The Importance of the Pesticide Formulation
By: ElRay M. Roper, Ph.D., Technical Representative, Syngenta
When choosing a pest control product, the formulation may not be something you have historically taken into consideration. However, the formulation can have a major impact on the effectiveness of a product, including how well it mixes and performs in various environmental conditions.
Pesticide products are composed of the active ingredient and the formulation, which either allows the active ingredient to be diluted in water for application or serves as the carrier, like in a bait, dust or aerosol. There are several types of formulations that have been developed over the years. Some of the most common formulations used in Structural Pest Management include:
o Emulsifiable Concentrate (EC): non-water soluble active ingredient is dissolved in an organic solvent mixed with emulsifiers. When added to water it creates a milky-looking emulsion.
o Suspension Concentrate (SC): active ingredient is mixed with a suspending agent, like a clay particle mixed with suspending agents (soap-like chemicals). This suspends the active ingredient in the spray solution but particles will settle out so it must be agitated frequently.
o Capsulated Suspension (CS): active ingredient is encapsulated inside a polymer shell to create very small microcapsules. These are mixed with a suspending agent and suspend the microcapsules in solution. Requires some agitation.
o Wettable Powder (WP): active ingredient is coated onto powder particles that have been treated with a wetting agent. The powder is added to water and creates a suspension very similar to the suspension concentrate formulation.
o Wettable Granule (WG): active ingredient is formulated into granules with a carrier (like clay or similar material). The granules often contain a wetting agent so when they are mixed with water they rapidly disperse to create a suspension.
o Baits (B): active ingredient is dissolved or suspended into a food matrix like grain, protein paste or sweet gel that is attractive as a food source to target pests.
The formulation not only helps the active ingredient mix for easy application, it helps it adhere to a surface, making it more readily available to insects. The formulation can also help protect the active ingredient from the effects of sunlight, heat and moisture, which allows the product to control insects for a longer period of time.
Demand® CS insecticide uses iCAP technology™ to create a unique and proprietary capsule suspension formulation for the active ingredient, lambda-cyhalothrin. iCAP technology creates a dual-wall capsule that provides structural integrity, helping the protection hold up in harsh conditions like high pH, heat and sunlight. Optimal cross linkage in the polymer walls allows for controlled release of the active ingredient to provide extended residual control of pests.
The physical properties of the capsules cause them to readily adhere to the waxy cuticle of an insect much like Styrofoam peanuts cling to your skin when you remove a shipped item from a box. The active ingredient is then rapidly defused across the polymer membrane into the insect cuticle. (See Figure 1)
Figure 1. Demand CS diffusing on insect cuticle
Bait formulations can be challenging to develop for maximum effectiveness. The formulation should mix with the active ingredient so it is evenly distributed in the bait matrix and the matrix can’t break down the active ingredient. The bait formulation should also be shelf-stable and be attractive enough to target pests to compete with other food sources in the environment. For social insects, the formulation should also be easily transferable within the insect colony.
Optigard® Ant Gel Bait meets these rigorous criteria with a clear, sugar-based formulation that is highly attractive to sweet feeding ants such as Odorous House ants and Argentine ants. It is readily transferred from foraging workers, to the brood and the queen. Optigard Ant Gel bait retains enough moisture to remain attractive to ants for several days after application and its clear formulation won’t stain surfaces where applied.
Formulation is Fundamental
When selecting products for your pest management needs think beyond the active ingredient and consider the formulation that will ultimately help carry the active ingredient to your target pests. Advanced formulation technology can be the key to superior efficacy.
©2012 Syngenta. Important: Always read and follow label instructions before buying or using Syngenta products. The instructions contain important conditions of sale, including limitations of warranty and remedy. Demand®, Optigard®, iCAP technology™ and the Syngenta logo are registered trademarks of a Syngenta Group Company.
Syngenta Customer Center, 1-866-SYNGENT(A) (796-4368). www.syngentapmp.com