Euscelus oaxacensis, Hamilton, R. W., 2001

Hamilton, R. W., 2001, New Species Of Euscelus Schoenherr From Central America (Coleoptera: Attelabidae), The Coleopterists Bulletin 55 (4), pp. 453-470 : 458-459

Euscelus oaxacensis , new species

Figs. 1 , 8 , 15

Type Locality. Mexico, Oaxaca, El Cameron­Tehuantepec .

Type Series. The type material consists of 21 specimens from Mexico. The holotype male and allotype female are labeled as follows: Mexico, Oaxaca, El Cameron­Tehuantepec , km 171, 25­vii­1981, Terminalia, G. Vogt ( USNM) . The sex and label data of the 19 paratypes are as follows: 2 females [same as primary types except, km 237–227]; 1 female, Mexico, Chis. [Chiapas], Sumidero , 4,000 ft, July 8, 1955, P. and C. Vaurie collectors ( AMNH) ; 13 males and 2 females, Mexico, Chiapas, Chorreadero St. Pk., 26­v­1987, collected at mercury vapor and black light, DB Thomas, DA Rider, EG and TJ Riley ( CWOB) ; 1 female, Mexico, Chiapas, El Chorreadero, east of Tuxtla Gtz. , 13 June 1989, PK Lago, S Testa ( CWOB) .

Type Deposition. All types are located in their parent collections except the following: 1 female, same data as primary types ( RWHC) .

Color and Pubescence. Body reddish­brown; middle legs, hind legs and abdomen paler. Elytra with slightly raised yellowish markings. Pubescence absent above on head, pronotum and elytra; with some widely spaced pale erect setae on the elytra mainly near apical and apico­lateral margins. Rostral apex, antennae, pygidium, legs and mid­ventrals more or less sparsely set with fine pale reclinate setae.

Size Range. Male 5.8 × 2.4 mm to 7.2 × 3.0 mm; Female 5.5 × 2.3 mm to 6.4 × 2.6 mm.

Adult Descriptive Synopsis. Head more or less rectangular; vertex smooth, shiny, with scattered fine punctures; with postocular punctate band along margin of eye; genae moderately to densely punctured; frons with deep narrow median sulcus; eyes weakly protuberant. Rostrum short, about ½ length of head; in lateral view weakly arcuate; in dorsal view distinctly widened from antennal insertions to apex; width at apex 1/3 wider than width at base; base about four times wider than frons; dorsal apex moderately punctured. Antenna inserted dorso­laterally just behind basal 1/3 of rostrum; club compact; basal and terminal segments subequal in length; middle segment slightly shorter; terminal segment acuminate. Pronotum wider than long; in dorsal view sides arched out in anterior half; dorsal anterior edge broadly emarginate; anterior and posterior width subequal; moderately punctured, more densely punctured postero­laterally; interspaces smooth, shiny; with two shallow oblique grooves; grooves not meeting in middle; anterior collar ringlike, weakly delimited, subequal in width throughout; subbasal constriction weak, linelike, indistinct laterally; width of basal piece at midline slightly more than midline width of anterior collar. Elytra about 2/5 longer than wide; widest behind middle; weakly depressed in middle behind scutellum; weakly raised around scutellum; declivity abrupt; strial punctures distinct throughout; intervals smooth shiny, weakly convex, as wide or slightly wider than width of striae; each elytron with eleven yellowish marks; one large irregular mark near scutellum; two humeral marks, one at humeral apex and one posthumeral and lateral; four barlike interval marks staggered across middle; and four interval marks near apex forming two V­shaped groups on intervals 1 and 3 and 5 and 7. Thorax with pleura and lateral edges of sterna coarsely punctured; metathoracic sternum smooth, bulbous each side of middle. Legs with front pair greatly enlarged; profemora swollen, stalked, armed. Abdomen with sterna 1–4 more or less subequal; smooth, shiny, minutely crenulate; laterally with scattered punctures; sutures weakly delimited; sternum 5 narrow, ringlike, moderately to densely punctured; suture between 4 and 5 distinct; pygidium and tergum between elytral apices densely punctured.

Profemoral Sexual Dimorphism. The profemur in males is armed with a disti­ventral thornlike projection, a straight medio­ventral peglike projection and a blunt projection on the rim of a small round seta bearing pit ( Fig. 1a ) near the base of the medio­ventral projection. The profemur in females is armed with a disti­ventral thornlike projection and a medio­ventral peglike projection

Distribution ( Fig. 15 ). Euscelus oaxacensis is known only from three sites in southern Mexico; the type locality in Oaxaca and two sites in Chiapas near Tuxtla Gutierrez.

Comments. Euscelus oaxacensis is easily distinguished from other New World euscelines by the elytral markings and the profemoral armature ( Fig. 1 ). This is Euscelus sp #6 of Vogt (1992). Vogt reported it from Terminalia sp. (Combretaceae) and did not associate it with a pterocoline thief weevil. He states that the host trees grow in dry washes, canadas and barrancas across the pacific slopes of Oaxaca. The species is related to E. breviceps , E. similis , and E. stockwelli based on color pattern, elytral markings and the shape and sculpture of the ponotum. It is distinctly larger than these three and obviously differs from them in the arrangement of the yellowish elytral marks and the profe­ moral armature. Also, the aedeagus ( Fig. 8 ) in E. oaxacensis is easily distinguished by the large wide TA bearing a fingerlike process and the irregularly rectangular TA guide. The specific name is derived from the Mexican state of Oaxaca.

Figures

Figs. 1–6. New species of Euscelus, males,16X; left profemur (a) and dorsal habitus (b). 1) E. oaxacensis; 2) E. stockwelli; 3) E. similis; 4) E. spinosus; 5) E. bivittatus; 6) E. maculicollis.

Figs. 8–11. Species of Euscelus, male genitalia, dorsal view, 64X; tegmen (a) and median lobe (b) with endophallic sac in repose. 8) E. oaxacensis, n. sp.; 9) E. stockwelli, n. sp.; 10) E. breviceps (Sharp); 11) E. similis, n. sp.

Fig. 15. Distribution of Euscelus n. spp. E. oaxacensis [black squares], E. stockwelli [black circles], E. similis [black triangles].