Choosing a Pesticide
When a homeowner goes to the store to find a pesticide they will find that there are a number of products from which to choose. They may find that there is a limited amount of information provided to them related to which product would be most effective for their situation. Quite often store personnel are not properly trained to provide recommendations to the consumer about a pest or pesticide product. There are several things to consider before heading to the store to make that purchase. When purchasing a pesticide, remember to always read the label before mixing or applying the pesticide. To see a sample pesticide label and its components visits EPA’s Read the Label First! page.
Considerations when purchasing a pesticide
While many pests can be a nuisance not all cause personal harm or damage to property. Consider whether or not the pest presents any true threat or whether there is an alternative way to control or manage it. Some pests can be easily managed through simple physical removal or control. There are times when an insect might wander indoors through an open door or window. It could easily be removed by either using a tissue then carrying it outside or killed with a fly swatter. The weeds in the flowerbeds could be removed by hand or with a garden tool. If there are dandelions in the yard, can you tolerate them or remove them by hand? If an outdoor pest continually finds its way inside, exclusion techniques would need to be considered. Before purchasing a pesticide determine what your tolerance of certain pests will be and what other methods of management may be effective. To learn more about alternative methods of pest management read “What about Integrated Pest Management (IPM)?” a topic included in the Pest Management Guide: Home Grounds & Animals which is published by the Virginia Cooperative Extension and discussed on Virginia Tech's Pesticide Programs (VTPP) website.
Pesticides are specifically designed to control a specific group of pests. An insecticide, for example, may control insects by killing them, repelling them or impairing their biological processes. It may seem basic, but notice that the word insecticide starts with the word insect, which corresponds to the class of pest that you are trying to control. In some cases, the pesticide will target a specific pest within the group so it would be important to know the specific pest’s name. For example, while there are multi-purpose insecticides available, they may not be suitable for all insects or similar arthropods. Miticides which are sold specifically for controlling mites may not be very effective in controlling other insects or arachnids. The pesticide label will indicate what specific pests are controlled by the product. In many cases, the pest species will be identified specifically on the label. Below is a table of some commonly used types of pesticides and the pests that they control.
Type of Pesticide:
Target Pest Group:
Disinfectants & Sanitizers
Bacteria & Viruses
Fungi & Similar Organisms
Fruit, Vegetable and Wood Molds
Dandelions, crabgrass, chickweed
Insects, Arachnids or “Bugs”
Ants, Spiders, Flies, Ticks
Insects, arachnids & animals
Mosquitoes, ticks, snakes, deer
Rats, mice, moles
A more inclusive list may be found on EPA’s website, on the page titled Types of Pesticide Ingredients.
Knowledge of the pest may also influence whether you purchase a pesticide that will provide rapid control or one that that will act more slowly. For pests which pose an imminent danger to human health, a pesticide which provides rapid control may be necessary especially if other management practices cannot be employed. When dealing with pest species which present no imminent danger but are recurrent a slow acting pesticide may provide longer term control.
If you are unsure what type of pest you are dealing with, you can contact the local or regional cooperative extension office. Be prepared to provide an accurate description of the pest. To make identification easier, you can also collect specimens or take a clearly focused photo of the pest to share with the agent or specialist. To find the extension office which services your area, select your county from the list provided here.
For tips on collecting insect specimens or taking a photograph for submission to an agent, researcher or professional visit the Professional Pest Identification page.
As you consider the type of pesticide to buy, it is important to determine where it will be used and how it will be applied. The pesticide label specifies crop, plant, or site where the pesticide can be used. An insecticide which is labeled for outdoor use only cannot be legally used inside. A fungicide labeled to control a mold on tomatoes may not be used on apples unless they are both listed on the label. In some cases, using the pesticide on a site other than the one specified could cause harm or injury. For instance, a flea control product labeled for dogs could cause injury to a cat.
The label may also specify the manner in which it is applied. Some insecticides labeled to control German cockroaches may be sold in aerosol containers with a special straw-like adapter. German cockroaches hide in small cracks and crevices. The label will likely say something like “For crack and crevice use only.” This statement would mean that the product can only be applied, using the adaptor, to cracks or crevices such as those found behind baseboards. It could not be applied as a broadcast spray to surfaces. You would need a different product if you intend to treat those areas. Additionally, some products have restrictions about use in food preparation or serving areas such as kitchens. Pay attention to these precautions when purchasing a pesticide as the use may either not be allowed or limited.
Before you purchase a pesticide review the label and make sure both the pest and site of application appear on the label. If the site requires specialized application techniques, search for a product suitable for that use.
The Virginia Department of Agriculture & Consumer Services (VDACS) provides information about currently state registered products through two partner websites. Consumers can search the registration data to find a pesticide product based on site or pest. While these databases will help narrow down the number of products, remember to always review the product label at the place of purchase. Visit the Pesticide Product Registration page to access the online databases.
Pesticides come in many sizes. Some are sold already prepared while others are sold as concentrates which the customer will mix at home. Before heading to the store, determine the size of the treatment area or the number of plants that will be treated. Pesticide labels will provide recommendations based on square footage (area), linear footage, animal weight, basal diameter of a tree or other similar units of measurement. Determining how much pesticide you need will prevent you from spending unnecessary sums of money and minimize the amount of excess product you have left over. Unless you expect to use the additional product in the near future, you should only purchase enough product for the current treatment.
If you are planning to purchase a weed and feed product or a granular pesticide which you will apply to your lawn, the Virginia Department of Conservation has developed a pamphlet which will help you determine how much product to purchase. Although the pamphlet was specifically written for fertilizers, it can be used when measuring your yard to apply pesticides as well. For more information view the pamphlet titled “How to Measure Your Yard.”
Additionally, check your storage areas to see if you may already have a product suitable for controlling the pest. Many pesticides include multiple pests and sites on their label. Be careful though, not to apply a pesticide in a way not permitted by the label. As was mentioned earlier, a site must be specified on the label and you want a pesticide that is specific to the type of pest. Herbicides, for instance, are designed to kill weeds and not insects.
Not only are pesticides sold in different quantities, they are also sold in different forms. In considering how much pesticide you need you will also need to be familiar with the various formulations that are available. Pesticides can be sold as ready-to-use solutions, ready-to-spray concentrates, gels, granular formulations, concentrated liquids, and wettable powders. The advantage of ready-to-use dilutions, gels and ready to apply granular formulations is that they do not need additional preparation. Additionally, ready-to-use pesticide sprays and gels are typically sold inside of a container which also serves as the application device. The amount of active ingredient in a ready-to-spray solution will be similar to that present when a concentrate is mixed. Ready-to-spray concentrates are also sold inside an application device which attaches to a water hose. The device is designed to automatically dilute the pesticide as the water flows through it. Granular formulations may be purchased in a package designed for application of smaller quantities of product but for larger quantities they will be sold separately from the application equipment. If you need larger amounts of pesticide, as might be the case for weed killer which control broadleaf weeds, you may want to consider purchasing a concentrate. Because they are not diluted, the quantity that you purchase will make a much larger quantity when mixed. Concentrated liquids and wettable powders will require mixing prior to applications. Regardless of which formulation you purchase always read and follow the label directions found on the product packaging. For additional information view Selecting the Right Package: Pesticide Formulations and Quantity, an excerpt from Pest Management for Water Quality by Extension Specialist Diane Relf.
While you’re at the store preparing to purchase the pesticide, read the label and determine if there are any related purchases you need to make. For all pesticides, it is important to look for any specified personal protection equipment (PPE) such as a long sleeved shirt, long pants, chemical resistant gloves, goggles, respirators or similar items. While all of these are not required unless specified by the label, you may still want to consider their purchase for additional protection.
If purchasing a concentrate you will have to be prepared to measure the substance and mix it in a separate sprayer. When purchasing concentrated pesticides, consider the following:
- How will you measure the pesticide when mixing? Consider purchasing measuring tools specifically for mixing pesticides. Don’t use measuring tools from your kitchen.
- How will you apply the pesticide? Commonly used equipment would include a hand sprayer, back pack sprayer or spreader of some type.
7. What are the risks associated with the pesticide?
Pesticide labels contain signal words which indicate the products relative toxicity. The three signal words are: Caution, Warning or Danger. Look for products which bear the word Caution since that is the least toxic category. Follow the label precautions. The EPA has evaluated the toxicity of each federally registered pesticide and incorporated precautions into the product label to minimize risks to the user. Consider using ready-to-use solutions over concentrates. They pose less risk than concentrated liquid formulations since they contain less of the active ingredient and do not require mixing. To learn more about signal words and pesticide toxicity view the Signal Word Topic Fact Sheet developed by the National Pesticide Information Center.
Additionally, there are products which the Environmental Protection Agency has determined pose minimal risk when used. These products are exempt from federal registration but must still be registered in the state prior to sale. Since they are exempt from federal registration, the packaging will not have an EPA Registration Number. Manufacturers of products which are classified as minimum risk are not required to submit toxicology data or proof that their product is effective to EPA or the state. Click here to learn more about minimum risk pesticides and their ingredients.
There are some pest problems that cannot be easily managed by someone not trained in the field of pest management. Management of certain pest species requires advanced knowledge about the pest biology, behavior and management techniques. Treatment could also require specialized tools or pesticides which are not available to untrained applicators.
When dealing with any of the following pest issues or if you have recurring pest issues, consider hiring a professional:
- Ants (Indoors)
- German Cockroaches
Specialized training, equipment or materials may be necessary for effective control of these organisms.
The following resources provide additional information about selecting a pesticide. The extension publication links found throughout this website will provide guidance and recommendations specific the pest you are managing. To find a specific pest management recommendation visit the Common Pests of the Home, Lawn and Garden link or query the pest in the search field at the top of this page.
Virginia Cooperative Extension
Choosing Pesticides Wisely
National Pesticide Information Center (NPIC)
University of California, Davis
Pesticides: Safe and Effective Use in the Home and Landscape