In the past several years, my Northern Lights azaleas get attacked in mid-spring by little green worms who devour the leaves, leaving only the ribs and prominent veins behind. The worms disappear after a few weeks. Meanwhile, a bird or two will eat some of them and I've tried some organic sprays to eradicate them. But the damage is done for the season. Would these be some sort of root weevil larva? Is there an organic systemic that might help fight the battle?
Hard to tell but I would use Bt, a.k.a. bacillus thuringiensis. It can be used against most all caterpillars too. I also recommend using Bt early next year to prevent a re-occurrence. Apply it, say, in early May? But if the damage was not much, they are not visible and appear to have left, I may just do nothing too.
This message was edited May 25, 2014 3:16 PM
luis - thanks for mentioning BT as that didn't even occur to me. I'm thinking now that the pests might be sawfly larva. I've had problems with them in the past, particularly on a rose that I yanked out years ago. Seems that they really only bother the azaleas and nearby columbine.