(Stephanitis pyroides)

General:

Azalea, laurel, pyracantha, sycamore, hawthorn, quince, American elm, apple can be host plants for lace bugs. With the azalea lace bug both the nymph and adult feed on the underside of the leaves of the azalea plant. This causes a mottled gray appearance (chlorosis) to the upper surface of the leaf. The appearance may be like that from an infestation of spider mites. If the infestation is heavy the leaf may turn yellow and drop off. The lower surface of the leaf may be covered with brown/black tar-like spots of fecal residue from the feeding bugs. The adult is about 1/8 of an inch long with lacy, transparent wings that have brown and black markings. The nymph is smaller than the adult, oval in shape, white initially then turning black and spiny looking. When feeding the bugs penetrate the leaf cells with piercing-sucking mouthparts. There are three stages to the life cycle - egg, nymph and adult. The eggs overwinter partially embedded in tissue on the under side of the leaf. They may even be in the leaves that have fallen to the ground. There may be four generations in Georgia. Hatching usually begins in February and March, that is when to start looking on the under side of the leaf for activity or for stippling on the upper surface.

Hawthorn lace bug, Corythucha cydoniae
Rhododendron lace bug, Stephanitis rhododendri
Andromeda lace bug, Stephanitis takeyai

CONTROL:

Identify: Inspect the plant and be sure of the identification of the pest. If you are not sure of the identification take it to your Extension Service office before attempting chemical control. Otherwise you may be using the incorrect control and wasting money.

Plant Site Selection: Lace bugs usually don't harm their host plants that are in heavily shaded areas. Lace bugs seem to prefer bright, sunny areas so plant susceptible plants in shady areas.

Biological Control: Green lacewings, mites and assassin bugs attack lace bugs but may not show up until the infestation is heavy. To preserve the natural predators use the least harmful control methods possible until the predators take over.

Chemical: For the best control, time applications to start when the first generation is present and make sure the undersides of the leaves are covered. Early treatment may reduce the amount of control effort required. If the lace bug population is small and little or no damage is apparent, wash the bugs off with a strong water spray from a garden hose. When the infestation is light and water doesn't seem to work then try using an insecticidal soap as the first step in chemical control. For a heavy infestation, use products containing dimethoate (Cygon), acephate (Orthene), carbaryl (Sevin), or malathion. Repeat at 10- to 14-day intervals, if necessary, to maintain effective control.

References:

Azalea Culture for Georgia Gardeners, http://www.ces.uga.edu/pubcd/b670-w.html#Insects

Azalea Lace Bug, http://ipmwww.ncsu.edu/AG189/html/azalea_lace_bug.HTML

Control of Lace Bugs on Ornamental Plants, http://www.ces.uga.edu/pubcd/b1102-w.html

Lace Bugs, HYG-2150-91, http://www.ag.ohio-state.edu/~ohioline/hyg-fact/2000/2150.html

AZALEA LACE BUG, http://virtual.clemson.edu/groups/hort/homehort/oiazlcbg.htm

Control of Common Pests of Landscape Plants, http://www.ces.uga.edu/pubs/b1074-w.html

Ornamentals and Turf Insect Note 39 (ENT/ort-39), LACE BUGS, http://www.ces.ncsu.edu/depts/ent/notes/Ornamentals_and_Turf/shrubs_contents/ort039e/ort039e.htm

written by a former program assistant, Jack Arnott

The University of Georgia and Ft. Valley State University, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.