Hi, I have a Zestar apple tree. It blossomed well this year and had healthy...

Asked September 6, 2015, 8:52 PM EDT

Hi, I have a Zestar apple tree. It blossomed well this year and had healthy appearing fruit. We went on vacation for one week, and when we returned we found almost all of the fruit on the ground. The apples remaining on the tree and also on the ground were 1/2 eaten and crawling with hornets. There were also fruit flies present on the fruit. The tree is fenced such that deer should not have been able to reach the tree. Since then, the apples on the ground have almost been completely consumed. Could this have been due only to the hornets? Is there any way to prevent this in the future?

St. Louis County Minnesota apples

2 Responses

It's hard to say what might have happened to these apples, but the hornets are not to blame. They are busy stocking up on calories for the winter and are very conspicuous at this time of year. Any injury to these fruits will attract them but they do not make the first "breach" of the skin - something else got there first.
Birds may peck a hole in the fruit and that is enough to attract the hornets who will continue to dine on the fruit.

Many different critters will consume the fallen fruits, from insects to small mammals.
I suspect that squirrels may be a major player. I lost my entire crop of Honeycrisp apples this year to squirrels. Half were bitten into, and the other half were knocked to the ground and partially consumed.

The chipmunks (in my neighbor hood anyway) have learned to climb into the
canopy of the trees and grape arbor to eat the fruits.

You may have to find some way to provide a barrier to access from the ground, nearby fence, roof or other trees to keep these animals out of the tree. Some folks claim that a spray of capsaicin works as a repellent but it must be frequently applied.

Here is a fact sheet about controlling squirrel damage:
http://icwdm.org/handbook/rodents/ro_b171.pdf

I realize this is not a definitive answer, but without your direct observation of the damage-causing agents there is little we can do to help ensure the safety of your apples at this point.

If there are other signs of disease or other insect activity (such as apple maggot, apple curculio, etc) we can offer some recommendations. In the meantime, here is a link that discusses most of the problems that we northern gardeners face when growing Apples:
http://www.extension.umn.edu/garden/diagnose/plant/fruit/apple/



Sorry for the "canned response". Here is the "Live response":
It's hard to say what might have happened to these apples, but the hornets are not to blame. They are busy stocking up on calories for the winter and are very conspicuous at this time of year. Any injury to these fruits will attract them but they do not make the first "breach" of the skin - something else got there first.
Birds may peck a hole in the fruit and that is enough to attract the hornets who will continue to dine on the fruit.

Many different critters will consume the fallen fruits, from insects to small mammals.
I suspect that squirrels may be a major player. I lost my entire crop of Honeycrisp apples this year to squirrels. Half were bitten into, and the other half were knocked to the ground and partially consumed.

The chipmunks (in my neighbor hood anyway) have learned to climb into the
canopy of the trees and grape arbor to eat the fruits.

You may have to find some way to provide a barrier to access from the ground, nearby fence, roof or other trees to keep these animals out of the tree. Some folks claim that a spray of capsaicin works as a repellent but it must be frequently applied.

Here is a fact sheet about controlling squirrel damage:
http://icwdm.org/handbook/rodents/ro_b171.pdf

I realize this is not a definitive answer, but without your direct observation of the damage-causing agents there is little we can do to help ensure the safety of your apples at this point.

If there are other signs of disease or other insect activity (such as apple maggot, apple curculio, etc) we can offer some recommendations. In the meantime, here is a link that discusses most of the problems that we northern gardeners face when growing Apples:
http://www.extension.umn.edu/garden/diagnose/plant/fruit/apple/