MILD SPRING, SUMMER PROMOTES STINGING CATERPILLARS

Writer: Robert Burns, (903) 834-6191,rd-burns@tamu.edu
Source: James Robinson, (903) 834-6191,jv-robinson@tamu.edu

EAST TEXAS — Spiders, American cockroaches and stinging caterpillars. East Texans should expect to see more of all these insects this fall, says an entomologist with the Texas Agricultural Extension Service.

Dr. James Robinson, Extension entomologist based in Overton, suspects the mild spring and summer promoted higher survival rates of insect eggs and larvae.

The good news is that though a nuisance, the more numerous spiders are of the non-lethal variety and American cockroaches, a.k.a. waterbugs, are easy to control, Robinson said.

Stinging caterpillars are not lethal either, but they can pose a hazard to children who pick them up in yards or playgrounds.

Symptoms of the sting vary from person to person, ranging from mild pain to severe pain. Just as with other insect stings, some people will be hypersensitive and require hospitalization.

“Most commonly, the sting is painful and remains inflamed and irritated for several days,” Robinson said.

Texas is home to several kinds of stinging caterpillars. The most common species are puss caterpillar, the io moth, the saddleback caterpillar, the buck moth and hag moth.

None of the stinging caterpillars have stingers. Instead, their venom is contained in stiff, hollow spines which to the human eye appears to be fuzz or hair.

This time of year, puss caterpillars, sometimes incorrectly called “asps,” will be about one inch long. Puss caterpillars have feather-like hair that makes them look like off-white, tan or gray balls of fluff.

After picking up or touching a puss caterpillar, a person will experience an intense burning pain at the point of contact. Inflammation may spread several inches from the sting. Sensitive persons may go into shock within two hours of being stung.

The sting of the io moth larva is less severe. Reports of hypersensitive reactions are less frequent, but this may be due to the io moth being less common. The io moth larva has a segmented green body with fleshy bumps armed with tufts of spines. When mature, it is 2 to 2+ inches long.

The buck moth looks similar to the io moth larva but is purple-black with a reddish head. As with the io moth larva, its sting is less severe.

The saddleback caterpillar looks like a slug with spines. It’s mostly brown but with green markings on its back and sides that suggest a saddle blanket. It’s typically about an inch long.

Hag moth larva are only about 5/8 inch long. It has nine pairs of what look like hairy arms extending from its body.

There’s no home remedy to relieve the pain. The spines, which remain in the sting, can be removed with transparent or masking tape. Washing the sting with soap and water may help to remove venom. Antihistamine drugs are not effective. Most off-the-shelf pain relievers such as aspirin are ineffective against relieving the pain or the headache.

If the victim becomes weak and nauseated, or lymph glands in the groin become swollen, take the person to a physician immediately.

The best remedy may be prevention, Robinson said.

Though not all caterpillars are venomous, the best advice is to warn children about picking up or touching fuzzy caterpillars — “especially this time of year,” he said.

Those wishing more in-depth information on stinging caterpillars and their control should visit their local county Extension office. In most phone directories, the office will be listed with other official county offices under “Agricultural Extension Service” or something similar. The Extension publication #L-1312, “Stinging Caterpillars” by Phillip J. Hamman, is free and has line drawings of the more common species.

An online version of the publication is also available at <http://dallas.tamu.edu/factsheet/H&Lpests/Ent-1033.html> and includes color photos of some of the species and the marks caused by their stings.

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