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Puss Caterpillar (Megalopyge opercularis) - September 13, 2014


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I was getting ready to clean the pool filter when I noticed something on the top of the filter system.  I recognized it as a poisonous caterpillar (although I couldn’t immediately bring to mind the name) and knew I needed to be careful in handling the top of the filter system.  I didn’t want to hurt the caterpillar so I thought I would simply leave it in place and clean the filter without disturbing it.  I got my camera and took a few shots of the caterpillar with my macro lens. 

I put the camera away and when I went to get the hose I totally forgot about the caterpillar.  In removing the top of the filter system, my right thumb briefly touched the caterpillar’s back.  It was enough of a brush the caterpillar dropped off the top of the system.  At first, nothing happened.  However, as I was cleaning the filter with the hose, I began to feel a warm sensation on my thumb. 

I finished cleaning the filter and put everything away and began to notice a more intense burning sensation.  At that point, I decided to go ahead and identify the beast.  It was not in my caterpillar picture key book so I went online and typed in “poisonous caterpillars”.  What immediately came up was Puss Caterpillar (Megalopyge opercularis) with the statement this was the most poisonous caterpillar in the United States.  It’s common in the southeastern part of the U.S. and at times, is more common and then less common.  I must have hit the common time frame.  Not to mention the poisonous spines along the back.  I must have only gotten a few in my thumb.  I can’t imagine the pain for someone who gets a good dose of them.

The article I found on the poisonous nature of the caterpillar suggested that medical attention was advisory but at the very least, take an antihistamine and use cellophane tape to remove the spines.  I did the tape bit and then took a Benadryl. 

An hour later, my thumb throbbed and there was an intense burning sensation. By the evening, my entire right arm was throbbing and the burning sensation was still there.  At bedtime, I took a couple of Advil for the pain and managed to get a little sleep.  The pain and burning continued the next day and by the third day, it was beginning to subside. 

I’ve been stung by saddleback caterpillars before when I was collecting plants in graduate school.  That’s the most intense burning sensation I’ve ever had but it goes away after a few hours. This sting lasted three days! 

I’ll not be so absent minded about the next one I run across.  It seems it likes oak trees and citrus, two things I have in abundance in my neighborhood, so I’ll bet there’s a good chance I’ll have another encounter. 

© Fred Searcy 2017