Elaphidion mayesae Ivie

Ivie, Michael A. & Schwengel-Regala, Michelle L., 2007, The Elaphidion Audinet-Serville of the Puerto Rican Bank: new species, distributions, taxonomic corrections, and a key to species (Coleoptera: Cerambycidae: Elaphidiini), Zootaxa 1503, pp. 55-68 : 58-60

Elaphidion mayesae Ivie , new species

( Figs 3–10 )

Elaphidion glabratum [not Fabricius]: Wolcott, 1951: 338.

Elaphidion pseudonomon Ivie, 1985: 312 , in part [Puerto Rican paratypes only]. Monné and Giesbert, 1995: 55 in part [Puerto Rican record only]. Monné and Hovore, 2005: 66, in part [Puerto Rican record only].

Elaphidion n. sp. (Ivie in prep.): Lingafelter and Micheli, 2004: 50.

Elaphidion sp.: Chalumeau and Touroult, 2005: 103.

Discovery of this species was a real surprise, given the long and extensive study of the insect fauna of St. Thomas, Virgin Islands, and Puerto Rico. The type series was taken in a light trap located in a dense forest on the north side of St. Thomas, near the top of St. Peter Mountain. This tiny spot is the wettest point on the island, and is the only known Virgin Islands locality for three cerambycids also otherwise known only from Puerto Rico ( E. mayesae , Linsleyonides portoricensis Fisher and Cacostola leonensis Dillon and Dillon , vouchers in WIBF). Very extensive trapping and collecting on other parts of St. Thomas has never yielded E. mayesae , although hundreds of E. pseudonomon have been examined from virtually every other part of the island, and from many other islands in the northern Virgin Islands.

The populations on Puerto Rico are also limited to wet forests. Specimens of the Puerto Rican population are not included in the type species, as they differ somewhat from those from St. Thomas (see diagnosis below). All previous Puerto Rican records for Elaphidion glabratum and Elaphidion pseudonomon almost certainly belong here, and the paratypes mistakenly included in the original description of E. pseudonomon are now placed here.

DIAGNOSIS: Elaphidion mayesae is divided into two populations that may eventually be considered sister-species. Extensive attempts to find consistent characters to distinguish them failed, however, and in every case at least one exception could be found. Therefore, they are considered vicariant populations of a single species, probably separated since the rising sea levels after the Pleistocene eustastic minimum divided the islands of the Puerto Rican Bank. Within the Puerto Rico-Virgin Islands region, E. mayesae is most similar to the E. glabratum / pseudonomon species pair, but is easily distinguished from them by the fourth antennomere short relative to the third and fifth ( Figs 3–6 ). They also have the metafemur distinctly spined, rather than the dentiform condition of the E. glabratum / pseudonomon species pair.

Elaphidion mayesae will imperfectly key to Elaphidion bahamicae Cazier and Lacy in Gilmour’s (1968) key to West Indian Elaphidion , because of the shared short fourth antennomere. However, this is more exaggerated in E. bahamicae , which is also much narrower-bodied (elytra 3 × as long as width across humeri vs 2.5 × in E. mayesae ), and has the anterolateral pronotal calli black and weakly longitudinally carinaform, rather than concolorous and rounded as in E. mayesae . The elytral setae of E. bahamicae are denser, while in E. mayesae they are patchier.

The St. Thomian and Puerto Rican populations differ in overlapping relative characters. When the intact antenna is directed posteriorly, the apex of the main stem of the third antennomere does not reach the basal margin of the pronotum in the typical population, but reaches the base of the elytron in the great majority of Puerto Rican specimens. St. Thomian specimens are, on average, somewhat darker, tending towards a piceous-brown, while the Puerto Rican form is a more classic castaneous. The prosternum between the procoxae and anterior collar is more distinctly transversely rugose in those from St. Thomas, while the Puerto Rican population is usually almost totally smooth. The profemora of the Puerto Rican specimens are more heavily clavate than those from St. Thomas, and the hind femora are more strongly arcuate above.

The male genitalia of the two populations are highly variable and overlap in form. The range of variation is shown in Figs 7–10 . In general, those from Puerto Rico tend to be more elongate with the lateral margins of the apical portion of the aedeagus sinuate ( Fig. 9 ) and the distance between the basal and apical notches of the parameres rather long ( Fig. 10 ). Those from St. Thomas tend to be shorter and broader, with the lateral margins of the apical portion of the aedeagus straight ( Fig. 7 ) and the distance between the basal and apical notches of the parameres rather short ( Fig. 8 ). However, both populations have individuals that exhibit all the forms, and genitalia cannot be used to distinguish them.

This situation is complicated by variation that is similar to the major/minor male variation so common in the Scarabaeidae , especially so in the Puerto Rican population. This variation is exhibited in the punctation of the pronotum and length of the male antenna relative to the total length of the body. Many cerambycid species are characterized by the length of the antenna relative to the body (cf. Linsley 1963). In E. mayesae , the length of the male antenna is quite variable. The antennomere that reaches the apex of the elytron varies in this species from the midpoint on number 8 to the midpoint of antennomere 10. Males with short antennae usually have the pronotum like the female condition, i.e. more heavily punctate and rugose, than those with longer antennae. The carinae of the antennae are more distinct in the longer-antenna specimens, and the relative length of the last antennomere increases out of scale with the total length, so that it varies from shorterthan to longer-than the scape. Interestingly, the shorter-antenna form has relatively stronger spines on the antennomeres.

DESCRIPTION: With the characteristics of Elaphidion, ( Lingafelter 1998) .

MALE: Elongate subparallel; dark chocolate brown, densely covered with golden recumbent pubescence of two types – those arising from distinct punctures and those placed between these punctures. Eye emarginate, encompassing bases of antenna. Antennae ( Fig. 3 ) variable in relative length, ninth or tenth antennomere reaching elytral apices; third antennomere only rarely reaching base of pronotum; fourth antennomere ½–2/3 length of third, 3–5 spined meso-apically, 6 sometimes apically dentate; spine of third ¾ or more length of fourth; eleventh equal to or shorter than third; 5 or 6–11 weakly carinate externally. Pronotum very slightly wider at base than apex, arcuate laterally; apical margin with narrow submarginal groove, incomplete medially; basal margin with deep, complete, submarginal groove; disk with bare, shining median longitudinal callus, narrowly complete at anterior margin, more broadly complete to posterior margin; disc laterally with pair of calli on shared slight swelling 1/3 distance from apical margin, arranged transversely with mesad callus larger, nearly round, smooth, impunctate, separated from laterad callus by band of appressed transverse setae, laterad callus round to oblique; additional lateral smooth glabrous calli behind anterior pair, reaching basal groove; rest of disc and lateral area punctate, punctures varying from coarse ocellate punctures to fine, simple punctures. Scutellum setose laterally, with bare median line. Elytra only weakly sculptured; raised areas more often rubbed of dense pubescence, leaving a highly variable pattern that often includes a narrow longitudinal band just mesad humerus and a broad area on central disc; each puncture in this rubbed area with a single scale-like seta remaining; apices bispinose, outer spine slightly longer. Prosternum smooth mesally from intercoxal processes to submarginal groove. Profemur only weakly clavate, in frontal view maximum width 2X width at distal end of trochanter. Apices of meso and metafemora distinctly spinose, spine narrow, acute, subequal in length to apical width of tibia. Genitalia variable, usually as in Figs. 7–8 , but variation extending to 9–10. Length: 11–13 mm.

FEMALE: Differs from the male in having a slightly broader body, larger diameter pronotal punctation, shorter antennae not surpassing elytral apices, a shorter fourth antennomere and the last antennomere being short and broad ( Figs 4, 6 ). Length: 11–14 mm.

VARIATION: Members of the Puerto Rican populations exhibit the following variation not seen in typical specimens from the Virgin Islands. Color reddish-brown. MALE: Antenna ( Fig. 5 ) variable in relative length, eighth, ninth or tenth antennomere reaching elytral apices; third antennomere reaching base of elytron; fourth antennomere up to 3/4 length of third, 6 spined; eleventh shorter than third. Pronotum with a very slight indication of a rounded angle at midpoint; median longitudinal callus, narrowly complete at anterior margin, more broadly complete to posterior margin; laterad callus longitudinal-obliquely elongate, semi-carinate, sometimes indistinct, sometimes posteriorly connected to mesad callus by narrow band. Elytra weakly depressed along suture in basal ¼ and in apical ½; weakly longitudinally gibbous postero-laterad of scutellum, this raised area reaching suture between sutural depressed areas; narrow depression laterad of this in basal ½; behind humerus very weakly longitudinally raised, joining other raised areas in median portion of elytron. Length: 9–15 mm. FEMALE. Length: 11–14 mm.

DISTRIBUTION: Known only from wet forest on the north side and near the top of St. Peter Mountain, St. Thomas, Virgin Islands and wet forests of Puerto Rico.

TYPES. HOLOTYPE MALE: VIRGIN IS: St. Thomas; Est. St. Peter, ca 1450ft; 3-H-4 North Star; 04JAN–30 JUNE 1983; Carol Mayes, u. v.light / WIBF 0 21377 (from WIBF, deposited in NMNH).

PARATYPES: 5 MALES, 9 FEMALES—Same data as Holotype, WIBF 021379 –82, 84–88, 90–95 (WIBF).

ADDITIONAL MATERIAL STUDIED BUT NOT INCULDED IN TYPE SERIES: 3 MALES, 2 FEMALES—PUERTO RICO: El Verde, 250m; 22 SEP 1987; M. A. Ivie, at light; 3 MALES, 5 FEMALESibid., 23 SEP 1987; 1 MALE, 1 FEMALE— ibid., 24 SEP 1987; 1 MALE— ibid., 25 SEP 1987; 1 MALE, 2 FEMALES— ibid., 26 SEP 1987; 4 MALES, 2 FEMALES— ibid., 27 SEP 1987 (WIBF). 2 MALES— PUERTO RICO: Caribbean; National Forest, base of; El Toro trail, 600 meters; 18°16’55”N, 65°51’10”W; tree cut – 26 June 2002; Steven W. Lingafelter (NMNH). 1 MALE, 1 FEMALE — PUERTO RICO: Caribbean; National Forest, Road 186 at; Km 14.4, Rio Grande bridge; 18°17’50”N, 65°50’33”W; 475 meters, 27 June 2000; dead tree cutting; Steven W. Lingafelter (NMNH). 1 FEMALE—ibid, Charyn J. Micheli (JAMC). 2 FEMALES—PUERTO RICO: Maricao For; Near Cabins, 850–900m; 18°08’45”N, 65°58’52”W; 19 June 2002, Lights; Steven W. Lingafelter (NMNH). 1 FEMALE —ibid., Norman Woodley (NMNH). 1 FEMALE—ibid., 17–18 June 2002, at lights, Charyn J. Micheli (JAMC). 2 MALES, 1 FEMALE — PUERTO RICO: Bosque Estatal; de Guajataca, along Road 446; 18°25’00”N, 65°58’30”W; 20 June 2003 / Beating veget.; Steven W. Lingafelter (NMNH). 1 FEMALES—PUERTO RICO: Ponce; Rd. 132, km 20; X- 22-1976; J. Micheli/ at light (NMNH). 1 MALE—PUERTO RICO: Rd 10 Km 24; VI-8-1977; J. Micheli (NMNH). 1 MALE—PUERTO RICO: Rd 10 Km 24; 5/ 11-XI-1978; J. Micheli; blacklight trap (JAMC). 1 MALE, 2 FEMALES — PUERTO RICO: Rd 10 Km 24; 1/ 7-V-1978; J. Micheli; blacklight trap (JAMC). 1 MALE—ibid., 5/ 11-XI-1978; J. Micheli; (JAMC). 1 FEMALE—Unknown host; Central Rufina; Ponce, P.R.; coll. 11 Dec. ’33; R. G. Oakley (NMNH). 1 FEMALE—Mayagüez, P.R.; 190 [sic] (NMNH). 1 MALE—ibid., II-7-1912 / F. W. Hooker collector (NMNH). 1 FEMALE—El Yunque; 800 ft., PR/Feb; 21.00/ C. W. Richmond; collector (NMNH). 1 FEMALE—Bayamon; PR, I-27-34; Lesene &; Anderson/ San Juan; No. 5130. 1 FEMALE—Puerto Rico; Santurce; X-13 -’35; Sta. 65; Blackwelder (NMNH). 1 FEMALE—Flight; Ponce, P.R.; D.DeLeon, v.2. ’40/ Hopkins US; 33100-A-9 (NMNH). 1 FEMALE—Roosevelt Rds; Puerto Rico; unknown; A.B. Cochran/ 4 March 1963; San Juan, P.R.; [no. symbol] 18392; 63 7416 (NMNH). [The next four specimens were included in error with the paratype series of E. pseudonomon by Ivie (1985). They bear the paratype labels of both species]. 3 MALES, 1 FEMALE Roosevelt Rds; Puerto Rico; unknown; A.B. Cochran/ 4 March 1963; San Juan, P.R.; no.18392; 63 7416 (NMNH).

ETYMOLOGY: A noun in the genitive case, named in honor of Dr. Carol H. Mayes, Director, U.S. Virgin Islands Program in The Nature Conservancy’s Caribbean Region, who kindly ran the trap that yielded this species under the porch of her house in the wettest forest on St. Thomas.

Figures

FIGURES 1 – 6. Antennae (scale bar = 1 mm). 1. Elaphidion pseudonomon, male; 2. E. pseudonomon, female; 3. E. mayesae, male from St. Thomas; 4. E. mayesae, female from St. Thomas; 5. E. mayesae, male from Puerto Rico; 6. E. mayesae, female from Puerto Rico.

FIGURES 7 – 11. Elaphidion. 7. E. mayesae, from St. Thomas, aedeagus; 8. E. mayesae, from St. Thomas, parameres; 9. E. mayesae, from Puerto Rico, aedeagus; 10. E. mayesae, male from Puerto Rico, parameres; 11. E. pseudonomon, male, habitus.