New records of Caribbomerus from Hispaniola and Dominica with redescription of C. elongatus (Fisher) and a key to species of the genus in the West Indies (Coleoptera, Cerambycidae, Cerambycinae, Graciliini)

Abstract Three species of Caribbomerus Vitali are newly recorded for the Dominican Republic: Caribbomerus decoratus (Zayas), Caribbomerus elongatus (Fisher), and Caribbomerus asperatus (Fisher). The first two also represent first records for Hispaniola. Caribbomerus elongatus (Fisher) is redescribed based on additional material, including the first known males. Caribbomerus similis (Fisher) is newly recorded for Dominica. A key to the species of the genus from the West Indies is provided.


Introduction
Only one genus of Graciliini occurs in the West Indies, Caribbomerus Vitali (formerly known under the preoccupied Merostenus Walker and formerly placed in the Callidiopini) (Vitali and Rezbanyai-Reser 2003;Monné and Bezark 2010). Caribbomerus is most easily recognized by the following combination of characters: long, narrow body (4-11 mm long; 0.7-1.9 mm wide); elongate, usually parallel-sided elytra (elytron length 5-9 times its width); anterior coxal cavities closed posteriorly by a procoxal process which is extremely narrow between the procoxae and then abruptly widened behind; coarsely faceted eyes; and antennae distinctly longer than body (in part, based on Martins and Galileo 2005). Other characters include: third antennomere distinctly shorter than all others (with exception of pedicel); elytral apex of most species impunctate and with integument smooth and distinctly paler than remainder; prothorax 0.16-0.25 length of body and widest at or near posterior third in most species.
Prior to Napp and Martins (1984), Caribbomerus was known only from the Antilles. With the species they described from Brazil, Mexico, and Jamaica, along with a species Micheli (2003) described from Puerto Rico, the number of species was increased to twelve.
Th ree species of Caribbomerus: C. decoratus (Zayas), C. elongatus (Fisher), and C. asperatus (Fisher) are recorded from the Dominican Republic (new country records) (unrecorded in Monné and Bezark 2010;Perez-Gelabert 2008). For the fi rst two, Hispaniola represents a new island record. Caribbomerus elongatus is redescribed based on additional material (including newly discovered males) revealing broader morphological variation than refl ected in the original description. All Hispaniolan Caribbomerus are restricted to the southern and southwestern parts of the Dominican Republic, along and southwest of the Cordillera Central (Fig 6). A key, table of measurements (Table 1), and photos (Figs 1-5) to all the species of Caribbomerus from the West Indies are provided.

Methods
Most of the material examined in this study was collected by R. H. Turnbow, Jr. (RHTC), E. F. Giesbert (FSCA), J. Rawlins and R. Davidson (CMNH), and M. Ivie and K. Guerrero (WIBF). Holotypes are deposited in the Smithsonian Institution (USNM) and images are available in the online Smithsonian Primary Type database (Lingafelter et al. 2010).
Images were captured with a Zeiss AxioCam HRc camera mounted on a Zeiss Discovery V20 stereomicroscope with Sycop motorized zoom and focus control. Objectives used included a PlanApo S 1.0× and 0.63×. For illumination, a Zeiss KL 2500 LCD with ring light attachment was used. Axiovision software enabled preparation of montaged images and precise, automatically calibrated measurements.
In the course of this work, these collections and others were examined for Caribbomerus specimens. Nearns et al. (2006)

Caribbomerus elongatus (Fisher)
Figs 1-4, 5a,f, 6, Table 1 Diagnosis. Based on the availability of additional non-type material (including males), the variation within this species can now be more fully documented. Although the holotype female has uniformly pale testaceous antennae, the antennae of males are narrowly dark annulate at the apices of most antennomeres (except scape and pedicel). Th e pronotum of females is slightly swollen posteriorly and then moderately constricted at the base but in males it is nearly parallel-sided and not or barely wider at posterior third unlike most of the remaining species of the genus. Th e pronotum of both sexes is densely punctate throughout, but in some females there is a very small, vaguely defi ned median callus lacking punctures and surrounded by a slight depression. Th e pronotum and elytra have a coating of tawny, appressed pubescence which does not obscure punctures. Th e elytral apices are abruptly smooth and impunctate with the anterior margin of this region slightly depressed.
2 Zayas (1975) reports the holotype as 4.5 mm (outside the range I have seen from Hispaniola).
3 Zayas (1975) reports a specimen as small as 5.5 mm (outside the range I have seen from Hispaniola). 4 Zayas (1975) reports a specimen as small as 4.0 mm. 5 Chalumeau and Touroult (2005) reports this species as large as 6.8 mm.  Discussion. Using the key to Caribbomerus of Vitali and Rezbanyai-Reser (2003), this species would run nearest C. howdeni (Napp and Martins), a Mexican species, based on the coloration, and shape and pubescence of the pronotum. However, their key is incorrect in coding C. elongatus as having a glabrous pronotum. Th e holotype of C. elongatus (and all of the new material seen) clearly has translucent pubescence on the pronotum as noted in Fisher's (1932) description. Th is species, previously known by the female holotype from Cuba (Fisher 1932;Monné and Bezark 2010) and an unspecifi ed number from Oriente, Las Villas, and Pinar del Rio provinces in Cuba as mentioned by Zayas (1975), is now documented for the Dominican Republic (new island & country record).

Caribbomerus decoratus (Zayas)
Figs 5e, 6, Table 1 Diagnosis. Th is species is recognized by the densely, coarsely punctate pronotum with a distinct (and sometimes paler), mostly impunctate median longitudinal callus surrounded by less distinct and mostly punctate peripheral calli (one on either side). Caribbomerus decoratus (Zayas) is very similar to C. picturatus (Napp and Martins) which is known only from Jamaica. In both species, the elytra have a vague, pale macula at the middle near the suture and have the elytral apices impunctate and pale. Th e leg color of C. decoratus ranges from uniformly pale yellow to reddish-brown with the clavate portions of the femora darker than the rest of the legs (in C. picturatus (Napp and Martins) the legs are uniformly pale yellow and much paler than the dorsum). Caribbomerus picturatus also can be distinguished from C. decoratus by the heavy surface sculpture and contiguous punctation of the frons, vertex, and antennal tubercles. In C. decoratus, the punctures are sparse and not contiguous.
Discussion. Th is species was described by Zayas (1975) from Cuba. His description of the pronotum and exposed terminal tergites, among many other features, suggests that the photograph of this species is mislabeled in Nearns et al. (2006). In that paper, fi gure 5a should be C. exiguus (Zayas) and fi gure 5b should be C. decoratus (Zayas) (E. Nearns, pers. comm). Th is species, previously known only from Cuba (Zayas 1975;Monné and Bezark 2010), is now documented for the Dominican Republic (new island & country record).

Caribbomerus similis (Fisher)
Figs 5j, Table 1 Diagnosis. Like C. attenuatus (Chevrolat) and C. asperatus (Fisher), C. similis (Fisher), has a rugulose pronotum that lacks calli and pubescence. It is distinguished from C. asperatus by having the integument mostly light reddish-brown in color with the elytra distinctly paler than the pronotum, having the antennal tubercles unelevated, and in having the elytral apices distinctly impunctate. It is distinguished from C. attenuatus in having a matte integument with micropunctation between punctures.
Discussion. Th is is an uncommonly collected species. It was originally described from two specimens from Antigua (Fisher 1932). Monné and Bezark (2010) record it from Barbuda. One specimen was examined in the USNM from Dominica and this is a new country record.