Metamasius bellorum 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 : 53-55

Metamasius bellorum Anderson , new species

( Figs. 53­54 , 63­67 )

Identification.—The single known specimen of this species, although closely related to M. bromeliadicola , M. nudiventris , and M. quadrilineatus , is quite distinctive based mainly on the male secondary sexual characters of the vestiture of the hind tibiae ( Fig. 65 ) and the extensive and dense vestiture of ventrite 5 ( Fig. 67 ). In M. bellorum the inner margin of the hind tibia has a tuft of dense elongate hairs at about the midlength, the hairs progressively shorter towards the tibial apex ( Fig. 65 ). In M. bromeliadicola and M. nudiventris the hairs along the inner margin of the hind tibia are similarly long but arranged in an row along the tibial length, not as a distinct tuft. On the other hand, in M. quadrilineatus the hairs are long and arranged as a distinct tuft; however, there are no progressively shorter hairs extended to the tibial apex. As in M. bromeliadicola , the apex of the pygidium is subtruncate in M. bellorum ( Fig. 66 ) and much broader than in M. quadrilineatus or M. nudiventris . Also, the front coxae in M. bellorum are widely separated by about one­half the width of a coxa whereas the front coxae in M. bromeliadicola , M. nudiventris and M. quadrilineatus are more narrowly separated by no more than about one­third the width of a coxa. In addition, the apical pilose part of the antennal club is one­third the length of the entire club ( Fig. 64 ).

Description.— Male, length, 11.7 mm; width, 4.9 mm. Female not known. Color mostly black, pronotal disc, dorsal portion of pronotal flanks, and elytra, piceous (elytra variously infuscate); elytra with elongate yellow stripe in interval 4 from near base to apical one­third, and shorter yellow stripe on interval 2 slightly beyond apical one­third.

Rostrum about two­thirds length pronotum; elongate, cylindrical, evenly curved, densely, very finely, shallowly punctate; dorsally at base and laterally at point of antennal insertion with punctures slightly larger, deeper; apical one­half glabrous and virtually impunctate, shining; base of rostrum slightly expanded in dorsal view, basal expanded area short, about one­fifth total rostral length. Rostrum glabrous ventrally; peduncle flat, bilamellate anteriorly. Scrobe with posterior margin separated from anterior margin of eyes by about width of base of scape. Antennal scape about one­half length rostrum; club elongate­oval; apical pilose part one­third length of entire club. Pronotum with lateral margins subparallel to slightly sinuate in basal one­half, convergent subapically, tubulate to apex; moderately densely, deeply punctate on flanks, across apical margin and at middle of base, otherwise disc impunctate; flat at base. Pronotum with length slightly greater than width. Elytra one and one­half times length pronotum; intervals impunctate, flat; striae with distinct, moderately deep, small punctures. Scutellum broadly “V” shaped, length one and one­half times width at base, concave anteriorly, slightly emarginate. Pygidium very slightly convex, not tumescent; coarsely deeply punctate and setose throughout; apex subtruncate; apical margin with row of short setae, also with small patch of denser, erect setae medially near base. Ventrally with front coxae separated by slightly more than one­half width of coxa; prosternum moderately densely, regularly punctate, flat. Lateral portions of meso­, metasternum and ventrites 1 to 5 moderately densely, deeply punctate; punctures larger laterally on metasternum and ventrites 1 and 2; middle of metasternum and ventrites 1­4 virtually impunctate, shining; last ventrite flat, with large round patch of dense long erect hairs covering middle of apical three­quarters. Legs short, sparsely, very shallowly punctate; femora slightly clavate, short, hind femur reaching apex of ventrite 4; inner margins of all tibiae slightly sinuate subapically; hind tibiae with distinct tuft of dense elongate hairs at about the midlength, the hairs getting progressively shorter towards the tibial apex. Tarsi each with third article widely dilated, pilose ventrally except in broad “V” shaped median area; all tarsi with third articles symmetrical; apical margins of third articles moderately deeply emarginate.

Sexual dimorphism.—Although females are not yet known in this species, it can be inferred (based on the related species M. bromeliadicola , M. nudiventris and M. quadrilineatus ) that they will lack the pilosity on ventrite 5 and along the inner margin of the hind tibiae.

Material Examined.—Male HOLOTYPE labelled “ Panama. Chiriqui Prov. / Cont’l Divide Trail / 3­4­VII.1997 / Morris & Wappes” (CMNC).

Distribution.— Panama (Chiriqui).

Natural history.—No information is available on natural history of this species. The habitat along the Continental Divide Trail near the La Fortuna Dam is a wet ridgetop cloud forest. Given the plant associations of its close relatives M. bromeliadicola and M. quadrilineatus , it is suspected that this species also is associated with bromeliads.

Derivation of specific name.—Through their support of the Nature Discovery Fund at the Canadian Museum of Nature, this species is named after the Bell family of Grimsby, Ontario, Canada.

Figures

FIGURES 51 - 56. Metamasius species. 51 - 52. Metamasius atwoodi Anderson. 51. Dorsal habitus. 52. Lateral habitus. 53 - 54. Metamasius bellorum Anderson. 53. Dorsal habitus. 54. Lateral habitus. 55 - 56. Metamasius burcheri Anderson. 55. Dorsal habitus. 56. Lateral habitus.

FIGURES 63 ­ 67. Metamasius bellorum Anderson. 63. Lateral view of head, male. 64. Antenna. 65. Hind leg, male. 66. Pygidium, male. 67. Apex of abdomen, male.