Participants in the Diagnostic Walkabouts held as part of the Ohio Chapter ISA Field Day last week in Heritage Park, Westerville, OH, observed high populations of Buckeye Lace Bugs (Corythucha aesculi) feeding on their namesake host (Aesculus sp.). Their characteristic “leaf stippling” damage was becoming evident.
Buckeye lace bugs are one of the earliest lace bugs to appear on their hosts in Ohio and they arrive in large numbers. Most lace bugs slowly build populations through the season which accounts for why past BYGL Alerts on lace bugs were posted in mid-to-late summer (Boggs, 2018; Boggs, 2022; Boggs and Scheckelhoff, 2023; Boggs et al., 2025)
Chantilly Lace (Bugs)
Lace bugs (order Hemiptera; family Tingidae) are so named because of the intricate, lace-like pattern of the veins and membranes in their wings, which are held flat over their body. The pronotum, which is the dorsal part of the thorax just behind the head, is commonly highly ornamented with lace-like lateral extensions that resemble flattened “shoulders.”
Some species have a bulbous structure called a “hood” that rises from the pronotum and extends over the head. Buckeye lace bugs have an obvious hood that is easily seen with a 10x hand lens.
It's common to inadvertently call lace bugs “lacewings.” I’ve done it myself. It’s an easy mistake given that both names reference lacy wings. However, lacewing (order Neuroptera) larvae are specialized predators, so lacewings are good. I keep it straight by remembering, “Bugs are bad, wings are good.” Maybe that just works for me.
Lace Bug Needlework
There are around 160 species of lace bugs belonging to 23 genera found in America north of Mexico (Arnett, 2000). Members of the genus Corythucha focus their attention on deciduous trees and shrubs and are confined to lower leaf surfaces.
A close examination of the leaves of plants infested with lace bugs will reveal the characteristic “stippling” produced by lace bugs, which consists of numerous tiny yellow spots. The symptom is named for the monochromatic art technique of shading drawings by repeatedly tapping the tip of a black pen on paper to produce numerous small dots. Speaking from personal experience, it works best if you drink a lot of coffee.
The stippling is produced by lace bug adults and immatures (nymphs) using their piercing-sucking mouthparts. They stab their mouthparts into the succulent leaf mesophyll, sandwiched between the upper and lower epidermal layers, to rupture the cells. Then they suck up the contents. Although they are feeding on the underside of the leaves, the stippling appears on the upper leaf surface.
The stippling will eventually coalesce with heavy infestations to produce large white patches, causing leaves to look "bleached-out." As the damage progresses, portions of the leaf, or entire leaves, will turn yellow to copper brown.
As with other lace bugs, buckeye lace bugs cover the lower leaf surface with unsightly black tar-like fecal deposits. However, this tell-tale symptom occurs later in the season.
The Intricacies of Buckeye Lace Bugs
The native buckeye lace bugs may be found on yellow buckeye (A. flava), red buckeye (A. pavia), and Ohio’s official state tree, Ohio buckeye (A. glabra). I’ve never observed the lace bugs on bottlebrush buckeye (A. parviflora) or horsechestnut (A. hippocastanum), nor have I found a reference listing these Aesculus as hosts.
Stehr (1938) provided an account of the biology of the buckeye lace bug that has yet to be supplanted, although it was published almost nine decades ago. I’ve drawn heavily from his published work, which focused on yellow buckeyes in Ohio.
Buckeye lace bugs spend the winter as adults protected beneath the bark of buckeyes as well as other nearby trees. Stehr noted that they tended to overwinter high in trees and are not found on the lower portion of the trunk, or in leaf litter beneath trees.
The overwintered adults emerge in early spring, mate, and lay eggs to initiate what Stehr labeled the “spring brood.” The lace bugs practice an unusual oviposition behavior by partially inserting their eggs into leaf tissue along the principal veins on the underside of the leaves. Most lace bugs deposit black to dark brown, oval or flask-shaped eggs in clusters that are not associated with veins.
Stehr found that females deposited an average of 178 eggs over 10 days, with an average of 322 eggs per leaflet. Once the 1st instar nymphs hatch, they commonly congregate and remain clustered together as they develop through an additional 4 instars, with wing pads appearing on the 4th and 5th instars. The clusters of nymphs produce concentrated stippling. This behavior is shared with other lace bugs and can produce unusual early-season stippling patterns.
Stehr reported that the spring brood nymphs develop and feed from late April through mid-June in Ohio. Adults guard the nymphs throughout their development, a behavior that’s also shared with other lace bugs.
New adults appear around the first of June in Ohio to mate and lay eggs. Stehr called this new generation the “summer brood.” There is some overlap between late instars of the spring brood and early instars of the summer brood.
The summer brood nymphs develop from the first of June until mid-to-late July when new adults appear. These adults feed until late September and then seek overwintering sites.
A Lacy Threat?
Although high populations of buckeye lace bugs can produce noticeable leaf damage, it’s rare for the damage to threaten the overall health of their buckeye hosts. On the other hand, the impact may depend on location.
Stehr observed lace bugs on yellow buckeyes growing in forests. He found that the spring brood included more nymphs than the summer brood and noted a greater abundance of predators targeting the summer brood.
Buckeye lace bugs appear in Ohio early in the growing season. Perhaps they flourish in forest ecosystems before many of their predators arrive on the scene. Damaging populations may be reduced once the predatory cavalry arrives on the scene.
I’ve observed the opposite in Ohio landscapes. Population densities and damage tend to increase with the summer brood. Stehr was observing buckeye lace bugs that were enmeshed in the fabric of forest ecosystems. Landscape ecosystems are not the same. They are like snippets cut from the rich tapestry of a forest ecosystem. Plant pests, along with their enemies, may not behave the same in landscapes as in forests.
The bottom line is that landscape and nursery managers should closely monitor buckeyes at this time of the year. While Stehr’s observations support the possibility that the 3-Ps (predators, parasitoids, and pathogens) have the potential to regulate buckeye lace bug populations, there are no guarantees. This means suppression applications of systemic insecticides, or topical insecticides targeting the underside of the leaves, may be required.
References Cited
Boggs, J. (2018). More Lace Bugs. Buckeye Yard and Garden OnLine (BGYL), June 19.
https://bygl.osu.edu/node/1073
Boggs, J. (2022). Lace Bug Damage is on the Rise. Buckeye Yard and Garden OnLine (BGYL), July 16.
https://bygl.osu.edu/node/2017
Boggs, J., & Scheckelhoff, B. (2023). Lousy with Lace Bugs. Buckeye Yard and Garden OnLine (BGYL), July 28.
https://bygl.osu.edu/node/2207
Boggs, J., Young, C., & Scheckelhoff, B. (2025). Lace Bugs Litter Ohio Landscapes. Buckeye Yard and Garden OnLine (BGYL), Sept. 12.
https://bygl.osu.edu/node/2558
Stehr, W. C. (1938). The Biology of Corythucha Aeschuli O. & D. (Hemiptera, Tingitidae) on the Yellow Buckeye, Aesculus Octandra Marsh.
https://kb.osu.edu/server/api/core/bitstreams/7f6a1083-e7a3-5c68-be54-bf08e1e3569e/content
Arnett Jr, R. H. (2000). American insects: a handbook of the insects of America north of Mexico. CRC Press Taylor & Francis Group. ISBN: 0-8493-0212-9
