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LACE BUGS

Steven D. Frank and S. Bambara, Extension Entomologists

CAUTION: This information was developed for North Carolina and may not apply to other areas.


Azalea lace bug, Stephanitis pyrioides (Scott), Tingidae, HEMIPTERA
Hawthorn lace bug, Corythucha cydoniae (Fitch), Tingidae, HEMIPTERA
Rhododendron lace bug, Stephanitis rhododendri Horvath, Tingidae, HEMIPTERA
Sycamore lace bug, Corythucha ciliata (Say), Tingidae, HEMIPTERA

General Information and Biology

lace bug life cycyle drawing There are more than thirty reported lace bug species in North Carolina. Most are not considered a pest. The azalea lace bug may be the best known. Each species tends to feed only on it's preferred host and closely related plants. Lace bugs cause a blotched or spotted appearance of the upper leaf surface, however, immature(nymph) and adult lace bugs are found mostly on the underside of leaves. Spots of excrement resembling dark varnish are a distinguishing characteristic and appear on the underside of the leaves. Infested leaves turn yellow and may drop off prematurely.

Female lace bugs lay groups of eggs on the underside of leaves, most often along the midrib. These eggs are dark colored and are partially inserted into the leaf tissue or are pale and completely hidden inside the leaf. Dark, spiny nymphs hatch from the eggs.

Adult lace bugs have lace-like wings and an expanded, lacy hood back of the head. Several different species of lace bugs are found in North Carolina. Most of them produce two or more generations in a year. Following are brief descriptions of four of our most common lace bugs.

azalea lace bug on underside of leavesAzalea Lace Bug

Adults are about 1/8 inch long and 1/16 inch wide. They have brown and black-marked wings. The legs and antennae are light brown. Nymphs are almost colorless at birth but soon turn black and spiny. This insect usually spends the winter in the egg stage.

Azalea lace bug is found, to some degree, on most azaleas in the landscape.  Damage may be unnoticeable or it may give the foliage a bleached-out appearance.  Control is a matter of how much cosmetic damage one is willing to tolerate.  Adults may be treated early in the spring which may keep later populations low.  The diagnostic characteristic for azalea lace bug is the black fecal speck on the underside of the leaf.  For high value shrubs, a more expensive systemic product is available for appropriate settings.  In general, reduce the plant stress by providing the proper growing conditions for the azalea.  Many azaleas with problems are not planted correctly.  A diverse or more complex landscape may have fewer lace bug problems.  Populations of the azalea plant bug may also reduce problems from lace bugs. 

See a University of Maryland study on how landscape diversity affects azalea lace bug populations or a University of Florida Azalea Lace Bug Information note.

Hawthorn Lace Bug

Adults of this species are small and dark. Hawthorn, cotoneaster, pyracantha and Japanese quince are the usual host plants. This insect may overwinter in the egg or adult stage.

rhododendron lace bug drawingRhododendron Lace Bug

These lace bugs have black bodies about 3/8 inch long and grayish wings. They may attack rhododendron, mountain laurel and related plants. This lace bug overwinters in the egg stage on the plant.

sycamore lace bug drawingsycamore lace bugs on underside of leafSycamore Lace Bug

The wings on the 1/8 inch long lace bug are almost transparent. Both nymphs and adults are black. Nymphs are spiny and very ugly. A complete life cycle takes only 30-40 days. In addition to sycamore, this pest has been known to attack ash, hickory and mulberry trees.

Control

Repeated applications of some insecticides may be needed to control lace bugs effectively. Make the first application as soon as nymphs appear in the spring. Follow with a second application 7 to 10 days later if needed. Repeat as needed at monthly intervals. Thorough coverage is essential when applying sprays if good control is expected. Make sure the undersides of the leaves are covered. For the most current recommendations, and recommendations for specific situations, consult the North Carolina Agricultural Chemicals Manual. Some homeowner lawn and garden products containing some of these active ingredients may also be available.
The University of Georgia has identified varieties of azaleas less susceptible to lace bug damage. 
 

Active ingredient

Trade name

Labeled location

Activity

 

Signal word

IRAC MOA group

Compatible with beneficials

*acephate
Orthene TTO, other
L, N
Contact, Translaminar
Caution
1B
No

chlorantraniliprole

Acelepryn

L, I

Translaminar Systemic

none

4A

Yes

dinotefuran

Safari

G, N, L, I

Systemic

Caution

4A

Yes

*horticultural oil

many

G, N, L, I

Contact

Warning

-

Yes

imidacloprid

Marathon II

G, N

Systemic

Caution

4A

Yes

*imidacloprid

Merit

L, I

Systemic

Caution

4A

Yes

*insecticidal soap

many

G, N, L, I

Contact

Warning

-

Yes

thiamethoxam

Flagship 25 WG

G, N

Translaminar Systemic

Caution

4A

Yes

G = Greenhouse, L = Landscape, I = Interiorscape, N = Nursery

* Suitable for homeowner use

Useful reference:
Horn, Kelly et al. 1979. The Lace Bugs (Hemiptera:tingidae) of North Carolina and Their Hosts. NC Ag.Exp. Stat., Tech. Bul No. 257.


Recommendations of specific chemicals are based upon information on the manufacturer's label and performance in a limited number of trials. Because environmental conditions and methods of application by growers may vary widely, performance of the chemical will not always conform to the safety and pest control standards indicated by experimental data.

Recommendations for the use of chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by the North Carolina Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage and examine a current product label before applying any chemical. For assistance, contact your county North Carolina Cooperative Extension Service agent.


Other Resources

For assistance with a specific problem, contact your local North Carolina Cooperative Extension Service personnel. 
Published by North Carolina Cooperative Extension Service
Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability.
© 2001 NC Cooperative Extension Service

Written by J.R. Baker, April 1994. Revised by S. Bambara, 1998. Revised by Steven D. Frank, May, 2009.
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Web page last reviewed January, 2011 by the webperson .