Crawlies with Cri: Western leaf-footed bug

Western leaf-footed bug (Leptoglossus clypealis)
(Photos by Christy Solo for the Illinois Valley News)

This week we’ll meet a crawly who is having a problem with identity theft. Meet the western leaf-footed bug. The real western leaf-footed bug (Leptoglossus clypealis).
Their problem is that their pesty cousin Leptoglossus zonatus has co-opted their common name and they are running around damaging citrus crops telling everyone, “I’m the western leaf-footed bug!”
It doesn’t help our bug that their sketchy cousin looks quite similar (we all probably have a sketchy cousin like that).
The good news for the western in Oregon is that (to date) sneaky L. zonatus hasn’t been sighted here.
Westerns are actually found throughout the United States, with the heaviest populations up and down each coast and then in a swath down the center from Nebraska to Texas.
Pesty cousin zonatus is found in a big “U” shape only along the southern edge of the U.S., as far north as South Carolina on the East Coast and a smattering of sightings up to Redding, Calif. on the West Coast with the heaviest concentrations in Central California – pesky zonatus love citrus fruit.
We also have the western conifer seed bug (Leptoglossus occidentalis) who we’ve met in the past. They have brighter colors/pattern and a thinner zigzag across their back. They are like the super pretty cousin who never does anything wrong.
Westerns aren’t perfect; they can be a pest in almonds and plums, but they aren’t on anyone’s Most Wanted list.
If you see one, you’ll most likely only see one. They don’t form the huge groups that seed bugs like boxelder bugs do. In our area they live a fairly solitary life, feeding on a wide variety of plant fruits and seeds. For most ornamentals and garden plants, westerns feeding on the leaves and shoots causes no visual damage and is of little concern.
Westerns overwinter as adults, so as our weather starts to warm, you might spot one sunning itself on the siding of your house or near some other protected area where they may have weathered out the cold temperatures.
Westerns are excellent flyers and will disperse in spring to find their own little patch of food. They start out in spring by eating the seeds from last year’s weeds. They give us weed control in exchange for munching on a few of our decorative plants later on in summer.
When food is more readily available, females will lay just five or six eggs on a foodplant. The nymphs will chow down and grow until they go into hibernation in late fall.
What’s in a name? As you can see in the photo, leaf-footed bugs have some flared flair on their back legs. This is called a “flange.” The term comes from heraldic imagery, probably deriving from a “flinch,” which is a curving figure borne on a heraldic shield or coat of arms. Fancy!
That flange is also how you can tell the western apart from pesky cousin zonatus. The westerns’ flanges are more oval-shaped. On zonatus they are broader and have two spikey bits on the outer edge.
Hopefully, though, zonatus will stay to the south of us and we’ll never have to identify one.