I have eight new climbing, rose bushes, and some of the leaves are starting to show holes it looks like ants, but i’m not sure whether ants would do that or not.Anybody have any suggestions?
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Clear photos would definitely help make accurate diagnosis but they could easily be either due to Saw Fly Larvae or Leaf Cutter Bees. Which of these appear closest?
https://hortsense.cahnrs.wsu.edu/fact-sheet/rose-leafcutting-bees/
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Thank you for all your help. I sent pictures. Haven’t seen flies just ants.
You’re welcome. You likely won’t see flies, just tiny green worms on the undersides of the foliage eating the “green” off them and leaving the cuticle, “skin” of the leaf so it almost resembles “windows” in the leaf. Ants are there because there is some sort of sucking insect sucking out the sap and releasing “honey dew”, which is literally sugar water. The ants eat the honey dew. The sucking insects could be scale or aphids.
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What do I do to handle the problem?
If it’s leaf cutter bees, nothing. They are beneficial insects and pollinators which cause minimal damage and are good for the environment. If it’s saw fly larvae, here is information from the University of California Integrated Pest Management which shows photos of the larvae so you will know what you’re looking for as well as suggestions for management. Very often, they are temporary pests as with aphids, they prefer spring, “green house” conditions…warm, moist and usually move on once the temperatures become hotter and air becomes drier. If those conditions are fleeting where you are, you can probably just let Nature take her course and allow the naturally occurring beneficial insects to handle the problem. If those conditions remain for a significant portion of the season, the article suggests products to handle them. Just remember that even the most innocuous “treatment” often damages beneficial insects before it does the pests. Rose Sawflies (Roseslugs) / Home and Landscape / UC Statewide IPM Program (UC IPM)
Here on the Central Coast of California, we experience them early and late in spring and fall as well as in protected spots where air flow isn’t as strong. Often, I can alleviate the issue by pruning back surrounding foliage so the moisture dries out better, allowing air and sunlight into it which reduces the mild conditions the larvae enjoy.
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To roseseek….Great articles…thank you….I just moved to flatlands USA and I meet a new bug every day now….Thanks for posting those….
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You’re welcome, Brenda! Congratulations on the “new adventures”! I’m glad they helped you.
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