QUESTION:

How do NUVAN Prostrips control gnats in a residential home if the strips are limited to closets and cupboards? What exactly do they emit to affect the adult and fly larvae/egg stages?

ANSWER:

Nuvan contains the fumigant dichlorvos, which we have known so well in the past as "vapona", and these Prostrips have really breathed new life into this active ingredient. In particular, Nuvan Prostrips and Prostrips Plus are THE answer, at this time, for eliminating bed bugs and their eggs from within electronic equipment. Other than heating there may be no other useful method for ensuring that bugs and their eggs are killed within computers, TV's, and other items where spraying or dusting is not an option. Dichlorvos vapors are released from the resin strips to fill an enclosed space with the active ingredient, and technically it is a fumigant, but one with very low volatility and little hazard to people or pets who are only briefly or casually exposed to it. We are not talking methyl bromide or sulfuryl fluoride here. Because of this, it requires a much longer exposure period to kill insects as well, so keeping the treated area closed is necessary to keep the level of vapors in it high enough to be effective.

Dichlorvos is effective on any stage of an insect, but obviously the insect (or egg or larva) must come into contact with the vapors, and with "gnats" this might be a tad iffy. The word "gnats" is probably a catch-all name for just about any small fly, so it could include fungus gnats, drain flies, phorid flies, or even fruit flies in the minds of people bothered by these small flies. However, as professionals we should take the extra step to actually capture some of the offending flies and make the actual identification. We know that each of these flies may be breeding in a very different micro-environment than the others do, so just accepting that we have small flying insects and using a shot gun approach in the hopes of eliminating them is not the best course of action. For all kinds of fly management we must focus on the source, not on the adult flies, and clearly you recognize this from your question.

We may have fungus gnats flying around anywhere inside a home, but the source may be larvae living within potted plants or coming from the crawl space or breeding within walls where excessive moisture is present. Putting some dichlorvos strips in a small enclosed space to kill the adult gnats may not be much more than a flyswatter approach. The vapors may never actually reach the larvae to control the problem at its source, and this is what is needed. Identification, inspection to determine where the origin of these flies is, and making corrections to that origin to eliminate the ability for the flies to continue breeding there are the best steps to take for long term satisfaction. The use of Nuvan strips for fly management would only be for the temporary relief from the adult flies. Of course, if you had the strips placed where the vapors could move into that breeding site it could kill the eggs too, but we would have to be honest and admit that the problem (the conducive conditions) probably continue to exist, and this could lead to more flies in the future.

Nuvan strips are GREAT tools for some difficult pest problems, so we should consider their use where they are effective.

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