Coilodera Hope, 1831

Qiu, Jian-Yue, Xu, Hao & Chen, Li, 2017, Taxonomic review of the Oriental flower beetle Coilodera penicillata species complex (Coleoptera: Scarabaeidae: Cetoniinae), Zootaxa 4350 (3), pp. 511-537 : 514-515

Coilodera Hope, 1831

Coilodera Hope, 1831: 25 ; Arrow 1910: 41 (synonym of Macronota ); Arrow 1946: 141 (as replacement name of Macronota ); Krikken 1984: 63; Sakai & Nagai 1998: 356; Krajčík 1998: 88 (catalogue); Ek-Amnuay 2008: 246; Smetana & Smith 2006: 39 (spelling); Smetana 2006: 306; Krajčík 2011: 53; Krajčík 2012: 76 (catalogue); Bezděk 2016: 401. Coelodera Hope : Burmeister 1842: 320 (incorrect spelling); Harold 1869: 1297 (synonym of Macronota ); Schoch 1894: 203 (in key); Schoch 1895a: 38; Schoch 1896b: 34 (catalogue); Schenkling 1921: 133 (catalogue); Miwa 1931: 305; Miwa & Chûjô 1939: 83; Yu et al 1998: 180.

Type species: Coilodera penicillata Hope, 1831 by monotypy.

Characterization of the Coilodera penicillata species complex (Male). Length: 18.5–26.1 mm; width: 8.8–11.7 mm. Body black, more-or-less fusiform, shiny; with several orange-red, orange, yellow, or lemon-yellow tomentose areas; small, round setiferous punctures evenly covered on tomentose areas. Dorsal midline of body distinctly impressed. Head, pronotum, and protibia with wine-red, red, or metallic green reflections. Head: Dorsal surface densely microsculptured; anterior margin of clypeus bisinuate, not raised; midline of frons slightly convex; frontolateral area clad with tomentum and sparse, long setae. Eye canthus extending laterally, narrow, long. Antenna brown, simple. Gula rounded, with a few short setae on sides. Pronotum: Widest at base; pronotal ridges strongly raised; lateral margin curved and posterior margin distinctly protruding; except margin and pronotal ridges, other areas clad with tomentum and setiferous punctures. Posterior margin of the median tomentose area of pronotum notched or curved. Scutellum: Longitudinal triangle in shape, with or without tomentum. Elytron: Prediscal area, humeral umbone and costa almost glabrous; lateral and distal declivities with short, sinuous striolae and sparse, long setae; mediodiscal and postdiscal areas of each elytron with 4 grooves, clad with sparse, long setae. Mesepimeron, mesepisternum, and metepimeron: Mesepimeron and mesepisternum clad with tomentum and setiferous punctures; metepimeron glabrous. Sternum: Preprosternum and mesosternum clad with sparse setae. Preprosternum without distinct preprosternal apophysis. Mesometasternal process glabrous, very short, apex nearly straight or slightly pointed; mesometasternal suture depressed or not depressed, with or without long setae. Middle portion of metasternum glabrous; anterior portion clad with tomentum and setiferous punctures; posterior portion with round or sinuous setiferous punctures. Pygidium: A large, round, tomentose macula in middle; setae dense, very long. Abdomen: Six sternites visible; abdominal sides exposed in dorsal view. Middle portion glabrous or with sparse setae. Sternite 2–6 (or 5 in some individuals) with a large macula and long setae on each side. Sternites 5–6 with sparse, long setae. Legs: Slender, with sparse, long setae; protibia with 2 or 3 large teeth along outer margin; metatibia with 3 teeth on apex. Male genital: Parameres annular in frontal view; apex barbed in shape.

Sexual dimorphism. Female similar to male, but lateral margin of pronotum slightly angular, protibia a little wider, abdomen convex with sixth visible abdominal segment more exposed. Outer tooth of metatibia always longer than ventral tooth in female.

Distribution. Oriental region (excluding the Philippines).

Commensalism. The larvae and fresh adults of five Coilodera species were discovered in the galleries of some wood-feeding cockroaches (Blattaria: Blaberidae : Panesthiinae ) in rotten wood, and they were regarded as facultative commensal species ( Kon et al. 2002, 2003, 2004; Ueno 2015). This view is coincided with our observation in field and artificial breeding, and we consider Coilodera spp. occasionally as inquilines of some xylophagous insects. It is presumed that Coilodera larvae can feed only on soft, highly rotten wood that decayed naturally or chewed by other wood-feeding insects in field, such as cockroaches and the larvae of Passalidae and Lucanidae .

Nomenclature. The genus Coilodera was not characterized by Hope (1831) and only brief description of the type species was provided. The first generic description was given by Burmeister (1842), but he changed the generic name spelling as Coelodera , an incorrect subsequent spelling ( Smetana & Smith 2006). The incorrect spelling was followed by many authors ( Schoch 1896b; Moser 1902; Janson 1917; Schenkling 1921; Mikšić 1976; Miwa & Chûjô 1939; Paulian 1960; Antoine 1986), some attributing authorship to Bumeister ( Mikšić 1972, 1976; Ma 1995, 2002b).

Considering their ambiguous definition, Arrow (1910) combined the genus Coilodera and several Taenioderina genera according to their uncovered abdominal sides, and used the earliest name Macronota Hoffmannsegg, 1817 with C. diardi Gory & Percheron, 1833 erroneously cited as the type species. The genus Macronota was erected without any species ( Hoffmannsegg 1817) until Wiedmann (1823) described three new species, hence Arrow’s designation is not valid, and the type species can only be one of the three species (Article 67.2, International Commission on Zoological Nomenclature 1999). Unfortunately, two of them were already transferred to Clinteria by Burmeister (1842), and the remaining species, M. anthracinus , is conspecific with Thaumastopeus nigritus (Frölich, 1792) . Macronota thus became a synonym of Thaumastopeus , leaving Coilodera as the oldest available name for this genus ( Kuntzen 1929; Arrow 1946). The genus Macronota was not well defined, and Arrow’s combination produced several secondary homonyms that were originally placed in different genera, so this controversial treatment was only followed by few authors ( Paulian 1960; De Lisle & Chûjô 1964; Ruter 1972), and most followed the subdivided arrangement in Schoch (1896b), Schenkling (1921), and Mikšić (1976).