Apple maggot monitoring model
- Background

        This model counts accumulated rain and number of days from last spray to estimate when residual coverage will begin losing ability to kill apple maggot flies.  This is the recommended date to clean off apple maggot traps and begin counting trap captures again, comparing the total cumulative average caught per trap against the treatment threshold. 

        The standard threshold for unbaited red sphere traps is a cumulative average of 2 AM fly per trap.  For traps accompanied with fruit odor-bait, the threshold is a cumulative average of 5 AM trap.  At least 3 traps per block should be used to calculate the average.

        Residual protection from previous full-dose Imidan or Guthion is considered depleted when one of the following conditions is met:

   2 inches of cumulative rain within the first 10 days after application,
or
   1.5 inches of cumulative rain from 10-14 days after application,
or
   14 days. 

         After discussion with manufacturer representatives for Avaunt and Assail, these rules are also applied for those products.  Lacking information to the contrary, these rules seem to be the best available for Actara, Calypso and pyrethroids.

        These respray estimates are not appropriate for use with insecticides having shorter residual activity against apple maggot, such as spinosad (SpinTor, Entrust) or carbaryl (Sevin) products.