Wheat bulb fly is most prevalent in eastern England, the East Midlands and north-eastern England. All cereals except oats can be attacked by wheat bulb fly: winter wheat crops sown from November onwards, or crops sown in spring before the end of March, are particularly vulnerable. Incidence generally increases following a wet harvest period and is lowest after a hot, dry summer.

Information from the HGCA wheat bulb fly survey is published every year in September to aid decision-making on seed treatments. Visit www.hgca.com/pests for the latest information.