WATERLOO — If you find a cute white caterpillar, it might be wise to resist the temptation to pick it up.
Experts say the white caterpillar is a white hickory tussock moth caterpillar. Its white hairs have black-tipped bristles that contain an irritating substance that could cause an itch or allergic reaction should the substance get into your skin.
Alice Didona of Serven Road said she found a white caterpillar on her back porch Wednesday morning.
“Living in the country, I’ve seen many caterpillars. I’ve never seen a white one like this,” Didona said. “I saw one earlier in the week near the barn and don’t know if it was a second one or the same one that crawled to the porch.”
Not thinking it could be harmful, she was more curious to see if the white caterpillar may be an indicator of the type of winter to come. So she did a Google search and found the warning from entomologists and others about its unique defense mechanism.
She picked it up with a piece of paper and put it into a container, not wanting their new puppy to find it a delicacy to consume.
“There was quite a bit of information about the substance in the hairs that could cause a bad reaction, itch or irritation. I forgot about the winter indicator and want people to know they might want to not touch these caterpillars,” Didona said.
She took the puppy for a walk in the afternoon and looked for other white caterpillars but didn’t find any.
Experts say the white hickory tussock moth caterpillar has a defense mechanism in those white hairs that embeds in human skin and sends a small dose of irritating poison, causing itching, rash and allergic reactions.
In August 2011, a warning about white caterpillars began circulating online. They are native to Canada, crawling around from Nova Scotia to Ontario, and in the United States from the northeast to the south central part of the country. It appears between June and September and feasts on deciduous trees such as willow, ash, aspen, apple, oak, and nut-bearing trees, plus raspberry plants and corn stalks.
Most people who handle these caterpillars will experience a burning, itchy rash of mild to moderate severity. Washing the affected area with soap and water and then applying ammonia or calamine lotion and icing the area is recommended to deal with the situation.
Some people may be hypersensitive to the poison and have allergic reactions. Those symptoms include swelling and nausea. If that happens, experts say the person should get medical care as soon as possible.
The caterpillar has two long, sharp black hairs that protrude from the front and rear. These hairs are connected to poison glands, which excrete venom on contact.