Stop Citrus Leaf Miners the easy way:
What actually worked for us !
After three summers / years of plague level citrus leaf miner infestations, you're probably as exhausted of chasing these moths as we are.
It's a moth that lays her eggs INSIDE the leaf, meaning you can't spray them away until they emerge 10 days later as pupae, and drop into the dirt to grow some more. And they didn't log in on you cell phone calendar when that event is going to happen.
adult cirus leaf miner moth with wings extended
adult citrus leaf miner moth
So while the cedar oil kills them on contact, it's become a game of chase. And in our situation, every new plant shipment is a potential new infestation.
Sprayed every day or two and got beautiful new growth on the citrus, about 6-8" all over. Then something would happen and I missed a day or two. By the time I got back to the citrus all that new growth was ruined. Automation would have helped.
What else could I do?
Citrus leafminer adult moth.
What is working?
Simple: large, nylon mesh bags cinched around the foliage of the tree. The moth can't get through to lay her eggs. Theoretically, I suppose she could still lay eggs on a leaf here or there that is pressing up against the mesh -- maybe -- but it looks as though we stopped the onslaught.
We first cut every damaged leaf off each tree and destroyed it, because potentially there could be live eggs inside. Then we gave the entire tree a good spray in cedar oil to kill whatever might be crawling on a leaf that we couldn't see, also soaking the dirt at the base and around a six foot circle out from the tree. Then we slipped a nylon cover over the tree and cinched it closed around the trunk.
this damage is caused by bugs: citrus leaf miner moth
Make sure to buy 60 count mesh, not 40 count mesh to block the smallest bugs possible. approx. 4'x5' nets did our 10g trees and come with a drawstring only, for about $2.50 to $5.50ea. Larger 15x15 nets with a zipper side did our 3yr established trees nicely for around $15ea.
Two weeks later we removed the cover to snip any damaged leaves or branches we may have missed, sprayed the tree again, then replaced the cover. Now, 3 months later, there's lots of new undamaged growth all over the tree: big beautiful dark green leaves with NO leaf miners in sight! It's that simple.
When you choose your tree covers, look for the ones that say 60 count threads, not 40 count threads, so the mesh will be smaller. Maybe we'll stop the Asian citrus psyllids at the same time. This is what the pro-growers are using in their orchards around the state.
My suggestion is to use these covers for at least 2 seasons while you eradicate any larvae in the dirt that continues to survive in dormancy. Just spray the dirt with the cedar oil at least 4-6 times a year -- seasonally. And of course if you see moths swarming at twilight, spray them.
Don't expect these covers to work on other trees to deter squirrels. Squirrels will eat right through the mesh. More on squirrel control next time.