WATCH OUT for pollen beetles in winter oilseed rape. Warmer weather has seen them moving onto crops, and backward stands checked by the earlier cold snap are especially at risk, warns ADAS.With prospects for early and perhaps substantial flights into crops, vigilance will be needed after the high numbers recorded last season, it says. The pests, which bite into green buds for pollen and can do damage right through to flowering, merit spraying with an approved pyrethroid insecticide once average thresholds are reached. For more susceptible backward crops that is 5-15 beetles/plant across fields – not just on headlands. Well established crops can tolerate 15 before spraying is justified.