Inspect, wash and prevent azalea lace bug infestations

Now is the time to prevent lace bug attacks on your azaleas.

The azalea lace bug, or Stephanitis pyrioides, overwinters as eggs on the underside of infested leaves.

Eggs hatch in late March and early April. The insect then passes through five stages before becoming an adult. It takes approximately one month for the insect to complete development from egg to adult, and there are at least four generations per year.

Valuable plants that are susceptible to lace bug damage should be inspected in the early spring for the presence of overwintering lace bug adults, eggs and newly hatched nymphs. Inspect these plants every two weeks during the growing season for developing lace bug infestations.

Both adults and nymphs have piercing-sucking mouthparts and remove sap as they feed on the underside of the leaf.

Lace bug damage to the foliage detracts greatly from the plants’ beauty, reduces the plants’ ability to produce food, decreases plant vigor and causes the plant to be more susceptible to damage by other insects, diseases or unfavorable weather conditions.

The azalea can become almost silver or bleached in appearance from the feeding lace bug damage.

However, lace bugs often go undetected until the infested plants show severe damage sometimes into the summer. By then, several generations of lace bugs have been weakening the plant.

Inspecting early in the spring and simply washing them off the underside of the leaves can help to avoid damage later and the need for pesticides.

Adult lace bugs are flattened and rectangular, measuring 1/8- to 1/4-inch long.

The area behind the head and the wing covers forms a broadened, lace-like body covering. The wings are light amber to transparent. Lace bugs leave behind shiny black spots of excrement.

Lace bug nymphs are flat and oval, with spines projecting from their bodies in all directions. At each stage of growth, the nymph sheds its skin and these old skins often remain attached to the lower surface of infested leaves.

Azalea lace bug eggs are football-shaped and transparent to cream colored. The eggs are found on the lower leaf surface, usually alongside or inserted in a leaf vein.

Adult females secrete a varnish-like substance over the eggs, which hardens into a scab-like protective covering.

See http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm for more information.

Sheila Dunning is an agent at the University of Florida's Institute of Food and Agricultural Sciences Extension office in Crestview.

This article originally appeared on Crestview News Bulletin: Inspect, wash and prevent azalea lace bug infestations