Pesticide Active Ingredients

An "active ingredient" for a pesticide is one that prevents, destroys or hinders a targeted pest. In other words, it is the chemical that takes "action" to control the pest. It is the ingredient in a formulation that is the most potent or is the chemical which has the highest concentration in a solution.

There are a number of pesticide active ingredients that are staples in the pest control industry which have been tested and proven effective for many years. Other pesticide active ingredients have been recently developed and are newly introduced in a variety of pesticide products. Choosing an active ingredient depends on a few factors that should be considered before making a purchase.

In the guide below, we will go over common pesticide active ingredients and how you can determine what pesticide active ingredient you should use for any given situation. Here you can also find pesticide active ingredients that you can learn about more in-depth.

How Active Ingredients Work

Mode of Action

Active ingredients are usually classified based on their chemical structure and also their mode of action. A mode of action is the way that the active ingredient affects the target pest. For the most part, active ingredient modes of action can be divided into two main groups: active ingredients that target the nervous system and active ingredients that don’t target the nervous system.

For instance, there are active ingredients that are classified as neurotoxins which have a mode of action that affects the target pests nervous system. An example of some neurotoxins are natural pyrethrins (which are derived from the chrysanthemum flower) and their synthetic (man-made) version, pyrethroids. When you see active ingredients like bifenthrin, permethrin, cyfluthrin, beta-cyfluthrin, deltamethrin, cypermethrin, and lambda-cyhalothrin—they are pyrethrins or pyrethroids.

Active ingredients that don’t target the nervous system affect another function or part of the body, the exoskelton, for example. One such type are insecticides with active ingredients that act via desiccation (affecting exoskeleton of pests so they die by dehydration). Active ingredients like diatomaceous earth and silica gel are examples of dehydrating dusts that act via desiccation. An active ingredient like Methoprene is classified as an insect growth regulator and its mode of action works by affecting the reproductive process of the target insect so that eggs don’t develop or have complications when developing.

Knowing an active ingredients mode of action can be helpful in selecting one product over another based on your preference and what you hope to accomplish.

Identifying The Pest

Pest problems can occur in many different scenarios and under many different circumstances. What pesticide chemical you choose to address the problem depends on a number of different factors such as what pest is being targeted, where the chemical should be applied and what you are hoping to accomplish.

Identifying the pest problem is the first step in picking out a pesticide with a specific active ingredient because once you know what pest you have—whether it's an insect, a rodent, a weed or a disease, you can then move forward with how you want to address the issue.

Once you have identified the pest issue, you will then need to analyze how to approach controlling the problem. Below are a few questions you should ask yourself before selecting a pesticide chemical.

• What are the characteristics of the pest?
• What is the severity of the infestation?
• Where is it found (what areas are frequented)?
• What are conducive conditions of the area?
• How quickly do you want to eliminate the problem?

These are just a few important questions that can help you in determining a pesticide formulation that contains specific active ingredients.

Factors In Selecting an Active Ingredient

Based on our expert study and research, we have determined these top factors to consider when selecting a product with a particular active ingredient: how it works in terms of being a repellent vs. a non repellent, how quickly you would like it to work vs. how long you’d like it to work, and finally user safety.

How the Active Ingredient Works: Repellent vs. Non-Repellent

Some active ingredients serve as a repellent, meaning that they don’t necessarily kill the insect, but rather is off-putting enough to keep the insect away. The pest will immediately recognize that the active ingredient is applied somewhere and will avoid it. Some examples of repellent insecticides are ones that contain pyrethroids like deltamethrin (D-Fense SC) or bifentrhin (Talstar Pro).

Non-repellent active ingredients are those that the target pest will not be able to detect as a chemical designed to kill them and will unknowingly crawl over the active ingredient where it is applied and then the chemical will eventually kill them without them suspecting anything is wrong. Some examples of non-repellent insecticides are those that contain fipronil (Taurus SC, MaxForce Baits) or imidacloprid (Apex Cockroach Bait, Dominion 2L).

When choosing between repellent and non-repellent insecticides the main difference is the length of time it takes for the product to knock down an insect and whether the insect has time to transfer the lethal active ingredient to others in the population, which brings us to our next factor:

Speed of Kill vs. Length of Effectiveness

How quickly you want the active ingredients to eliminate the pest or how long you want the active ingredient to do its job is another big factor in selecting an active ingredient. If you want a product that is fast-acting, then you will want to select an active ingredient known for quick knockdowns like a pyrethroid.

Pyrethroids are fast-killing and can also be a repellent, so they are good for creating barriers to keep pests away. The con is that the residual effects of these products (how long they remain effective) are not very lengthy, probably just a few weeks.

Active ingredients like imidacloprid and fipronil are not fast-killers and actually work slowly. They are non-repellent and so they allow the insect to come into contact or ingest the product then go about their business and share the product or interact with others in their nest so they all eventually die from exposure to the active ingredient. The residual effects of these insecticides are also much longer, remaining effective for several months.

So you would have to weigh your options when it comes to active ingredients: do you want a quick kill with little to no residual effect or long residual affect but slow acting?

User Safety

When applying pesticides, you of course want a product that is safe to apply. When applied according to the product label directions and safety warnings, all products can be safe no matter the active ingredient. But, factors like if you have pets and children around or you need to apply around a sensitive area like where food is handled or plants are present should be considered before selecting a pesticide active ingredient.

Some active ingredients also may be harmful to you if ingested or if it comes into contact with your skin. This is why reading the label is very important to do before making any purchase.

Some Helpful Examples

Person A has a mosquito problem and he wants them killed quickly:

Person A should consider using a pyrethrin product with an insect growth regulator like methoprene. Mixing Flex 10-10 with Martin's IGR Insecticide would be our best recommendation for controlling the mosquito population around her home.

Person B has cockroaches in his home. He’s tried sprays that kill them quickly, but there’s so many that he’s at a loss of what to do.

Person B should consider using a product that contains imidacloprid, like Apex Cockroach Bait. Imidacloprid is a slow killer. When it does kill, it will wipe out a significant population of the roaches or take out the entire infestation, because it allows time for the active ingredient to be transferred between the roaches so all are poisoned.

Person C has a wide variety of pest problems and doesn’t want to spray all the time to address them. She wants to keep the pests gone with a quarterly treatment.

Person C should consider using an active ingredient like bifenthrin (Reclaim I/T), which is a pyrethroid. Pyrethroids can kill pests quickly and have a repellent quality while also carrying a long residual of up to 90 days.