As we move into August, codling moth will be of lesser concern, except in those orchards where problems have occurred in the past month or so. In orchards where it has not been a problem all year (i.e., the vast majority of orchards), it is highly unlikely that damaging populations would appear at this time. From this point on, the brown marmorated stink bug (BMSB), oriental fruit moth (OFM), and apple maggot are key potential pests to be focused on. However, the threat that any one of these insects pose will vary among orchards, which emphasizes the importance of monitoring populations in individual orchards.
BMSB: Based on the BMSB phenology model (currently at 850 DD in Henderson County), about 15% of first generation adults have emerged. Where BMSB populations are a potential threat to the crop, between now and next week would be good timing of insecticide sprays to minimize damage. However, the model does not provide information on the need for insecticides – i.e., population abundance. Pheromone traps are the only tool we have to estimate abundance, but there is not a good relationship between trap captures and damage, so they should be used as a guideline. As mentioned in previous posts, populations have declined considerably in the past several years, as has damage to apples. While emergence of first generation adults is underway, trap captures are still relatively low, ranging from 0 to a maximum of 5 adults per trap. Before 2022, when BMSB damage was common, trap captures averaged between 10 and 20 at a similar point in time.
In Cleveland County, almost 75% of BMSB adults have emerged. Between the advanced development and high temperatures (detrimental to BMSB development) in lower elevation orchards, the need for control seems to be of less importance compared to higher elevation orchards, especially later in the emergence period.
