Pesticides formulations: Baits
A pesticide formulation is a combination of active and inert ingredients that forms an end-use pesticide product. Pesticides are formulated to make them safer or easier to use. This is because many pesticide active ingredients, in “pure” (technical grade) form, are not suitable for application. In their concentrated form, some are extremely toxic, many do not mix well with water, some are unstable, and some are difficult (or unsafe) to handle, transport, or store. To address these problems, manufacturers add inert ingredients to end-use pesticide products. Inert ingredients have no pesticidal activity, and some simply serve as diluents or carriers.
A bait formulation is an active ingredient mixed with food or another attractive substance. The bait either attracts the pests or is placed where the pests will find it. Many baits are solid (blocks, granules, or pellets), but some are liquids, pastes, or gels. The amount of active ingredient in most bait formulations is quite low, usually less than 5%.
Baits are used inside buildings to control ants, cockroaches, flies, and other insects. Outdoors, they can control vertebrate pests, such as rodents, other mammals, and birds as well as snails, slugs, and some insects. Applicators must place bait stations in safe, strategic locations while following label directions to protect children and non-target organisms.
- Entire area need not be covered because pest goes to bait.
- Control pests that move in and out of an area.
- May be attractive to children and pets.
- May kill domestic animals and non-target wildlife.
- Require careful placement and inspection.
- Pest may prefer the crop or other food to the bait.
- Dead vertebrate pests may cause odor problems.
- If baits are not removed after the pesticide stops working, they may serve as a food supply for the target pest or other pests.
- May not work in situations where pests have many other food or water sources.
Pastes, Gels, and Other Injectable Baits
Pastes and gel baits are mainly used in the pest control industry for ants and cockroaches. In fact, insecticides formulated as pastes and gels are now the primary formulations used in cockroach control. They are designed to be injected or placed as either a bead or dot inside small cracks and crevices of building elements where insects tend to hide or travel. Two basic types of tools are used to apply pastes and gels: syringes and bait guns. The bait is forced out of the tip of the device by applying pressure to a plunger or trigger.
- Odorless; no vapors.
- Low human toxicity.
- Last for long periods.
- Low applicator exposure risk.
- Hidden placements minimize human and pet exposure.
- Very accurate in their placement and dosage.
- Easily placed where insects shelter for maximum effectiveness.
- Can become contaminated from exposure to other pesticides and cleaning products.
- When exposed to high temperatures, gels can run and drip.
- May stain porous surfaces.
- Repeated applications can cause an unsightly buildup.
Some insecticides and rodenticides are now formulated as liquid baits. Most liquid insecticides are concentrated sugar solutions. They are packaged in ready-to-use bait stations to kill ants and cockroaches. As a rule, liquid rodenticide baits are mixed with water and placed in specially designed bait stations. They are useful in sites where sanitation is poor because traditional food-based baits “compete” with other food sources. As is the case with solid baits, you must place bait stations in safe, strategic locations while following label directions and taking care to protect children and non-target organisms.
- Liquid ant baits are very useful in controlling sugar-feeding ants.
- Ants that will feed on liquid baits carry this material to the colony.
- Liquid rodenticide baits will often control rodents in areas where food is abundant, but water is scarce or lacking altogether.
- Not all ants, cockroaches, and rodents will feed on liquid baits.
- You must refill or replace liquid-containing bait stations frequently.