Crenulister explanatus, 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 : 60-61

Crenulister explanatus sp. n. Figs 23B, 25 B–D, Map 5

Type locality.

ECUADOR: Orellana, Yasuní Research Station [0.674°S, 76.398°W].

Type material.

Holotype male: "ECUADOR: Napo, mid.Rio Tiputini, Yasuní Res. Stn. 0°40.5'S, 76°24'W, FIT#1, 23-30 Jun 1999. AKT#032, C.Carlton & A.Tishechkin" / “LSAM0045737” (FMNH).

Other material.

1: same locality as type, 26. vii– 4.viii.1999 (LSAM); 1: PERU:Junin, ~16km NW Satipo, Rio Venado, 11°11.677'S, 74°46.137'W, 1150m, 3-8.iii.2010, A.V. Petrov (LSAM).

Diagnostic description.

Length: 1.8-2.1 mm, width: 1.6-1.9 mm; as for generic description with the following diagnostic characters: body rufescent, elongate ovoid, subdepressed; frontal stria fine, complete, frontal disk moderately depressed, frontal stria fine, complete, disk with few rather conspicuous secondary punctures against fine background punctation; epistoma with rather well-developed lateral and anterior marginal striae; labrum about 4 × wider than long, apical margin subtruncate; pronotum with single median gland opening about one-third from anterior margin; pronotal sides with fine, slightly raised lateral submarginal stria; secondary punctures of pronotal disk small, sparse, slightly larger and denser in basal third; prescutellar impression small but distinct; elytron with single, complete, crenulate epipleural stria; subhumeral and dorsal striae 1-4 complete, 4th weakly arched to the sutural at base, 5th stria barely abbreviated basally, sutural stria largely obsolete in basal fourth, may be represented by few serial punctures, all striae shallowly but coarsely impressed; inner elytral interstriae irregularly, sparsely punctate, with 8-10 punctures, fewer in outer intervals; prosternal keel acutely but not too deeply emarginate at base, with carinal striae narrowly united anteriorly; prosternal lobe weakly deflexed, marginal stria present only at middle; mesoventrite with marginal stria fine, mesometaventral stria crenulate, subangulate to basal third of mesoventrite; postmesocoxal stria recurved anterad around mesocoxa, reaching mesepimeron; lateral metaventral stria weakly crenulate, abbreviated in front of metacoxa; metaventral disk with secondary punctures smaller and sparser anteromedially; metepisternal punctures separate, not coalesced into a stria; lateral stria of 1st abdominal ventrite weakly impressed along inner edge of metacoxa; secondary punctures of median portion of 1st abdominal ventrite becoming obsolete in posterior half, with slightly oblique punctures toward sides behind metacoxa; punctures along posterior margins of ventrites 1-4 transversely elongate, intermittently coalesced into marginal strioles; protibia 5-6 spined, marginal dentation weakly developed; meso- and metatibia with 4-5 thin, elongate spines, mainly along apical half of margin; propygidium with secondary punctures shallow but rather large, uniformly separated by about half their diameters in basal half, sparser in posterior half; propygidial gland openings present in anterolateral corners; propygidial strioles absent; pygidium with few small secondary punctures, more conspicuous at sides; pygidial gland openings not evident; pygidial margin lacking striae. Male (Fig. 25 B–D): accessory sclerites weakly sclerotized, present; T8 with ventrolateral apodemes rather broad beneath, narrowing to apex; S8 with halves meeting only at basal corner, inner margins short and strongly divergent, with about 3 strong setae toward apex; T9 with apices subacute; T10 apically entire; S9 weakly emarginate, quadrate at base, apex narrowly and shallowly emarginate; tegmen widest near midpoint, apices only very narrowly separated, medioventral process produced beneath about one-third from base; median lobe about one-third tegmen length, basal piece nearly half tegmen length.

Remarks.

This species is closely related to the following, with simple pronotal gland openings, the elytral interstrial punctures largely restricted to the inner intervals, the postmesocoxal stria reaching the mesepimeron, and the metepisternum nonstriate. This species does not have the protibial margin appearing as strongly dentate, and has the sutural stria basally obsolete. The three specimens we assign to this species in fact vary considerably in size, coloration, and sculpturing, and we exclude two of them (females) from the type series due to associated uncertainty, regardless the fact that one is from the same locality as the holotype.

Etymology.

This species’ name refers to the slightly explanate lateral pronotal margins (Fig. 23B).