Pocadius decoratus Kirejtshuk 1984

Cline, Andrew R., 2008, Revision of the sap beetle genus Pocadius Erichson, 1843 (Coleoptera: Nitidulidae: Nitidulinae, Zootaxa 1799 (1), pp. 1-120 : 51-52

Pocadius decoratus Kirejtshuk 1984

(Figs. 96, 139, 254)

Specimens examined. HOLOTYPE ♂ ( ZISP): [N] Vietnam, mountains, 50km; NE Thai-Nguen, 300m; 9/1/ 1964, O. Kabokav / Holotypus Pocadius ; decoratus; det. Kirejtshuk 1983.

Diagnosis. Differs from other Pocadius by distinctive color pattern of orange and black on pronotum and elytra; short fine dorsal pubescence; tegmen with almost truncate apex and sparsely setose lateral margin; bullet-shaped median lobe with low L:W ratio.

Redescription. Length 4.1mm, Width 2.1mm, Depth 2.0mm. Body moderately convex, shining, orange with black markings on pronotum and elytra, setae short and fine. Pronotal and elytral margins scarcely fimbriate.

Head deeply punctate, becoming dense near orbits, punctures small near fronto-clypeal region; interspaces smooth to slightly alutaceous. Small punctures 0.75 larger ones, large punctures 7–8 times eye facets. Pronotal surface with large and small punctures interspersed. Large and small punctures similar to respective large and small punctures on head; interspaces 1–2 diameters apart, smooth to alutaceous. Scutellar surface scarcely punctate, similar to small punctures on head, interspaces alutaceous, granular. Eytral surface with serial rows of large punctures 2–3X diameter of large punctures on head, giving rise to short fine setae. Small serial punctures 0.2 diameter of large punctures, giving rise to short fine setae; interspaces smooth between punctures, large punctures separated by <0.5 diameter, small punctures separated by 2 diameters. Large and small rows separated by 1 large puncture diameter. Pygidium moderately punctate, punctures equal to small punctures on elytra, interspaces alutaceous with some minute microreticulation, punctures separated by 1 diameter.

Venter with similar pubescence as dorsum. Mentum alutaceous with no distinct punctation. Prosternum and epimeron irregularly punctate, punctures subequal to large punctures on head, interspaces smooth with faint alutaceous areas, prosternal punctures separated by 0.5 diameter, those on epimeron by 0.25–0.5 diameter. Mesoventrite with faint small punctures. Metaventrite irregularly punctate with small faint punctures on disc similar to those on head, interspaces smooth on disc, punctures separated by 2–3 diameters. Large punctures on lateral region of metaventrite equal to large punctures on elytra; interspaces smooth and ~1–2 diameters apart. Abdominal sternite 1 with faint large punctures in all but anterior 0.33 which is alutaceous; interspaces alutaceous, punctures separated by 1 diameter. Hypopygidium densely deeply punctate, punctures equal to those on sternites 2–4, interspaces smooth to alutaceous with faint microreticulation, punctures separated by 0.25–0.5 diameter.

Head much wider than long (W:L = 1.4:1), broadly triangular. Antennal club compact, oblong oval, asymmetrical with terminal antennomere longer than 9–10 combined. Antennomeres 6–8 disc-like, equal to length of 9. Antennal scape asymmetrical, globular to somewhat hemispherical, 3X length of pedicel. Pedicel subcylindrical. Antennal segment 3 subequal to pedicel. Segment 4 subquadrate, 0.5 length of segment 3. Antennal club large, 0.75 length of segments 1–8 combined, asymmetrical. Elevated region of mentum with anterior angles obsolete, anterior margin rounded, overall broadly hemispherical, flattened in lateral view.

Pronotum widest near posterior angles (L:W = 1:2.97), anterior margin shallowly concave to truncate. Scutellum large and broadly hemispherical. Prosternal process in lateral view with apex slightly depressed behind procoxae. Mesoventrite extending to midway between mesocoxae. Metaventrite wider than long (W:L = 3:1). Metepisternum narrow, only slightly concave medially, anterior 0.33 moderately produced anteriolaterally. First abdominal sternite with broadly truncate process between metacoxae, 2X longer than sternite 2. Sternites 2–4 subequal. Hypopygidium subequal to sternite 1.

Protibia with apical tooth prominent, longer than tarsomeres 1–2 combined. Outer apical notch with 90° angle, notch depth equal to tarsomere 1–2 combined. Inner apical spine subequal to tarsomere 1. Mesotibia more heavily armed than protibia with slender spines along lateral edge and scattered on ventral surface. Outer apical process elongate and robust, larger than protibial process. Inner apical spine equal to tarsomere 1 and part of 2 combined. Metatibia heavily armed with slender elongate spines of varying lengths, but most longer than those on mesotibia. Outer apical process elongate and robust, equal to inner apical spine, projecting more posteriorly than pro- or mesotibial processes. Inner apical spine subequal to tarsomeres 1–2 combined.

Male genitalia moderately well-sclerotized. Anal sclerite large broadly curved apically; apex moderately fimbriate. Spiculum gastrale not observed. Tegmen evenly broadly rounded (Fig. 96), longer than wide (w:l = 1:3), lateral row of setae visible from median fossa around apex, inner row of setae absent. Median lobe large and robust, bullet-shaped, 0.5 length of tegmen, apical opening well-developed extending posteriorly (Fig. 139). Internal sac sclerites not observed.

Variation. No variation observed.

Seasonality/Habitat. Holotype collected in September in a wet tropical forest.

Distribution. Known from type locality.

Notes. No host records available. Due to attachment of genitalia directly to card mount with water insoluble adhesive, some characters of the aedeagus were not visible. No attempts were made to remove genitalia from card mount due to fragility of organ and extensive amount of adhesive. Kirejtshuk (1984) places this species in his “nobilis-complex”, which contains P. nobilis and P. martini . This placement and grouping is not discussed and no characters are given to provide a basis for such a grouping. Cline (in prep.) did not find support for a grouping that included P. nobilis , however there was consistent support for a P. decoratus , P. martini , P. majusculus and P. femoralis grouping based on external (surface sculpture, tibial and scutellar features) and internal (genitalia) morphological characters.