Cactophagus silron 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 : 41-42

Cactophagus silron Anderson , new species

( Figs. 35­36 , 42­45 )

Identification.—This very distinctive species is easily recognized by its small size (<7 mm in length), uniform grey­black color ( Figs. 35­36 ), somewhat oblique form of the antennal club with only a narrow apical pilose part ( Fig. 43 ), and most significantly, the broadly expanded and keeled hind tibiae ( Fig. 44 ). Among Cactophagus it is most closely related to Cactophagus strigosus (Erichson) , C. rubricatus Hustache and C. limulus (Vaurie) , based on the asymmetrical form of the antennal club.

Description.— Male, length 6.7 mm; width 2.6 mm. Female, not known. Color greyblack with only humeri pale orange. Pronotum with pair of darker velvety black slightly curved paramedial lines.

Rostrum slightly longer than length pronotum; elongate, narrow, cylindrical, slightly evenly curved, virtually impunctate except for scattered minute punctures in basal onehalf; base of rostrum slightly expanded, basal expanded area very short, about one­fifth total rostral length. Rostrum glabrous ventrally; peduncle flat, bilamellate anteriorly. Scrobe with posterior margin about one­half width of base of scape from anterior margin of eyes. Antenna with scape about one­half length rostrum; club slightly laterally compressed, asymetrical, with form oblique with inner margin slightly shorter than outer margin; apical pilose part visible as a narrow oblique line. Pronotum with lateral margins slightly convergent in basal one­half, moderately convergent to apex; very sparsely and very shallowly punctate on disc, flanks with punctures slightly deeper; flat subbasally.

Pronotum with length greater than width. Elytra about one and one­half times length of pronotum; intervals impunctate, flat; intervals 2 and 3 curved inwardly at base, intervals 4 and 5 wider at base, interval 6 constricted subbasally; striae punctate, shallowly impressed. Scutellum elongate “V” shaped, length two and one­half times width at base, slightly swollen towards apex. Pygidium sparsely but deeply punctate throughout, with apical one­half tumescent, acutely carinate and setose along midline; lateral and apical margins finely, sparsely setose; apex narrowly rounded. Ventrally with front coxae separated by about one­quarter width of coxa; prosternum flat between and anterior to front coxae. Meso­ and metasterna and ventrites sparsely shallowly punctate (less so medially); last ventrite of male deeply sparsely punctate apically at middle. Legs finely and shallowly punctate; femora slightly clavate, hind femur almost reaching apex of ventrite 5; inner margins of femora glabrous, of all tibiae with only very short, dense setae arranged in pectinate manner; hind tibiae markedly expanded and keeled along outer margin, middle and front tibiae slightly inwardly arcuate. Tarsi each with third article slightly dilated, pilose ventrally except for extreme base at middle; third articles of all tarsi symmetrical; apical margin of third articles slightly produced, rounded.

Material Examined.—Male HOLOTYPE labelled " July 6, 1957 / Golfito, Costa Rica / Truxal & Menke (CMNC; in exchange from LACM).

Distribution.— Costa Rica (Puntarenas).

Natural history.—No information is available about the natural history of this species.

Derivation of specific name.— Through their support of the Nature Discovery Fund at the Canadian Museum of Nature, this species is named after Silvana and Ron Macdonald of Toronto, Ontario, Canada.

Figures

FIGURES 33 - 38. Cactophagus species. 33 - 34. Cactophagus riesenorum Anderson. 33. Dorsal habitus. 34. Lateral habitus. 35 - 36. Cactophagus silron Anderson. 35. Dorsal habitus. 36. Lateral habitus. 37 - 38. Cactophagus sunatoriorum Anderson. 37. Dorsal habitus. 38. Lateral habitus.

FIGURES 42 ­ 45. Cactophagus silron Anderson. 42. Lateral view of head, male. 43. Antenna. 44. Hind leg, male. 45. Pygidium, male.