Euscelus spinosus, 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 : 463-466

Euscelus spinosus , new species

Figs. 4 , 14 , 16

Type Locality. Panama, Trinidad Rio .

Type Series. The type series consists of 5 specimens from the Republic of Panama. The male holotype is labeled as follows: Trinidad Rio, Pan. 19.3.12 [19­iii­1912], A. Busck ( USNM) . The allotype is labeled the same as the holotype except 20.3.12. The holotype has only the two basal segments present on the right antenna while the allotype has only the two basal segments present on the left antenna. The sex and label data of the 3 paratypes are as follows: 1 male, Panama: Pma. Pr., Llano­Carti rd. , km 9, el. 350 m, 15 Feb. 93, Stockwell ( HPSC) ; 1 male, same as previous except 5 Jan. 91; 1 female, Panama: Zona del Canal , Barro Colorado Island, 13 Nov. 1984, M Wong ( HPSC) .

Type Deposition. All types are located in the USNM except: 1 male, Panama, Llano­Carti rd. , Km 9, el. 350 m, 5 Jan. 91 ( RWHC) .

Color and Pubescence. Body reddish­brown and shiny throughout. Pronotum with two reddish brown basally divergent longitudinal stripes. Head behind eyes, apices of elytral spines, and front legs (except femoral stalk and coxae) darker. Pubescence absent above on head, pronotum and elytra; elytra with only a few widely spaced erect pale setae along lateral margins. Antennae, pygidium, legs and mid­ventrals sparsely set with fine pale reclinate setae.

Size Range. Male 5.3 × 2.3 mm to 6.2 × 2.6 mm; Female 5.6 × 2.4 mm to 6.1 × 2.6 mm.

Adult Descriptive Synopsis. Head elongate, weakly conical, widest at base, smooth, shiny, with postocular row of very small punctures along margin of eye, otherwise without punctures; frons smooth, shiny, without sculpture; eyes moderately protuberant. Rostrum slightly more than ½ length of head; in lateral view weakly arcuate; in dorsal view widened from middle to apex; width at apex ½ wider than width at base; about 2 ½ times wider at base than width of frons; dorsal apex with fine punctures; interspaces smooth, shiny. Antenna inserted dorso­laterally at basal 1/3 of rostrum; club compact­

Fig. 16. Distribution of Euscelus n. spp. E. maculicollis [black squares], E. bivittatus [black circles], E. spinosus [black triangles].

elongate, slightly shorter than funicle; basal segment longer than middle and terminal segment; middle and terminal segment subequal in length; terminal segment acuminate. Pronotum wider than long, widest at base, strongly narrowed from base to apex; in dorsal view sides nearly straight; smooth, shiny, without punctures; with two basally divergent longitudinal stripes; dorsal anterior edge straight; with weak depression on either side near middle; anterior collar weakly delimited, widest at middle, subbasal constriction linelike, distinct throughout; width of basal piece at midline subequal to midline width of anterior collar. Elytra about 1/3 longer than wide; widest across humeri; weakly depressed behind scutellum; in dorsal view distinctly narrowed posteriorly; with large thornlike posthumeral spines, outer apical margin curved posteriorly; elytral midbase with irregular large strial punctures; striae becoming much smaller posteriorly beyond base, indistinct apically; intervals flat, wide, smooth, shiny, becoming indistinct apically. Thorax with pleura smooth, shiny, sparsely punctured. Legs with front pair greatly enlarged; profemora swollen, stalked, armed. Abdomen with sterna 1–5 more or less subequal, smooth, shiny; sutures distinct medially, indistinct laterally; pygidium moderately punctured.

Profemoral Sexual Dimorphism. The profemur in males ( Fig. 4a ) is armed with two close set spinelike projections. The disti­ventral projection is straight, peglike and apically acuminate while the medio­ventral projection is wider, strongly angled and apically blunt. A small setose patch is present at the base of the medio­ventral projection. The profemur in females is armed with a single straight disti­ventral, peglike, apically acuminate projection.

Distribution (Fig.16). All known specimens are from the Republic of Panama.

Comments. Euscelus spinosus is easily recognized by the two stripes on the pronotum and the thornlike posthumeral spines of the elytra ( Fig. 4b ). Euscelus bivittatus also has two pronotal stripes but the elytral humeri are simple. Elytral spines or spinelike projections occur in other New World euscelines. None are distinctly thornlike as in this species except in E. spiniger Voss from South America. However, in E. spiniger the thornlike spines are larger and more posthumeral in location. The spines are straight, acute and located midlaterally in E. inaequalis Sharp and E. armatus (Gyllenhal) . Some West Indian euscelines, E. dentipes (Fabricius) , E. cancellatus Voss and E. scrobiculatus Voss , have smaller elytral projections near the humeri that are either bluntly tipped or denticulate. The aedeagal median lobe in E. spinosus ( Fig. 14b and c ) has a distinct TA and TA guides and the endophallic sac has more sclerotized accessory structures than in the other new species. No host plant or pterocoline association has been recorded for this species. It is named for the large thornlike spines on the elytra.

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. 12–14. Species of Euscelus, male genitalia, dorsal view except 14c ventral, 64X; tegmen (a) and median lobe (b and c) with endophallic sac in repose. 12) E. bivittatus, n. sp.; 13) E. maculicollis, n. sp.; 14) E. spinosus, n. sp.