RESISTANCE TO THE FLEA BEETLE PHYLLOTRETA CRUCIFERAE (COLEOPTERA: CHRYSOMELIDAE) IN FALSE FLAX, CAMELINA SATIVA (BRASSICACEAE)

Abstract

AbstractFeeding damage by the crucifer flea beetle, Phyllotreta cruciferae (Goeze), was assessed on 51 accessions of false flax, Camelina sativa L., and compared with damage to seven other crucifer species. Three experiments were conducted on seedlings in laboratory arenas infested with field-collected beetles. Feeding damage was estimated visually at daily intervals for up to 7 days. Natural infestation of false flax and other crucifers was observed in the field. Flea beetles fed little (0–10% consumption) on cotyledons or true leaves of any of the false flax accessions, and fed more (59–100% consumption) on the other crucifers. Flea beetles were observed sitting on false flax in the field, sometimes in high numbers, but they did not feed. In the laboratory, beetles eventually fed on cotyledons and leaves and once feeding was initiated, it tended to continue. Resistance in false flax may result from the absence of cues that initiate feeding, rather than a feeding deterrent. The high level of resistance in false flax would likely be economically beneficial if this species is developed as an oilseed crop. False flax could also be useful experimentally for identifying the cues that attract flea beetles to plants and stimulate their feeding.