Q.raspberry pests
Last year my late harvest raspberries had hundreds of very tiny white larvae or worms on them. Many I could see, and rinse off, but putting berries in water brought out scores more. I was reticent to eat any of the late harvest. How can I prevent this infestation? I live in lower Michigan and the berries have produced very well. I have never fertilized them. Should I?
I usually prune to about 3-4 feet in late fall. I am unclear as to whether or not that is correct. My early-bearing a nd late-bearing berries have pretty much merged in their 15×6 foot plot.
Thank you.

These articles may help
https://www.gardeningknowhow.com/edible/fruits/raspberry/raspberry-fruitworm-control.htm