Miridiba Reitter, 1902

Li, Chun-Lin, Yang, Ping-Shih & Wang, Chuan-Chan, 2015, A review of the genus Miridiba Reitter (Coleoptera: Scarabaeidae: Melolonthinae) of Taiwan, Zootaxa 3955 (4), pp. 521-536 : 522-523

Genus Miridiba Reitter, 1902

Miridiba Reitter, 1902: 170 . Type species: Rhizotrogus trichophorus Fairmaire, 1891 by monotypy.

Holotrochus Brenske, 1894: 75 . Type species: Holotrochus vestitus Brenske, 1894 , by monotypy. Junior homonym of Holotrochus Erichson, 1840 ( Coleoptera : Staphylinidae )

Shangaia Lucas, 1920: 592 , new name for the junior homonym Holotrochus Brenske, 1894 .

Neodontocnema Arrow, 1948: 50 . Type species: Ancylonycha coromandeliana B1anchard, 1851, by original designation.

Hippotrichia Arrow, 1948: 51 . Type species: Hippotrichia hainana Arrow, 1948 , by original designation.

Description of male. Body length 14.0– 25.5 mm. Body oval-elongate; dark reddish brown to yellowish brown; weakly to moderately shiny. Dorsal surface densely punctate, punctures usually deep and rugose; dorsum glabrous or setiferous, setae fine (usually requiring high magnification for observation) or hair-like. Lateral margins of pronotum and elytra with fringe of long, robust setae. Antennae with 9 or 10 antennomeres; antennal club composed of 3 antennomeres, significantly shorter than basal antennomeres. Clypeus transversally narrow; frons flat, base of frons transversally carinate; lateral declivities with or without gibbosity behind middle of pronotum. Scutellum densely punctate. Elytral sutural costa well developed, discal costae absent. Pygidium convex centrally. Protarsi and mesotarsi with a tuft of short, dense setae on lower side of apex of tarsomeres 1–4. Parameres of male genitalia usually divided into upper and lower parts; inner margins of upper and lower parts with or without fringe of robust, long setae, tip of upper part with or without a beak-like small process. Female. Antennal club shorter than in male and round; apex of clypeus more deeply emarginate at middle than in male; setae on dorsal surface (if any) thinner and shorter than in male; length of metatarsi subequal to metatibia; metatibia and metafemora more stout than in male.

Diagnosis. The genus Miridiba can be separated from Holotrichia (sensu Nomura (1977)) by the following combination of characters: dorsal surface densely punctate (particularly on pronotum, elytra, and scutellum), punctures usually deep and rugose (usually sparsely and unevenly distributed in Holotrichia ); lateral margins of pronotum and elytra with fringe of long, robust setae (lacking in Holotrichia ); clypeus transversally narrow; frons flat, base of frons transversally carinate (clypeus widened, frons convex and without carina in Holotrichia ); elytral sutural costa well developed, discal costae absent (discal costae well developed in Holotrichia ); protarsi and mesotarsi with a tuft of short, dense setae on lower side of apex of tarsomeres 1–4 (lacking in Holotrichia ); parameres of male genitalia elongate (usually capsular in shape in Holotrichia ), usually divided into upper and lower parts, inner margins of upper and lower parts with fringe of robust, long setae (not divided and lacking robust, long setae in Holotrichia ).

Distribution. Eastern to southwestern China, Indochina, Sumatra, Java, Indian Subcontinent, Himalaya, Korean Peninsula, Japan, Ryukyu Archipelago (islands of Iriomotejima and Ishigakijima), Taiwan.

Remarks. Adults of Miridiba are active nocturnal and strongly or weakly attracted by lights. Zhang (1984) reported that adults of Miridiba do not feed and he also described four species larvae from China, which have oneyear life cycle and sometimes caused severe damages to corn, sweet potato, legumes, and peanuts by feeding on underground parts of the plants.