Embates biguttatus (Champion)

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

15. Embates biguttatus (Champion)

(Fig. 71–74, 243)

Ambates biguttatus Champion 1907: 164 . Lectotype female, here designated, Mexico, labeled: “Sp. figured”, “ ♀ ”, Mexico./ Salle Coll., “Yolotepec” (BMNH). Paralectotypes 5, here designated: Group A ( E. biguttatus ): Sinanjá (BMNH, NMNH), Playa Vicente (BMNH); Group B ( E. bicoctura s. l.): Yolotepec (BMNH 2); Group C ( E. ocellatus s. l.): Cerro Zunil (BMNH). Two specimens from Teapa, labeled as variety, are not regarded as type specimens. Two specimens from Trece Aguas, Guatemala (BMNH, NMNH) were identified by Champion, but do not belong to the type series. O’Brien & Wibmer 1982 (cat.); Hustache 1938 (cat.)

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

Redescription. Habitus: similar to Fig. 1 (figured in original description), total length 4.2– 6.1 mm (m=5.1, n=18). Color: integument piceous, basic vestiture of light brown scales; elytron with black subcircular macula slightly behind middle, macula usually bordered by ochreous scales to various degrees, distal margin with variously developed oblique fascia of light yellow scales (Fig. 72); pronotum with dorsolateral vitta of ochreous scales. Head: frontal fovea absent, rostrum slender, subcylindrical (Fig. 71), costate dorsomedially, basolateral margin edged, length of rostrum ♂♂ 1.17–1.48 x (m=1.28, n=7), ♀♀ 1.11–1.36 x (m=1.24, n=10) pronotal length, length of ante­antennal portion ♂♂ 0.31–0.39 x (m=0.36, n=7), ♀♀ 0.35–0.40 x (m=0.39, n=10) total rostral length, dorsal margin of antennal scrobe reaching rostral base well before eye; funicular segment 2 much longer than 1, club oblong ovate. Pronotum: length 0.80–1.00 x (m=0.91, n=18) maximum width, sides rounded, widest in basal third, anterior portion tubulate; disk densely punctate, with isolated granula. Elytra: length 1.67–1.85 x (m=1.75, n=18) width at humeri, width 1.32– 1.54 x (m=1.42, n=18) maximum pronotal width, sides subparallel in basal half, then increasingly narrowed toward apex, apices rounded conjointly, preapical callus moderate, striae fine, punctures indistinct to moderate, interstriae flat, 9 (7 partially) subcostate. Legs: tibiae almost straight, ventral margin slightly bisinuate, metatibia ventrodistally with cluster of cupreous hairs, tarsal claws arcuate and separate at base. Male: apex of aedeagus rounded narrowly, middle sclerotized, anterolateral portion membranous (Fig. 73), body of aedeagus of moderate length, angular in basal third, apodemes 1.7 x longer than body of aedeagus, flagellum thin, as long as apodemes, transition to curved base gradual, basal appendage slender, slightly projecting beyond base of flagellum, fused laterally (Fig. 74).

Plant association. Piper sp. (Prena 2).

Distribution. Southern Mexico (Atlantic side) to northern Nicaragua (Fig. 243).

Material examined. MEXICO. Chiapas: 8.6 km S Rayón ( CWOB 9 , JPPC) ; 8.9 mi S Tapilula , 1600 m ( CMNC) . Oaxaca: Yolotepec ( BMNH) ; Vista Hermosa ( CWOB) . Puebla: Teziutlán ( CMNC, HAHC 2 ) . Tabasco: Teapa ( BMNH 2 ) . Yucatan: 7 km S Oxkutzcab ( CMNC) . Veracruz: Playa Vicente ( BMNH) . GUATEMALA. Izabal: Cerro San Gil, 8 km N Las Escobas , 800 m ( HAHC) . Verapaz: Trece Aguas ( BMNH, NMNH) ; Sinanjá ( BMNH, NMNH) . Zacapa: La Unión, 1500 m ( CMNC, CWOB) . HONDURAS. Cortés: Cusuco N.P., 20 km W San Pedro Sula , 1500 m ( JPPC 2 ) . NICARAGUA. Matagalpa: 7 mi N Matagalpa , 1600 m ( CWOB) . Total 30 specimens.

Discussion. Champion assigned to E. biguttatus seven specimens with almost circular black elytral macula from Mexico and Guatemala, and recognized an unnamed “variety” from Teapas, Mexico. The seven syntypes appear to belong to three distinct taxa. Two of the taxa (groups B and C in the lectotype designation further above) cannot be classified with confidence for the time being. Four of the syntypes belong to the taxon figured in Champion (1907, plate 9, fig. 31), and it is desirable to choose one of them as lectotype of E. biguttatus . Since the only male included is an aberrant specimen with very short rostrum, I chose the female specimen figured in the original description. Embates biguttatus , as here understood, is a relatively small species with separate claws and circular elytral macula with variable but consistently narrow circumambient line. Often, the post­macular portion of the latter is slightly expanded and modified to an oblique fascia. Even under the new definition, the species still exhibits considerable variability in terms of body proportion and vestiture. The specimens from Rayón are included under E. biguttatus in the wider sense. The distinction from other species of the complex remains unsatisfying and will need further refinement when more material becomes available. This applies particularly to E. nigronotatus and the new Costa Rican species E. paucilimbatus and E. mendax .

Figures

FIGURES 1–12. E. caecus: 1, habitus and color­pattern, dorsal; 2, thorax and abdomen, ventral; 3, posterior tergites, dorsal; 4, head and prothorax, lateral; 5, metafemur and tibia; 6, sternite 8, male; 7, sternite 9, male; 8, tegmen; 9, apex of aedeagus, dorsal; 10, aedeagus, lateral; 11, sternite 8, female; 12, female genital tract, lateral