Pumpkin plants continue to grow slowly under the mid 90’s heat of this week. Some rain hit the station mid-week but more is needed to avoid plant stress. Cucumber beetle damage has been minimal given systemic insecticide applications. Cucumber beetles have been reported in high numbers at other locations across the state.
Squash bugs were nearly undetectable but typically increase quickly as plants grow larger and adults find local cucurbit fields.
Squash bug eggs and mating adults.
Squash bug eggs.
No squash vine borer moths have been detected at the station despite the trap being up for two weeks; SVB have been detected in nearby Greene County site and near Akron. They are likely active over most of the state at this point in the season.
Squash vine borer adult on pumpkin leaf.
Around mid-July, begin scouting for powdery mildew on pumpkin, squash and other cucurbits. This disease does not over-winter in Ohio but spores are blown up on wind currents from Southern states. Check the upper and lower leaf surface at the edge and middle of the field for confectionary sugar looking spots to indicate initial infections. Powdery mildew will likely be found lower in the canopy, so be sure to inspect more than the top most leaves. There are many fungicide effective at controlling PM as determined by both lab and field studies by OSU researchers. Results are posted here:
2023 PM Fungicide Trial Results:
https://bpb-us-w2.wpmucdn.com/u.osu.edu/dist/f/4395/files/2025/01/PM-Fungicide-Demo-Report-2024.pdf
2024 PM Fungicide Trial Results:
https://bpb-us-w2.wpmucdn.com/u.osu.edu/dist/f/4395/files/2024/07/PM-Fungicide-Demo-Report-2023.pdf
Initial powdery mildew infestation
Heavy powdery mildew infestation
For a full list of recommended fungicides on PM and other diseases, consult the cucurbit chapter of the Midwest Vegetable Production Guide. https://mwveguide.org/uploads/pdfs/Cucurbit-Crops_2024-12-03-155451_othe.pdf
In other news, Spotted Wing Drosophila, were detected in red raspberries on June 24 in Greene County, check your berry patches for signs of infestation (small, white larvae) in the fruit. Management guidelines and images of these insects can be found here: https://u.osu.edu/pestmanagement/pests/swd/
Male and female SWD adults. Note only male has single spot on wings.