Larvae emerge every February-March - Ask Extension
Hi there!
Can you please help me identify these strange larvae? Year after year, like clockwork, they emerge in my master bathroom on the tub deck...
Knowledgebase
Larvae emerge every February-March #781650
Asked February 10, 2022, 4:15 PM EST
Hi there!
Can you please help me identify these strange larvae? Year after year, like clockwork, they emerge in my master bathroom on the tub deck every February-March. Some of them are teeny tiny, almost too small to see. Some are much bigger and easily visible with the naked eye. They are striped and a rusty, almost orange-brown color.
I kill them whenever I see them, but even staying on top of it, there are days where there will be dozens of them.
The strangest part is Ive never seen them anywhere else in the house (and believe me I've looked!) only in this particular bathroom, and ONLY on the bathtub deck. Not even on the tiled bathroom floor surrounding it. Not in our bedroom surrounding the bathroom.
I've looked for hours, year after year at photos trying to identify them. The closest larvae photos I've seen are carpet beetles. But I've never seen a carpet beetle in our house either.
But here's the strange thing that makes me question that. I tried something new last year and put pantry pest traps out thinking they might crawl onto the sticky surface and get trapped. I didn't catch any of them, but I did catch half a dozen smaller moth-looking flies. They are mostly light colored and have powdery, delicate-looking wings with some darker spots. I've also never seen anything flying around, so literally no clue where they came from either. Could this larvae be of the same moth-looking flies that I caught? Or are they likely two different species of pests/problems?
The last bit of info that could be helpful is the bathroom is on the second story of the house, and above it is an attic. We've never opened up the crawl space door to the attic (it's sealed and has been sealed since the house was built in 1994), but there is a bathroom fan above the tub and Ive often wondered if they could be crawling through that somehow? The attic has some sort of brownish colored blown fiber insulation. When we first moved in, we thought we heard the scurrying of critters up there, but it's stopped since getting new exterior siding which would've sealed up any potential holes.
Yuck.
We have a meticulously clean home so I'm puzzled and seriously grossed out. Please help so that I can act accordingly and get this taken care of. (And if you have any information on how to get rid of them, I would be so grateful!)
The weirdest part is that we only see them in the winter and then they disappear until the following year.
Thank you so much!
Scott County Minnesota
Expert Response
We agree that you may have carpet beetles. That is the closest match to your photos and descriptions. You might have a meticulously clean house and still have them, because they often reside in woolens and other natural fibers. This includes carpeting and upholstery. Please read the following article on this pest to see if this might be a match to what you are seeing. The article talks about identification and prevention. Good luck with your invasion.
http://cues.cfans.umn.edu/old/em/pdfs/Carpet%20beetles%20and%20clothes%20moths.pdf
http://cues.cfans.umn.edu/old/em/pdfs/Carpet%20beetles%20and%20clothes%20moths.pdf