Solitary folded-winged wasps of the genus Zethus Fabricius (Vespidae, Zethinae) parasitised by two new species of Strepsiptera on different continents

Two new species of Strepsiptera from the genus Zethus Fabricius, 1804 (Hymenoptera: Vespidae) are described. Although the stylopisation of the genus Zethus has been known for almost a century, we provide the first description of its strepsipteran parasites. Zethus brasiliensis fuscatus R. Bohart & Stange, 1965 is parasitised by Eupathocera zethi sp. nov. in the Neotropical Region (French Guiana) and Zethus favillaceus Walker, 1871 by Deltoxenos impressus sp. nov. in the Afrotropical Region (Kenya). An independent switch to the same host genus is supported by molecular and morphological data. Diagnoses and detailed descriptions of the species are provided based on characters of the female cephalothorax and male cephalotheca. Diagnostic characters are discussed.