Case Bearing Moth Larvae

household bug
Location: ireland, dublin – ceiling and under beds
November 30, 2011 3:42 pm
dear mr. bugman
for many years now i have had these white small 1cm size chrysalis hanging from my ceiling and now i have uncovered them under the beds, along with oodles of small black piles…? they seem to like leather and clothing under the beds but i have never seen them produce anything like a moth or worm? can you advise
I do not think them any harm but wonder if they contribute to my asthma and allergies, dust mites etc
Signature: debbie m

Dear Debbie,
These are Case Bearing Moth Larvae, a common creature found in homes worldwide.  While we do not believe they contribute directly to your asthma, they often feed on organic debris like shed hair from pets as well as people.  The accumulation of debris under beds and various other places might be contributing to your asthma, and the Case Bearing Moth Larvae are just symptoms of a pre-existing dust problem in your home.

Really interesting! Do you mean the moth lives inside the casing and moves about in it? As I have never seen any moths in the house or anything emerge from them? Are they living and moving about in the white case
Kind regards
Debbie Millington

Hi again Debbie,
The case is spun by the larva and occasionally incorporates sand and debris in its construction.  The larva lives in the case.  Eventually the larva will pupate in the case.  Perhaps they have never had a chance to emerge as tiny adult moths because you have discovered them and cleaned them away.  It is possible that Case Bearing Moth Larvae my eat organic fibers and protein, hence being considered Household Pests.