Apple Tree Problem

Asked June 27, 2016, 5:22 PM EDT

Hi! I noticed that most of my apples (Sweet Sixteen & Honeycrisp) have little dots all over them like an insect bore into them. I'm wondering if you are able to tell what the problem is based on my photos and if you have any suggestions for me so I can prevent this from happening in the future. Thanks, Stefanie

Sherburne County Minnesota apples apple insects apple trees

3 Responses

Thank you for the question. It does look like something has pierced the skin of your apples. It might be plum or apple curculio beetle damage. Plum is much more common than apple but I can't tell from the photo which it is. The plum curculio beetle pierces the apple skin to lay eggs but the apple flesh is too hard to allow development and the apple continues to develop, often sustaining only cosmetic damage and will still be edible. Sometimes there are distinctive crescent shaped tan areas by the holes. If damage is too great, there are chemical controls that can be used. Read more here: http://www.extension.umn.edu/garden/yard-garden/fruit/apple-pest-management/plum-curculio/

If damage is from the apple curculio beetle, the beetle pierced the skin of the apple in the spring, deposited eggs, and the only way the eggs mature is if the apple drops to the ground prematurely. Again, the apple may be just cosmetically damaged and still edible. There will be no crescent shaped areas by the holes. Read about it here: http://www.extension.umn.edu/garden/insects/find/apple-curculio/ Note that our Extension entomologist, Jeff Hahn, would like to know about this finding in an attempt to understand how widely distributed it is and how much damage it is causing. Let him know if you think this is what it is by following the link at the end of the publication.

You might want to cut a few of the apples in half to see if there are any larvae tunneling in the flesh because another problem can be from apple maggots although it might be too early in the season to see their damage. We did have a long warm spring so maybe they are ahead of schedule. This pest will destroy apple flesh, making them inedible. Read more here:

http://www.extension.umn.edu/garden/yard-garden/fruit/apple-pest-management/maggot/

http://extension.oregonstate.edu/gilliam/sites/default/files/Apple_Maggot_in_Oregon_EC1633_0.pdf I included this link because the photo included most closely matches the damage in your photos.

Here is another link to our self diagnostic program "What's Wrong with my Plant"? You might find it helpful: http://www.extension.umn.edu/garden/diagnose/plant/

And finally, here is the University of Minnesota's apple pest management calendar. http://www.extension.umn.edu/garden/yard-garden/fruit/apple-pest-management/

It describes when to use certain products as well as what you can do to monitor your trees to make sure you know what pest you are trying to treat. Compare it to how you are managing your tree and make changes as indicated.

Thank you for contacting Extension.





Hi! Yes, I do believe the damage to my apples is caused by the curculio beetle. I'm guessing it's the plum curculio beetle and not the apple curculio beetle since we have two plum trees (Toka and Superior) near the two apple trees and the curculio beetle destroyed all of my plums. I attached a photo of the affected plums in case that is helpful to you.

Thanks for the response!
Stefanie

How heartbreaking to have this level of damage to your fruits. Please read the publications provided to learn how to control the pest next year as much as possible.