Cymatodera uncina Rifkind, 2020

Cymatodera uncina Rifkind , new species

zoobank.org/ urn:lsid:zoobank.org:act:

( Figs. 6 View Figs , 39, 40 View Figs )

Specimen Examined. Holotype male: Mexico, Oaxaca, Tequisistlan , 4 Jan., 1956, [collector information missing] ( UCRC).

Description ( Holotype). Length: 11.5 mm. Color: Medium brown; head, pronotum and legs dark reddish brown; metaventrite reddish brown; mouthparts and abdomen testaceous; elytra with a broad, indistinct, undefined, transverse testaceous fascia posterior to middle. Head: Surface rather densely, finely but shallowly punctulate, and shallowly transversely rugulose, inconspicuously set with fine, very short, adpressed pale setae; eye moderate in size; antenna elongate; antennomeres conical to subserrate: Antennomere 2 not quite half the length of antennomere 3; antennomere 11 longer than antennomere 10, narrowed at apex. Pronotum: Elongate, about 2× as long as wide; disc subflattened above; surface shining, minutely transversely rugulose, inconspicuously micropunctate, rather sparsely set with short, fine, suberect pale setae, occasionally interspersed with erect, more elongate and more robust, darker setae. Elytra: Elongate (together more than 2× as long as broad), disc subflattened above; umbones moderately prominent; sides subparallel, gradually, arcuately convergent from posterior 1/5 to dehiscent, subsinuate apices; surface rather dull, strial punctures deep, moderately coarse, smaller and more shallow posterior to middle, obsolete on posterior 1/6; vestiture moderately dense, but very inconspicuous, composed of extremely short, adpressed, pale setae, intermixed with a few longer, more robust suberect setae. Metaventrite: Shallowly, minutely rugulose-punctate; carinae and tubercles absent; surface rather densely but inconspicuously clothed with short, fine, pale setae. Legs: Surface densely asperate-punctate; vestiture conspicuous, composed mostly of short, fine, pale adpressed setae. Abdomen: Ventrites 1–5 densely, finely punctulate, inconspicuously setose; ventrite 5 ( Fig. 39 View Figs ) with sides oblique, posterior angles subacute, posterior margin rather broadly, arcuately emarginate; ventrite 6 ( Fig. 39 View Figs ) elongate-triangular, convergent posteriorly, angles rounded at apex, posterior margin deeply, narrowly cleft at middle; surface sparsely punctate; tergite 6 ( Fig. 40 View Figs ) triangular, convergent posteriorly, depressed at middle above, hind margin subtruncate, feebly inflected at middle. Aedeagus: Apex of phallus elongate, upwardly curved, acuminate.

Variation. Known from the holotype only.

Etymology. The specific name refers to the hooklike shape of the phallus.

Distribution. The holotype, a unique specimen, was collected in the Isthmus of Tehuantepec, Oaxaca state, Mexico.

Biology. The habitat at the type locality is probably tropical deciduous forest.

Diagnosis. The new species can be distinguished from congeners on the basis of a unique combination of surface sculpturing and the shape of the male pygidium. Its plausible affinity is with the allopatric species Cymatodera tlahuica Rifkind, Toledo and Corona : They share similar facies, densely punctate legs, metaventrite with neither carinae nor tubercles, and aedeagus with the apex of the phallus produced as a dorsally recurved, elongate spine. They differ, however, in the shape of the male pygidium, which is much simpler in C. uncina: Most notably, its sixth abdominal ventrite lacks extended, posterolateral angles.