How to Choose an Insecticide

What is a formulation?

Insecticides are available in various "formulations". A formulation is simply the form of a specific active ingredient that you use. Some insecticide formulations include dusts, gels, granules, liquids, aerosols, wettable powders, concentrates, and pre-mixed solutions. A formulation typically consists of an active ingredient, plus several inactive components such as diluents, wetting agents, emulsifiers, solvents, and carriers.

Before choosing a formulation for insecticide application, consider the following:

1- Can the formulation be applied safely in sensitive areas?

Before using any insecticide product, check the label to make sure its application is approved for any sensitive areas you might be treating. Such areas could include food-preparation areas, classrooms, hospitals, nursing homes, zoos, etc. Baits are usually an excellent, effective, and safe choice for sensitive areas.

2- Is the formulation indicated as effective for the target pest?

While it seems obvious, some people actually use product formulations that are not intended for the target pest. Whether you are trying to eliminate cockroaches, fleas, or termites, check the product label to make sure that pest is listed. In addition, when applying the product, remember that it must be applied in areas the pest will contact in order to be effective. For residuals, this means treating surfaces where pests crawl, or where flying pests most often land. Baits must be placed in areas where the target pest will most likely feed on it.

3- Will the formulation cause harm to plants that are treated?

Some insecticide formulations contain solvents which are toxic to plants when combined with sunlight. To find out if a formulation is toxic to plants, read the label. When you are treating plants, select a WP, SC, or ME formulation. These do not contain solvents. (By the way, these letters, representing various formulations, are usually tacked on to the product name; i.e. Suspend SC, or Demon WP). Emulsifiable concentrate formulations (EC's) should not be used to treat plants. If in doubt, you can always treat a very small portion of the plant first and wait several days to check for adverse reactions.

4- Is the formulation compatible with the surface to be treated?

Residual insecticides (residual means they stay on the surface and continue working for several weeks or months after the initial treatment) can sometimes interact with various surfaces to affect product performance. Studies show that EC formulations are absorbed into porous or semi-porous surfaces and therefore not available to crawling pests, but ideal for termites or other pests that live below surfaces. However WPs, SCs, MEs, and dust formulations are not easily absorbed by porous surfaces and are therefore available to crawling pests

Another consideration when applying residuals is the cleanliness of the surface. Surfaces that are coated with grease, oils, food, debris, dust or other organic matter will reduce the effectiveness of the insecticide. Ideally, surfaces should always be cleaned before applying residual insecticides, especially kitchen surfaces.

5- Will the formulation leave a visible residue on treated surfaces?

Visible residues are more of a problem on indoor surfaces than outdoor surfaces. WP formulations especially tend to leave unsightly residue when applied at high spray volumes. EC, SC, or ME formulations are far less likely to leave a visible residue behind.

6- Are there any environmental factors present that may affect the formulation, such as humidity, temperature, or light?

A few environmental factors that have been shown to reduce the effectiveness of insecticides over time include high temperatures, ultraviolet lights, air currents, and wind. All of these factors will eventually break down the insecticide with direct, prolonged exposure. Indoors, always apply insecticides where they are exposed to as few environmental factors as possible. Outdoors, insecticides will probably break down more quickly and need to be applied more frequently; follow reapplication directions on the label.

7- Is the product cost effective?

The least expensive product is not always the more cost effective product. To answer this question, you must first consider the product's use rate (found on the label) and use that information to determine the cost of treating a given area. The effectiveness of the product and what is being saved in time and labor should also be evaluated.

8- Can the formulation be easily mixed with other insecticides?

With the exception of ready-to-use products, most professional insecticide products (like those you find at domyownpestcontrol.com) must be tank mixed. You will find that some are easier to mix and to handle than others. Before mixing an insecticide, always refer to the product label for strict mixing instructions, and then follow them exactly! The label should also indicate whether the product has any compatibility restrictions with other products.

9- Are there any conditions present that may cause the formulations to run off or drift during application?

Insecticides should not be applied in the presence of adverse weather conditions such as high wind or rain. Especially avoid spray treatments when it is windy outside. Use a low-pressure or coarse fan nozzle under all circumstances to avoid drift and inhalation. When conditions do not favor the use of spray formulations, a granule formulation may be used instead. Granules are much heavier and will not drift.

10- Is the formulation limited in use by any regulatory issues?

Regulatory issues are strict guidelines that limit a product's use due to the potential for hazard. For example, some chemicals may produce fatal reactions when mixed. Other chemicals are not to be applied in rooms that are occupied. Always read the entire label before using any insecticide, and follow all directions explicitly. If directions are unclean or you have any questions as to its use, check with the product distributor, manufacturer, or a professional pest control operator.