QUESTION:
What is the best method and product for exterior flea control?
ANSWER:
We’ll get the “product” part of this out of the way first by suggesting that MANY products are labeled for flea management outdoors and all of which will kill the fleas successfully. A popular active ingredient is permethrin, and Dragnet SFR is the original product containing this a.i. It is a pyrethroid, and thus subject to the new label restrictions found on all pyrethroids, but your applications outdoors for fleas are not going to be on “impervious” surfaces such as patios or driveways. These would just not be habitats where flea larvae are going to be living and developing, and thus would not need to be treated for the larvae. If you have a lot of adult fleas hopping around on paved areas that could not legally be treated with a pyrethroid you would have to use an alternative product or simply spray with pyrethrum to kill the adult fleas present there.
It is very important to determine exactly where the fleas are coming from. The complaint is going to be about adult fleas, and I have seen major infestations of adult fleas on paved areas. Clearly this is not where they originated, but they “hopped” their way to that pavement from some site where the larvae were developing, and this will be a moist, cool, shaded habitat that is conducive to the survival of the larvae. It also will be where those larvae can find their required foods, one of which must be dried fecal material from adult fleas, telling us that this micro-habitat of the larvae must be a place where host animals spend time – dogs, cats, raccoons, etc. Look for these places where the large animals would spend time and focus your treatment on those places. If you do not eliminate the SOURCE of the problem you can kill all the adult fleas you want and they will continue to be produced.
Outdoor habitats could be under decks, where leaves accumulate, moisture is retained, and shade is provided. Cats and other animals love to reside under decks, so these need to be addressed to permanently exclude those animals. You then can remove as much of the debris as possible under that deck and treat the soil with a contact insecticide. Dense plantings of ground cover or shrubbery also provides resting habitat for warm blooded animals, and every time they go there they seed that substrate with flea eggs and dried blood feces from the fleas on them. Removing layers of plant material on the soil and trimming the plantings to expose the soil to sunlight will help to alter the environment and make it less conducive for flea larvae to survive there. As one flea expert stated in a seminar, treating the open, sunny places for fleas will do very little. You also have no need to spray dry, dusty soils, as these too are not appropriate breeding locations. Focus on the places where animals may go during hot days, looking for shade and cooler places to rest.
An IGR may be helpful along with the residual contact product, but do not use Precor or any other methoprene product outdoors. This IGR does not hold up in sunlight and generally is not labeled for exterior use. Go with a nylar product instead and there are many, Archer being one.
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