Classical biological control in Montana for wheat midge Sitodiplosis mosellana (Diptera: Cecidomyiidae) using Macroglenes penetrans (Hymenoptera: Pteromalidae)

The orange blossom wheat midge, Sitodiplosis mosellana, is one of the most significant pests of wheat to enter Montana in the last ten years. Larval feeding damages developing wheat seeds and reduces crop value and yield. In a multi-pronged study aimed at monitoring pest populations and deriving solutions to reduce damage from this pest, the natural enemy of Macroglenes penetrans was captured in Alberta, Canada and released into the state of Montana. This parasitoid lays its eggs inside the eggs of S. mosellana, where they develop and ultimately kill the midge larvae. The population growth potential of this natural enemy matches that of the midge and promises to be a powerful tool in mitigating midge damage in Montana wheat. Seven hundred individuals were collected and released in Conrad and Kalispell areas of Montana. Monitoring the midge and the establishment of M. penetrans at different locations across showed the parasitoid had already established in Montana via natural migration. This study demonstrates the natural ability of parasitoids to find hosts across wide geographic areas. In the future, we plan to import two additional parasitoids Euxestonotus error and Platygaster tuberosula from Saskatchewan to Montana.