Hi Jean! This appears to be damage from a cucurbit leafminer. There is not much you can do once you see the damage. It is recommended to keep your garden clean and weeded and potentially consider a physical barrier for your garden. Pesticides won't prevent larvae from feeding once they are hatched so it is not suggested to spray as some pesticides can harm natural/native predators to the leafminer. I hope this helps! Thank you for posting!
Posted by: Annalyse Kehs
Posted: April 10, 2019