Hello,

It sounds like your apple tree may be dealing with some common issues. The codling moth, a common pest for apple trees, likely causes the worm problem. The codling moth's larvae are often called apple worms, which can cause significant damage to the fruit. More information at this link:

How can you get rid of apple worms? - Cooperative Extension: Garden and Yard - University of Maine Cooperative Extension (umaine.edu)

Non-chemical controls such as trapping and fruit bagging can be adequate for treatment. Good hygiene practices, like removing fallen apples and disposing of them from the storage area, are also recommended. If you’re comfortable with organic pesticides, products like Surround (kaolin clay) and Bt (Bacillus thuringiensis) can help mitigate codling moth issues. More information at this link:

How can you get rid of apple worms? - Cooperative Extension: Garden and Yard - University of Maine Cooperative Extension (umaine.edu)

Regular application of insecticides every 10 to 14 days from after bloom to near harvest can also result in a high rate of worm-free fruit. More information is at this link:

Codling Moth | Yard and Garden (iastate.edu)

Blossom end rot could be a symptom of black rot, a fungal disease that causes fruit rot and cankers on branches. To manage black rot, practicing good sanitation, taking good care of your trees, and pruning correctly is essential. Fungicides are rarely needed, but if the problem persists, they can be considered. More information at this link:

Black rot of apple | UMN Extension

For both issues, contacting your local university plant diagnostic clinic (MSU Plant and Pest Diagnostic Lab) can provide more personalized assistance and confirm the diagnosis. They can also guide you on the best management steps for your situation.

Remember, it’s crucial to follow all label directions when using pesticides and consider the impact on beneficial insects and the environment. It’s always a good idea to consult with local experts familiar with Michigan's specific conditions.

BEFORE YOU DO ANY OF THE TREATMENTS I MENTIONED ABOVE:

PLEASE INCLUDE AN ADDITIONAL IMAGE OF THE COMPLETE TREE ALSO

I recommend that you get a confirmed and precise identification of the problem. I recommend that you send all your images by e-mail to the MSU Plant & Pest Diagnostics Lab. The experts there can also provide you with the best treatment options. Their email is <personal data hidden>. Please include your name. The lab will let you know if they need a sample sent. FYI, the lab may also ask for additional images.

Their website is at this link:

Plant & Pest Diagnostics (msu.edu)

Their Contact Information is at this link:

Contact Us - Plant & Pest Diagnostics (msu.edu)

This link will explain the details of submitting a sample to MSU Plant & Pest Diagnostics Lab:

Submit Samples - Plant & Pest Diagnostics (msu.edu)

I hope this helps!