Derelomus thalioculus, Poinar & Legalov, 2015

Poinar, G & Legalov, AA, 2015, New Curculioninae (Coleoptera: Curculionidae) in Dominican amber, Palaeontologia Electronica 677 (1), pp. 1-15 : 2-3

Derelomus thalioculus sp. nov.

Figure 1 , Figure 2

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Holotype. Deposited in the PACO (accession # C-82).

Description. Length body, 2.4 mm; length rostrum, 0.5 mm. Body reddish-brown, appearing glabrous but actually with a covering of fine, dense setae. Rostrum elongate, equal in length to pronotum, 4.6 times longer than wide in the middle, weakly curved, without carinae, finely punctate; antennal scrobes lateral and directed toward lower edge of the eyes; forehead wide, flattened, punctate; eyes large, rounded, distinctly convex, diameter slighter greater than rostrum at base; vertex weakly convex and finely punctate; temples elongate, equal in length to eye; antennae inserted in middle of rostrum, elongate, almost reaching apex of pronotum; scape elongate, 8.0 times longer than wide; funicle with first to seventh antennomeres conical; first antennomere 2.1 times longer than wide; second antennomere 1.3 times longer than wide, 0.3 times as long and 0.4 times as narrow as first antennomere; third to fifth antennomeres subequal in length; third antennomere equal in length and width, 1.3 times as wide as second antennomere; fourth antennomere 0.8 times longer than wide, 1.2 times as wide as third antennomere; fifth antennomere equal to fourth antennomere; sixth antennomere 0.9 times longer than wide, 1.4 times as long and 1.3 times as wide as fifth antennomere; seventh antennomere 0.7 times longer than width, 1.3 times as wide as sixth antennomere; club compact, 1.4 times longer than wide, 0.4 times as long as funicle.

Pronotum almost conical; 1.6 times longer than wide at apex, of equal length and width in middle, 0.9 times longer than wide at base, with lateral carinae; disk flattened, densely and finely punctate; scutellum trapezoidal.

Elytra elongate and distinctly flattened, 1.7 times longer than wide at base, 1.6 times longer than wide in middle, 2.4 times longer than wide at apical fourth, 2.4 times as long as pronotum; greatest width behind middle, humeri weakly convex; striae regular and thin; strial punctures small, oval, dense; elytral intervals flattened, wide, 4.0-5.0 times as long as striae; apices of elytra not rounded; pygidium concealed.

Thorax punctate; precoxal portion of prosternum elongate, 2.3 times as long as procoxal cavities, 14.0 times as long as postcoxal portion; procoxal cavities contiguous; mesocoxal cavities widely separated, metepisternum narrow, 3.7 times longer than wide in middle.

Abdomen weakly convex ventrally; first and second ventrites elongate, equal in length; third and fourth ventrites short, equal in length; third ventrite 0.5 times as long as second ventrite; fifth ventrite elongate, 1.3 times as long as fourth ventrite.

Legs long; pro- and mesocoxae round; metacoxae transverse; femora weakly clavate, without teeth; trochanters obconical; metafemora 3.2 times longer than wide; tibiae with very small, blunt mucro; protibia almost straight; meso- and metatibiae slightly curved; metatibiae 3.8 times longer than wide in middle; tarsi long; first to third tarsomeres conical; fifth elongate; tarsomeres with pulvilli on underside; tarsal claws free, large, clearly diverging, with basal teeth; metatarsus: first tarsomere 1.7 times longer than wide at apex; second tarsomere 1.5 times longer than wide at apex; third tarsomere bilobed, 0.8 times longer than wide at apex; fifth tarsomere 5.0 times longer than wide at apex, 2.0 times as long as third tarsomere.

Type Locality. Amber mine in the Cordillera Septentrional of the northern portion of the Dominican Republic.

Etymology. The specific epithet is from the Latin “thalus” = dome and the Latin “oculus” = eye in regards the convex eyes.

Remarks. The pronotum with lateral carinae, concealed pygidium, antennal scrobes directed to the eye, short precoxal portion of the prosternum and convex eyes are features of the genus Derelomus of the tribe Derelomini . The covering of fine, dense setae separates this species from other members of the genus whose bodies are all glabrous.

Figures

FIGURE 1. Lateral view of Derelomus thalioculus sp. nov. in Dominican amber. Bar equals 0.550 mm.

FIGURE 2. Dorsal view of Derelomus thalioculus sp. nov. in Dominican amber. Bar equals 0. 440 mm.