Strigister Caterino, Tishechkin, and Proudfoot, new genus

Strigister Caterino, Tishechkin, and Proudfoot, new genus Type species: Strigister tecolotito Caterino, Tishechkin, and Proudfoot, new species Description. Size: Length 2.3–2.9 mm; width 2.0– 2.7 mm. Body: Body piceous, elongate oval, sides rounded, moderately strongly convex dorsoventrally. Head: Frons flat to weakly convex, with frontal stria complete along inner edge of eye, recurved dorsad, acute at middle; supraorbital stria absent; epistoma weakly depressed, shallowly emarginate apically; labrum about 4X as wide as long, emarginate apically; mandibles strongly bent mediad, with very strongly pointed apices, right mandible with simple, acute tooth at base of incisor edge, left mandible with weakly bifid tooth at base; submentum produced into base of oral cavity; mentum about 3X wider than long, emarginate apically, with numerous long setae; maxillary cardo bare, stipes with several long setae near lateral margin, ultimate labial and maxillary palpomeres narrowed, subulate apically; antennal scape slightly longer than funicle, sides uneven, slightly widened apically, bluntly dentate apicomedially; funicle widening to cupuliform 8 th antennomere; antennal club small, about length of apical 3 funicular antennomeres, increasingly setose toward apex, with single evident, weakly v-shaped annulus. Pronotum: Pronotal sides narrowed slightly from base to apex, disk without obvious gland openings, marginal stria complete along side, interrupted at anterior corner and behind head, submarginal stria complete along lateral and anterior margins; pronotal disk lacking prescutellar impression, variously sculptured. Elytra: Elytral disk with conspicuous ground punctation, secondary punctation denser apically; striae somewhat varied, but with most dorsal striae more or less complete. Prosternum: Prosternal keel truncate to weakly emarginate basally, with weak or no carinal striae basally, middle of keel interrupted by deep transverse incision, anterior to which the keel profile is depressed, with anterior carinal striae diverging from incision; prosternal lobe about two-thirds as long as keel, truncate to weakly emarginate apically, with very fine marginal stria. Mesoventrite: Mesoventral disk about 3X wider than long, anterior margin truncate to weakly produced, marginal stria complete, with varied anterolateral strioles. Metaventrite: Mesometaventral stria complete across front, continued by lateral metaventral stria toward metacoxa; postmesocoxal stria present, recurved anterad toward mesepimeron; metaventral disk weakly to moderately punctate. Abdomen: First abdominal ventrite with single complete lateral stria, disk moderately punctate, posterior margin moderately (females) to strongly (males) emarginate; ventrites 2–5 weakly punctate at sides; propygidium and pygidium very large, similar in midline length, variably punctate, lacking obvious gland openings or striae. Legs: Profemur weakly notched at inner apex; protibia with outer edge weakly rounded, weakly 4–5 dentate, with 2 small, apical spurs; protarsus with simple ventral spines in both sexes; mesotibia weakly curved, with 5–6 prominent marginal spines and a few submarginal spines along anterior surface; metatibia longer, more or less straight, with 4–5 marginal and a few weakly submarginal spines. Male genitalia: Accessory sclerites absent, T8 with deep, narrow basal emargination, sides weakly rounded to apex, with narrow, shallow apical emargination, ventrolateral apodemes weakly produced, widely separated beneath; S8 divided along midline, hinged to T8 near base, apices with few divergent setae, emarginate on inner edges and curved inward, with apical and midline membraneous velum; T9 with rather thick basal apodemes, sclerotized along their lower edges, ventromedial apodemes well-developed, strongly recurved proximad, T9 apex rather narrowly truncate; T10 elongate cordate, weakly desclerotized along midline; S9 elongate, narrow along most of stem base bulbous, apex narrowly T-shaped, with very weak median emargination and strong lateral and apical flanges; tegmen very narrow, elongate, parallel-sided in basal two-thirds, narrowed to weakly bifid apex, lacking ventral tooth or process, but with moderately well-defined median ventral keel; median lobe short, simple, extruded through ventral foramen one-third proximad apical narrowing; basal piece nearly one-half tegmen length. Female genitalia: T8 forming a single plate, apically narrowly desclerotized, with deep, arcuate, basal emargination, ventrolateral edges desclerotized/incised about midway from base to apex; S8 divided along midline with basal baculi narrowly attached at basolateral corners, basally convergent and subparallel in proximal half; S9 small, triangular, articulated with strap-shaped extension from apex of S8; T10 broad, desclerotized along midline; valviferae paddle-shaped, paddles about one-third total length; coxites rather stout, apically weakly tridentate, with distinct, articulated apical stylus; bursa copulatrix mostly membraneous, not strongly expanded, with paired sclerites above attachment of spermatheca; spermatheca weakly sclerotized, approximately spherical, with elongate, weakly spiraled spermathecal gland attached near its base. Diagnosis. This new genus can be easily recognized by several features unusual or unique among New World Exosternini. The single v-shaped annulus of the antennal club (Fig. 1) and the transversely incised prosternal keel (Fig. 2) are unique in Exosternini. The recurved and angulate frontal stria (Figs. 5–6), the truncate base of the prosternal keel (Figs. 7–8), the apically truncate prosternal lobe (Figs. 7–8), and the weakly bifidly toothed left mandible (Figs. 5–6) are found in few other New World Exosternini, and never in combination. Etymology. The name of this genus refers to the habits of the new species, showing an apparently exclusive but somewhat general preference for the cavity nests of true owls (family Strigidae), in combination with the common histerid ending –ister. The name is masculine.
Published as part of Caterino, Michael S., Tishechkin, Alexey K. & Proudfoot, Glenn A., 2013, A New Genus and Species of North American Exosternini Associated with Cavity-Nesting Owls and a Reassignment ofPhelister simoniLewis (Coleoptera: Histeridae: Histerinae), pp. 557-565 in The Coleopterists Bulletin 67 (4) on pages 558-559, DOI: 10.1649/0010-065x-67.4.557