Pests associated with two brassicaceous oilseeds and a cover crop mix under evaluation as fallow replacements in dryland production systems of the northern Great Plains

Identifying pests associated with novel crops is important for forecasting impacts on their production and determining if they could be reservoirs of pests moving over onto cash crops. We carried out preliminary pest surveys in two bioenergy crops, carinata (Brassica carinata Alexander Braun (Brassicaceae)) and camelina (Camelina sativa (Linnaeus) Crantz (Brassicaceae)), and a cover crop mix under evaluation to replace fallow in rotations with wheat. Insect pests were sampled in each of the three crops over two years. Crucifer flea beetles, Phyllotreta cruciferae Goeze (Coleoptera: Chrysomelidae), dominated the pest complex associated with carinata and the cover crop mix, comprising more than 70% of the insects sampled. In contrast, the pest complex associated with camelina was dominated (40-91%) by generalist Lygus spp. (Heteroptera: Miridae). Crucifer flea beetles were 200-1000 times more abundant in carinata than in camelina, suggesting that they could be a serious pest of carinata. Camelina, in contrast, appears less likely to be attacked by, or serve as a reservoir for, crucifer flea beetles. Future work to assess feeding damage and population buildup of pests in these crops is needed to determine impacts on their production and the extent to which they may be reservoirs of canola pests over broader spatial scales.