Thysdariella, A New Genus of the Myrmecophilous Supertribe Clavigeritae (Coleoptera: Staphylinidae, Pselaphinae) from Madagascar Author Hlaváč, Peter text The Coleopterists Bulletin 2005 2005-09-30 59 3 304 309 http://dx.doi.org/10.1649/741.1 journal article 10.1649/741.1 1938-4394 10105054 Thysdariella gen. nov. ( Figs. 1–3 ) Type species: Thysdariella fieldiana sp. nov. (here designated). Gender feminine. Etymology. The name of the genus is derived from the name of the subtribe Thysdariina and to indicate the relationship to Thysdarius Fairmaire and Thysdariopsis Jeannel. Diagnosis. Thysdariella is included in the subtribe Thysdariina through the following characters: (1) 4-segmented antennae; (2) eyes present and large; (3) body smooth, shining, with sparse pubescence; (4) head without constriction behind eyes; (5) humeral angles rounded; (6) lateral margins of pronotum rounded, not diverging posteriorly; and (7) presence of large flat plate on ventral surface of head. Thysdariella differs from Thysdarius Fairmaire and Thysdariopsis Jeannel in having last antennal segment shorter than segment III and pronotum with large, entire, deep median depression. Description. Body ( Fig. 1 ) moderately covered with golden setae, shiny, light reddish brown. Head elongate, about 1.5 times as long as wide, with two basal ventral fovea; eyes large; vertex 304 Fig. 1. Thysdariella fieldiana sp. n. , habitus. long, slightly more than twice as long as eyes and slighlty convergent, neck large, well separated from head by sharp constriction. Large flat plate on head venter well defined and well visible dorsally. Maxillary palpi minuscule, not visible in dorsal view. Antennae relatively long, reaching the elytral bases, scape slightly longer that pedicel, pedicel quadrate, segment III longest, 306 cylindrical, distinctly longer than pedicel and almost twice as long as apical segment. Apical segment expanded and hemispherical apically. Figs. 2–3. Thysdariella fieldiana sp., aedeagus. 2) Dorsal view; 3) lateral view; scale 0.2 mm. Pronotum approximately circular in outline, with large, entire, deep median depression. Lateral foveae well defined. Elytra longer than pronotum, with large rounded humerae, lateral margin of elytra slightly diverging posteriorly, with long setae on sides, disc glabrous, outer apical corners of elytra with few long, bristle-like setae that replace trichomes. Venter with large epipleura, all coxae round, meso and metasternum smooth, metasternum about twice as large as mesosternum, metasternal apex very large, truncate, metacoxae widely separated. Abdomen about as wide as elytra, tergal basin narrow, trichomes absent. Key to Genera of Thysdariina 1 Antennae 3 segmented - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2 19 Antennae 4 or 5 segmented - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4 2 Last segment of antennae very long, Zimbabwe - - - - - - - - - - - - - - - - - - - Arnoldiella Brauns 29 Last segment of antennae very short - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3 3 First visible tergite simple without trichomes, pronotum with median and lateral foveae, Angola , Cameroon , Rep. Congo - - - - - - - - - - - - - - - - - - - - - - - - - - - - Eurycheiles Jeannel 39 First visible tergite with two pairs of large trichomes, pronotum lacking foveae, Madagascar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Trichomatosus Célis 4 Antennae 4 segmented, Madagascar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5 49 Antennae 5 segmented, South Africa - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Brausniella Raffray 5 Last antennal segment shorter than segment III, pronotum with large, entire, deep median depression, Madagascar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Thysdariella sp. nov. 59 Last antennal segment longer than segment III, pronotum lacking large, deep median depression - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6 6 Head not separated from neck by deep constriction, antennal segment III narrower than pedicle, Madagascar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Thysdarius Fairmaire 69 Head separated from neck by constriction, antennal segments II and III subequal in size, Madagascar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Thysdariopsis Jeannel Note: Soalala Dajoz, 1982: 512 assigned to Thysdariina in its original description, belongs to the subtribe Apoderigerina (Besuchet, pers. comm.).