Eudiagogus Schoenherr

O'Brien, Charles W. & Kovarik, Peter W., 2000, A New Species Of Eudiagogus Schoenherr From South America (Coleoptera: Curculionidae), The Coleopterists Bulletin 54 (3), pp. 313-317 : 313-316

Eudiagogus Schoenherr

Eudiagogus Schoenherr 1840:307 [type­species: Promecops episcopalis Gyllenhal 1834:164 , by original designation].

Eudiagogus stenosoma O’Brien and Kovarik , new species Figs. 1–5

Holotype Male. Integument black, shiny, with antennae and legs dark brown. Vestiture of closely appressed, shiny, black, white, and few brassy metallic scales that conceal most of integument. Head clothed primarily with black scales, with few pinkish to white strap­like scales scattered on rostrum and encircling eyes. Eyes large, oval, subtruncate behind. Frons continuous with rostrum, medially with elongate, deep fossa at base of rostrum continued to near apex as narrower, shallower sulcus. Rostrum stout, thick, 1.27 X wider than long, dorsally strongly and broadly impressed medially, with dense, ap­

313

= 1.0 mm.

pressed, black and few whitish to pinkish scales; apex emarginate, with four, long, silvery, hair­like setae. Antennae moderately long; scape and funicle with moderately coarse, hair­like, whitish scales; club densely pubescent, dark brown. Pronotum in dorsal view 1.08 X as wide as long, sharply narrowing to base; postocular lobes well­developed, projecting ventrally; surface sparsely and moderately coarsely punctate; vestiture dense, of closely appressed shiny, black, striate scales and convex, nonstriate, white and pinkish scales; pale scales present on lateral margins and on disc, forming an indistinct median longitudinal and a posterior transverse bar on vertical portion of posterior margin. Scutellum large, transverse, densely covered with white scales. Elytra with black vestiture as on prothorax with mostly white and few brassy, metallic scales forming longitudinal stripes from base to declivity on interval 1 and with few scattered small spots on disk and on lateral margins ( Figs. 1–2 ); parallel sided to beyond middle, then gently rounded to apex; intervals of unequal width; striae of elongate, or round, deep punctures, each puncture with black scales. Legs with dense vestiture of greyish white, striate scales intermixed with small, white, setae­like scales; hind femur with ring of large, whitish scales; tibiae straight, mucro strong, corbel of posterior tibia closed and clothed with a single row of erect, whitish, setae­like scales; tarsus normal, dorsally clothed with whitish, and brown, setae­like scales, ventrally densely pubescent, segment 4 moderately long, slender, claws free. Venter with dense white, and few brownish, elongate scales; visible abdominal sternum 5 less scaly, but on apical half with numerous, erect, hairlike setae; each sternum lacking evident spots; visible sterna 1 and 2 medially concave, visible sternum 5 completely flattened. Length, pronotum and elytron: 4.70 mm. Genitalia as figured ( Figs. 3–4 ).

Allotype Female. Differing from male by evenly convex visible abdominal sterna 1 and 2, and convex shorter visible sternum 5. Length, pronotum and elytron: 3.70 mm. Sternum 8 as figured ( Fig. 5 ).

Paratypes. Length 4.10–5.70 mm, average length 4.67 mm. Like holotype and allotype except some specimens with more distinctly pinkish scales on pronotum and elytra. Distribution : Argentina: Formosa 45 km. Southwest of Formosa, I­28­1989, C.W. & L.B. O’Brien & G.J. Wibmer (holotype, allotype and 3 paratypes; deposited in the collection of the senior author, CWOB) .

Diagnosis. Superficially, Eudiagogus stenosoma resembles the South American E. episcopalis . However, the combination of a narrower body, a broadly, strongly, medially impressed rostrum, and an elongate, deep fossa at the base of the rostral groove will readily distinguished it from the latter species. The two species are also readily separable by obvious differences in their respective scale pattern. In E. stenosoma , the mostly black pronotal disc is divided (at most) by a single pale longitudinal vitta. Transverse thoracic vittae, present in a number of Eudiagogus , are completely lacking in this species. Elytral vittae of E. stenosoma are restricted to interval 6 and end at the declivity. In Eudiagogus episcopalis , the pronotal disc is divided transversely and longitudinally by pale, metallic vittae. Pale, metallic elytral vittae are present on the suture, interval 6, and the lateral margins and are complete from the base to the apex. In addition, the frons of Eudiagogus episcopalis is broader and the rostrum more convex than that of E. stenosoma . Eudiagogus stenosoma is easily separated from the other South American species by the distinctive median lobe of the male genitalia and by the other characters given in the key.

Etymology. The specific epithet is a noun in apposition based on the Greek, stenos = narrow, and soma = body, and refers to the unusually slender body of this species.

Biology. Unfortunately, no biological information is available for E. stenosoma . However, since the host plant for all other species of Eudiagogus is Sesbania , we predict that this legume will turn out to be the host plant for E. stenosoma as well.

Figures

Figs. 1–2. Eudiagogus stenosoma. 1) dorsal habitus. 2) lateral habitus. Line scales

Figs. 3–5. Eudiagogus stenosoma. 3) aedeagus, dorsal view. 4) aedeagus, lateral view. 5) sternum 8, dorsal view. Line scales = 0.5 mm.