Crenulister umbrosus, Caterino, Michael S. & Tishechkin, Alexey K., 2014

Caterino, Michael S. & Tishechkin, Alexey K., 2014, New genera and species of Neotropical Exosternini (Coleoptera, Histeridae), ZooKeys 381, pp. 11-78 : 54-56

Crenulister umbrosus sp. n. Figs 18 A–G, 25 E–G, Map 5

Type locality.

BRAZIL: Pará: Tucuruí [3.75°S, 49.67°W].

Type material.

Holotype male: “BRASIL:Pará, Tucurui, 3°45'S, 49°40'W. Piège d’interception. IV.1985" / "Caterino/Tishechkin Exosternini Voucher EXO-03005" (UFPR). Paratypes (3): same locality as type, 2: 10-29.vii.1985 (CHND, MSCC, FMNH), 1: 9-17.xii.1985 (CHND).

Other material.

Same locality as type, 9-17.xii.1985 (CHND).

Diagnostic description.

Length: 1.9-2.0 mm, width: 1.7-1.8 mm; as for generic description with the following diagnostic characters: body rufopiceous, elongate ovoid, slightly more parallel-sided than most, subdepressed; frontal stria fine, complete, frontal disk moderately depressed, with fine, dense punctation consisting of ground punctation and barely larger secondary punctation; epistoma with lateral ridges delimiting median depression bearing weak fragments of lateral striae; labrum about 4 × wider than long, apical margin weakly emarginate; pronotum with gland opening track nearly reaching midline, with 3-4 openings lying within the impunctate track; pronotal sides with weakly crenulate, complete lateral submarginal stria; secondary punctures of pronotal disk rather small, mostly restricted to basal fourth; weak prescutellar impression present; elytron with complete, crenulate epipleural stria and secondary stria in posterior half; all dorsal striae complete, coarsely impressed; elytral interstriae irregularly but distinctly punctate, intervals with 20-25 coarse punctures; prosternal keel deeply emarginate at base, with carinal striae slightly abbreviated anteriorly, united; prosternal lobe slightly deflexed, marginal stria present only at middle; mesoventrite with marginal stria weakly crenulate, mesometaventral stria crenulate, arched forward to basal third of mesoventral disk; postmesocoxal stria recurved anterad around mesocoxa, ending short of mesepimeron; lateral metaventral stria rather weakly crenulate, ending short of metacoxa; metaventral disk with secondary punctures slightly smaller and sparser anteromedially; metepisternal punctures coalesced into a short stria; lateral stria of 1st abdominal ventrite fragmentary along inner edge of metacoxa, curving laterad behind metacoxa; secondary punctures of median portion of 1st abdominal ventrite smaller and sparser in posterior half, with slightly oblique punctures toward sides behind metacoxa; punctures along posterior margins of ventrites 1-2 transversely elongate but separate, those of ventrites 3-4 intermittently coalesced into marginal strioles; protibia 5-6-spined, with marginal dentation weakly developed; meso- and metatibia with thin, elongate spines, mainly along apical half of margin; propygidium with secondary punctures shallow but rather large, uniformly separated by 1 –1.5× their diameters; propygidial gland openings borne on faint tubercles in anterolateral corners; propygidial strioles absent; pygidium with secondary punctures more conspicuous at sides and apex; pygidial gland openings present near sides about one-fourth from base; pygidial margin with fragmentary striae along apical two-thirds, not complete around apex. Male (Figs 25E-G): accessory sclerites absent; T8 with ventrolateral apodemes strongly narrowed beneath; S8 with halves meeting along short inner margins apices moderately strongly divergent, with about 5 strong setae; T9 with apices narrow, obliquely truncate; T10 weakly desclerotized along midline; S9 slightly widened to weakly emarginate base, apex rather deeply emarginate; tegmen with sides very weakly rounded, widest toward apex, apices rather narrow and slightly separated, medioventral process produced beneath about one-fourth from base; median lobe nearly one-half tegmen length, basal piece about one-third tegmen length.

Remarks.

This species is the darkest of the smaller species. Its coloration in combination with complete elytral striation, conspicuous interstrial punctation (Fig. 18C), and fragmentary marginal pygidial stria will fairly readily distinguish it from other species in the genus. The single specimen excluded from the type series is slightly larger and more coarsely punctate, especially ventrally, than the other specimens, despite being collected in the same locality (and even same dates).

Etymology.

This species’ name refers to its relatively dark coloration.