Katydid eggs are small, flat, oval structures laid in distinctive overlapping rows on twigs, leaf edges, and sometimes even window screens. If you’ve spotted a neat double row of grayish-brown scales running along a branch in your garden, you’re almost certainly looking at katydid eggs. They overwinter in place and hatch the following spring, making them a common sight on dormant shrubs and trees from late summer through early spring.
What Katydid Eggs Look Like
Katydid eggs are brown to gray, flat, and oval. Each one is roughly the size and shape of a small seed, and they’re typically arranged in a way that makes them easy to spot once you know what to look for. The classic pattern, especially from the greater angle-wing katydid, is two overlapping rows running along a twig. Each egg tucks partly under the one ahead of it, creating a continuous low ridge that looks like a miniature roofline. Extension guides have compared the arrangement to fish scales for over a century, and the description holds up: flat, overlapping, and uniform.
Not all species use the same layout. The fork-tailed bush katydid skips twigs entirely and inserts its eggs directly into the edge of a leaf. Instead of visible rows, you’ll see small oval swellings along the leaf margin, almost like the leaf itself has a bumpy seam. These are harder to notice unless you’re inspecting leaves closely.
Where Females Lay Their Eggs
Twigs and small branches of shrubs and young trees are the most common sites. The female isn’t random about placement. She roughens the bark first by biting it, then glues each egg down individually. Garden shrubs like butterfly bush, lilac, rose, and fruit tree branches are all frequent hosts. Citrus trees in warmer climates are another common target.
Katydids will also lay eggs on surprising surfaces. Window screens are a well-known alternative, since the mesh gives the ovipositor (the blade-like egg-laying structure at the end of the female’s abdomen) something to grip. A female will work an entire row right into the screen fabric. Clothesline wire and fence wire attract them for the same reason: a thin horizontal surface she can straddle while depositing eggs.
The ovipositor itself looks alarming if you’ve never seen one. It resembles a long, sharp stinger extending from the tail end of the insect. It’s not a stinger at all. Females use it to cut into plant stems, push eggs into soil, or wedge eggs into bark and leaf tissue.
Timing: When Eggs Appear and When They Hatch
Most katydid species produce one generation per year. Adults appear in midsummer, mate, and females begin laying eggs in June and July. The eggs then sit through fall and winter, surviving freezing temperatures in a dormant state called diapause. This is why you’ll often notice the rows of eggs in winter, when bare branches make them more visible.
Hatching happens the following spring. Broadwinged katydid and fork-tailed bush katydid eggs hatch from late March through May, depending on local temperatures. Angular-winged katydid eggs tend to hatch a bit later, around late May. In all cases, the tiny nymphs that emerge look like miniature wingless adults and begin feeding on leaves immediately.
There’s one exception to the single-generation rule. A small percentage of fork-tailed bush katydid eggs hatch midsummer, in July and August, producing a second generation of nymphs and adults that same year. This is uncommon enough that most people will only encounter the spring hatch.
Do the Eggs Damage Plants?
The egg-laying process does create minor wounds. The female bites and roughens bark before gluing eggs in place, and species that embed eggs into leaf edges puncture the tissue. On healthy, established plants, this damage is cosmetic. A row of eggs on a twig won’t kill the branch, and leaf-edge eggs rarely affect the plant’s ability to photosynthesize.
Katydids are considered sporadic pests rather than serious threats. University of Florida’s extension service notes that they rarely need treatment unless populations spike due to unusual weather or disruptions in the local ecosystem. Even in citrus groves, where katydid damage is monitored more closely, the recommendation is spot treatment of heavily infested areas rather than broad application of pesticides.
Removing Eggs From Plants or Screens
If you find rows of eggs on garden shrubs and want to remove them, the simplest approach is pruning the affected twig. The eggs are glued firmly, so scraping them off without damaging the bark underneath takes some care. For eggs laid on window screens, a stiff brush or the edge of a putty knife works to pop them free from the mesh.
On leaf edges, removal usually means pulling the affected leaves. Since most katydids produce just one generation per year, removing a cluster of eggs in winter or early spring eliminates that group entirely. Whether removal is worth the effort depends on how many eggs you’re seeing. A single row on one branch is nothing to worry about. Dozens of rows across multiple plants in a small area could mean noticeable leaf feeding once the nymphs hatch in spring, though even then, healthy plants typically recover without intervention.