Astaena nigrona Saylor, 1947

Pacheco, Thaynara L., Monné, Marcela L., Vaz-De, Fernando Z. & Ahrens, Dirk, 2021, Revision of type specimens of Astaena (Coleoptera: Scarabaeidae: Melolonthinae: Sericini) described by L. W. Saylor, European Journal of Taxonomy 750 (750), pp. 94-123 : 107

Astaena nigrona Saylor, 1947

Figs 3K–O , 7A

Astaena nigrona Saylor, 1947b: 435 .

Astaena nigrona – Frey 1973: 331 (identification key).

non Astaena nigroana (incorrect subsequent spelling) – Evans 2003: 25 (checklist). — Evans & Smith 2005: 10 (checklist); 2007: 10 (checklist); 2009: 10 (checklist).

Type material examined

Holotype COLOMBIA • ♂; “ Rio Chil. Colum / L.W. Saylor Collection / California Academy of Sciences Type nº 7915 / Holotype Astaena nigrona L.W. Saylor ”; CAS.

Paratype COLOMBIA • 1 ♀; “ Bogota VI- Colum / L.W. Saylor Collection / Collection of the California Academy of Sciences, San Francisco, California / Allotype Astaena nigrona L.W. Saylor ”; CAS .

Holotype redescription

MEASUREMENTS. Length: 12 mm. Width: 5.8 mm.

HEAD. Reddish-brown. Labroclypeus, shape of anterior margin weakly sinuated medially. Ocular canthus without terminal setae, ratio to eye: 1/4. Antennae with eight antennomeres; antennal club with three antennomeres; ratio antennal club/remaining antennomeres: 1/1.5; ratio third vs fourth antennomere: 1/3; fourth antennomere, lateral projection absent; ratio fifth vs fourth antennomere: 1/5.

PRONOTUM AND ELYTRA. Surface of pronotum and elytra with setae. Pronotum bicolored, reddish-brown with two red spots on laterals, widest at middle, anterior marginal line present, posterior marginal line absent, lateral margin strongly convex and smooth (not serrate), antero-lateral angle dorso-ventrally flattened, postero-lateral angle dorso-ventrally flattened, punctation on disc dense, setae of lateral margin sparse, median longitudinal excavation absent. Scutellum, punctures absent medially. Elytra unicolored, blackish-brown, surface opaque, microsculpture absent, punctation on intervals present, diameter of strial and interval punctation equal.

ABDOMEN. Lateral carina present. Second visible ventrite with row of setae in medial region. Apical visible ventrite without suture to apical tergite.

LEGS. Metacoxa without longer lateral bristles, a laterally extended longitudinal shelf present. Metatibia, widest at apex, distal spines groups disposed at two thirds of metatibial length. First metatarsomere, ratio to dorsal metatibial spur: 1/3. Dorsal surface of tarsi glabrous, without punctures. Metatarsi, length of first protarsomere subequal to second and third combined, ventral margin serrated. Protibia with three teeth. Protarsi, length of first protarsomere subequal to second and third combined, second protarsomere narrow, claws asymmetrical, inner protarsal claw bifid, apex of basal tooth of inner protarsal claw truncate.

AEDEAGUS. Fig. 3M–N .

Figures

Fig. 3. A–E. Astaena incachaca Saylor, 1946, holotype, ♂ (Type No. 7913; CAS). – F–J. A. maqueta Saylor, 1947, holotype, ♂ (Type No. 7914; CAS). – K–O. A. nigrona Saylor, 1947, holotype, ♂ (Type No. 7915; CAS). A, G, M. Aedeagus, lateral view. B, F, N. Parameres, dorsal view. C, H, O. labels. D, I, L. Habitus, dorsal view. E, J, K. Habitus, lateral view. Scale bars: A–B, F–G, M–N = 0.5 mm; D–E, I–L = 1 mm.

Fig. 7. Distribution of type localities of the South American Sericini species described by Saylor. A. Astaena abaca Saylor, 1946, A. biciliata Saylor, 1946, A. bogotana Saylor, 1946, A. excisipes Saylor, 1947, A. explaniceps Saylor, 1947, A. incachaca Saylor, 1946, A. maqueta Saylor, 1947, and A. nigrona Saylor, 1947. B. A. fusagona Saylor, 1946, A. pygidia Saylor, 1946, A. rugithorax Saylor, 1946, A. salta Saylor, 1946, A. yungasa Saylor, 1946, and A. zyrota Saylor, 1946. C. Sayloria abcora (Saylor, 1946) comb. nov., S. bicoloripes (Saylor, 1946) comb. nov., and S. pottsi (Saylor, 1946) comb. nov..