First generation anti-coagulants (FGARs)
First-generation anticoagulant rodenticides (active ingredients: chlorophacinone, diphacinone ), or FGARs, are federally restricted use materials when applied in agricultural lands. FGARs are considered multiple feeding anticoagulants, which means that ground squirrels must feed on the bait multiple times over several days to ingest a toxic dose. FGARs have low primary toxicity concerns (i.e. mortality of nontarget wildlife that directly consume the toxicant), partly because they require multiple feedings to acquire a toxic dose and also because FGARs can be applied in bait stations that are not generally accessible to nontarget species. If bait is available to nontarget species, then alternative management options must be considered. Anticoagulants are the only rodenticide registered in the United States for which an antidote is available to reverse the effects.
Varying active ingredient concentrations ranging from 0.0025% to 0.01% are available.
Jump to: 0.01% products | 0.005% products
Pelletized baits, oats, and other grains are often used as bait carriers. There are three options for bait application of FGARs when managing California ground squirrels: broadcast applications, spot treatments, or bait stations. It is extremely important that the appropriate application method is used for each individual product. Always consult the label to verify that the designated baiting application method is being used for the correct bait.
Antidotes for Pets
It is extremely important to be vigilant while using these products in the presence of domestic pets. If dogs or cats are inclined to interfere with bait stations, then other management options must be considered. Antidotes are available for pets that accidentally ingest anticoagulant baits or consume poisoned rodents.
Collect dead rodents and dispose of them by deep burying or burning. Check with your local Agricultural Commissioner’s Office to make sure burning is permitted in your area. It is also acceptable to dispose of carcasses by double-plastic bagging or wrapping in newspaper and discarding in the trash. Ensure that trash cans are not accessible to nontarget wildlife. Wear disposable plastic gloves or other suitable hand protection if you must pick up carcasses by hand.
All 0.01% active ingredient products must be applied by broadcasting . Some require a ground-based mechanical spreader or an aircraft. Others can be spread by hand (always use gloves) and are not approved for application by aircraft. The application rate per swath acre depends on the product label and the density of California ground squirrels. Some products require a slightly lower application rate. Consult the product label to determine the timing of a second application.
Broadcast baiting is not permitted for homeowner use.
Many 0.01% chlorophacinone and diphacinone products require bait acceptance trials using nontoxic bait. This is to ensure that California ground squirrels are readily accepting the bait. If nontarget species appear to be present and consuming bait, then alternative baiting and management strategies should be considered. To prebait, manually scatter crimped oat groats or some other grain around the area intended for treatment. Examine the area to confirm that California ground squirrels are consuming the prebait before distributing toxic bait. It is important to collect ground squirrels carcasses on a daily basis. Nontarget wildlife may be at risk of secondary toxicity if they consume the poisoned squirrels.
For 0.005% products, bait may be applied via bait stations or spot treatments. Unlicensed homeowners may only apply certain 0.005% bait products via bait stations.
Secure tamper-resistant bait stations near active California ground squirrel burrows and runways at intervals of 20 to 100 feet, depending on the density of ground squirrels at the site. Place 1 to 5 pounds of bait in each bait station; the exact mount will depend on the observed rate of bait consumption. Bait consumption may not occur immediately; it may take several days to a few weeks for ground squirrels to acclimate to the bait stations in a given area. Follow these steps to maximize bait effectiveness:
0.005% FGAR may also be applied using spot treatments. It is important not to over-bait or place bait in piles. A wide distribution of bait is needed to exclude consumption of grain by nontarget species. With a bait spoon, evenly scatter the label designated amount of bait (typically 1/3 cup) of bait over 40 to 50 square feet near active ground squirrel burrows and runways. 40 to 50 square feet is a large area; it is suggested that applicators measure out the designated application size and make initial, practice applications with non-toxic grain. Use the same procedure when making a second application. Always consult the product label to determine the specific day for the second application. Do not apply more than 10 pounds of bait per acre per treatment.