Rhodobaenus howelli Anderson

Anderson, Robert S., 2002, The Dryophthoridae of Costa Rica and Panama: Checklist with keys, new synonymy and descriptions of new species of Cactophagus, Mesocordylus, Metamasius and Rhodobaenus (Coleoptera; Curculionoi, Zootaxa 80, pp. 1-94: 85-87

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http://doi.org/ 10.5281/zenodo.156033

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scientific name

Rhodobaenus howelli Anderson

new species

Rhodobaenus howelli Anderson  , new species

( Figs. 129­130View FIGURES 129 - 136, 137­ 141View FIGURES 137 ­ 141)

Identification.—This species was first recognized from a single very distinctive female specimen from Monteverde. In this female, almost the entire dorsal surface of the rostrum is covered with very long, dense golden, wispy hairs ( Figs. 130View FIGURES 129 - 136, 137View FIGURES 137 ­ 141). Two conspecific males have since been found but each lacks the pilosity on the rostrum ( Fig. 138View FIGURES 137 ­ 141). The species is virtually identical in color pattern and, on cursory examination, appears to be similar in structure to R. rubicundus  . Aside from the obvious pilosity of the rostrum on the female, R. howelli  also differs in the shorter length of the apical pilose part of the antennal club (which is subequal in length to the basal glabrous part in R. rubicundus  ), in the shorter length of the hind femur (which extends beyond the apex of the pygidium in R. rubicundus  ), and in the more basal placement of the point of antennal insertion (which is more distant from the eye in R. rubicundus  ). In addition, the rostrum is narrower and less deeply punctate in R. howelli  than in R. rubicundus  . The peduncle in both sexes is quite distinctive being convex and carinate and with a sharp apical angle ( Figs. 137­138View FIGURES 137 ­ 141).

Description.— Male, length, 6.7­6.8 mm; width 2.3­2.4 mm. Female, length, 6.4­7.5 mm; width 2.3­2.5 mm. Color orange­red with black markings. Head and rostrum red, except for small black spot immediately behind eyes; antennae somewhat infuscate. Pronotum red with median narrow black line as well as narrow irregular black line along midheight of flanks; lateral margins also spotted with black at midlength and more medially at basal one­quarter. Elytra red, with humeral region black, this black marking extended obliquely, posteriorly in irregular band towards sutural interval at midlength of elytra; apical callus also with elongate black markings on intervals 2, 6 and 8. Ventrally with prosternum red, posterolateral angles of metasternum infuscate with black.

Rostrum subequal to length pronotum, strongly humped at base; elongate, narrow, cylindrical, slightly evenly arcuate; female with deep, dense punctures dorsally in basal five­sixths, also with long, dense, fine, wispy golden hairs in basal five­sixths; male, lacking such pilosity, at most finely punctate; lateroventrally impunctate, glabrous, shining; base of rostrum slightly expanded, basal expanded area very short, about one­sixth total rostral length. Rostrum glabrous ventrally; peduncle convex, carinate, with sharply acute and produced apical angle, not toothed. Scrobe with posterior margin slightly more than width of base of scape from anterior margin of eyes. Antenna with scape about one­half length rostrum; scape expanded apically, not flattened, inner face with shallow irregular sulcus at apex; club slightly laterally compressed, elongate­oval; apical pilose part about one­half length of basal glabrous part. Pronotum with lateral margins subparallel to slightly convergent in basal one­half, gradually convergent to apex; very sparsely and shallowly, indistinctly punctate throughout; flat subbasally; middle of disc slightly tumescent. Elytra with length twice length pronotum; with striae and intervals impunctate, flat; interval 2 slightly wider near apex than intervals 1 or 3. Scutellum elongate, lateral margins subparallel in basal one­half; length twice width at base, flat. Pygidium with subapex at middle slightly tumescent, regularly punctate and setose in apical one­half; apex broadly acuminate. Ventrally with front coxae separated by width of base of scape; prosternum slightly concave between, and flat anterior to, coxae. Meso­ and metasterna and ventrite 1 sparsely, shallowly punctate throughout; ventrites 2 to 4 impunctate; last ventrite flat, impunctate in basal one­half, punctate in apical one­half, narrowly, deeply impressed at middle at apex. Legs elongate, matte, coarsely, shallowly punctate throughout; femora clavate, long, hind femur almost reaching apex of pygidium; inner margins of all tibiae with only very short, sparse setae; all tibiae slightly inwardly arcuate. Tarsi each with third article moderately widely dilated, pilose ventrally except in narrow band along basolateral margins; tarsi with third articles symmetrical; apical margin of third articles truncate; claw­bearing segment flat ventrally at apex; tarsi long and slender, first article about three times as long as wide.

Material Examined.—Female HOLOTYPE labelled “ Costa Rica, Punta. / MonteVerde Biol.Res. / IX­ 7­1998, 1500m / C.W.&L.B. O’Brien” ( CWOB). Male ALLOTYPE labelled " Costa Rica Puntarenas / Monteverde / 20­24 Jun 1986 / W. Hanson, G. Bohart ( CWOB). PARATYPE (1, 1). HEREDIA PROVINCE. La Virgen (16 km S.S.E.), 1050­1150m, 10 ° 16 'N, 84 °05"W, 21 February 2001, INBio, OET, ALAS Transect (1; 3203343). PUNTARENAS PROVINCE. Monte Verde, 1570m, 16 May 1989, J. Ashe, R. Brooks, R. Leschen, ex. berlese (1). Paratypes in CMNC, INBC.

Distribution.— Costa Rica (Heredia, Puntarenas).

Natural history.—Specimens were collected in montane forest from 1050m to near 1600m. One specimen was collected from leaf litter in a berlese funnel. No other information is available.

Derivation of specific name.— Through her support of the Nature Discovery Fund at the Canadian Museum of Nature, this species is named after Susan Howell of Ottawa, Ontario, Canada.

Comments.—As noted, this species is very closely related to R. rubicundus  . In her original treatment of R. rubicundus, Vaurie (1967)  considered that the venter of the clawbearing articles of the tarsi of that species were flat and not bilamellate or excavated. Accordingly, but somewhat enigmatically, she placed the species with the R. nawradii  group. In a later treatment ( Vaurie 1980) she noted that the tarsi were in fact very indistinctly bilamellate in R. rubicundus  and removed that species from inclusion in the R. nawradii  group. In the known specimens of R. howelli  , the ventral surface of the clawbearing articles of the tarsi appear flat thus confusing the issue once again.


National Biodiversity Institute, Costa Rica


Instituto Nacional de Biodiversidad (INBio)