Oaxacanthaxia bicolorata, Bellamy, 2011

Bellamy, C. L., 2011, A new dichromatic species of Oaxacanthaxia Bellamy 1991 (Coleoptera: Buprestidae) from Quintana Roo, México, Zootaxa 3053, pp. 59-62 : 59-61

Oaxacanthaxia bicolorata , sp. nov.

( Figs. 1, 4)

Description of male holotype. Small, 6.07 mm in length from midpoint of frontovertex to elytral apices, 2.83 mm across elytra at approximately anterior 1/4; slightly elongate ovoid; transversely convex; dorsal surface mostly red-cupreous with greenish reflections on frontovertex, pronotum, scutellum, near anterior margin of elytra and just at elytral apices; when viewed directly head appears mostly shining green; ventral surface black with blue-green reflections; coarsely shallowly punctate on dorsal surface; head with narrow transverse portion of frontoclypeus just dorsad antennal cavities areolate; most of ventral surface, especially prosternal disc, process and thoracic ventrites foveolate; head, pronotum and elytra with one very short recumbent white seta from each puncture; ventral setae each longer, finer, especially on abdominal ventrites. Head: frontovertex convex between eyes; inner margins of eyes slightly sinuate, subparallel; frontoclypeus feebly constricted between widely separated antenna1 cavities; distal margin concave; anteclypeus partially visible; labrum feebly bilobed distally; mandibles robust, recurved, acuminate distally; maxillary palpi elongate, palpomere 2 shorter than either 1 or 3, 3 slightly curved, apex round; mentum broadly rounded trapezoid; antennomere 1 elongate, longer than 2 + 3, wider distally; 2 shorter than 3; 3–10 serrate; 3 longer than 4; 4–10 each decreasing in length; 11 oblong, longer than 10; 3–11 moderately setose, sensory pores concentrated in single apicolateral fovea on ventral surface. Pronotum: 2.11x wider than long, widest at base; posterior margin biarcuate with slight medial convexity; lateral margins broadly arcuate, unicarinate, entire, viewed from above feebly arcuate; posterolateral angles subacute; posterior margin feebly bisinuate; disc flattened medially, feebly transversely convex laterally. Scutellum small, subtriangular, lateral margins feebly concave. Elytra: wider than pronotal base, widest beyond a point opposite humeri; humeri small, moderately elevated; lateral margins carinate, explanate dorsad epipleura, arcuate in anterior 1/2, attenuate in posterior 1/2, serrate from before posterior 1/3; apices separately rounded; elytra with very feebly elevated, irregular, oblique costae mostly visible in median portion of disc; epipleuron broad from past base to opposite metacoxal plate then narrowing and becoming confluent with lateral margin near posterior 1/4; pygidium not visible past elytral apices. Underside: prosternum compressed laterally, with feebly bilobed anterior margin; process with sides subparallel between procoxae, apex with truncate medial lobe between mesosternal lobes; metacoxal plates with posterior margin oblique on lateral 1/2, feebly dilated; sutures between abdominal ventrites transverse medially; abdominal ventrite 5 attenuate laterally, broadly rounded apically. Legs: femora fusiform; tibiae straight, with two apical spines; metatibiae with setal comb along outer edge; tarsomeres 1–4 with ventral pulvilli, pulvillus on 1 only on apical 2/3; 5 with claws appendiculate. Genitalia: as in Fig. 4 (mounted on point with specimen).

Variation. The female allotype ( Figs. 2, 3) differs from the holotype as follows: length 5.96 mm, width 2.86 mm; head and pronotum essentially the same green to blue-green color, with only a hint of that color reflecting near the anterior margin of elytral disc medially and scutellum; the eyes are slightly smaller, not quite so convex and slightly more widely separated. The allotype appears to be slightly more robust (L/ W 2.083) in comparison to the slightly more slender holotype (L/ W 2.144).

Specimens examined. Holotype, ♂ ( CNIN): MÉXICO: Quintana Roo, 1 km N Xel-há [ca. 20° 19' 00" N 087° 21' 15" W], 7–11.vi.2011, J. Cope, beating legumes; allotype, ♀ ( CLBC): same data as holotype.

Etymology. The specific epithet bicolorata is chosen for two reasons, both specimens, but especially the female, is at least of two colors and unlike the four congeners, there is a clear sexual dichromatism in this species.

Remarks. Surprisingly this new species reverses the usual pattern sexual dichromatism that occurs in buprestids, i.e. males with different colors, principally on the head, which leads to an expectation that at least some species ‘see’ in color. Before the two type specimens were dissected, I would have wagered excessively that the allotype specimen was the male due to the more strongly bicolorous dorsal coloration. Simply due to the coloration differences and southeastern Mexico coastal type locality, I have chosen not to repeat or append the very detailed key and character state matrices presented by Hornburg & Gottwald (2008), but suggest that a comparison of the dorsal habitus figures in Figures 1, 2, 5– 8 and the separation of type localities is sufficient to separate the five species now placed in Oaxacanthaxia , along with the use of Hornburg & Gottwald’s (2008) very detailed key and table if needed.