Coptoborus pseudotenuis (Schedl)

Atkinson, Thomas H., Rabaglia, Robert J. & Cognato, Anthony I., 2010, Two newly detected bark and ambrosia beetles from southern Florida (Coleoptera: Curculionidae, Scolytinae), Zootaxa 2338, pp. 63-68 : 63-65

Coptoborus pseudotenuis (Schedl)

( Figs. 1–4 )

Xyleborus pseudotenuis Schedl 1936: 109

Xyleborus tenuis Schedl 1948: 269 (Synonomy: Wood 1976a)

Diagnosis. This small xyleborine ambrosia beetle is most easily distinguished from relatives found in the U.S. by the elytra which are tapered posteriorly ( Figs. 3, 4 ). The presence of 2 sutures on the posterior face of the antennal club is diagnostic and is shared only with Theoborus and Dryocoetoides (Atkinson, 2009) among genera known from the U.S. The genus Coptoborus (Hulcr et al. 2007) includes 10 Neotropical species, of which C. pseudotenuis is the most widely distributed ( Fig. 5 ). This species is a polyphagous inbreeding ambrosia beetle.

Description. Female: 1.8–2.2 mm long, 2.9 times as long as wide. Color yellowish brown. Frons convex, surface reticulate, shining. Punctures in central area between eyes sparse, shallow. Frontal vestiture of fine, sparse setae, most abundant near epistomal margin. First segment of antenna corneous, occupying less than 1/ 3 of club; 2nd and 3rd segments pubescent. Antennal sutures almost straight, slightly recurved. Pronotum 1.16 times as long as wide, anterior margin rounded, unarmed. Summit in middle of pronotum. Anterior asperities low, less pronounced in postero-lateral areas, forming triangular area. Disc smooth, shining, punctures shallow. Elytra 1.6 times as long as pronotum. Sides parallel on basal 2/3, tapering to approximately 1/3 of maximum width at narrowly rounded apex. Striae not impressed, punctures small. Interstriae nearly flat, shining on disc and declivity, 3–4 times as wide as striae. Vestiture of erect, uniseriate interstrial setae and recumbent strial setae, becoming more abundant posteriorly and on declivity. Declivity gradual, convex in profile, conspicuously narrowed behind in dorsal view. Interstria 2 slightly impressed, 1 and 3 with 3–5 small granules or denticles. Apical margin of interstriae 1–2 elevated, with 1–3 small granules.

Male: not known.

Distribution. Florida: Broward Co., Ft. Lauderdale, IFAS Research & Education Center, 6–V–2004, ex Delonix regia “with fungus”, S. Ortiz (1, FSCA). The single specimen was reared out along with several other species of ambrosia beetles ( Theoborus ricini (Eggers) , Euwallacea fornicatus (Eichhoff) , Ambrosiodmus lecontei Hopkins , Premnobius cavipennis Eichhoff , and Xyleborus ferrugineus (F.)). Florida: Palm Beach Co., West Palm Beach, Winding Waters Natural Area, 30–IV–2008, Lindgren funnel trap baited with ethanol lure, B. Mayfield (1, MSUC). This species is known from lowland areas of Mexico, Costa Rica, Panama, Venezuela and Brazil.

The following modified key to genera of Xyleborina of the U. S. is based on Rabaglia et al. (2006). In addition to Coptoborus , three genera are added to the key: Anisandrus , following resurrection of the genus for several native and exotic species (Hulcr et al. 2007) plus newly detected exotic species (Rabaglia et al. 2009); Ambrosiophilus , a new genus for certain previously established exotic species (Hulcr and Cognato, 2009); and Dryocoetoides , to include a new species for Florida (Atkinson, 2009).

Figures

FIGURE 5. Known collection localities for Coptoborus pseudotenuis in the Caribbean Basin. Also known from Brazil (Wood and Bright 1992 a).

FIGURES 1 – 4. Coptoborus pseudotenuis female. 1. Lateral view. 2. Head and frons. 3. Dorsal view. 4. Declivity.