Euwallacea tristis (Eggers)

Smith, Sarah M., Beaver, Roger A., Singh, Sudhir & Cognato, Anthony I., 2018, Taxonomic clarification and neotype designation for three Indian xyleborine species (Coleoptera: Curculionidae, Scolytinae), Zootaxa 4394 (1), pp. 138-140 : 138

Euwallacea tristis (Eggers)

Xyleborus tristis Eggers, 1930: 194 . Type spurious. Neotype here designated.

Neotype. Female. INDIA: Meghalaya, 3 km E Tura , 25°30′N, 90°14′E, 1150 m, 4.v.1999, Dombický & Pacholátko (currently in Roger A. Beaver’s collection, Chiang Mai, Thailand to be placed permanently in the collection of the Natural History Museum, Basel at the conclusion of the present project).

Original type locality: INDIA: Assam (Nakachari, Sibsagar ), C.F.C. Beeson, 17.v.1921, ex. Vatica lanceaefolia ( Eggers 1930).

Diagnosis: This species can be distinguished from other Euwallacea by the large size (3.2–4.0 mm long), very elongate body (3.0 ¯ 3.25 times as long as wide), pitch black body with limbs pitch brown, and by the scutellar space margined by a ‘U’ shaped ridge.

Discussion: The pinned holotype bears labels that match the description however the specimen does not fit the description and is of Cyclorhipidion distinguendum rather than a Euwallacea species (Smith et al. in prep). Both Wood and Bright (1992) and Maiti and Saha (2004) place this species in Euwallacea . In addition Maiti and Saha’s (2004) description does not match the holotype but matches Eggers’ description. It is not clear when or how the specimen became mislabeled. Euwallacea tristis is the rarest Indian Euwallacea ( Maiti and Saha 2004) . Specimens of this species from the type locality, Assam, could not be located. However specimens were found from nearby Meghalaya state and are thus the most suitable for use as the neotype.