Karshomyia caulicola (Diptera: Cecidomyiidae) associated with sclerotinia-infected soybean in the United States and Canada

The white-mold gall midge, Karshomyia caulicola (Coquillett), (Diptera: Cecido-myiidae) was documented in association with soybean, Glycine max (L.) Merr., infected with the fungus Sclerotinia sclerotiorum (Lib.) de Bary. This mycetophagous cecidomyiid appears widespread in the northern soybean producing region, with confirmed detections from Minnesota, North Dakota (U.S.) and Québec (Canada). Though likely not a pest of soybean plants, the presence of K. caulicola in soybean fields may complicate identification, population assessment and decision making for soybean gall midge, Resseliella maxima Gagné, which is a recently described pest of soybean. Here, we provide an overview of the known biology and distribution of K. caulicola and descriptions to aid in distinguishing these two cecidomyiids.