Embates polymorphus (Champion)

Prena, Jens, 2005, The Middle American species of Embates Chevrolat (Coleoptera: Curculionidae: Baridinae), Zootaxa 1100 (1), pp. 1-151 : 1-151

55. Embates polymorphus (Champion)

(Fig. 182–186, 247)

Ambates polymorphus Champion 1907: 157 . Lectotype male, Panama, here designated, labeled: “sp. figured”, “Type”, “ ♂ ”, “V. de Chiriqui / 25–4000 ft. ”, “Genus/ Cholinambates / Casey 1922 “ (BMNH). Paralectotypes 3, Panama, here designated: Volcán de Chiriquí, without varietal status (5 specimens labeled as var. No. 1–2 are not considered to be type specimens; all BMNH). Hustache 1938 (cat., Cholinambates to subgenus)

Cholinambates polymorphus . Casey 1922: 6

Embates [ polymorphus ]. Alonso­Zarazaga & Lyal 1999 (global combination of all species of Ambates Schönherr 1836 with Embates Chevrolat 1833 )

Redescription. Habitus: Fig. 182, total length 6.8–11.2 mm (m=9.2, n=59). Color: integument rufous to black; basic vestiture of minute to medium­sized cupreous scales variously intermixed with yellow scales along elytral striae, light yellow to red ochreous scales condensed in dorsolateral and ventrolateral pronotal vittae; compound elytral color­pattern different from place to place (Fig. 183, see diagnosis of subspecies further below); venter with light yellow to red ochreous scales on metasternum, metepisternum and sides of ventrites 2–4. Head: frontal fovea minute or absent, rostrum moderate, subcylindrical (as Fig. 178), sides attenuated between apex and antennal insertion, costate dorsomedially, basolateral margin edged, length of rostrum ♂♂ 1.15–1.40 x (m=1.27, n=39), ♀♀ 1.25–1.41 x (m=1.32, n=20) pronotal length, length of ante­antennal portion ♂♂ 0.33–0.39 x (m=0.37, n=39), ♀♀ 0.36–0.42 x (m=0.39, n=20) total rostral length, dorsal margin of antennal scrobe reaching rostral base before eye; funicular segment 2 much longer than 1, club oblong ovate. Pronotum: length 0.79–0.91 x (m=0.86, n=59) maximum width, sides rounded, widest in basal half, anterior portion tubulate; disk finely punctate, intervals smooth. Elytra: length 1.82–2.00 x (m=1.93, n=59) width at humeri, width 1.28–1.45 x (m=1.34, n=59) maximum pronotal width, sides subparallel in basal half or slightly converging, apices rounded conjointly, preapical callus developed moderately, striae fine, punctures indistinct, interstriae flat, none costate. Legs: tibiae variously curved, ventral margin slightly bisinuate, distally with fringe of yellow to brown hairs, tarsal claws flat and approximate at base. Male: apex of aedeagus round, middle sclerotized, anterolateral portion and tectum membranous (Fig. 185), body of aedeagus of moderate length, basal half angular in lateral view, apodemes 1.9 x longer than body of aedeagus (Fig. 186), flagellum thin, nearly as long as apodemes, transition to curved base abrupt, basal appendage thick, fused subdistally with base of flagellum, projecting beyond base (as Fig. 181).

Plant association. Associated with various large­leafed species of Piper with the shoot­apex emerging from within the leaf­base at flowering nodes. Adult specimens hide frequently in the leaf sheath of the petiole.

Distribution. Costa Rica and Panama, evergreen montane forests between 900 and 2500 m (Fig. 247).

Discussion. Embates polymorphus can be recognized by the fringe of bristly hairs present on the ventral metatibial edge. Champion included under this name three “varietal forms” with different color­patterns. Those and three others agree well in morphometrical and genital character states. Specimens with different color­pattern usually exhibit allopatry (Fig. 247). All local populations themselves demonstrate various degrees of heterogeneity in the color­pattern. Some color­patterns appear to have very little in common, but these extremes are bridged by intermediate forms of other local populations. There is no question, that E. polymorphus is about to disintegrate into an Atlantic and a Pacific complex, but complete separation seems not to have been accomplished yet as evidenced by two specimens of E. polymorphus aff. altrimsecus from Tierras Morenas. Despite the enormous heterogeneity of the color­pattern, I follow Champion in his opinion and lump the entire material under one species with the apt name E. polymorphus , but distinguish the following six subspecies based on the color­pattern and the geographic distribution.