Metamasius richdeboeri 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: 67-70

publication ID 10.5281/zenodo.156033

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Metamasius richdeboeri Anderson

new species

Metamasius richdeboeri Anderson  , new species

( Figs. 101­102View FIGURES 101 - 108, 109­ 114View FIGURES 109 ­ 114)

Identification.—This species is difficult to characterize although the elytral color pattern, with a single red broad transverse median band, and in some specimens, a red subapical irregular spot and reddish humeri, is distinctive ( Figs. 101­102View FIGURES 101 - 108). The pronotum is marked with red medially at the base and in two variously developed oblique lateral lines. In its color pattern, this species resembles some specimens of M. dasyurus  but the pattern of setae on the pygidium is different and males do not have the long hairs on the inner margins of the front tibiae found in the latter species. In contrast to M. dasyurus  , the tibiae have only small, stout, spine­like setae along the inner margins, giving an overall “comblike” or pectinate appearance ( Fig. 112View FIGURES 109 ­ 114), and the pygidium has two apical tufts of setae ( Fig. 113View FIGURES 109 ­ 114). The hind and middle tibiae are also slightly inwardly expanded subbasally in the males, but not as distinctly as they are in M. hebetatus  . The pronotum is distinctly impressed subbasally with the punctures deeper and denser in this impressed area. In males, there is a very slight ventral swelling on the rostrum at the midlength ( Fig. 109View FIGURES 109 ­ 114), a feature otherwise seen only in M. sanguinipes  and M. tibialis  , but in these latter species the swelling is much more angulate and acute.

Description.— Male, length, 11.9­14.3 mm; width, 5.1­5.5 mm. Female, length, 10.4­ 12.8 mm; width, 5.0­ 5.4 mm. Color black with red; pronotal disc red, or black with red laterally in variously developed oblique longitudinal stripe and at middle of base; elytra black with red variously in a broad complete median band (on some specimens band abbreviated laterally to a large oblique spot extended from intervals 2 to 8), on humeral angle and subapically on intervals 3 to 5. Venter black, some specimens with lateral portions of metasternum, middle of ventrite 1, and metepisternum variously infused with red.

Rostrum shorter than pronotum; elongate, subcylindrical, evenly curved, densely, finely, shallowly punctate; base of rostrum slightly, abruptly expanded in dorsal view; in lateral view, only slightly wider at base, expansion gradual, basal expanded area about one­fourth total rostral length; also with slight ventral swelling at more or less midlength in male. Rostrum glabrous ventrally; peduncle uniformly produced ventrally, bilamellate.

Scrobe with posterior margin separated from anterior margin of eyes by about width of base of scape. Antennal scape slightly more than one­half length rostrum; club slightly laterally compressed, oval; apical pilose part subequal to length basal glabrous part. Pronotum slightly longer than wide; lateral margins subparallel to slightly divergent in basal two­thirds, convergent subapically, tubulate to apex; moderately densely, shallowly punctate, except slightly larger and deeper subbasally at middle, medially just behind anterior margin, and on flanks; with moderately deep, round impression medially at base. Elytra one and two­thirds times length pronotum; intervals impunctate, flat; striae with distinct, moderately deep, small punctures. Scutellum broadly “V” shaped, slightly longer than width at base, concave and sloping anteriorly. Pygidium flat, with slightly raised, sparsely setose, median region, not tumescent; coarsely deeply punctate throughout; apex narrowly rounded; apical margin with pair of tufts of setae. Ventrally with front coxae separated by from one­fourth to one­half width of coxa; prosternum moderately densely, regularly punctate, variously impressed, concave between and anterior to front coxae. Lateral portions of meso­, metasternum and ventrites 3 to 5 shallowly, sparsely punctate; punctures larger, deeper laterally on ventrites 1 and 2; last ventrite flat. Legs moderate in length, shallowly punctate, finely setose; femora slightly clavate, hind femur almost reaching apex of ventrite 5; inner margins of middle and hind tibiae of male slightly inwardly expanded subbasally, straight in female; with setae in apical two­thirds, setae of more or less uniform length, short, stout, overall appearance pectinate. Tarsi each with third article widely dilated, pilose ventrally except in narrow, median fusiform line in basal two­thirds; all tarsi with third articles symmetrical and with apical margins very slightly emarginate.

Variation.—There is some variation in the color pattern of this species. In all specimens there is a single red broad transverse median band, but in some specimens, there is also a red subapical irregular spot evident from intevals 3­5, and in these same specimens, the humeri also are reddish. In all specimens but one, the pronotum is black with red markings medially at the base and in two variously developed oblique, anteriorly convergent, lateral lines. In this exceptional specimen the pronotum is entirely red.

Sexual dimorphism.—In males, the rostrum is more slightly robust in lateral view and possesses a slight ventral swelling at about the midlength. Also, the inner margins of the middle and hind tibiae are slightly inwardly expanded in males, not so expanded in females.

Material examined.—Male HOLOTYPE labelled “Rancho Quemado, 200m, / Peninsula de Osa, Prov. / Puntarenas. Costa Rica / F. Quesada, Mar 1992 / L­S 292500, 511000 ”, INBio barcode 864097 ( INBC), with pupal cell attached. Female ALLOTYPE labelled as holotype, INBio barcode 864131 ( INBC). PARATYPES (8, 10). COSTA RICA. HEREDIA PROVINCE. La Selva Biological Station, 3 km S. Puerto Viejo. Apr 1990, J. Wetterer (1). 25 Jun 1985, H. A. Hespenheide (1). LIMON PROVINCE. Res. Biol. Hitoy Cerere, Est. Hitoy Cerere, R. Cerere. 4­20 Dec 1991 (1; 490101). Amubri, 70 m, 4­30 Apr 1995 (1; 2144776). PUNTARENAS PROVINCE. Peninsula de Osa. Cerro Rincon. 23 Jan 1997 (emerged 19 Feb 1997), 775 m. 274700 521700 (4 d, 3 φ). Rancho Quemado. 21 Mar- 7 Apr 1992 (3 φ; 412638, 412634, 412639); Mar 1992 (1 d; 864130); Apr 1992 (1 d; 495142). PANAMA. CHIRIQUI PROVINCE. Bocas del Toro, Corriente Grande, Rio Changuinola, 917 ' 30 " N, 8232 ' 41 " W, 18.IV. 1980, H. Wolda (1 φ). PAN- AMA PROVINCE. Cerro Campana, 850m, 840 N, 7956 W, 14 Jul 1974, H.P. Stockwell (1 φ). Paratypes in CMNC, INBC.

Distribution.— Costa Rica (Heredia, Limon, Puntarenas), Panama (Chiriqui, Panama).

Natural history.—All specimens have been collected in lowland rainforest. Little information is available on natural history although a number of the specimens collected in the Osa Penninsula have fibrous pupal cells mounted along with the adult beetles. This suggests these specimens were collected in the pupal cells or had recently emerged from them. One series of such specimens from Cerro Rincon (775 m) was collected in the roots of “chonta” ( Socratea exorrhiza  ; Arecaceae  ) along with larvae. It is possible that the other Osa specimens were from the same species of palm.

Derivation of specific name.— Through their support of the Nature Discovery Fund at the Canadian Museum of Nature, this species is named after Richard deBoer of Manotick, Ontario, Canada as a gift from his wife Coralie Lalonde.


National Biodiversity Institute, Costa Rica


Instituto Nacional de Biodiversidad (INBio)