Piesocorynus unibullus, 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 : 9-10

Piesocorynus unibullus sp. nov.

Figure 5

zoobank.org/ ABA40B18-FBAB-46A5-AECC-4409859372CB

Holotype. Probably female. Deposited in the PACO (accession # C-83).

Description. Length body, 5.2 mm; length rostrum, 1.0 mm. Body brownish-black with a covering of distinct, dense, pale, appressed setae. Rostrum wide and short, equal in length and width, 0.5 times as long as pronotum, flattened, without dorsal median carina; antennal scrobes foveiform, lateral; forehead wide, flattened, punctate; eyes coarsely faceted, fewer than 26 rows of ommatidia perpendicular to long axis, not emarginate, large, weakly convex, 1.2 times longer than wide; vertex weakly convex, densely and finely punctate; temples short, 0.3 times as long as length of eye; antennae inserted in first third of rostrum, elongate, reaching pronotal transverse carina; first antennomere (scape) 2.3 times longer than wide; funicle with second to eighth elongate-conical antennomeres; second antennomere 3.0 times longer than wide, 0.9 times as long as and 0.7 times as narrow as first antennomere; third to fifth antennomeres subequal in width; third antennomere 12.0 times longer than wide, 2.0 times as long as and 0.5 times as narrow as second antennomere; fourth antennomere 8.0 times longer than wide, 0.7 times as long as third antennomere; fifth antennomere equal in length to fourth antennomere; sixth antennomere 5.0 times longer than wide, 0.8 times as long as and 1.2 times as wide as fifth antennomere; seventh antennomere 4.2 times longer than wide, 0.8 times as long as and equal in width to sixth antennomere; eighth antennomere 1.3 times longer than wide, 0.8 times as long as and 2.5 times as wide as seventh antennomere; club not compact, 0.5 times as long as funicle; first antennomere of club 1.6 times longer than wide, 1.5 times as long as and 1.7 times as wide as eighth antennomere; second antennomere of club 1.4 times longer than wide, 0.9 times as long as and equal in width to first antennomere of club; third antennomere of club 3.0 times longer than wide, 1.3 times as long as and 0.6 times as narrow as second antennomere of club. Pronotum bell-shaped; 1.1 times longer than wide at apex, 0.8 times longer than wide in middle and 0.9 times longer than wide at base, with short lateral carinae; disk weakly flattened, densely and rugosely punctate, transverse dorsal pronotal carina antebasal; distance between transverse carina and base of pronotum 0.2 times as long as pronotum; scutellum trapezoidal. Elytra distinctly convex, 1.5 times longer than wide at base, 1.3 times longer than wide in middle, 1.5 times longer than wide at apical fourth, 2.2 times as long as pronotum; greatest width behind middle; elytron with one tubercle on base of second and third intervals; humeri weakly convex; striae regular and thin; strial punctures small, rounded, dense; elytral intervals flattened, wide, 3.3–6.0 times as wide as striae, sparsely and finely punctate; apices of elytra not rounded; pygidium not concealed. Thorax coarsely punctate; precoxal portion of prosternum elongate, 2.5 times as long as procoxal cavities, 5.0 times as long as postcoxal portion; postcoxal portion 0.5 times as long as procoxal cavities; procoxal cavities narrowly separated; mesocoxal cavities widely separated, metanepisternum narrow, 7.3 times longer than wide in middle. Abdomen convex; first ventrite 0.7 times as long as length of metacoxal cavities; second ventrite 1.1 times as long as length of first ventrite; third ventrite equal in length to 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; profemora 3.3 times longer than wide; mesofemora 3.0 times longer than wide; metafemora 3.1 times longer than wide; tibiae almost straight; mesotibiae 6.7 times longer than wide in middle; metatibiae 7.8 times longer than wide in middle; tarsi long; first to third tarsomeres conical; second tarsomere embracing third tarsomere laterally; fifth elongate; tarsomeres with pulvilli on underside; tarsal claws free, large, diverging, with basal teeth; metatarsi: first tarsomere 3.6 times longer than wide at base; second tarsomere 1.3 longer than wide at base, 0.6 times as long as and 1.6 times as wide as first tarsomere; third tarsomere equal in length and width, 0.6 times as long as and 0.8 times as wide as second tarsomere; fifth tarsomere 4.7 times longer than wide at base, 1.4 times as long as and 0.4 times as wide as second tarsomere.

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 “unis” equals one and the Latin “bullus” equals knob, in reference to the single tubercle on each elytron.

Remarks. The coarsely faceted eyes, fewer than 26 rows of ommatidia perpendicular to the long axis, antebasal pronotal transverse carina and eye margin not emarginate on the side nearest the antennal scrobes (also in PACO no. 83, 85, 86, 91, 101–105 and ISEA DA no. 2015/1) are features of the tribe Piesocorynini . These specimens (PACO no. 83, 85, 86, 101–105 and ISEA DA no. 2015/1) belong to the genus Piesocorynus based on the eyes with 15 or more rows of facets perpendicular to the maximum length and the third antennomere longer than either the second or fourth antennomeres.

Figures

FIGURE 5. Holotype of Piesocorynus unibullus sp. nov. PACO no. C-83 in Dominican amber. 1, dorsal view, scale bar equals 1.3 mm; 2, lateral view, scale bar equals 1.3 mm; and 3, ventral view, scale bar equals 1.2 mm.