Dinoxyleborus cognatoi, Smith, 2017

Smith, Sarah M., 2017, Dinoxyleborus Smith, a new genus of Neotropical xyleborine ambrosia beetle (Coleoptera, Curculionidae: Scolytinae), Zootaxa 4303 (1), pp. 131-139 : 133-135

Dinoxyleborus cognatoi sp. nov.

(Figs 3–6)

Type material. Holotype, female, FRENCH GUIANA, [Cayenne], 30 km SE Roura, Kaw Rd, Amazon [e] Nat [ure] Lodge , 4.5595N, 52.2072W, 300m, 5-19.II.2010, J. Eger, UV light ( NMNH) . Paratype, female, PERU, Madre de Dios, Los Amigos Biological Station , CM 2, ¯12.4492° –70.2517°, 258 m, Smith and Hulcr coll. DNA voucher “ Cor peru” ( MUSM) .

Description. Female. Length 2.5–2.6 mm and 3.6–3.7 times as long as wide. Body color ferruginous apically and transitioning to dark red brown posteriorly with the elytral declivity and spines the darkest. Legs and antennae ferruginous.

Head. Epistoma entire, transverse, lined with a row of hair-like setae. Frons slightly convex from epistoma to upper level of eyes; surface shagreened, dull, punctate; punctures above epistoma small, coarse, shallow, punctures increasing in size, coarseness, and depth from epistoma to upper level of eyes. Eyes moderately emarginated above level of antennal insertion, upper portion of eyes smaller than lower part. Submentum flat, slightly impressed below genae, broadly triangular. Scape narrow, elongate, about 3/4 length of club. Antennal funicle four segmented, segments equal in size. Pedicle longer than funicle. Club approximately circular, club type 4 ( Hulcr et al. 2007), flattened, round; segments 1 and 2 strongly procurved, corneus, segment 3 slightly procurved, corneous, visible on both sides of club.

Pronotum. Pronotum prolonged posteriorly (Type 8a, Hulcr et al. 2007), 1.4 times as long as wide. Anterior margin basic, elongate, parallel-sided, rounded when viewed dorsally (Type 9, Hulcr et al. 2007), lacking a row of serrations. Surface shagreened, anterior half finely asperate, asperities close, arranged in concentric rings from midpoint of pronotum to anterior and anteriolateral areas; disc finely and evenly punctate. Lateral margins rounded, slightly carinate on basal quarter. Base transverse.

Legs. Procoxae contiguous, prosternal posterocoxal piece short, triangular. Protibia slender, broadest at apical third, posterior face inflated, tuberculate; three small denticles present on outer margin of apical third. Meso- and metatibia with evenly rounded outer margin, flattened, posterior face unarmed. Mesotibia armed with 7 socketed denticles on outer margin, metatibia armed by 6 socketed denticles on outer margin.

Elytra. 2.1–2.3 times as long as wide. Elytral base transverse, humeral angles rounded. Scutellum small, triangular, flat, flush with elytra. Sides straight from base to declivity midpoint; apex entire. Disc longer than declivity. Disc smooth, shining, finely punctate; each interstrial puncture bearing a single erect, fine, golden, hairlike seta 1.5–2.0 times the length between punctures (may be abraded); interstriae equal to width of striae. Interstriae parallel on disc and broadened towards elytral apex. Declivity deeply concave, separated from disc by large elevated sulcus bearing denticles and spines. Declivital face densely shagreened, dull, sparsely, shallowly punctate, setose on basal half; setae long, erect, fine, golden, hair-like; basal third rugose. Declivital margin armed by three spines, 4 denticles and abundantly ornamented with long semi-recumbent setae; spines increasing in size from base to apex. Two denticles approximately evenly spaced from base to spine 1, one each on interstriae 1 and 2. Single large denticle located at midpoints between spines 1 and 2 (interstriae 4) and 2 and 3 (interstriae 6). Spine 1 originating at basal third, on interstriae 3, 1.5 times as long as basal width, apex acute. Spine 2 equidistant between spines 1 and 3 ( Peru) or closer to spine 3 ( French Guiana), originating on basal third, on interstriae 5, twice as long as basal width, apex acute. Spine 3 at apical margin, on interstriae 7, twice as long as basal width, thick, apex acute. Declivital interstriae armed with granules dorsad to the margin of the sulcate area.

Diagnosis. Dinoxyleborus cognatoi is most closely related to D. sexnotatus which both have three declivital spines that increase in size from base to apex. It can be distinguished by the declivity with two denticles approximately evenly spaced from base to spine 1, a single large denticle located at midpoints between spines 1 and 2 and 2 and 3, by the smaller size and more slender body.

PLATE 2. Dinoxyleborus cognatoi sp. nov. female. Figure 3. Dorsal view. 4. Lateral view. 5. Frontal view. 6. Declivity.

Etymology. This species is named in honor of my husband, Anthony I. Cognato, who has championed studies in scolytine systematics and taxonomy for more than 20 years.

Distribution. French Guiana (Cayenne), Peru (Madre de Dios).