Reduced Risk Insecticide: Exirel

Christelle Guedot, UW-Madison, Dept of Entomology

Exirel is registered for use in Wisconsin* on several crops including cranberry. It was first registered around 2014 on other crops and cranberry was just added to the label in 2019. It is marketed by DuPont under the formulation 10SE (10% of active ingredient as a Suspo Emulsion, which is an oil in water emulsion). Exirel, similar to Altacor, is in the class of the anthranilic diamides (IRAC group 28), with a mode of action acting on the insect ryanodine receptors in the muscles, causing an uncontrolled release of calcium in the cells.  Exirel contains the active ingredient cyantrailiprole. Exirel has contact activity but is most effective through ingestion of treated plants. Affected insects will rapidly stop feeding, become paralyzed, and eventually die within 1-3 days. Applications should be timed to the most susceptible insect stage, typically egg hatch and or newly hatched larvae.

         From a cranberry standpoint, Exirel is registered for control of cranberry fruitworm and suppression of tipworm (also known as blueberry gall midge). Other insects under the bushberries group are also included on the label but are not reported as pests in cranberry production.

         In our previous trials conducted by Jack Perry, Exirel showed great activity against cranberry fruitworm, sparganothis fruitworm, blackheaded fireworm, flea beetle, and the spanworm common Eupithecia. Our trials did not show efficacy of Exirel against tipworm and Exirel is listed for suppression only for tipworm. Timing and environmental conditions may have impacted our results (though we do not think that Exirel will be a good fit for tipworm control in cranberry).  Overall, Exirel performs similarly to Altacor on our cranberry pests and this is not too surprising as they both belong to the same IRAC class of insecticides (group 28). This means that Exirel and Altacor have the same mode of action and should NOT be used in rotation to delay insecticide resistance. Instead, Exirel could be used to replace an application of Altacor.

         Exirel may be applied by ground equipment, chemigation, and air (see label for specific application regulations). For ground foliar applications, use a minimum of 30 gallons of water per acre and the label recommends applying 100-150 gallons of water per acre for best results.

         Exirel is highly toxic to bees exposed to direct treatment or residues on blooming plants. Do not apply Exirel when bees are foraging and until flowering is complete. Exirel is toxic to aquatic invertebrates and oysters and must not be applied directly to water.

*Exirel is labeled for use in Oregon as well.