Macronotops Krikken, 1977

Qiu, Jian-Yue, Xu, Hao & Chen, Li, 2019, A revision of the rare flower beetle genus Macronotops Krikken (Coleoptera: Scarabaeidae: Cetoniinae) from Asia with biological notes, Zootaxa 4556 (1), pp. 1-65 : 6-7

Macronotops Krikken, 1977

Macronotops Krikken, 1977: 207 ; Krikken 1984: 63; Sakai & Nagai 1998: 350; Krajčík 1998: 90; Antoine 2000: 130; Smetana 2006: 307; Krajčík 2011: 57; Krajčík 2012: 151; Bezděk 2016: 403.

Pleuronota (nec Kraatz): Mikšić 1971: 208; Mikšić 1976: 164; Ma 1993: 179; Ma 1995: 34.

Type species Pleuronota sexmaculata Kraatz, 1894 , by original designation.

Description. General: Body middle sized (length 14.0–20.0 mm). Surface dark brown, densely punctuate; clad with black, brown, fulvous, or light yellow setae. Scutellum and the adjacent area depressed. Head: Dorsal surface clad with short, sparse setae, setae long on frons; midline of frons raised; clypeus flat, non-notched, the length of clypeus equal to/or greater than the width, anterior margin slightly raised; antenna developed. Dorsal surface: Pronotum nearly heptagonal; posterior margin significantly extended backward and covered anterior margin of scutellum; disc clad with long, dense setae; posterior margin usually glabrous; disc of some species with two pronotal ridges and a distinct, narrow, longitudinal ridge medially. Scutellum elongated triangular; lateral sides glabrous. Elytra widest near the humeral umbone, gradually narrowed to the apex; most area clad with brown or black setae; sutural and discolateral costae distinct, discolateral costae and humeral umbone glabrous; maculae yellow, tomentose; posthumeral macula, median macula, lateral macula, and distal macula presented, or partially absent on elytra; setae distinctly longer between sutural and discolateral costae. Abdominal sides visible in dorsal view, and clad with yellow and brown (or dark brown) setae. Mesepimeron, metepisternum and metepimeron: Clad with light yellow to fulvous setae; mesepimeron with a yellow tomentous macula in some species. Ventral surface: Clad with fulvous to yellow setae, setae denser on sides; median portion of metasternum, abdominal sternites II–VI, and whole abdominal sternite VII usually glabrous or just with sparse setae; mesometasternal process short, glabrous, apex rounded. Pygidium: Usually evenly clad with long setae; with a small, or large, yellow macula in some species. Legs: Slender, trochanters glabrous; tibia and femora sparsely clad with setae; protibia with 3 teeth; an external protrusion in middle of mesotibia; metatibia straight or slightly inturned; tarsi usually with sparse hard setae.

Sexual dimorphism. Male: body usually slender; setae on surface longer; antenna club longer; tarsi longer; abdomen more flat; widest of pronotum at the basolateral angle; metatibia with long setae along inner margin. In some species, median portion of male abdomen with a longitudinal groove. Female: body usually wider; antennal club short, about as long as the length of antennomeres 2–7 combined ( Figs. 1–23 ); the widest of pronotum near the middle; protibia wider, with 3 larger and distinct teeth along outer margin ( Figs. 24–47 ); external protrusion in middle of mesotibia larger; ventral tooth of mesotibia larger ( Figs. 48–71 ); more setae on abdominal sternite VII.

Differential diagnosis. By unnotched clypeus, well-developed setae, yellow tomentose maculae on elytra, and median lobe present in male genitalia, this genus can be easily separated from other genera of the tribe Taenioderini. Differences to the most similar genus Bombodes: Body size usually larger; setae on body surface sparser and shorter; anterior margin of clypeus straight or slightly arcuate, but bisinuate in Bombodes ; the widest of male pronotum at basolateral angle, but at the middle in Bombodes ; male antennal club distinctly longer than female, but in Bombodes slightly longer than female.

Natural history. Specimens data and field observation show that species of the genus Macronotops live at elevations of 900 to 2,500 m in the mountainous region. Mature larvae can be easily found under the bark of highly rotten trunks since autumn to early spring, especially in the humid environment in narrow valley or near stream. Larvae also inhabit the galleries of some cockroach Panesthia spp., Lucanidae larvae, and Passalidae adults and larvae. It is implied that Macronotops species are facultative commensal. Sometimes larvae hid in the gaps between the hard parts of rotten wood, and to be hurt easily during chopping. Hence, follow their fecal pellets is more suitable for excavating. In captivity, the larvae fed rotten wood and developed well. The feeding activity of larvae almost stopped from December to February at room temperature of Chongqing, China. However, they were unbearable for the temperature above 30°C. So all containers were placed in the room temperature below 25°C, and almost all individuals were successfully developed to the adult stage, except that few larvae (presumably infected in the field) were killed by entomopathogenic fungus Metarhizium . Mature larvae pupate soon after pupa cells appearing in April and May. The exact duration of the stages of prepupa, pupa, and dormancy of teneral adult is not clear, about three to four weeks in total. Once the pupal cells are broken, it will result in either individual died easily or occurrence of teratisms increases significantly during pupating and emerging.

Adults usually emerge in May under artificial condition; and according to label data, wild adults occur in southern China from June to August, with peaks in late July and early August. Based on our field observation, the beetles are not flower visitors (like other Taenioderina), but exhibit similar sap feeding habits to most members of Asian Goliathini. Under artificial condition, adults were mated on the surface of the rotten wood in the daytime and hid in wood pieces at night. One attempt was undertaken to bred adults of M. olivaceofuscus for reproduction, but all larvae died of heat, and the number of eggs produced per female was unknown.

Distribution. Northern Oriental and Palearctic Regions. It is the most northern genus of Taenioderina.

Nomenclature. The gender of the generic name Macronotops was not indicated in the original publication, and the ending of all species names were not changed when Krikken (1977) transferred them from the genus Pleuronota . According to the Article 30.1.4.3 of ICZN (1999), genus-group names ending in - ops are treated as masculine, that resulted in the changes of the species names ending in the updated and revised edition of Catalogue of Palaearctic Coleoptera ( Bezděk 2016) .

Remarks. In order to facilitate the comparison of the morphological characters, two species groups of the genus Macronotops are proposed in the present paper (see following text).

Figures

FIGURES 1–23. Head of Macronotops (male in left, female in right). 1, M. biserratus new species; 2–3, M. dianensis new species; 4–5, M. fulvoguttatus; 6–7, M. fulvopilosus; 8–9, M. miksici new species; 10–11, M. nigropubescens; 12–13, M. olivaceofuscus; 14–15, M. sexmaculatus; 16–17, M. vuilleti; 18–19, M. curvimarginatus; 20–21, M. medogensis new species; 22–23, M. ovaliceps. Arrows emphasize the length of antenna club.

FIGURES 24–47. Protibia of Macronotops (male and female). 24, M. biserratus new species; 25–26, M. dianensis new species; 27–28, M. fulvoguttatus; 29–30, M. fulvopilosus; 31–32, M. miksici new species; 33–34, M. nigropubescens; 35–36, M. olivaceofuscus; 37–38, M. sexmaculatus; 39–40, M. vuilleti; 41, Macronotops sp.; 42–43, M. curvimarginatus; 44–45, M. medogensis new species; 46–47, M. ovaliceps. Arrows indicate the angle between large teeth and the outer margin of protibia.

FIGURES 48–65. Metatibia and basitarsus of metatarsus of the Macronotops sexmaculatus species group (male in left, female in right). 48, M. biserratus new species; 49–50, M. dianensis new species; 51–52, M. fulvoguttatus; 53–54, M. fulvopilosus; 55–56, M. miksici new species; 57–58, M. nigropubescens;59–60, M. olivaceofuscus; 61–62, M. sexmaculatus; 63–64, M. vuilleti; 65, Macronotops sp. Red arrows indicate the difference in the dorsal and outer tooth of the metatibia in females; yellow arrows indicate the difference in the dorsal and outer tooth of the metatibia in males; blue arrows indicate the density of setae on the basitarsus of the metatarsus.

FIGURES 66–71. Metatibia and basitarsus of metatarsus of the Macronotops ovaliceps species group (male in left, female in right). 66–67, M. curvimarginatus; 68–69, M. medogensis new species; 70–71, M. ovaliceps.