Boxwood leaf miner larvae are developing fast. I stopped by some boxwood bushes and peeled open some blistered leaves. You can see
the larvae wiggling inside. The maggots pupate in the leaf blister and will emerge as adults in a few weeks. The adults hover around boxwood bushes but only for a couple weeks. In addition to the small orange adults you will see pupal casings sticking out of leaves. As the adult emerges the pupal case get caught on the leaf. This holds the leaf in place so the adult can wriggle out. Boxwoods can be treated with a pyrethroid to prevent flies from landing on the bush to lay eggs but again you only have a short window when adults are active. That is why it is good to pick a few leaves each week to see how close they are to emerging. Imidacloprid will kill maggots within the leaves but be careful
because plants are flowering now so it should not be applied. If applying pyrethroids or imidacloprid watch out for mite outbreaks.