Eugonus adustus, Poinar & Legalov, 2016

Poinar, George & Legalov, Andrei A., 2016, New Anthribidae (Coleoptera: Curculionoidea) in Dominican and Mexican ambers, Palaeontologia Electronica 148 (1), pp. 1-38 : 5-7

Eugonus adustus sp. nov.

Figure 3

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Holotype. Deposited in the PACO (accession # C-99).

Description. Length body, 3.1 mm; length rostrum, 0.5 mm. Body brownish-black with covering of quite distinct, dense, pale, appressed setae. Rostrum wide and short, 0.5 times as long as pronotum, flat, without dorsal median carina; antennal scrobes sulciform, dorso-lateral, contiguous with eyes; forehead wide, weakly convex, punctate; eyes large, rounded, distinctly convex, 1.2 times longer than wide; vertex weakly convex, densely punctate; temples short; antennae inserted at base of rostrum, quite long, almost reaching middle of pronotum; flagellum black; antennal club not compact, 2.7 times longer than wide. Pronotum almost bell-shaped; 2.0 times longer than wide at apex, 1.1 times longer than wide in middle and at base, with long lateral carina reaching front margin of pronotum; disk weakly convex, densely and finely punctate; faint transverse dorsal pronotal carina basal; scutellum trapezoidal. Elytra cylindrical, elongate and distinctly convex, 1.9 times longer than wide at base and in middle, 2.2 times longer than wide at apical fourth, 1.9 times as long as pronotum, without setae; greatest width in middle; humeri weakly flattened; striae regular and distinct; strial punctures oval, dense; elytral intervals weakly convex, 1.0–1.5 times as wide as striae, finely punctate; apices of elytra not rounded; pygidium not concealed. Thorax punctate; precoxal portion of prosternum quite elongate, 1.3 times as long as procoxal cavities, 3.1 times as long as postcoxal portion; postcoxal portion 0.5 times as long as procoxal cavities; procoxal cavities narrowly separated; mesocoxal cavities widely separated; metaventrite finely punctate, metanepisternum narrow, 8.8 times longer than wide in middle. Abdomen convex; first ventrite 0.8 times as long as length of metacoxal cavity; second ventrite 1.5 times longer than length of first ventrite; third ventrite 0.8 times as long as length of second ventrite; fourth ventrite 0.8 times as long as length of third ventrite; fifth ventrite 1.1 times as long as length of fourth ventrite. Legs long; pro- and mesocoxae round; metacoxae transverse; femora clavate, without teeth; trochanters obconical; mesofemora 3.8 times longer than wide; metafemora 3.8 times longer than wide; tibiae black, flattened, almost straight; metatibiae 8.4 times longer than wide in middle; tarsi long, black; first to third tarsomeres conical; second tarsomere embracing third tarsomere laterally; fifth elongate; tarsomeres with pulvilli on underside; tarsal claws free, large, distinct diverging, with basal teeth.

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

Etymology. The specific epithet is taken from the Latin “adustus ” equals dark brown, in reference to the color of the fossil.

Comparison. The new species is similar to E. ornatus Jordan, 1904 from Brazil but differs by the smaller body size, black flagellum, tibiae and tarsi, elytra without pockets of setae and a finely punctate metaventrite. From E. bicolor Valentine, 1972 in North and Central America it differs by the smaller body size, brownish-black body, black antennae and legs, elytra without hair spots and the narrow pronotum and elytra.

Remarks. Both specimen no. C- 99 and the following no. C-112 belong to the tribe Eugonini based on the dorso-lateral sulciform antennal scrobes contiguous with the eyes and a cylindrical body with a basal transverse dorsal pronotal carina The lateral carina reaching the front margin of the pronotum is a feature of the genus Eugonus .

Figures

FIGURE 3. Holotype of Eugonus adustus sp. nov. PACO no. C-99 in Dominican amber. 1, dorsal view, scale bar equals 0.6 mm; 2, ventral view, scale bar equals 0.6 mm; and 3, lateral view, scale bar equals 0.9 mm.