None of the trials showed any evidence for involvement by white apple leafhopper. This mesophyll feeder feeds on different tissue than that normally most vulnerable to infection by Erwinia amylovora . On the other hand, potato leafhopper sometimes caused a significant increase in fire blight infection as it fed on vascular tissue in succulent shoot tips. A protocol to manage apple maggot that will allow Virginia growers to export apples to Brazil was recently approved . As modified from earlier versions, it seems to be a usable protocol.
Several options are available, at the grower's discretion.
One involves the use of regional trapping. Both of these approaches call for traps to be in place before first fly activity. The third option uses degree day accumulation. If growers can provide daily max and min temperatures, the expected fly emergence can be determined, and correlated with spray records.