Jan, Webster, Reginald P., Sikes, Derek, Bourdon, Caroline & Labrecque, Myriam, 2015, A review of Canadian and Alaskan species of the genera Clusiota Casey and AthetaThomson, subgenusMicrodota Mulsant & Rey (Coleoptera, Staphylinidae, Aleocharinae), ZooKeys 524, pp. 103-136 : 105-106

Taxon classification Animalia Coleoptera Staphylinidae

Subgenus Microdota Mulsant & Rey

Microdota (Mouthparts illustrated by Lee and Ahn 2015)

Diagnosis.

The following combination of characters is distinctive for Microdota : small and subparallel body (Figs 1, 9, 17, 25, 33, 41, 49, 56, 61, 69, 80, 84), length 1.5−2.7 mm, antennomere I enlarged but not extremely swollen, longer than II, II longer than III, V−X slightly to strongly transverse; median region of prementum very narrow and without pseudopores; labial palpus with 3 articles; glossa split apically forming Y-shaped structure; maxillary palpus with 3 articles, last one narrowly elongate; pronotum transverse, more than 1.2 times as wide as long, midline pubescence directed in most specimens anteriorly and laterad elsewhere (Figs 1, 9, 17, 25, 33, 41, 49, 56, 61, 69, 80, 84); pronotal hypomeron fully visible laterally; elytra in some species with wavy pattern of pubescence in postero-sutural section of disc (Figs 33, 49); median lobe of aedeagus with large bulbus and triangularly shaped apex of tubus in dorsal view, internal sac of median lobe of aedeagus with well-developed complex structures (Figs 4, 5, 12, 13, 20, 21, 28, 29, 36, 37, 44, 45, 51, 52, 64, 65, 72-75, 87); spermatheca of variable shape, L- or S-shaped, capsule usually in a form of a narrow sac or club-shaped, and stem often sinuate (Figs 8, 16, 24, 32, 40, 48, 55, 59, 60, 68, 78, 79, 83); male tergite VIII in most species simple, truncate apically and without teeth, sometimes with minute crenulation and small pairs of teeth (Figs 2, 10, 18, 26, 34, 42, 50, 62, 70, 85).

Some species of Microdota , due to small body size and some superficial external similarity, may be confused in collections with members of the subgenus Datomicra Mulsant and Rey, from which they may be distinguished by having a fully exposed pronotal hypomeron in lateral view; the pronotal hypomeron is only partially visible in Datomicra . Many species of Datomicra also have a more densely and coarsely punctate forebody than that of Microdota .

Microdota may be distinguished from Dimetrota by the following combination of characters: body usually parallel-sided, small, on average 2 mm long ( Microdota - 1.5-2.8 mm; Dimetrota - 1.8-3.8 mm, with elytra usually distinctly broader than pronotum); glossae Y-shaped (deeply split in Dimetrota ); pronotum with sparse to moderately dense and slightly asperate punctation (dense and strongly asperate in Dimetrota ); lateral margins of pronotum and elytra, and middle and hind tibiae with moderately pronounced macrosetae (strong bristles in Dimetrota ); hypomera fully visible in lateral view (partially to less often fully visible in Dimetrota ); and male tergite VIII truncate apically, rarely crenulated, and usually without large lateral teeth (with two large lateral teeth and often distinctive form of margin between them or with pattern of smaller teeth in Dimetrota ). Details on diagnostics of Microdota are provided by Brundin (1948), and Lee and Ahn (2015). Species of Nearctic Dimetrota badly need revision.

Clusiota may be distinguished from Microdota by the following combination of characters: basal antennal article swollen (some species); antennal articles V-X strongly transverse; glossae deeply split medially; pronotum narrower than elytra; elytra flattened, truncate posteriorly and without distinct lateral emargination; abdomen often swollen; spermatheca more or less sinuate with narrowly pear-shaped capsule and small and short apical invagination; and by the median lobe of the aedeagus with large bulbus, strongly ventrally produced tubus bearing elongate subapical part, and with crista apicalis located on elevated part of bulbus.

Key to Canadian and Alaskan species of Microdota