Pocadius dimidiatus Jelínek 1977

Cline, Andrew R., 2008, Revision of the sap beetle genus Pocadius Erichson, 1843 (Coleoptera: Nitidulidae: Nitidulinae, Zootaxa 1799 (1), pp. 1-120 : 52-54

Pocadius dimidiatus Jelínek 1977

(Figs. 13, 54, 97, 140, 182, 220)

Specimens examined. PARATYPE ♂ ( NMP): ARGENTINA: prov. Entre Rios; Conocordia; Hayward lgt. Additionally ,> 20 specimens: ( CMN, ARCC) ARGENTINA: Salta Prov.; 45km W Salta, 1950m; 1-29-XII- 1987, El Alisal; S&J Peck, moist ravine thicket, malaise-FIT. ( CMN, ARCC) ARGENTINA: Salta Prov.; El

Rey Nat. Park, 900m; 11-15-XII-1987, S&J Peck; Aguas Negras Trail, Prosopis forest, malaise-FIT. ( CMN, ARCC) ARGENTINA: Salta Prov.; 17km N La Caldera, Alto de la Sierra; 1550m, 2-30-XII-1987; S&J Peck, malaise-FIT; subtropical humid forest. ( CMN) ARGENTINA: Salta Prov.; El Rey Nat. Park , 900m; Rio La Sala , S &J Peck; 5-15-XII-1987, malaise-FIT; humid mossy Chaco forest .

Diagnosis. The species is distinguished by: greatly enlarged terminal antennomere; elongate pronotal and elytral fimbriae and overall long dorsal pubescence; pronotum with trapezoidal anterior margin and simple almost truncate posterior margin; prosternal process with prolonged apex; proportionately elongate tegmen to body size of adult; large robust median lobe; ejaculatory rods fused medially; and both lateral and inner rows of setae on tegmen incomplete.

Redescription. Length 3.2 mm, Width 1.8mm, Depth 1.4mm. Body moderately convex, shining, reddishbrown to dark brown, most specimens with elytral apices and lateral regions dark brown. Pronotal and elytral margins with elongate fimbriae. Dorsal and ventral pubescence golden and elongate.

Head surface deeply, irregularly, densely punctate, punctures larger on vertex, becoming smaller towards fronotclypeal region. Large punctures 4–5X diameter of eye facet, small punctures 3–4X diameter; interspaces smooth to finely alutaceous. Pronotal surface with large punctures equal to or slightly larger than large punctures on head, interspersed with few small punctures, 0.75 diameter large ones; interspaces smooth to alutaceous, 0.5–1 diameter apart. Scutellar surface with shallowly impressed small punctures, no punctures in apical 0.25, smaller than small ones on pronotum, interspaces smooth. Elytral surface with serial rows of small punctures equal to smaller punctures on pronotum, serial large punctures 2X diameter of smaller ones. Small punctures giving rise to erect elongate curved setae, serial large punctures giving rise to short decumbent setae; interspaces more narrow between punctures of a row than between different rows. Within a row, small punctures separated by 1 diameter, large punctures by 1 diameter. Rows separated by 1 large diameter; interspaces shining but variable from alutaceous to finely microreticulate. Pygidium densely punctate, punctures equal to smaller punctures on pronotum, interspaces narrow, 0.7–1.2 diameters, alutaceous to granular.

Venter less pubescent than dorsum. Mentum with large faint punctures, equal to large punctures on head, interspaces smooth to alutaceous. Prosternum and epimeron faintly irregularly punctate, punctures larger than those on mentum, interspaces alutaceous to rugose, prosternal punctures separated by 0.5–1 diameter, those on epimeron by>1 diameter. Mesoventrite with shallow punctures, 1.25 diameter of those on prosternum, interspaces alutaceous to granular, separated by 0.25–0.5 diameter. Metaventrite irregularly punctate with large punctures laterally, becoming slightly smaller and more faintly impressed on disc, lateral punctures similar to those on mesoventrite, interspaces smooth on disc, becoming microreticulate to granular laterally, separated by 1 diameter. Abdominal sternite 1 with large faint punctures equal to smaller punctures on metasternal disc, interspaces alutaceous, separated by 1–1.5 diameter. Hypopygidium with moderately deep punctures, similar to sternites 2–4, interspaces alutaceous to granular, separated by 0.5 diameter.

Head wider than long (L:W = 1:1.5). Antennal club compact, obovate, asymmetrical with terminal antennomere longer than 9–10 combined. Antennomeres 6–8 disc-like. Antennal scape asymmetrical, hemispherical, 1.9X length of pedicel. Pedicel subcylindrical. Antennal segment 3 slightly longer than pedicel. Antennal club large, 0.75 length of segments 1–8 combined. Elevated region of mentum with anterior angles faint, anterior margin angulate, overall pentagonal, convex in lateral view.

Pronotum widest near middle (L:W = 1:2), anterior margin trapezoidal, lateral margins less arcuate posteriorly, anterior and posterior angles present. Scutellum large, elongate triangular, apex narrowly rounded. Prosternal process in lateral view with anterior and posterior ends prominent with slight medial convexity; posterior face prominent and oblique. Mesoventrite extending to midway between mesocoxae, sharply concave for reception of metaventrite. Metaventrite wider than long (W:L = 1.6:1). Metepisternum with slight medial concavity, oblique line dividing anterior 0.125. First abdominal sternite with acuminate process between metacoxae. First sternite 2X longer than sternite 2. Sternites 2–3 subequal, 4 larger than 2 or 3. Hypopygidium subequal to sternite 1.

Protibia with apical tooth not prominent, slightly longer than tarsomere 1. Inner apical spine subequal to tarsomeres 1 and part of 2 combined. Outer apical notch absent. Mesotibia more heavily armed than protibia with dense stiff setae and slender spines along lateral edge. Outer apical process larger than protibial process. Inner apical spine equal to tarsomeres 1–2 combined. Metatibia more developed than mesotibia, outer apical process large and robust.

Male genitalia well-sclerotized. Anal sclerite with apex sparsely fimbriate (Fig. 13). Spiculum gastrale with wide lateral flanges, medial margins concave proximally, short stiff setae originating from angulate apical margin (Fig. 54). Tegmen evenly rounded (Fig. 97), longer than wide (w:l = 1:2.1), lateral row of setae visible from median fossa to around apex, small shallow concavities in apical 0.33. Median lobe elongate, 0.75 length of tegmen, apex acuminate, apical opening well-developed (Fig. 140). Ejaculatory rods not fused to basal piece, but fused to each other in apical 0.33, concave medially. Basal piece of internal sac sclerites with three pieces, two lateral asymmetrical tear-drop pieces, and medial bilobed globular section (Fig. 182).

Female genitalia well sclerotized. Paraprocts large with sclerotization along median line to baso-lateral angles. Gonocoxite with two basal lateral prominences, basal ridge with two short medial baculi. Gonocoxal apices with recurved “tooth” absent. Three elongate setae originate from small depressions on lateral region of gonocoxal apices (Fig. 220).

Variation. Variability in dark coloration on lateral and apical regions of elytra.

Seasonality/Habitat. Collected in December in lowland, mid-, and high elevation wet forest.

Distribution. Jelínek (1977) noted this species was in the LaPlata museum under P. helvolus , the eastern North American species, which was likely the basis of Blackwelder’s (1945) account of P. helvolus in Argentina. The type series are from eastern Argentina and non-type material from northwestern Argentina. Leschen and Carlton (1994) identified specimens of the new species P. peruensis (see below) as belonging to P. dimidiatus , however, dissection of the Peruvian material indicated they are distinct. Thus, P. dimidiatus appears to be restricted to north and central Argentina.

Notes. No host records exist.