Case Bearing Moth Larva

Subject: Weird worm creature
Location: Singapore
January 17, 2015 9:47 am
Hi there… I hope you can help identify this creature in my bathroom… It’s only seen in my bathroom. It freaks me out. Please help identify this.
About 1.5cm long. Has a leaf shaped soft shell it can crawl out from both ends.
Signature: Sandra from Singapore

Case Bearing Moth Larva
Case Bearing Moth Larva

Dear Sandra,
The Case Bearing Moth Larva or Household Casebearer,
Phereoeca fallax, is a common household pest that is found in many parts of the world.  You individual has a very distinctly marked case.  According to BugGuide:  “The larval case is silk-lined inside and open at both ends. The case is constructed by the earliest larval stage (1st instar) before it hatches, and is enlarged by each successive instar. In constructing the case, the larva secretes silk to build an arch attached at both ends to the substrate. Very small particles of sand, soil, iron rust, insect droppings, arthropod remains, hairs and other fibers are added on the outside. The inside of the arch is lined exclusively by silk, and is gradually extended to form a tunnel, while the larva stays inside. The tunnel is closed beneath by the larva to form a tube free from the substrate, and open at both ends. After the first case is completed, the larva starts moving around, pulling its case behind. With each molt, the larva enlarges its case. Later cases are flattened and widest in the middle, allowing the larva to turn around inside.”  The bold black and white spiral pattern on your individual’s case is likely due to fibers that were incorporated in the making of the case.

6 thoughts on “Case Bearing Moth Larva”

  1. Thanks!! Appreciate the really quick reply. They do seem pretty harmless, so we mostly leave them alone. Do they eventually develop wings??

  2. Please advise how harmful and how to totally exterminate them. The case bearing moth larva. Found in the bedroom on the mattress.

  3. I think I have an infestation of the case bearing moths and larvae and I don’t know if it’s related but there’s some other parasite and it seems to be able to take on the form of anything like if it’s a hitchhiker it seems to get into the hitchhiker and then that becomes some kind a cocoon threading it gets into the clothing lines and it looks like whatever organic creature or thing it attaches to it almost blends in like camouflage I don’t know if it’s the same thing Bug but I have pics . Am I going nuts I put my food down and notices my dices tomoto was swollen I cut it in half and a brown sticks like think was in it. I also motice hitch hikers from the yard all over cracke open. My clothes have threads under belt looops that I pull out dozens at a time. Sometimes a brown cacoon like thing or spade shaped insect will fall out. I’m getting bitten too my little girl as well . All of my expensive bags have been destroyed makeup too. I see white caxooms black lines of goop what’s this thing are there more bc sometimes I swear they look like different things Like they’re also master of disguise . Also lots of blots of stuff like drag marks.

  4. As of May 1, 2017
    I have the exact EXACT problem.
    But on other note of my discovering this awful moth infestation to this one room one bath place i live (for quite a long time) the mirro i hadn’t moved off the wall for … years maybe. That’s where moth nests attached to the wall and the mirror! I had to pry and scrape off wall. Ok, but before that and to this day i have something else that i found out at least i think it is, but i saved a black flying bug that while cleaning up all this crap tried ot go into my eye! And i put in a baggie or one of those jewelery that my elec. came in with zipper on it. Ok well today one of those bit my ear and it swelled up it looks red and i grabbed it. I just sat down after boarding train to go to work, i had to take my hand and pry it off my ear! It fell apart and hit the floor i couldn’t even see it after that! I had just before leaving home this morning, used ear and nose trimmer to cut back hair out of ears and nose (obviously) and every day i wake up and i’m sure those things are on my face because the same looking lines run down my eyes as if it’s part of one of those legs of that flying creature. I use tea tree oil on my toenail fungus that is horrific! To say the least. And it goes on and on and i’m just now reading about mold yeast and all the like and now it’s hard to go to sleep of course. Last night same drag on and the larvae i douse with spray bottle of 70% rubbing alochol mix and it’s an all the time now deal. It’s like it’s invisible and then it’s there. I’m afraid now to eat in here to sleep in here and it’s hard to just “move.”


Leave a Comment