June 29,2021. So happy we’re not broiling today. Since many of us will be eager to enjoy the outdoors the rest of the week, I’m sharing something I’ll describe as an “insect-related public health announcement.” Please find some humor and some good advice in my post.
While we are lucky we live here and not in the south where bugs are much more likely to bite and transmit all sorts of icky things (like Dengue, West Nile, Yellow Fever, EEEV, and a long laundry list of others), we still get various bites and stings that cause reactions.
If you’re like me, your skin may over-react (large, localized reactions), or worse if you’re extremely allergic or even anaphylactic.
After living here almost 12 years, I’ve become pretty familiar with the bugs, including the biting and stinging ones. Every year, when the grass is tall, I’ve gotten these extremely irritating, itchy bites that look a lot like the chigger bites I used to get in the south. They are angry-red, and the itching can last for WEEKS!
Well, a little over a week ago, I was sitting outside in our freshly mowed “yard” which is really a field of miscellaneous native and non-native grasses. We have 3 different colors of lawn chairs – royal blue, white, and brown. I love the blue, so I plopped down to relax and watch my bearded dragon while we both enjoyed some sun. I made a couple of mistakes here, but also solved a mystery.
First mistake. I wore my new shorts. Yep. After this much time, you’d think I would finally learn. Wearing shorts in the San Juans is like coating yourself with sugar water and sitting down next to a nest of yellow jackets. You’re advertising you’re open for dining.
Second mistake. The chair. Yep. That blue chair is a bug magnet. If you’ve been following my posts, you’ll notice I’ve photographed a few bugs on that blue chair. I should have picked the brown chair…or at least worn long pants.
I felt the bite when it happened. My desire to figure out what critter has caused me a multi-annual summer season of itchy aggravation that compels me to cover up with long pants to prevent future bites, and hide the leprosy-looking splotches, was finally realized when I found I had the teeny culprit between my fingers. I ran into the house to stick it under the microscope and found…it was SQUISHED beyond determination. Sigh!
But wait! I was able to rule out a few potential offenders. It was definitely NOT a spider. Come on! Spiders get blamed for more things than they deserve. Most spiders are innocent. It was not a mosquito, no-see-um, flea, tick, bee, wasp, and, I’ll repeat again – NOT a spider!
The thing about being an entomologist is you are 100% oriented to try to identify bugs. I’m ALWAYS looking at bugs. They are fascinating to me. Especially the ones that have super powers or weird behaviors and even the ones that bite. So, I sat down and became OBSESSED with trying to figure out what I squished.
My breakthrough came in going back outside. I took my cellphone and the little macro-lens that attaches to the camera since it helps me see tiny things that age makes impossible to see. My eyes failed at about age 50. If you’re younger than me, SEE what you have to look forward to! 👀
I scanned the chair for any salt-grain sized objects and THERE it was! I made a short video clip and then took a still image from my video. A thrips.
Thrips are tiny (1-2mm). Their name is also interesting. It’s the same for singular and plural. One thrips, two thrips! Sounds like Dr. Seuss should have written a story about these. I will forever remember thrips because when I was in Florida for my graduate school exit exams, I had to answer questions in front of my committee chair and a few other profs. One of the questions I got was about what insect order these were in. I went completely BLANK.
It is one of those moments where you want to slink down into your chair, slide under the table, and crawl away in shame. Even worse, the comment made by one of the committee members. He hinted, “but your committee chair made his career studying these!” OMG, I wanted to die. Nothing prompted my memory. I would have been utterly humiliated except for the fact that when they were trying to set up the computer to Skype in my co-committee chair who was in South Africa, they couldn’t get the technology to work and guess who fixed it? Yep. ME. I think that may have saved me that day.
Also, it WAS the only question I missed. And, in case you’re wondering, THRIPS are in the insect order THYSANOPTERA.
Back to thrips. They bite. I found quite a few records of folks being bitten by these TEENY, TINY bugs. Check my list of references when you’re done reading. If you can’t access these online and want to read more, shoot me an email and I’ll figure out how to get you a copy.
The most comprehensive study I found about thrips bites is in Florida Entomologist. You can read the full text by accessing the BioOne site at https://bioone.org/journals/florida-entomologist/volume-88/issue-4/0015-4040(2005)88%5B447%3AAROTSB%5D2.0.CO%3B2/A-REVIEW-OF-THRIPS-SPECIES-BITING-MAN-INCLUDING-RECORDS-IN/10.1653/0015-4040(2005)88[447:AROTSB]2.0.CO;2.full
This review was pretty interesting. They actually found reports of bites by thrips dating back to 1883. One article I found is actually titled, “Night of the Living Thrips: An Unusual Outbreak of Thysanoptera Dermatitis.” That one is about an outbreak of skin eruptions at the Marine Corps Training Area Bellows in Oahu, Hawaii. The photos I saw made me itchy just looking at them.
The itching is intense! My bite had the exact features described in the literature I found, down to the presentation of the classic “anaemic halo” or white ring around the bite. Irritation and itching is attributed to the thrips injecting you with saliva when they bite.
More about thrips. They have a variety of niches in ecosystems, typically as plant eaters (phytophagous), fungi eaters (fungivorous), and eaters of other invertebrates (predacious). I should add, occasional biters of vertebrates!
Most thrips species have two pair of wings and can fly. Some are known agricultural pests. Sometimes they swarm and people notice them then, but typically, when they bite a human, it’s a case of mistaken ID. That means, a mosquito gets blamed.
It’s an easy mistake to make. Thrips actually have mouthparts somewhat similar to mosquitoes. They have piercing sucking mouthparts with a single mandibular stylet and two opposable and interlocking maxillary stylets. That mandibular stylet is the hole puncher! More about how that all works in Childers et al. 2005. If you remember nothing else, just remember that adult and larval thrips can bite.
Another thing I found out in my obsessive reading. Thrips like BLUE. They like white too and have been reported getting on laundry hung outdoors to dry, then biting people when they bring that sun-dried, fresh shirt (or underwear) indoors and put it on. The blue chair is a thrips magnet. I’ve resorted to rinsing it off with the hose and wiping it dry before I sit down on it.
This most recent bite I had resulted in this baseball-sized diameter welt. It also had the white halo ring.
I ended up calling the after hours line at my doctor’s office to get an antibiotic prescription because it was the weekend and the bite sure looked to be getting infected. I took Benadryl. The call-a-nurse at my insurance company said if you’re ever having a bad reaction to chew Benadryl tablets. It gets into your system faster. I already knew this, but liquid Benadryl also works fast. The itching was miserable given the heat, but I also took a bath in hot water with a lot of iodized salt. I didn’t take the antibiotic because the salt seemed to stave off infection.
My bite is healing, but I ended up with another on my other thigh. The halo ring around this one is fainter, but still visible.
I didn’t see that bite happen, but I know it wasn’t a mosquito because I saw a mosquito bite my ankle when I was outside watering and even though I felt it, I didn’t get any mark or subsequent itching at all. Mosquitoes here don’t have the same effect on me as the mosquitoes in the south had.
Take away message here. Don’t blame the spiders next time you get a weird bite. Especially if it’s summer and you’ve been outdoors. Take a shower before getting into bed and if your pets go outside and come indoors to sleep with you and lie around on furniture, just be aware it may not be fleas biting you, but thrips. Also…avoid blue. Blue is one color that bugs in general seem to like, so unless you’re into entomology and WANT to attract bugs, wear another color. The way it’s looking to me is that gray and beige may be the only safe choices.
Oh…and before I go, the person who coined the term “delusory parasitosis…” Bah to you! Lucky for the poor farmer fellow I read about who complained of being bitten by an “invisible” bug. He’d been diagnosed with delusional parasitosis, but in his persistent presentation to his dermatologist, finally had the culprit of his irritation identified as a grain thrips.
Remember that while you might hope to have that bite diagnosed at your doctor’s office, medical professionals may not have the additional expertise in identifying what bug bit you. They’re there to treat symptoms, but in some cases, it’s important to know what bit you. So, if you feel a bite, look for a culprit and collect it if you can. In some situations, with tiny things, I’ve used scotch tape. A plastic baggie or small cup or jar with a lid works too. Collecting that specimen also means you’re less likely to walk out with “delusional” written in your file!
Carness, J.M., J.C. Winchester, M.J. Oras, and N.S. Arora. 2016. Night of the living thrips. Cutis. 97:13
Childers, C.C., R.J. Beshear, G. Franz, et al. 2005. A review of thrips species biting man including records in Florida and Georgia between 1986-1997. Florida Entomologist. 88:447-451. https://bioone.org/journals/florida-entomologist/volume-88/issue-4/0015-4040(2005)88%5B447%3AAROTSB%5D2.0.CO%3B2/A-REVIEW-OF-THRIPS-SPECIES-BITING-MAN-INCLUDING-RECORDS-IN/10.1653/0015-4040(2005)88[447:AROTSB]2.0.CO;2.full
Leigheb, G., R. Tiberio, G. Filosa, L. Bugatti, and G. Ciattaglia. 2005. Thysanoptera dermatitis. European Academy of Dermatology and Venereology. 19:722-724 DOE: 10.1111/j.1468-3083.2005.01243.x
*Author’s note – While this post attributes pest status to thrips, please know that although thrips can occasionally bite humans and animals, there are thousands of species. Not all of them are biters. Many are actually beneficial and pollinate plants. Lots become food for other organisms, including spiders (which are mostly friendly)! Pesticides are completely unnecessary and often do more harm than good.