As is always the case at this time of the year, captures of brown marmorated stink bug (BMSB) nymphs and adults in pheromone traps are beginning to increase and expected to continue to increase over the next several weeks. Peak captures tend to occur during the first half of September, but captures typically continue into October. Many of the nymphs being captured are in the later instars, which like adults, can cause economic injury at harvest. I have had one report from Virginia of increasing BMSB injury to Pink Lady apples over the last week or so. While BMSB captures have been relatively low until now, many varieties harvested in September and later are vulnerable to the highest BMSB populations of the season. It would be prudent to scout orchards for injury at this time, looking for any indications of external (small discolored holes, spots or depressions) or internal injury (discolored flesh). BMSB injury to apples tends to be highest in the mid- and upper canopy of trees in border rows that are adjacent to woodland, so evaluating apples from those locations should provide a good indication of current status. Insecticide options for BMSB with a 7-day PHI include Baythroid XL, Belay, Leverage 360, or Tombstone. Venom and Scorpion have a 3-day PHI under the Section 18 Emergency Exemption and Bifenture or Brigade (14-day PHI) can also be used under a Section 18, but with a 30-day minimum re-treatment interval. Danitol and Lannate also have a 14-day PHI in apples, and Warrior or Lambda-Cy have a 21-day PHI. Note that use of Lannate or the pyrethroids in this group at this time may incite higher fall populations of woolly apple aphid.
Until next time, best wishes.