Calochromus Guérin-Méneville

Motyka, Michal & Bocak, Ladislav, 2015, The classification of Flabellochromus and Dumbrellia (Coleoptera: Lycidae) with descriptions of two new species of Calochromus from the Sundaland Region, Zootaxa 3941 (1), pp. 125-130 : 126-127

Calochromus Guérin-Méneville

Calochromus Guérin-Méneville, 1833: 158

Type species. Calochromus glaucopterus Guérin-Méneville, 1833: 159 = Micronychus Motschulsky, 1861: 138 ; Kleine 1933: 106

Type species. Micronychus bimaculatus Motschulsky, 1861: 138 = Flabellochromus Pic, 1925: 11 (as a subgenus of Calochromus )

Type species. Calochromus pallidus Pic, 1925: 11

Diagnosis. Calochromus differs from Lucaina Dugès , Lygistopterus Mulsant and Macrolygistopterus Pic in the absence of rostrum and from Adoceta Bourgeois in the stout, elongate body (5–28 mm). The Nearctic genus Caloptognatha Green differs in having short mandibles. All species share the characteristic type of male genitalia with wide parameres and asymmetrical phallobase ( Figs 12–15 ).

Redescription. Male. Body 5 - 28 mm, parallel-sided to slightly widened backward. Head small, prognathous to slightly hypognathous, partly retracted in pronotum. Eyes small, hemispherically prominent, frontal interocular distance longer than maximum eye diameter. Labrum sclerotized, transverse, mandibles slender, slightly curved, incisor margin simple, maxilla with long, setose mala, maxillary palpi 4-segmented. Labium with plate-like mentum and shortly setose ligula, labial palpi 3-segmented. Antennal tubercles inconspicuous to deeply separated by narrow groove. Antennae 11-segmented, surpassing humeral third of elytra, filiform, weakly serrate to flabellate, scapus pear-like, robust, pedicel small, antennomere 3 much longer than pedicel, antennomere gradually slenderer to apex, sometimes middle antennomeres modified, antennomeres 3(4)-10 bearing lamellae in flabellate forms.

Pronotum transverse to subquadrate with two longitudinal obtuse keels ( Figs 1–4 ); anterior angles widely rounded, posterior ones acute to rounded. Scutellum long. Elytra flat, slightly widened backward; longitudinal elytral costae weak, often apically absent, transverse costae absent. Legs slender, femora robust and curved in some species, tibiae slender, tarsi 5-segmented, tarsomeres 3-4 with membranous pads, tarsomere 5 long, slender, claws simple.

Male genitalia trilobate, phallus and parameres similar in length, parameres wide, phallus stout, almost straight, laterally compressed; phallobase asymmetrical ( Figs 12–15 ).

Female. Similar to male, always with weakly serrate to filiform antennae. Ovipositor very slender, with short coxites and very long valvifers.

Distribution. Worldwide.

Remarks. Pic (1925) described Flabellochromus as a subgenus of Calochromus and based the taxon on the presence of flabellate male antennae. Kleine (1926) described Calochromus lamellatus Kleine, 1926 with similar flabellate antennae and noted a high similarity of external morphology and male genitalia of this new species and known Calochromus with filiform antennae. Kleine (1933) listed Dumbrellia in Calochromini and in contrast with his previous opinion transferred both Calochromus pallidus and C. lamellatus to Dumbrellia and treated Flabellochromus Pic, 1925 as a junior synonym of Dumbrellia Lea, 1909 . We compared the external morphology of numerous species of Oriental Calochromus with available species with flabellate antennae and we found that they do not differ in any character. Although many genus group taxa were based on antennal morphology, our research confirms Kleine's opinion and shows that flabellate antennae originated in many net-winged beetle lineages multiple times and that taxa based on this character often are polyphyletic ( Bocakova 2001, Sklenarova et al. 2014). Therefore, we propose to place all species of Calochromini with flabellate antennae in Calochromus and to consider Flabellochromus Pic, 1925 as a junior synonym Calochromus .

Figures

FIGURES 12 – 15. Male genitalia. 12 — Calochromus harauensis sp. nov.; 13 — C. lamellatus; 14 — C. kelantanensis sp. nov.; 15 — C. impressicornis. Scale 0.5 mm.

FIGURES 1 – 11. General appearance. 1 — Calochromus lamellatus; 2 — C. impressicornis; 3 — C. kelantanensis sp. nov.; 4 — C. harauensis sp. nov. Head. 5 — C. kelantanensis sp. nov.; 6 — C. harauensis sp. nov. Antenna. 7 — C. harauensis sp. nov.; 8 — C. lamellatus. Pronotum, the holotype of: 9 — Plateros brevicornis; 10 — P. melancholicus; 11 — P. barronensis. Photographs 9 – 11 taken by P. Hudson. Scales 2.0 mm (Figs 1 – 4), 1.0 mm (Figs 5 – 8).