Thank you for contacting the UVM Master Gardner Helpline with your question. The picture was very helpful in confirming our identification of the pesky rose chafer.  I'm sorry to hear that they are negatively impacting your trees.

Michigan State University published “Rose Chafer Management for Vineyards”, which you will find helpful: https://www.canr.msu.edu/news/rose_chafer_management_for_vineyards. They provide some excellent information about managing them on your fruit trees and recommend some pesticides. Master Gardeners are not certified to recommend pesticides, so I cannot speak to their recommendations. Be very careful to exactly follow the instructions provided so that anything you apply does not impact the quality of your fruits, nor harm our pollinators.

The University of Minnesota Extension has a fact sheet about rose chafers that you will find useful: https://extension.umn.edu/yard-and-garden-insects/rose-chafers. If your infestation isn’t too bad and your trees are not too large, you could try to put a floating cover or cheese cloth barrier around your trees to prevent the rose chafers from getting on the plants, but if the pests have gotten ahead of you, that might just trap them inside the barrier.

If you decide to go with pesticides, we recommend a visit to your local garden shop to get some advice from them. Be very careful to follow the instructions on the container precisely including the timing of any application since you want to eat the fruits. If there is any risk to bees and other pollinators, then apply when they are the least likely to be working and wash the fruit thoroughly before eating.

UVM Extension entomologist Margaret Skinner wrote an informative article about the rose chafer white grubs entitled “White Grubs (Family Scarabaeidae): A Serious Lawn Pest” which you can find at this link: https://www.uvm.edu/~entlab/Landscape%20IPM/WhitegrubsinsoilJune2023.pdf. In particular you should refer to the “Cultural Practices to Minimize Grubs” paragraph.

As you have been doing, it is part of my routine to hand pick them from my smaller/lower to the ground plants.  

Be aware that rose chafers contain a toxin poisonous to birds and should not be fed to chickens, other small birds or pets. [“Rose Chafer PDIC Factsheet” published by North Carolina State Extension: https://content.ces.ncsu.edu/rose-chafer ]

A note of caution regarding the “traps” that are available. Research has shown that while the traps catch an amazing number of the targeted pest, in the process they also attracted more into your garden.

I hope this information is helpful. If you need more information, please feel free to reach out. I hope you are able to keep these pests in control this year. Fortunately, they are relatively short lived.