Rhodobaenus labrecheae 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; Curculionoidea), Zootaxa 80, pp. 1-94 : 87-89

Rhodobaenus labrecheae Anderson , new species

( Figs. 131­132 , 142­146 )

Identification.—This species is known only from a male and female from Puntarenas Province in Costa Rica. Rhodobaenus labrecheae is a moderately large but generally nondescript black species similar in general form, size and color to R. cuneatus and R. subcristatus . It is clearly different however, and can easily be differentiated upon close examination by a variety of characters. Most notable among these characters is the form of the rostrum which in R. labrecheae is laterally compressed (especially throughout the middle portion of its length), more or less evenly moderately arcuate (although in the female there is a slightly stronger arcuation starting at the apical three­fifths) ( Fig. 147 ); in lateral view, has the lateral portion immediately in front of the point of antennal insertion to the midlength or slightly beyond, deeply, densely regularly punctate and distinctly setose, the apical one­half to one­third less densely and more finely punctate ( Fig. 147 ); and, in dorsal view with the apex distinctly wider than subapically. In addition, the point of antennal insertion is basal, separated from the front margin of the eye by less than the width of the base of the scape. This contrasts with the antennal placement in most other larger black species, which is more distal from the eye, separated from it by four or more times the width of the base of the scape. Also, the point of attachment of the funicle to the base of the antennal club is distinctly asymetrical ( Fig. 144 ) in the two available specimens. The pronotum is flat basally although it is very slightly reflexed and may appear to be very shallowly creased. The elytra, while not short compared to the length of the pronotum, appear somewhat truncated such that the pygidium is clearly, distinctly extended well beyond their apices ( Fig. 131 ). Although the members of this species have the appearance of small, non­maculate members of the R. nawradii group, the claw­bearing segments of the tarsi are slightly bilamellate ventrally, although this is easy to overlook.

Description.— Male, length, 9.4 mm; width 3.9 mm. Female, length, 10.2 mm; width 4.4 mm. Color black, matte; with indistinct whitish, very fine pilosity, most visible around punctures and in vaguely contrasting pattern on elytra.

Rostrum slightly shorter than pronotum, not humped at base; laterally compressed (especially throughout middle portion of length), more or less evenly moderately arcuate (female with slightly stronger, somewhat abrupt, arcuation starting at apical three­fifths); in lateral view, with lateral portion immediately in front of point of antennal insertion to midlength or slightly beyond, deeply, densely punctate, distinctly setose, the apical onehalf to one­third less densely and more finely punctate; base of rostrum abruptly expanded, basal expanded area about one­fourth total rostral length; in dorsal view with the apex distinctly wider than subapically. Peduncle flat, smooth; in female slightly pendant (but not toothed) at base. Scrobe with posterior margin less than width of base of scape from anterior margin of eyes. Antenna with scape about three­fifths length rostrum; scape slightly clavate apically; club laterally compressed, oval; apical pilose part one and one­half to two times length of basal glabrous part; point of attachment of funicle with club distinctly asymetrical. Pronotum with lateral margins subparallel to slightly divergent in basal one­half, gradually convergent to apex; very sparsely and shallowly, indistinctly punctate throughout; flat subbasally. Elytra with length one and two­thirds times length pronotum; with striae impressed, intervals finely, sparsely punctate, flat; some punctures of intervals with very fine white surrounding pilosity; humeral region, subapical callus to apex, and midlength from sutural interval to interval 5 in transverse “V” shape very slightly more shining, apparently lacking fine whitish pilosity; apex somewhat truncate Scutellum elongate­narrow, lateral margins subparallel in basal one­third; length two and one­half times width at base, flat. Pygidium exposed well beyond elytral apices, with subapex at middle tumescent in male, less so in female; regularly punctate and setose throughout; apex broadly acuminate. Ventrally with front coxae separated by width of base of scape; prosternum flat between and anterior to coxae. Meso­ and metasterna and ventrites sparsely, shallowly punctate throughout, last ventrite flat, apex shallowly medially impressed, slightly deflexed in male, flat, not deflexed in female. Front and middle legs short, hind longer; matte, finely irregularly punctate throughout; femora clavate, widest at extreme apex; front and middle femora short, hind femur longer, almost reaching apex of ventrite 5 in male, shorter in female, barely reaching apex of ventrite 4; inner margins of all tibiae with only short, sparse setae; all tibiae straight. Tarsi each with third article moderately widely dilated, completely pilose ventrally; tarsi with third articles symmetrical; apical margin of third articles truncate; claw­bearing segment faintly bilamellate ventrally at apex.

Sexual dimorphism.—Sexual dimorphism is quite evident in the two specimens examined. The male has a rostrum that is more evenly arcuate, whereas the female rostrum is somewhat more abruptly arcuate at about the apical three­fifths. In addition, the pygidium is slightly more tumescent in the male and the apex of ventrite 5 is slightly impressed and deflexed. The hind femur is slightly longer in the male, almost reaching the apex of ventrite 5, whereas in the female it barely reaches the apex of ventrite 4.

Material Examined.—Male HOLOTYPE labelled “C.R., Punt., Monte­ / verde Cloud Forest / Res. V­27, 31 ­1984 / Riley, Rider&LeDoux” (CWOB). Female ALLOTYPE labelled “ Costa Rica. Prov. Puntarenas. Fila / Cruces, Laguna Gamboa. 1400m. 30 / ABR 1996. I.A. Chacón. / L_S_304200_574850 #8233”, INBio barcode 2447812 (INBC).

Distribution.— Costa Rica (Puntarenas).

Natural history.—Both specimens were collected at or near 1400m. No other information on natural history 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 Adèle Labrèche as a gift from Mario Lalanne.

Figures

FIGURES 129 - 136. Rhodobaenus species. 129 - 130. Rhodobaenus howelli Anderson. 129. Dorsal habitus. 130. Lateral habitus. 131 - 132. Rhodobaenus labrecheae Anderson. 131. Dorsal habitus. 132. Lateral habitus. 133 - 134. Rhodobaenus patriciae Anderson. 133. Dorsal habitus. 134. Lateral habitus. 135 - 136. Rhodobaenus tenorio Anderson. 135. Dorsal habitus. 136. Lateral habitus.

FIGURES 142 ­ 146. Rhodobaenus labrecheae Anderson. 142. Lateral view of head, male. 143. Lateral view of head, female. 144. Antenna. 145. Hind leg, male. 146. Pygidium, male.

FIGURES 147 ­ 150. Rhodobaenus patriciae Anderson. 147. Lateral view of head, female. 148. Antenna. 149. Hind leg, female. 150. Pygidium, female.