AboutEric R. Eaton Expertise I can answer most questions related to wasps, solitary bees, grasshoppers and katydids, beetles, cicadas, and spiders, especially requests to identify "mystery bugs" in North America!
Experience
Past/Present clients Principal author of the "Kaufman Field Guide to Insects of North America" (in bookstores now!), Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker), Krohn Conservatory, Cincinnati (volunteer trainer, guest speaker).
Expert: Eric R. Eaton Date: 7/2/2008 Subject: Small larvae?
Question On Saturday while weeding a flower bed, I suddenly felt stinging sensations in an area about 2 inches long and about 1/2 inch wide on my side. I brushed the area with my hand, but felt nothing and there appeared to be nothing on my hand. The stinging continued and then started spreading out with stinging sensations moving away from the original area. Two days later, bright red welts started appearing. I found what appeared to be numbers of hair-sized black larvae (?) embedded in my clothes. They were about 1/16th inch long. When I pulled my fingernail across one of them, it left a red streak (like it had been blood filled). Since that time, I'm continuing to feel stings and the red welts are multiplying and moving down my arm and leg and across my body. The welts sting at first, then itch for about 15 minutes or so and then occasionally. They also form what looks like a blister on them. Any clue? Oh, and I live in northern Indiana.
Answer Dear Debbie:
I'm sorry that you are suffering, and I hope you get well soon!
Surprisingly, there are many caterpillars that can cause the pain and wounds that you are experiencing. The most violent reactions occur with stinging caterpillars such as those of the io moth (Automeris io), buck moths (Hemileuca sp.), saddleback caterpillars, slug caterpillars, and puss moth caterpillars. These creatures possess venomous spines that can break off. I suspect that is what you found embeded in your clothing. All it takes is brushing against one of these insects to get the full effect.
Many hairy caterpillars can cause allergic reactions in some people so that is another possibility. Typical allergy-causing caterpillars include those of tiger moths (family Arctiidae), and gypsy moths and brown-tailed moths. The caterpillar of the brown-tailed moth (another introduced species like the gypsy moth) are so toxic that two entomologists died while doing research on them. Luckily for you, that species does not occur in Indiana.
So, I would investigate those caterpillars as possibilities. It would at least pay to become familiar with them so that if you encounter one in the future you will know to be wary. Take heart, though, in the tropics, there are caterpillars that can kill people.
Feel free to get back to me if you have further questions, but do see your physician if symptoms persist and/or become worse. Every person's immune system is different, so it pays to be observant and pay attention if your "gut" tells you something is wrong. Take care.
