Genus Hedychridium Abeille de Perrin, 1878

Hedychridium Abeille de Perrin, 1878: 3 .

Type species: Hedychrum minutum Lepeletier, 1806

(= Chrysis ardens Coquebert, 1801), by subsequent designation of Ashmead 1902.

Hedychridium Abeille de Perrin, 1878 is the second largest genus within the family Chrysididae, after Chrysis Linnaeus, 1761, and the largest among the tribe Elampini, including more than 300 valid species. It is a heterogeneous genus of small to medium-sized cuckoo wasps (2.0–7.0 mm), distributed particularly in dry to arid areas of the Holarctic region. Semenov-Tian-Shanskij (1954) and Semenov-Tian-Shanskij & Nikol’skaya (1954) subdivided the genus Hedychridium into twelve genera, namely (besides Hedychridium s.str.): Actineuchrum Semenov-Tian-Shanskij,1954; Claudiola Semenov-Tian-Shanskij,1954; Colpopyga Semenov-Tian-Shanskij,1954; Cyrteuchridium Semenov-Tian-Shanskij, 1954; Cyrteuchrum Semenov-Tian-Shanskij, 1954; Euchridium Semenov-Tian-Shanskij, 1954; Euchrum Semenov-Tian-Shanskij, 1954; Homaleuchrum Semenov-Tian-Shanskij, 1954; Irenula Semenov-Tian-Shanskij & Nikol’skaya, 1954; Zarudnidium Semenov-Tian-Shanskij, 1954; Zarudnium Semenov-Tian-Shanskij, 1954. Currently, only Colpopyga Semenov-Tian-Shanskij, 1954 is considered as a valid genus (Rosa 2017), as recently confirmed by means of molecular analyses (Pauli et al. 2019). All other Semenov-Tian-Shanskij’s genera were synonymised with Hedychridium and treated as species groups by Linsenmaier (1968). The subgenus Prochridium Linsenmaier, 1968 was upgraded to genus rank by Kimsey & Bohart (1991), but we here follow Linsenmaier’s (1994, 1999) classification and consider it with subgeneric status only for practical reasons, as already did in Rosa et al. (2015).