Jan 11, 2012 – Food And Fabric For Thought

QUESTION:

What has contributed to the increase in carpet beetle infestations in recent years?

ANSWER:

I guess I will have to assume that there IS an increase in carpet beetle incidence, although I have not heard of this being a nationwide plague. Hopefully it is just a local observation in your area. If we do see an increase in the incidence of some pest indoors we have to consider what the reasons are that would cause more of them to be in that place. Carpet beetles eat not only things of animal origin, such as hair, feathers, and fabrics made from hair (wool, felt, etc.), but they also routinely feed on grain-based food materials. They also are Nature's cleanup crew, and quickly find dead insects to feed on them and return those nutrients to the soil. In a home the presence of accumulations of dead insects is definitely an attraction to the carpet beetles, and the recent increase in problems with the Brown Marmorated Stinkbug has generated that question. Will killing the bugs in large numbers indoors where they hide then lead to an increase in carpet beetles, and the answer is a likely Yes. 

So, there is my Guess #1 - perhaps we are having an increase in the numbers and kinds of over wintering insects inside homes, which leads to an increase in the numbers of dead insects, which brings the carpet beetles. I'm not into the area of sewing or other uses of fabrics, but perhaps there is some increase in the use of wool and other animal fibers for yarn and threads used for sweaters, scarves, hats, etc. This could provide more food resources indoors. There do seem to be fads coming and going with the use of alpaca wool and other trendy animal hairs, as well as the spinning of your own yarn from wool. Thus, Guess #2. 

Perhaps this is just a normal up turn in the population of these insects in your area. We do typically see rises and drops in the curve for populations of any living organisms, and it could be the carpet beetles' turn to be on the upswing. The adults normally live outdoors and feed on pollen and other plant materials, so their populations could be increased by good living conditions there such as an early spring that led to earlier emergence of the adult insects, more plants producing more pollen, and other factors that simply favored the survival and reproduction of the insects outdoors. 

My own problems with carpet beetles have generally stemmed from our improper storage of doggie treats in our laundry room, where dog biscuits were kept in an open tub that made it quick to grab one after the dog's meal. Carpet beetles also found these and thrived on the scraps in the tub and the occasional dropped biscuit that sat hidden from us. Improper food storage and storage of foods for a long time in the home can help these beetles to survive and breed and build up their numbers. I suggest an careful inspection of the infested homes to determine exactly what is infested, and deal with it first at that point - The Source. Perhaps an increase in rodent problems, for example, has led to an increase in the use of rodent baits indoors, and these when used by homeowners often get tossed into attics and crawl spaces and left forever, allowing carpet beetles to find the excess bait and feed on it, bringing them into the home for another reason. 

Just several speculations on the possibilities, but control of carpet beetles, like any other food or fabric pest, must begin with the careful inspection to find the infested source. Fogging and spraying baseboards will not have any effect on the beetle larvae hidden away in some void or some container, and it is the larvae that do the damage and that lead to more adult beetles. 


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