Chalcionellus amoenus : REICHARDT 1932
Creators: name: Lackner, Tomáš
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Histeridae
Chalcionellus
Chalcionellus amoenus

description: Chalcionellus amoenus (Erichson, 1834)
(Figs. 15, 49, 83, 112, 232–247)
Hister aereus: DEJEAN (1821): 48 (nomen nudum). Synonymized by GEMMINGER & HAROLD (1868): 782. Hister mediocris: DEJEAN (1821): 48 (nomen nudum). Synonymized by DEJEAN (1837): 142. Saprinus amoenus Erichson, 1834: 190. Saprinus amoenus: MARSEUL (1855): 681, t. XIX, Fig. 124. Saprinus sabuleti Rosenhauer, 1847: 24. Synonymized by SCHMIDT (1884): 237. Saprinus conjugens var. micans Hochhut, 1872: 228. Synonymized by SCHMIDT (1890): 17. Saprinus (Hypocaccus) amoenus: SCHMIDT (1885a): 311; GANGLBAUER (1899): 388; JAKOBSON (1911): 650. Hypocacculus amoenus: BICKHARDT (1916): 96. Chalcionellus amoenus: REICHARDT (1932): 22, 79, t. III, Fig. 6; REICHARDT (1941): 264, 270; HORION (1949): 340;
DAHLGREN (1969): 63, 67, Figs. 1H, 3B; KRYZHANOVSKIJ & REICHARDT (1976): 189, 192, Figs. 383–385; VIENNA
(1980):166; MAZUR & KASZAB (1980): 49, Fig.25F; MAZUR (1984):79; MAZUR (1997): 246; SECQ & GOMY (1999):
68, Figs. 1, 6, 10; YÉLAMOS (2002): 296, 302, Figs. 147C, 148B, 149C, 151C; MAZUR (2004): 90. Chalcionellus amoenus var. chalybaeus Reichardt, 1932: 22.
Type locality. Portugal.
Material examined: KAZAKHSTAN: Kujuk, Kara Tau, Jambol, 5.v.1981, 1 ♁, A. Olexa lgt.; Assa env., Jambol, 10.v.1981, 2 spec., A. Olexa lgt.; Alma Arasan, Alma Ata, 10.vii.1976, 1 ♁, A. Olexa lgt. UZBEKISTAN: Aman Kutan (Samarqand), 16.v.1974, 1 ♁, A. Olexa lgt. (TLAN).
Redescription. Body length: PEL: 2.375–2.50 mm; APW: 0.825 –0.875 mm; PPW: 1.625 – 1.875 mm; EL: 1.50–1.625 mm; EW: 2.00– 2.125 mm.
Body (Figs. 232–247) roundly oval, moderately convex; cuticle shining, dark brown to black, with slight greenish or bluish metallic luster; elytral humeri slightly prominent, legs, antennae and mouthparts reddish-brown.
Antennal scape (Fig. 235) moderately dilated, with two short setae; club without visible articulation, entire surface with short dense sensilla, intermingled with sparse longer sensilla; sensory structures of antennal club (Fig. 15) in form of stipe-shaped vesicle situated under a large circular sensory area on internal distal margin of the ventral side of antennal club supplemented by another sensory area under apical surface of club.
Mouthparts. Mandibles (Fig. 83) with rounded outer margin curved inwardly, sub-apical tooth on left mandible large, perpendicular, mandibular apex acutely pointed; labrum (Figs. 49, 237) punctated, anterior margin with median concavity interrupting convexity; disc of labrum with two well impressed labral pits fringed with two setae; terminal labial palpomere elongated, its width about one-third its length; mentum (Fig. 238) sub-trapezoid; anterior margin medially with a small acute notch (Fig. 112); anterior margin with four long setae; disc of mentum entirely with dense, much shorter setae. Cardo of maxilla (Fig. 238) on outer margin with few short setae; stipes (Fig. 238) triangular, with three somewhat longer setae; terminal maxillary palpomere elongated, its width about one-fourth its length, about twice as long as penultimate.
Clypeus (Fig. 237) flat, rounded laterally, coarsely punctate; frontal stria complete, almost straight, somewhat weakened anteriorly, continued as carinate supraorbital stria; frontal disc with fine even punctation, punctures separated by their own to twice their diameter; eyes convex, well visible from above.
Pronotal sides (Fig. 232) moderately convergent anteriorly; apical angles blunt; pronotal foveae large, deeply impressed; disc laterally with a band of coarse punctation running parallel to lateral margin; between it and pronotal margin punctation weakens and becomes very fine; median part of pronotum with scattered microscopic punctures; pronotal base with a row of coarse round punctures; marginal pronotal stria well impressed, carinate, stopping just short of posterior angles; pronotal hypomeron with microscopic setae, almost glabrous.
Elytral epipleuron almost smooth, with microscopic punctation; marginal epipleural stria well impressed, complete; marginal elytral stria well impressed, in deep round punctures; apically shortly prolonged onto elytron, thence obliterated. Humeral elytral stria well impressed on basal third; inner subhumeral stria present as a short medial fragment in a form of row of punctures; elytra with four dorsal striae 1–4; first the shortest, not reaching elytral half apically; second, third and fourth about the same length, reaching about two-thirds of elytral length apically; fourth the longest, basally well connected with the sutural elytral stria; sutural stria well impressed and complete, in deep punctures. Punctation of elytral disc confined to posterior third, punctures separated by about their own to twice their own diameter; intermingled with very fine scattered punctation.
Propygidium and pygidium with round punctures, separated by about their own to twice their diameter; punctation of propygidium somewhat denser and coarser than that of pygidium.
Anterior margin of median portion of prosternum (Fig. 239) evenly rounded; marginal prosternal stria shortly present anteriorly; pre-apical foveae well impressed, rather deep (according to KRYZHANOVSKIJ & REICHARDT (1976) some specimens of this species may lack pronotal foveae altogether); prosternal process flattened; dorso-laterally with sparse, moderately-sized punctures; carinal prosternal striae well impressed, almost parallel, united anteriorly; lateral prosternal striae carinate, convergent anteriorly, attaining united carinal striae. Anterior margin of mesoventrite (Fig. 239) moderately emarginate medially, discal marginal mesoventral stria well impressed, slightly carinate; disc of mesoventrite with fine scattered punctation, along lateral margins a row of coarser punctures present; meso-metaventral sutural stria weakly impressed, undulate; intercoxal disc of metaventrite with fine scattered punctures; along apical margin band of coarse punctures present; lateral metaventral stria well impressed, in deep punctures, extending obliquely, stopping short of hind coxa. Lateral disc of metaventrite with shallow, round setiferous punctures, separated by about half to their own diameter, becoming finer apically; metepisternum with similar punctation, punctures without setae, metepisternal stria absent.
Intercoxal disc of first abdominal sternite completely striate laterally; disc antero-laterally with round coarse punctures; medially punctation much finer and sparser; along apical margin a row of fine punctures present.
Protibia (Fig. 240) slightly dilated, outer margin with three moderately large triangular teeth topped with tiny denticle, followed by one low tooth topped by minute denticle and three minuscule denticles, becoming progressively smaller in proximal direction; protarsal groove shallow; outer row of setae sparse, setae short; median row of setae somewhat denser, but setae even shorter; anterior protibial stria shortened apically; near tarsal insertion two tiny tarsal denticles present; protibial spur very short, growing out from apical margin of protibia; outer part of posterior surface of protibia (Fig. 240) obscurely variolate, a row of 7–8 minute denticles separating it from glabrous median part of posterior surface; posterior protibial stria complete, with very sparse minute sclerotized setae, terminating in two tiny inner posterior denticles; inner margin of setae double, setae short and dense.
Mesotibia (Fig. 234) slightly thickened, outer margin with two rows of moderately sized denticles; outer row of setae sparse, setae about as long as denticles, growing in size apically; median row of setae double, setae much finer and shorter; posterior mesotibial stria shortened, present only basally; anterior surface of mesotibia with scattered minute punctures; anterior mesotibial stria almost complete, terminating in two tiny denticles; mesotibial spur moderately large; apical margin of mesotibia with several inner anterior denticles; claws of apical tarsomere slightly bent, about half its length. Metatibia slenderer than mesotibia, outer margin with much sparser and shorter denticles, otherwise in all aspects similar to mesotibia.
Male genitalia. Eighth sternite (Figs. 241–242) longitudinally separated medially, apically with small inflatable membrane (velum) with single row of short dense setae; apex with few longer sparser setae; eighth tergite and eighth sternite not fused laterally (Fig. 243). Morphology of 9 th tergite (Figs. 246–247) typical for the subfamily; spiculum gastrale expanded on both ends. Basal piece of aedeagus (Figs. 244–245) rather long, ratio of its length: length of parameres 1: 2.5; parameres fused along their basal half; aedeagus gently curved ventrad (Fig. 245).
description: Published as part of Lackner, Tomáš, 2010, Review of the Palaearctic genera of Saprininae (Coleoptera: Histeridae), pp. 1-254 in Acta Entomologica Musei Nationalis Pragae (suppl.) (suppl.) 50 on pages 80-84, DOI: 10.5281/zenodo.4272127