Pocadius adustus Reitter, 1888

Cline, Andrew R., 2008, Revision of the sap beetle genus Pocadius Erichson, 1843 (Coleoptera: Nitidulidae: Nitidulinae, Zootaxa 1799 (1), pp. 1-120 : 16-17

Pocadius adustus Reitter, 1888

(Figs. 1, 43, 84, 127, 170, 210, 249)

Pocadius lanuginosus Franz 1969 , syn. Audisio 1982, 1988

Specimens examined. HOLOTYPE (HNHM): Caucus. Occ.; Circassien; Leder Reitter / Holotypus 1888; Pocadius ferrugin.; v. adustus ; Reitter / coll. Reitter. Additionally,> 350 specimens (CAS, CSCA, DEI, FMNH, HNHM, MCZ, NMPC, RMNH, USNM, ZISP, ZMHB, ZMUC) from the Palearctic, ranging from the Iberian peninsula north through the British Isles and eastward through northern Italy, eastern Europe and Turkey, also from Sweden, Belarus, western Russia, and Ukraine. Kirejtshuk (1992) included P. adustus from Siberia, the Caucuses, and Malaysia. The latter of these countries was not confirmed, but should be verified before inclusion in the distribution.

Diagnosis. Most closely allied to P. ferrugineus , with which it is sympatric throughout most of its range. Pocadius adustus can be distinguished from P. ferrugineus by broadly concave apex of male pygidium, more elongate setae on meso- and metatibia, overall longer body pubescence, more pronounced apico-lateral spines on meso-metatibia of males, prosternal process in lateral view with highest convexity more posteriorly, and body punctation more widely spaced. Differs from P. africanus by longer body vestiture, particularly elytral and pronotal fimbriae which are 2–3X longer, terminal antennomere more symmetrical, interspaces between punctures more rugose and serial elytral punctures more approximate. Ejaculatory rods of male distinctive, in particular the basal piece which is more robust and resembles recurved spines.

Description. Length 4.2mm, Width 2.8mm, Depth 1.7mm. Body convex, somewhat shining, light to dark reddish brown, pubescence long pale grey to golden, pronotal and elytral fimbriae elongate (> length of scape).

Head surface densely irregularly punctate, interspaces smooth to alutaceous, 0.25 puncture diameter. Pronotal surface with large and small punctures interspersed throughout; large punctures>1 head puncture diameter, smaller punctures <0.5 head puncture diameter; interspaces 0.5–1 large puncture diameter, smooth to alutaceous. Scutellar surface moderately punctuate, punctures similar to small ones on pronotum; interspaces <0.5 puncture diameter, alutaceous to rugose. Elytra with series of large and small punctures; large punctures ~2X diameter of head puncture, giving rise to decumbent setae; small punctures 0.25 diameter of large punctures, giving rise to elongate semi-erect setae; interspaces alutaceous to rugose, large punctures within a row separated by 0.5–0.75 diameter, small punctures within a row separated by 2 small puncture diameters. Large and small puncture rows separated by 2 small puncture diameters. Pygidium densely irregularly punctate, punctures equal to small punctures on elytra; interspaces alutaceous to rugose with some microreticulation, punctures separated by 0.5–1 diameter.

Venter with shorter pubescence than dorsum except elongate setae on head and prosternal process. Mentum with scattered punctures similar to small punctures on pronotum, interspaces alutaceous with microreticulation, 1 diameter apart. Submentum and gula with similar sized punctures as mentum, interspaces alutaceous to rugose. Prosternum and epimeron faintly to moderately impressed with large punctures, punctures 2X larger than on mentum, interspaces alutaceous to rugose with microreticulation, 1–1.5 diameters apart. Mesoventrite with punctures aggregated near posterior margin, interspaces rugose. Metasternal disc faintly punctate with moderate sized punctures equal to those on mentum. Metaventrite densely punctate laterally; interspaces alutaceous to faintly rugose. Abdominal sternite 1 with faint punctures, equal to those on metaventrite, interspaces rugose, separated by 1–2 diameters, abdominal process mostly impunctate and alutaceous. Hypopygidium densely shallowly punctate, punctures equal to those on metaventrite, interspaces alutaceous with faint microreticulation, separated by 0.25–0.5 diameter.

Head wider than long (W:L = 1.5:1). Antennal club compact, terminal antennomere subequal to previous two segments combined, entire club equal to 1.3X length of antennal stem. Antennal scape asymmetrical, broadly hemispherical, 2X length of pedicel. Pedicel barrel-shaped. Antennal segment 3 equal to pedicel, narrowed proximally. Segments 4–5 globular, 0.75 length of segment 3. Mesoventrite extending to midway between mesocoxae, evenly concave for reception of metaventrite. Metaventrite wider than long (W:L = 2.4:1). Metepisternum angulate medially, anterior 0.33 strongly produced anteriomedially and impunctate with granular surface with some microreticulation. First abdominal sternite broadly rounded between metacoxae.

Protibial apical tooth as long as tarsomeres 1 and half of 2 combined. Outer apical notch indistinct, obliquely oriented. Mesotibia armed with slender spines along lateral edge, spines 0.5 length of setae on lateral mesotibial margin. Metatibia more heavily armed than mesotibia, lateral spines more elongate and numerous.

Male genitalia well sclerotized. Anal sclerite with apex densely fimbriate (Fig. 1). Spiculum gastrale more lightly sclerotized than anal sclerite and tegmen (Fig. 43), lateral region somewhat rounded and moderately explanate, apical border undulate with>10 setae. Tegmen evenly broadly rounded apically (Fig. 84), longer than wide (w:l = 2.6:1), lateral row of setae visible anterior to median fossa around apex, inner row of setae absent. Median lobe large and robust, 0.66 length of tegmen, apical opening well-developed (Fig. 127). Ejaculatory rods not fused to each other, evenly concave, basal piece of internal sac sclerites with recurved apices (Fig. 170).

Ovipositor moderately sclerotized. Gonocoxites with sclerotized basal border with one lateral prominence, basal border giving rise to two medial oblique sclerotized baculi extending apicolaterally. Gonocoxal apices moderately separated with intragonocoxal invagination evenly rounded at base, gonocoxal tips rounded at apex with a small lateral recurved “tooth” giving rise to 5–7 short seta (Fig. 210).

Variation. Color varies from light to dark red brown sometimes with dark brown elytral sutures, lateral elytral margins, and scutellum. Number of terminal setae on gonocoxal apices varies.

Seasonality/Habitat. Known from March – October.

Distribution. Throughout Europe eastward into Turkey and Western Caucasus in Russia ( Hansen 1972, Johnson 1976, Nash 1981, Allen 1992, Kirejtshuk 1992, Spronraft 1992, Audisio 1993, Borowiec and Kania 1994, Kubisz 1995, Alexander 1997, Maciejewski 1997, deOude 1999, Whitehead 1999, Audisio et al. 2000, Otero et al. 2003, Jelínek and Audisio 2007).

Notes. Adults of P. adustus have been collected from Pleurotus ostreatus Fries (Tricholotamaceae) and from drying fruiting bodies of several other fungi, while larvae only develop on the following: Lycoperdon Tourn. (Lycoperdaceae) , Bovista Pers. (Lycoperdaceae) , Calvatia Fries (Lycoperdaceae) , and Langermannia Rostkovius (Lycoperdaceae) . This species was recently treated by Audisio (1993) and Whitehead (1999).