QUESTION:

I have a question in regards to service for cluster flies. We would like to use Talstar Pro but it does not list cluster flies, but does list flies. Do you know if this is good for cluster flies or do you have another option that you have heard works well for cluster flies?

ANSWER:

Most states continue to allow the use of a pesticide for any pest that occurs on a labeled site as long as the Label for that product does not specifically prohibit use for non-labeled pests or has any other restrictive wording. For example, the recent RMD (Rodenticide Mitigation Decision) required rodenticide manufacturers to place the words "for use ONLY for" on their labels for products used for the house mouse and for Norway and roof rats, clearly restricting the use to only these three species. There may be similar statements on many insecticides, but most often the product labels are vague for a reason, and that reason is to allow flexibility on the part of the end user - the professional in pest management. In our resource on PestWeb listing all of the products for various pests and various sites we often take it down only to the basic level - flies, cockroaches, spiders - and not to specific house flies, german roaches, black widow spiders, because that is as far as the Label goes.

So, in my opinion if the product is labeled for "flies" then it gives you the judgment call to use it for any kind of fly pest you encounter as long as you are using it in a manner allowed by the Label and on a site allowed by the Label. Since cluster fly management does include the use of residual insecticides this would probably be an effective material to use in some settings, such as applying it to resting sites indoors or outdoors as long as that site is on the label (attic, wall void, exterior surfaces of structures, etc.) Yes, pyrethroids like bifenthrin are good products for fly management, but it is possible that a different formulation may be more effective.

Microencapsulated products, and we have quite a few different brand names now, offer a few benefits over other formulations of products applied as liquid sprays. They hold up better once exposed to the environment, and if you are treating exterior surfaces for cluster flies that are gathering on the outside walls you want the product to last as long as possible. The microscopic capsules may be more inclined to adhere to the flies that land on that treated surface or walk across it, giving the fly a better opportunity to be exposed to a lethal dose of the active ingredient.

In general cluster flies should be controlled with the combination of good exclusion to prevent their entry into the structure, possibly placing UV light traps into larger void areas the flies occupy in the winter, and using insecticides within the voids where they are gathering as well as on the surfaces in the fall outside when the flies begin to congregate.

View past Ask Mr. Pest Control questions.