A synopsis of Gymnetron (Curculionidae: Coleoptera) from China with descriptions of adult and immature stages

Gymnetron Schoenherr, 1825 belongs to the Mecinini, Curculioninae. There are 4 species of Gymnetron in China now including G. miyoshii Miyoshi, 1922; G. villosipenne Roelofs, 1875; and two new country records, G. auliense Reitter, 1907 and G. vittipenne Marseul, 1876. G. miyoshii is distributed in 7 Middle Eastern provinces of China; G. villosipenne is distributed in 2 provinces of North Eastern China; G. auliense and G. vittipenne are found only in Xinjiang province. Diagnostic features of larvae of the genus Gymnetron are: (1) Frontal suture not extending to mandibular membrane; (2) Antennae contiguous with frontal suture; (3) Postoccipital condyles indistinct; (4) Mesothorax, metathorax and abdomen with two tergal folds; (5) Alar area without sclerotized or pigmented areas; (6) Spiracles bicameral; (7) Head brown with pale stripes at side and ecdysial line; (8) Accessory sensory appendage of antennae short; (9) Anus transversely cleft. G. auliense and G. miyoshii were collected on Veronica oxycarpa Boiss., with their eggs in ovaries of host plants. Larvae and pupae were living in galls of ovaries, with one larva per gall; G. vittipenne was collected on Veronica anagallis-aquatica L. Eggs were laid in stems between two leaf bases causing formation of galls. In one gall, there are several larvae, which are separated individually. Plants of Veronica anagallis-aquatica L. with Gymnetron galls are used as a Chinese traditional medicine for treating some painful and inflammatory human diseases.