Puss Caterpillar (Asp) Control in San Antonio, TX
That little teardrop of tan or gray "fur" on a San Antonio fence rail, patio chair, swing set or tree trunk is a puss caterpillar, known across Texas as an asp. It looks soft enough to pet, but venomous spines hide under the hair, and brushing against one causes intense, throbbing pain within minutes. Don't touch it, keep kids back, and knock it off structures with a stick or tool, not a hand. Seeing them again and again on the patio, play set or walls? Call or text (210) 281-1064, or book online.
Most stings happen at home #
A Texas Department of State Health Services study of poison-center reports from 2000 to 2016 found that 91% of puss caterpillar stings happened at the patient's own home (<a href="https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=29625901&rettype=abstract&retmode=text">Forrester, DSHS). That fits San Antonio, where Census survey data show 58.7% of housing units are detached single-family homes, most with a yard (Census ACS).
The caterpillars feed on common yard trees and shrubs. AgriLife lists oaks, pecan, elm, hackberry and dwarf yaupon, and B-6118 adds palms and holly. From there they crawl or drop onto whatever is nearby: fences, furniture, play equipment, walls and walkways. The cocoons stay on the trunk or branches over winter.
Fall is asp season #
Texas A&M's Mike Merchant describes the yearly cycle: the flannel moths emerge as spring turns to summer, each female leaving hundreds of eggs on a favored tree, and the state sees one or two broods, with caterpillars typically more plentiful in autumn. Poison-center numbers agree: July accounted for 12% of reported stings, and October and November together for 59%.
So when cooler fall weather draws people back into San Antonio yards, that's the time to check rails and play sets before little hands grab them.
On the trail #
If your family walks the city's natural-area parks, such as Eisenhower Park on NW Military Highway, the same rule applies there as in the backyard: look before you lean on a trunk, sit under a low branch or grab a railing. AgriLife suggests avoiding sitting under trees where caterpillars may drop, and covering up with gloves, sleeves and full-length pants for outdoor chores.
How to identify one #
- Shape: a furry teardrop, like a tuft of cotton, reaching an inch or an inch and a half when grown.
- Color: anywhere from yellow or gray to a reddish brown, with the hair lying flat.
- The adult: a fuzzy moth called the southern flannel moth.
- Dead ones still sting. B-6118 warns that dead larvae and even pupae can cause a reaction, so don't handle empty-looking ones either.
If someone gets stung #
Insects in the City says the pain comes on immediately or within five minutes and usually fades within an hour, and that the spots usually disappear within a day (Insects in the City).
- Get the caterpillar off the skin at once, flicking it away rather than grabbing it.
- Lay a strip of tape over the area and lift it to remove any spines left behind.
- Ice the sting site. An oral antihistamine can ease itching and burning.
- See a doctor immediately for generalized itching, trouble breathing, or any spines near the eyes.
Keep perspective: in the DSHS review, 93% of reported cases involved minor effects or none, and 89% were managed outside a hospital. The Poison Center line is 1-800-222-1222.
What we can and can't treat #
Texas licenses pesticide work by category, and pests on trees, ornamental plants and lawns belong to a separate one from the general pest work we do (TDA licensing). Our license covers general pest and termite control, which means tree and shrub canopies are off our list. AgriLife adds that asps seldom do real harm to the trees themselves, so there's no need to spray foliage out of fear.
Our part is the house and the built things around it, such as fences, walls, patios, decks and play sets, and explain your options for those surfaces. For abundant caterpillars in the trees themselves, ask a company licensed for that category.
How Pest Trappers handles asps in San Antonio #
A technician looks at where the caterpillars are turning up, which host trees overhang play areas and seating, and what can be done on the structures within our license. They'll explain the options, follow the label of any product used, and give practical advice on teaching kids what an asp looks like. Pest Trappers LLC (TPCL #0887549) quotes after the inspection. More is in the puss caterpillar guide, and the San Antonio service page covers our other Bexar County services.