Plant Problem Diagnosis Key / Pests
Lace bugs
Corythucha and Stephanitis spp.
Small bugs with lacy, see-through wings that feed under the leaves of sycamore, oak, hawthorn, elm, azalea, rhododendron and andromeda. The leaves look bleached and speckled from above, and shrubs in full sun suffer most.
Signs
- Fine white or yellow speckles on the upper leaf, merging until the leaf looks bleached.
- Black, varnish-like spots of excrement under the leaves.
- Lacy-winged adults and spiny nymphs under the leaves.
What favors it
Sunny sites, especially azaleas planted in the open; sycamore, oak, hawthorn and elm among trees.
Prevention
- Plant azaleas, rhododendrons and andromeda in part shade.
- Check leaf undersides from early May for black spots and spiny nymphs.
Crops it shows up on
Shade & ornamental trees; Roses & ornamentals.
Often confused with
Sources
- Lace Bugs on Trees and ShrubsUniversity of Maryland Extension
- Lace BugsOhio State University Extension
Treatment by crop
Cultural, biological and chemical options in the order to use them, and notes written for each crop.
Identification is free. Treatment is on the Home and Pro plans.
Questions in the key that lead here
- Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
No, only damage or discoloration - Where is the problem?
A tree or shrub - Which part of the tree or shrub shows the problem?
Leaves of a broadleaf tree or shrub - What do the leaves show?
Pale, yellow, speckled or bleached - What do the leaves look like up close?
Fine white or yellow speckles; black, varnish-like spots underneath
Not a match? Start the key or describe what you see.
More from university Extension: search Extension pages on lace bugs, or find a plant diagnostic lab through your state's Extension.
Other pests
- Aphids
- Bagworms
- Bark beetles of pine and spruce
- Broad mites and cyclamen mites
- Caterpillars
- Cicada and twig-cutting damage
- Colorado potato beetle
- Cucumber beetles
- Cutworms
- Elm leaf beetle
- Emerald ash borer
- Flea beetles
- Fungus gnats
- Galls on leaves and twigs
- Hemlock woolly adelgid
- Japanese beetles
- Leafminers
- Mealybugs
- Pine sawflies
- Root aphids
- Root-knot nematodes
- Russet mites
- Sapsucker damage
- Scale insects
- Shore flies
- Slugs and snails
- Spider mites
- Spongy moth (gypsy moth)
- Spotted lanternfly
- Squash bugs and stink bugs
- Squash vine borer
- Tent caterpillars and fall webworm
- Thrips
- Whiteflies
- Wood borers