Revision of the Species-group with Description of a Remarkable New Species from South Africa (Hymenoptera, Chalcidoidea, Mymaridae)

A new Afrotropical species of Haliday, 1833 (Hymenoptera: Mymaridae), Polynema (Polynema) sagittaria van Noort & Triapitsyn, , is described and illustrated based on specimens collected in the Cape Floral region in south-western South Africa. This species is morphologically closely related to the recently described Polynema (Polynema) dikobraz Triapitsyn, 2017 from Madagascar, both species possessing enlarged spine-like microtrichia on the fore wing disc that are unique among all the known world fairyflies. This new species belongs to the informal species-group of the nominate subgenus of , which previously was only known from Madagascar. In addition, has the ovipositor extending ventrally under the mesosoma to well in front of the head, in a bow-like curve, and housed in a narrow, anterior elongation of the metasoma, the basal sac. Occurrence and possible significance of such a bizarre ovipositor in other Mymaridae is discussed. All images and online keys are available on www.waspweb.org.