Do your rhododendrons look like this?

While you’re cleaning up in the yard, you might find some damage that went unnoticed over the summer. This particular damage was done by lace bugs. Many people are seeing the discolored leaves now, but the insect that injured the plant is long gone. Here’s what happened.

Last spring (mid-May or soon after) lace bug eggs hatched. The juvenile form started sucking the juices out of the leaf cells. Then the adults continued this process. The leaves ended up looking bleached. It might be mistaken for sunburn or that the plant needed fertilizer.

This insect is very tiny – less than an eighth of an inch. The wings are lacy (thus the name – lace bug), so they are hard to see. What you do see is their droppings. They look like little spots of ink or tar.

What can you do now? Sadly, nothing. But, it’s raining and cold outside, anyway. What you do want to do is mark your calendar for two things.

First, right after your rhododendrons flower, prune them to shape them up and remove any really damaged leaves – they won’t turn green again. This will remove many of the eggs, too. Don’t prune before flowering or the flowers will be gone.

Next, in late May or early June – if you see the same problem starting on new leaves, think about taking action. For small infestations, spiders and beneficial insect predators may be enough to avoid further injury. If more serious intervention is needed, consider Ortho® MAX Tree & Shrub Insect Control Ready-to-Spray or Bayer Advanced 12-Month Tree & Shrub Protect & Feed Concentrate.