Pocadius rubidus Erichson, 1843

Cline, Andrew R., 2008, Revision of the sap beetle genus Pocadius Erichson, 1843 (Coleoptera: Nitidulidae: Nitidulinae, Zootaxa 1799 (1), pp. 1-120: 99-101

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http://doi.org/ 10.11646/zootaxa.1799.1.1

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Pocadius rubidus Erichson, 1843


Pocadius rubidus Erichson, 1843  

(Figs. 37, 78, 121, 164, 205, 243)

Specimens examined. HOLOTYPE ♂ ( ZMHB): 8643   / Holotype; Pocadius   ; rubidus; ERICHSON, 1843 / rubidus; Er.; [illegible handwriting on last line]. Additionally , specimens ( USNM) with the following label data: ROSAS - F.C. SUD; Provincia de Buenos Aires; Juan B. Daguerre / ARGENTINA; 1968 colln.; J. Daguerre. BsAsTanolil; P. Köelerls / ARGENTINA; 1968 colln.; J. Daguerre. BsAs; Zelolya [sp?]; X-45, J. Daguerre / ARGENTINA; 1968 colln.; J. Daguerre. Cordoba; Alta Gracia; III-45, J. Daguerre / ARGEN- TINA; 1968 colln.; J. Daguerre   .

Diagnosis. The largest South American species, P. rubidus   can be distinguished from other Pocadius   by: elytral surface distinctly rugose to microreticulate and densely punctate; pronotum with posterior angles indistinct and broadly rounded; antennal club with terminal antennomere symmetrical and longer than previous two segments combined; body large and robust; dorsum densely pubescent with elongate golden setae;

metasternal disc glabrous with few widely distributed minute punctures; outer protibial tooth large and robust; anal sclerite with curved apical setae.

Description. Length 4.0 mm, Width 2.4mm, Depth 1.9mm. Body convex, surface shining, reddish-brown to dark brown, sometimes with apical third of elytra dark brown to piceous. Pronotum and elytra margins with elongate fimbriae. Dorsal and ventral pubescence long and conspicuous, golden.

Head surface deeply, irregularly punctate, large and small punctures densely aggregated throughout head. Large punctures 4–5X diameter of eye facet, small punctures 3X diameter; interspaces smooth to finely alutaceous, shining. Most small punctures giving rise to elongate curved golden seta. Pronotal surface with large punctures equal to large ones on vertex, interspersed with numerous small punctures, ~0.33–0.5 large ones; interspaces smooth to alutaceous, 0.33–0.5 diameter apart. Scutellar surface with numerous shallowly impressed punctures, somewhat larger than smaller ones on pronotum; interspaces alutaceous to granular. Elytral surface with serial rows of alternating large and small deep punctures, rows of small punctures confusedly dispersed often with 2 rows of small punctures between rows of large punctures. Small punctures equal to smaller ones on pronotum, large punctures 2X diameter of smaller ones. Smaller punctures giving rise to erect long golden setae, large punctures giving rise to semi-erect long golden setae; interspaces narrow between punctures of a row and between different rows. Within a row, small punctures separated by 0.75–1 puncture diameter, and large punctures by 0.1–0.25 diameter. Large rows separated by 1 large puncture diameter; interspaces moderately shining, variable from rugose/granular to microreticulate sculpture deep and distinct. Pygidium densely punctate, punctures equal to small ones on elytra, each puncture giving rise to short golden setae; interspaces narrow, 0.25–0.33 diameter with granular sculpture.

Venter with similar long golden pubescence as dorsum. Mentum with moderately large shallow punctures, equal to large ones on vertex, each giving rise to elongate setae; interspaces alutaceous to granular. Submentum and gula similar in punctation to mentum but with interspaces completely granular and some microreticulation present. Prosternum and epimeron more deeply irregularly punctate than mentum, punctures larger than those on mentum, interspaces granular with microreticulate areas, prosternal punctures separated by 0.5 diameter, those on epimeron by 0.25–0.5 diameter. Mesoventrite with more deeply impressed punctures, slightly larger than those on prosternum, interspaces completely granular, separated by 0.5 diameter and aggregated near metasternal border. Metaventrite irregularly punctate with minute faint punctures on disc similar in size to small ones on venter, interspaces alutaceous to granular on metasternal disc becoming granular to microreticulate laterally, punctures separated by>2 diameters on disc and becoming more dense laterally. Abdominal sternite 1 with large faint, almost obsolete punctures, punctures equal to those on prosternum, interspaces alutaceous to granular, separated by 0.75–1.5 diameter. Hypopygidium with moderately deep punctures, similar to those on sternites 2–4, interspaces mostly granular, punctures separated by 0.5 diameter.

Head wider than long (L:W = 1:1.45). Antennal club compact, elongate oval, mostly symmetrical with last antennomere subequal to previous two segments combined. Antennomeres 4–5 more or less compact, 6–8 disc-like. Antennal scape asymmetrical, shortened and somewhat hemispherical, 1.3X as long as pedicel. Pedicel subcylindrical. Antennal segment 3 shorter than pedicel. Antennal club moderately large, 0.55 length of segments 1–8 combined. Mentum with anterior angles obsolete, anterior margin angulate, overall transversely triangular, flattened in lateral aspect.

Pronotum widest in posterior 0.33, transverse (L:W = 1:2), anterior margin broadly concave, posterior margin moderately convex, lateral margins somewhat arcuate anteriorly, anterior angles distinct, posterior angles indistinct and broadly rounded. Scutellum large, obtusely triangular, apex rounded. Prosternal process in lateral view with anterior and posterior ends not prominent, convex medially with a steeper declivity in anterior 0.66; posterior apical wall not prominent, oblique with little concavity. Mesoventrite extending to midway between mesocoxae, evenly concave for reception of metaventrite. Metaventrite transverse (W:L = 3.1:1). Metepisternum with slight medial constriction, oblique line dividing anterior 0.20. First abdominal sternite with acuminate process between metacoxae. First sternite ~2X’s longer than second. Sternites 2–4 subequal in length. Hypopygidium subequal to first sternite.

Protibia with apical tooth moderately prominent, slightly longer than tarsomeres 1. Outer apical notch indistinct. Inner apical spine subequal to tarsomeres 1 and part of 2 combined. Protibia not heavily armed. Mesotibia more heavily armed than protibia with more dense stiff setae and a row of numerous short slender spines along lateral edge. Outer apical process elongate and robust, larger than protibial process. Inner apical spine equal to tarsomeres 1 and part of 2 combined. Metatibia with heavy armature, lateral row of spines 2– 2.5X longer than those on mesotibia.

Male genitalia well-sclerotized. Anal sclerite with apex fimbriate with characteristically curved setae (Fig. 37). Spiculum gastrale with wide tapering lateral flanges, medial margin evenly concave, numerous long stiff setae originating from apex (Fig. 78). Tegmen evenly rounded apically (Fig. 121), much longer than wide (w:l = 1:2.44), lateral row of setae visible from median fossa to prior to apex, small shallow elliptical concavity in apical 0.33, inner row of setae almost attaining apex. Median lobe large and robust, 0.66 length of tegmen, apex broadly rounded, lateral sides with slight constriction basally, apical opening well-developed (Fig. 164). Ejaculatory rods not fused to each other or to basal piece, curved inward and expanded outward basally and apically. Basal piece of internal sac sclerites with lateral inward projecting arms (Fig. 205).

Female genitalia moderately sclerotized. Paraprocts large with sclerotization along median line to basolateral angles. Gonocoxite with two basal lateral prominences, basal ridge well-sclerotized with two short widely diverging baculi. Gonocoxal apices with distinct recurved “tooth” present. Two elongate and at least two short setae originate from small depressions on gonocoxal apices (Fig. 243).

Variation. Specimens from Cordoba have a different color pattern than the other Argentinean material. In these individuals, the basal half of the elytra is lighter. A similar pattern is seen in P. helvolus   , a Nearctic species, where individuals in the same region have some specimens with darker bodies and lighter elytral bases.

Seasonality/Habitat. Specimens were collected in March and October.

Distribution. Known from northern and central Argentina.

Notes. No host records available.


Smithsonian Institution, National Museum of Natural History