GREEN COVE SPRINGS – Last week we discussed the popular azaleas that many have in their landscape but didn’t have much time to discuss the insects that attack them. With proper culture and care, you may never see some of these issues but it is best to be prepared if you do.
Some pests you may find on your azalea include lace bugs, spider mites, leafminers and azalea caterpillars.
Lace bugs are small insects that live on the underside of leaves and suck nutrients and water out of the leaves. This will cause a speckled look to the top surface of the leaf and tiny black dots of waste on the bottom. The insect itself may be difficult to see but is cream colored with lacey wings and is around 1/10 of an inch long.
These pests can be prevented by placing your shrubs in the right location, watering and fertilizing them correctly, or even with a strong spray from a hose to knock them off of the leaves. In spring, insecticidal soap or horticultural oil can be applied to the underside of the leaves and some systemic products can give year-round control if applied to the soil around the plant.
Spider mites are not insects, but will feed on leaves with their sucking mouthparts causing a bronzing or rusty discoloration of the leaves. These are very small and are often identified by placing a piece of white paper under the foliage and beating the leaves gently with your hand. Some mites should fall off and you can then identify them.
For control, insecticidal soap or horticultural oil can be applied to the undersides of leaves or use a miticide that is labeled for control of spider mites on ornamental plants. Always check the label before applying any pesticide and follow all directions and safety precautions.
Unlike the previous two pests, the leafminer is actually the larvae of a fly that eats its way through a tunnel it chews within the leaf. This is often noticed as a squiggly path on the top of the leaf. Once inside the leaf, this pest is difficult to control and they are often not in great enough numbers to cause major damage.
In our area it is also likely you may have issues with the azalea caterpillar. The damage of these pests will be chewed leaves and they are between one-half-inch and two inches long. Since they feed in groups and are fairly bright colored with a red body and black and yellow stripes, they are usually highly noticeable. For control, handpicking and crushing or placing the larvae in a container of soap water is often sufficient but if infestations are heavy enough, a pesticide labeled for control of these caterpillars could be used.
If you have any horticultural, agricultural, 4-H, or family and consumer science questions, contact the University of Florida/IFAS Clay County Extension Office online at http://www.clay.ifas.ufl.edu or call by phone at (904) 284-6355.