Pest Update: Insects

Berries are sizing, and there is still some fruitworm flight underway. Both cherry and cranberry fruitworm moths have been trapped this week in monitoring traps, so consider the length of activity if you applied a post-bloom insecticide. High pressure sites with a history of fruitworm infestation may need a follow-up spray to maintain protection.  

Galls are starting to develop in susceptible cultivar fields, and the window for effective chemical control is closing as they establish those galls. Refer to our E-154 publication for recommendations on the available options to penetrate young tissues to control this pest.  



The long period of hot dry weather would have severely impacted SWD early season development, so we are expecting there to be a late start to that pest in 2023. Our traps have not caught any SWD yet, but we are looking for them already. Third week of June is also typically when BBM can emerge from the soil. There is a model on enviroweather to guide this, but they typically wait for rain before emerging so its possible the light showers recently would trigger emergence, but we may still need more heat units and a heavier rain. Watch your monitoring traps for this pest in the coming weeks. 

Disease Update

We have been observing some virus symptoms throughout Michigan, these symptoms typically express more strongly in cool weather. Long dry periods are also typically a good thing for blueberry growers. These dry periods can allow growers to stretch spray intervals and limit control to specific rain events.



During this time of year anthracnose fruit rot and stem blights are the primary diseases to control. This may be a time to incorporate a multisite fungicide like Ziram into your spray program to help with resistance management. Other strongly effective FRAC codes for anthracnose are in groups 3, 7, 9, 11, 12 and 29. You may also wish to incorporate a biological fungicide later in the season as we near harvest.  

Don't Guess, Test!

The diagnostic program supported by the Michigan Blueberry Commission (MBC) first piloted last year, is continuing in 2023. This program funded by the MBC will cover the diagnostic fees for up to two samples per Michigan blueberry grower. The samples will be evaluated and tested as appropriate by specialists in the MSU Plant & Pest Diagnostics (PPD) lab.  If there is anything concerning or puzzling in your blueberry field, be sure to take advantage of this opportunity.

Extension Update

The southwest fruit team hosts weekly IPM meetings feel free to join us in-person or virtually from 5:30-7 at the southwest Michigan Research and Extension Center. 1 RUP credit is offered each week. Sign up here!