Is this a case of mites ( I don't see any) or sunburn? I don't water too much because I have softened water and the tree is in direct sunlight all day. I try not to use up all the water from my rain barrel on just the tree so it only get rain water direct. Any ideas for a treatment plan? Damaged Japanese Maple Leaves ( photo / image / picture from madakatude's Garden )
Wow...I can't beleive I stumped this panel I went to the nursey with a few leaves and they said it was beetles. The gave me some Sevin and I started spraying today.
I have leaves with this same pattern of eating in my garden and it is caused by three types of insects here: The earwig, the leafhopper and the small, green insects that look like miniscule katydids (for lack of a better term)--really, really tiny, green grasshopper-like things. I notice that the edges of the holes in your leaves are brown--do you see that? That means that whatever it was that was eating has left that leaf...and perhaps the whole tree to eat other things. The edges are brown and crispy when the eating is old... the edges of the holes are still green with NO browning of the edges when the damage is fresh and the little creatures are still active on the plant. From what I see in this one picture, I do not believe that your tree is in danger of dying due to this. It is sometimes difficult to discover the culprit--you need to have time and be a bit stealthy to catch the insect in the act. Then you can take measures to curtail its activities. You don't really need to do anything for your Acer at this point, I don't believe. Just check it thoroughly at mid-day and in the evening to be sure that they are not still present. I hope that my take on this has been helpful to you. As for the treatment plan that you asked for, should you discover exactly which insect it is-- you could use a commercial spray there are "biological" ones and more poisinous ones available. Or, you could catch them manually. Should you choose this latter option, be sure that your partner has a camera in their hands to capture you on film chasing after the bugs as they spring about the garden with you springing and bounding in hot pursuit. You will really enjoy seeing the films after a days' work.
If your photo was taken about the time it was posted and it lives in full sunlight; my guess is that is leaf scald. IMO no big deal. Japan maple is an understory tree. This stuph happens at times. You might try watering from under the drip edge of your saplings. Bright sunlight and afternoon watering leads to droplets of water acting like magnifying glass' I try not to use chemical sprays, but thats just me. You might turn a couple of the leaves upside down and looking for egg masses, or larval stage beasties lunching on your tree. How you deal with them will be up to you.
I'm not sure what causes leaves to go like that, but I've seen it quite a lot on Japanese maple. It shouldn't die because of it.
