May 28, 2012 – Bugs On Rugs
QUESTION:
In checking out damage to oriental rugs I confirmed the customer's suspicions. They were told by carpet cleaners that they should be treated first, if in fact it was carpet beetles. The rugs will be washed, not dry cleaned. Is this normal a procedure and would treating first actually help? It would seem the cleaning alone should solve the problem. If I were to treat would an adulticide plus an IGR be effective?
ANSWER:
Oriental rugs can be sensitive things to deal with. The concern with authentic rugs of this kind is that any chemicals you might apply could affect the dyes used on the rug to alter the color or appearance in some way. I think this was much more of a concern many years ago when many of our insecticides were EC's that used solvents like xylene to get the active ingredient into solution, and then petroleum based diluents to dilute it to the strength of the concentrate. There also were issues in the 1980's with some specific dyes in carpets dramatically changing color, and these were regular household carpets, not even exotic rugs. The named culprits in a couple of cases were active ingredients no longer in use inside structures. This also is the likely reason the carpet cleaning company chooses not to dry clean oriental rugs, as dry cleaning uses chemicals, and their effect on the colors in the rug would be an unknown.
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In checking out damage to oriental rugs I confirmed the customer's suspicions. They were told by carpet cleaners that they should be treated first, if in fact it was carpet beetles. The rugs will be washed, not dry cleaned. Is this normal a procedure and would treating first actually help? It would seem the cleaning alone should solve the problem. If I were to treat would an adulticide plus an IGR be effective?
ANSWER:
Oriental rugs can be sensitive things to deal with. The concern with authentic rugs of this kind is that any chemicals you might apply could affect the dyes used on the rug to alter the color or appearance in some way. I think this was much more of a concern many years ago when many of our insecticides were EC's that used solvents like xylene to get the active ingredient into solution, and then petroleum based diluents to dilute it to the strength of the concentrate. There also were issues in the 1980's with some specific dyes in carpets dramatically changing color, and these were regular household carpets, not even exotic rugs. The named culprits in a couple of cases were active ingredients no longer in use inside structures. This also is the likely reason the carpet cleaning company chooses not to dry clean oriental rugs, as dry cleaning uses chemicals, and their effect on the colors in the rug would be an unknown.
In your question you do not actually state that you have found carpet beetles feeding on this rug, although by saying you confirmed the suspicions I guess that means you did find beetle evidence. I am not overly familiar with oriental rugs and the materials used in them, but is this a wool rug? If this is a more recent rug perhaps it is made from synthetic fibers that carpet beetles would not actually feed on. But, we'll go with the idea that it is wool and there is feeding damage. Washing the rug in itself should kill and remove any beetles and larvae present on it. What might manage to get through the washing could be eggs that may be embedded in the fibers, and if the washing does not use really hot water the eggs could, I suppose, survive. The recommendation by the cleaners that the rug be treated first may just be their standard policy based on nothing more than it's their standard policy, or it may be on the idea that you need to kill any bugs first. However, since it is only eggs that might survive the cleaning I suggest to you that the eggs are not going to be affected by your insecticide treatment either, so treating first is probably the cart before the horse.
More logical to me would be to have the carpet cleaned and dried and THEN you apply an insecticide to provide some protection from any additional larvae that appear. Your management of this issue should extend well beyond these rugs, as carpet beetles are very active and wander all over a structure to seek other food resources as well. You should do your best to ensure that there are no other infestations in food items in storage, decorative things on walls or tabletops, no wool clothing or other fabrics infested, etc. It wouldn't do to eliminate the bugs on the carpets only to have them reinfested immediately, and you should structure any guarantees on this based on the fact that you cannot keep these beetles out of the home. I also don't think you can do anything to provide any long term protection of the carpets, other than constant insecticide applications, which is not reasonable.
If you choose to treat use only water based sprays and I suggest using a wettable powder. The powders are most likely to have no other solvents or chemical diluents in them. It would be best to treat a very small area first and then wait a week to see if any change whatsoever occurs to the carpets' appearance. Recognize too that whatever you apply to these carpets will likely be removed by an intensive washing, so no residual is going to exist following the washing and if you do not treat after the carpets are once again susceptible to beetle feeding. The IGR would probably be a good addition to whatever else you apply, and an IGR is more likely to last for many months. But, I agree with you that spraying ahead of time is of little value. Cleaning alone should remove all larva and perhaps the application of just an IGR afterward would provide some extended protection.
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