ICHNEUMONIDAE Latreille, 1802

Woelke, Jozef B., Pham, Khanh & Humala, Andrei E., 2020, New species of Stenomacrus (Hymenoptera: Ichneumonidae: Orthocentrinae) reared from Bradysia impatiens (Diptera: Sciaridae) in The Netherlands, Journal of Natural History (J. Nat. Hist.) 54 (25 - 26), pp. 1603-1616 : 1606

Family ICHNEUMONIDAE Latreille, 1802

Subfamily ORTHOCENTRINAE Förster, 1869

Genus Stenomacrus Förster, 1869

Stenomacrus is a large genus with 71 known extant species distributed worldwide, excluding the Afrotropical Region, where no species have been described yet ( Yu et al. 2016). The majority of described species (52 spp.) are known from the Palaearctic. Taxonomy of the genus is poorly developed, and the revision of the Western Palaearctic species by Aubert (1981) cannot be considered satisfactory. The boundaries between this genus and related genera like Neurateles Ratzeburg , Plectiscus Gravenhorst and the tropical Chilocyrtus Townes are poorly defined. As noted by Broad (2010), Stenomacrus Förster species as currently defined do not possess any suite of apomorphies that effectively exclude other genera. The genus Stenomacrus is characterised by significant morphological variety, which can make it difficult to distinguish from Neurateles and Plectiscus species. Very little is known about the biology of Stenomacrus . Unfortunately, a large part of host records for the genus, referred for example to species of Lepidoptera or Coleoptera, is doubtful. Among the reliable observations of Stenomacrus hosts should be noted S. curvulus (Thomson) reared from Trichosia sinuata Menzel et Mohrig ( Vilkamaa and Komonen 2001) and S. laricis (Haliday) reared from Bradysia confinis (Winn., Frey) ( Deleporte 1986) . Members of the genus Stenomacrus , and at least such closely allied genera as Neurateles and Plectiscus , seem to specialise on Sciaridae ( Broad et al. 2018) and are presumed to be larval koinobiont endoparasitoids.