Hypexilis Horn, 1885

Heffern, Daniel, Santos-Silva, Antonio & Nascimento, Francisco E. L., 2021, American Cerambycidae (Coleoptera): Four new species, new records and taxonomic notes, Zootaxa 4933 (3), pp. 361-378 : 364-365

On Hypexilis Horn, 1885 and Caribbomerus Vitali, 2003

Hypexilis and Caribbomerus differ only in the shape of their protrochanters, a characteristic which has never been mentioned before. In Hypexilis ( Figs. 15–18 ), they are almost vertical in relation to the anteroposterior axis of the body, oblique in relation to the axis of the profemur, and their apex is rounded. In Caribbomerus , they are more typical, coplanar or nearly so with profemur, and with acute apex ( Fig. 24 ).

Horn (1885) described Hypexilis as follows: “Antennae “male symbol” twice as long as the body, joints 3–11 gradually increasing in length. Eyes moderately prominent, coarsely granulated, deeply emarginate. Maxillary palpi much longer than the labial, the terminal joint broad, securiform; last joint of labial narrowly oval, truncate at tip. Femora clavate; first joint of hind tarsi longer than the next two.” Horn (1885) did not comment on the protrochanter shape either in the description of H. pallida .

Linsley (1935) described H. longipennis , but did not describe the shape of the trochanters. Linsley (1962) redescribed Hypexilis : “Form elongate, slender. Head broader across eyes than width of pronotum; antennae twice as long as body, 11-segmented, not ciliate, segments 3 to 11 gradually increasing in length, last segment shorter than ninth and tenth together; maxillary palpi less than twice as long as labial palpi. Pronotum distinctly less than twice as long as broad. Posterior tarsi with first segment shorter than following segments together.” Linsley (1962) was the first who reported the similarity of Merostenus White, 1855 (currently, Caribbomerus ) with Hypexilis : “This genus is related to the West Indian Merostenus .” However, he also did not comment on the shape of the protrochanters.

White (1855) described Merostenus as follows: “Head somewhat depressed, short before the eyes. Eyes projecting, wider than the thorax. Antennae as long as the body, third joint not as long as the fourth, fifth and the following joints longer than the fourth. Thorax somewhat narrow, longer than wide. Elytra elongated, flattened, at the apex produced. Legs with the femora slightly clavated, of two hind legs compressed.” Lacordaire (1868), Zayas (1975), and Villiers (1980) provided a short redescription, but they did not comment on the shape of the trochanters. Martins (2005) commented (translated): “As Merosternus [sic] is very similar, or even synonym, of Hypexilis Horn, 1885 , we deem it appropriate to transfer it to Graciliini .” Martins & Galileo (2005) also provided a redescription of Merostenus , without comment on the shape of the trochanters. Vitali (2003) pointed out the homonymy between Merostenus White, 1855 and Merostenus Walker, 1837 (Hymenoptera) , and used Caribbomerus as a replacement name for the former. Although Vitali (2003) provided a key to species of the genus, he did not provide a generic redescription.

Lingafelter (2011) provided another description of Caribbomerus , but no information on the trochanters was given. Finally, Devesa et al. (2015) provided a redescription of the species of Caribbomerus from Cuba and, although he did not point out the shape of the protrochanters, it is possible to see that they are normal through the photographs of the specimens illustrated in that work.

For now, it is not possible to provide keys to species of Hypexilis and/or Caribbomerus because it will be necessary to examine all species currently placed in these genera.

Figures

FIGURES 13–24. 13) Merostenus howdeni (= Caribbomerus howdeni; = Hypexilis pallida), paratype male, dorsal habitus. 14) Hypexilis pallida, male from the USA (Texas), dorsal habitus. 15–18) Protrochanters, Hypexilis pallida: 15) Merostenus howdeni, paratype male; 16) Male from the USA (Texas); 17) Merostenus howdeni, paratype male, detail; 18) Male from the USA (Texas), detail. 19–24) Caribbomerus jaliscanus sp. nov., holotype male: 19) Dorsal habitus; 20) Ventral habitus; 21) Head, frontal view; 22) Detail of scutellum; 23) Lateral habitus; 24) Protrochanters.