Blackberry plant damage

Question

I was wondering what is causing the damage to the leaves of the blackberry plants in the pictures and how can I correct it?

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Answer 1

This looks like leaf miner damage. Here is some information on how to prevent and treat this problem:

https://www.gardeningknowhow.com/plant-problems/pests/insects/leaf-miner-control.htm
http://www.fruit.cornell.edu/berrytool/raspberry/leavesstems/rasplfminerend.htm