Lace Bug

Several weeks ago, I heard from a reader looking for identification of an unusual insect she had found in her garden. By her description and later the image she sent I was able to let her know the insect she found was a lace bug. The one she found was the Andromeda Lace Bug and is native to Japan. They were first discovered in North America in 1955 and are well established throughout Eastern North America. These ancient bugs have been around since the cretaceous period and in recent years new species have been discovered in pieces of amber 

Lace bugs are host specific, meaning each species, of the nearly 2,000 species found worldwide, have their own host plant or genus of plants. Azalea lace bugs…azaleas, oak lace bugs… oaks, hawthorn lace bugs…hawthorns…. well, you get the idea. Therefore, identifying them to species is often straightforward. If you can ID the plant they are on, you will likely find their name will coincide with the name of the plant.

Their name lace bug comes from the lace-like appearance of their wings, reminiscent of your grandmother’s doilies. They are generally 1/8^th of an inch in length, with some species being a bit larger. They range in color from pale yellowish-white, brown, or black with decorative, intricate wing patterns. Females are larger than males and can be differentiated by the ovipositor projecting from the end of their abdomen. This apparatus is used to lay eggs in leaves. Most species are rectangular in shape, and all have piercing/sucking mouth parts used for jabbing into the leaves of their host plants.  Most evidence of feeding is visible in mid to late summer when populations have grown enough to cause visible damage. They are found on the underside of leaves feeding, often leaving pale or brown spots announcing their presence. You will also notice black spots on the underside of the leaves; this is the droppings left behind and are often referred to as varnish spots. Their continued feeding may cause leaves to prematurely drop from trees but rarely causes lasting damage to the trees or plants they feed on. However, if repeated feeding activity occurs year after year, it may kill weakened trees. There is some indication they may be effective biological control agents. Of the many species being used in weed and invasive plant research they are proving to be excellent at controlling noxious plant populations.

Control of lace bugs is rarely required as their feeding is not likely to cause lasting damage. However, if populations explode their feeding activity may stress trees and plants beyond what they can handle. Relying on predators such as birds, lady beetles, lacewings, parasitic wasps and spiders may be effective to control their populations. Try using a strong jet of water from a hose to dislodge them. Keep soil bare under plants and trees, especially if those plants have lost a significant number of leaves, that leaf litter may harbor eggs or nymphs.   Planting a variety of plants, shrubs and trees instead of one or two favored varieties can go a long way in reducing their numbers. Fewer host plants mean fewer lace bugs. If insecticides are needed, they should include environmentally friendly pest control options. We always want to be mindful that insecticides are not species specific and will kill unintended victims, many of them beneficial. With the dramatic decline in insect populations, we cannot afford to deliberately and wantonly kill insects that we depend on.