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Subject: Moths


From: Simon Moore <simon.moore>
Date: Tuesday, September 11, 2007
Lori Arnold <woodbldg [at] aol__com> writes

>They are tiny little moths, yellowish beige in color. ...
>They are tiny little moths, yellowish beige in color. The damage
>doesn't appear to create a hole in the clothing, though. An infested
>sweater will have little web-like casings all over it, usually in
>the direction of the knit. Another characteristic of the damage is a
>sandy debris under an object that hasn't been disturbed. For
>instance, a wool cat toy recently was discovered covered in the
>webbing. When I picked it up to throw it away, there was a pile of
>this sandy substance. Whenever I think I have found the article that
>is housing the majority of them--the "nest" lets say--I find
>something else that's worse.
>I know that freezing will get rid of infested pieces, but this is
>too big a problem for that at this point.

Sounds like you have an infestation of case-bearing clothes moth
(Tinea sp. aff. pellionella)  I'm not sure what species you may have
in Philadelphia but I'm sure that you will be deluged with other
replies from more local persons.

The adult moths tend to lay about 50 eggs each and then die shortly
after.  The larvae are the main despoilers; they feed on fur, hair
and natural fabrics and the 'dust' that you find is a mix of
digested end-products, known as 'frass'.  The protective cases they
make themselves and coat them with fibres from whatever they're
eating at the time.  They will also pupate inside these cases.  The
life cycle in favourable conditions (warm and humid) can go around 6
to 7 times per year, so they can multiply very rapidly and since
they are small and efficient fliers they can access the remotest
spots. Apart from the clothing fabrics ensure that there is no
culture medium for them--old bird nests, bird bodies down chimneys
behind boarded-up fireplaces and in attics.

Permitted fumigants are useful but I am unsure what is permitted in
the USA these days (dichlorvos?) but low RH is a useful preventive
measure. You need to get the humidity levels between 40 and 45% if
you can--any lower and your woodwork will start to protest!  Get in
a few dehumidifiers if local conditions are humid and you will find
that the moths will die out quite rapidly.

Lavender and Rosemary oils are more user-friendly ways of getting
rid of such pest infestations. Hope that this helps,

Simon Moore, MIScT, FLS, ACR,
Senior Conservator of Natural Sciences.
Hampshire County Council
Recreation and Heritage Department
Museums and Archives Service
Chilcomb House, Chilcomb Lane
Winchester SO23 8RD, UK
+44 1962 826737

                  Conservation DistList Instance 21:24
               Distributed: Saturday, September 29, 2007
                       Message Id: cdl-21-24-005
Received on Tuesday, 11 September, 2007

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