Adult Leaf Miner - Photo from cisr.ucr.edu
While I was working in south Texas all last week, the leaf miners decided to move in and have a party. The Asian citrus leaf miner is a little moth that lays its eggs on citrus leaves. The larvae then hatch and burrow into the leaves, where they leave sinuous trails as they feed on the interior leaf tissues. I have usually seen damage in April or May, but the hard freezes of the past two years have set them back a few months to July-August.
These little jerks just drive me crazy. To control them you can spray different organic pesticides, such as spinosad or neem oil, but I haven't found them to be particularly effective. Even when I've sprayed all of the trees but one to leave as a sacrificial lamb, they still strike wherever there is tender new growth. You also have to reapply the sprays after every rain (not a problem this summer), and I've pretty much given up spraying anything except on my newly-grafted trees. They're also hard to control because it is very difficult to get the sprays on both sides of every leaf, and once the larvae are inside the leaves they are impossible to kill.
Fortunately, leaf miners don't bother the developing fruits and won't kill the trees, although I'm sure they would be healthier and produce better if the little moths could be controlled. In my experience, they don't seem to prefer any one kind of citrus over another, they lay eggs on any tender new growth that happens to coincide with that part of their life cycle. If anyone has a good solution to this problem I'd love to see it, but then again, the more fruit I grow the less interested I am in spraying any kind of pesticides. I just may have to learn to live with ugly foliage for a few months out of the year.
These little jerks just drive me crazy. To control them you can spray different organic pesticides, such as spinosad or neem oil, but I haven't found them to be particularly effective. Even when I've sprayed all of the trees but one to leave as a sacrificial lamb, they still strike wherever there is tender new growth. You also have to reapply the sprays after every rain (not a problem this summer), and I've pretty much given up spraying anything except on my newly-grafted trees. They're also hard to control because it is very difficult to get the sprays on both sides of every leaf, and once the larvae are inside the leaves they are impossible to kill.
Fortunately, leaf miners don't bother the developing fruits and won't kill the trees, although I'm sure they would be healthier and produce better if the little moths could be controlled. In my experience, they don't seem to prefer any one kind of citrus over another, they lay eggs on any tender new growth that happens to coincide with that part of their life cycle. If anyone has a good solution to this problem I'd love to see it, but then again, the more fruit I grow the less interested I am in spraying any kind of pesticides. I just may have to learn to live with ugly foliage for a few months out of the year.
Leaf miner damage.
All over my small Ruby grapefruit.
Almost all the new growth is affected.
Boy #2 trying some pears
