Knowledgebase
Apple tree leaves turning brown #871727
Asked June 05, 2024, 1:31 PM EDT
Hi,
My apple tree leaves on some trees are turning brown and curling up at the end of the branches. These are located in Northeast Michigan and just finishing blooming about 10 days ok. We have had sufficient rain. I am attaching a picture of the leaves. I tried un-rolling the leaves and in one of them, I found a small worm/catepillar. I am also attaching that picture. Is this something I need to worry about?
Alpena County Michigan
Expert Response
Hello,
This is a Obliquebanded Leafroller: Since you found a caterpillar, this could be the culprit. Prune out affected leaves and consider using organic insecticides if needed.
Management
Monitor the adults with pheromone traps and use a degree-day developmental model to time insecticide sprays. Thinning of fruit and pruning water sprouts in midsummer is helpful in reducing fruit damage. These insects may be difficult to control with insecticides, even with selective insecticides (Bacillus thuringiensis and insect growth regulators). Selective pesticides will preserve important natural enemies. More than one spray may be needed during the summer because of this species' extended flight and egg-laying periods.
More information at this link:
Obliquebanded leafroller - Integrated Pest Management (msu.edu)
I hope this helps
