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Entomology (Study of Bugs)/Los Penasquitos Canyon bugs


First Bites on Finger
First Bites on Finger  

The Culprit!
The Culprit!  
First, I'd just like to thank you for this service. Even if nothing gets figured out, this is a truly amazing resource.
I work near Los Penasquitos park in San Diego, CA and starting last month would stretch my walking route (which is mainly in a business park) near this area, but never went inside into the canyon proper. At the beginning of this month I noticed bites on my finger that barely itched one day only for the next day to have my finger completely swollen. The bites continued onto my elbow, up my arm and one on my back. Needless to say they itched something awful (and at times still do though not nearly as intensely). I went to urgent care where they couldn't identify the bites but was told they weren't from ticks--good. Since then I've experienced more horrific bites and have noticed more and more these little tiny beetles that look like Carpet Beetles around my bed and room. They're they only thing I can relate these bites to as they live in that park and may have a hitched a ride on my clothes back to my home. Is it at all possible that I have an allergy to any secretions they may have that you know of? They get extremely swollen, itch terribly; the swelling goes down in two days but I still have remnants of the bites from 3/3/15 I got on my arm and back. Any other bugs you may know that live in Los Penasquitos that may have hitched a ride and cause terrible allergic reactions? Your help would be so absolutely tremendous.


First of all, this is a medical question.  Second, I'm not sure that your symptoms are the result of "bites" at all.  Virtually any unexplained wound, rash, or whatever is invariably blamed on insects, even when (*especially* when) there is no insect observed in the act of biting or stinging, or alighting on the victim.

There are no doubt a number of environmental irritants in the park, probably in your home.  These include chemicals in the air, in detergents you use to wash your clothing and linens, lawn chemicals....

Yes, prolonged exposure to carpet beetle LARVAE can produce contact dermatitis in some people, but this is pretty uncommon, and I'm not sure this is what your symptoms demonstrate anyway.  Adult carpet beetles do *not* bite.

I would advise that you see your physician and figure out what, besides your walking route, might have changed recently to help pinpoint potential causes of your symptoms.  I cannot rule out some kind of insect, but I cannot conclude that *is* the cause, either.  At the very least, your doctor would know how best to treat the symptoms until a cause can be determined.

Get well soon!


Entomology (Study of Bugs)

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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

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One of the top 50 experts in all categories for, 2009.

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Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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