Under current regulatory pressure for eradication of light brown apple moth, local caneberry growers have been striving to maximize leafroller control to the greatest extent possible. The pesticide Confirm 2F, which has excellent efficacy on leafrollers while having little activity on non-lepidopterous insects, has become a point of interest. It is worth the while to discuss the use of this material, along with a comparison to the related, but unregistered in caneberries, Intrepid 2F.
It should be emphasized that while Confirm 2F has excellent leafroller control characteristics, the label is restrictive in that the required interval between application and harvest (also known as the “pre-harvest interval” or PHI) in caneberries is 14 days, meaning harvest season applications without the loss of crop are not possible.
Additionally, since Confirm 2F needs to be ingested by leafroller larvae to realize the highest efficacy, uniform and thorough coverage in the field is essential. Use of high per acre rates of water carrier, high application pressure and spreader sticker adjuvants are all recommended as a way of increasing the effectiveness of this material.
Confirm (tebufenozide) and Intrepid (methoxyfenozide) are chemically similar pesticides and have the same mode of action. Both mimic the action of ecdysone, a hormone involved in initiating molting and metamorphosis. The result of ingestion or contact of either of these materials is a premature acceleration of the molt of the immature stages of target larvae and death a few days later.
Intrepid can be thought of an upgrade of Confirm, and is generally more efficacious,
as it has longer residual activity against some pests. In crops where it is currently
registered, Intrepid has a fairly short pre-harvest interval. For example, the preharvest
interval for Intrepid is one day in strawberries, versus 14 days for Confirm in caneberries.
With this in mind, it will be worth pursuing an Intrepid label similar to strawberries in
caneberries. Replacing Confirm with Intrepid for most crop uses is a worthy goal.
There are pesticides mentioned for management of leafrollers in this article. Before using any of these products, check with your local Agricultural Commissioner's Office and consult product labels for current status of product registration, restrictions, and use information.