Parasitism of the biological control agent Hyles euphorbiae (Lepidoptera: Sphingidae) by Winthemia datanae (Diptera: Tachinidae): a new host record

Leafy spurge, Euphorbia esula L. (Euphorbiaceae), is an invasive perennial weed for which a number of biological control agents have been released in Canada. In surveys of biological control agents in patches of E. esula in Spruce Woods Provincial Park, Manitoba, tachinid eggs were detected on final instar larvae of the biological control agent, Hyles euphorbiae (L.) (Lepidoptera: Sphingidae). The tachinids were reared and identified as the Nearctic species, Winthemia datanae (Townsend) (Diptera: Tachinidae). This is a new host record for W. datanae. Mecha- nisms by which the new host association arose are discussed.