Here is an excellent fact sheet on pecan nut casebearer (link).
· The Arkansas pecan sites are past the five day spray decision window as of June 1. See the Pecan Nut Casebearer Decision Window Risk Map (link).
During that five day decision window, growers examine 10 nut clusters on each of 31 trees (310 clusters). A cluster is considered infested if it has a casebearer egg or nut entry. If, on this date, you found two or more infested clusters before 310 nut clusters were sampled, the casebearer population was large enough to damage more than 5 percent of the harvest and it was recommended to apply an insecticide within the next few days.
Backyard trees - Be careful when applying insecticide sprays in backyard and urban areas, because spray may drift onto nearby gardens, pets and living areas. In home landscapes, use only products labeled for pecans such as: spinosad (Green Light Lawn and Garden Spray with Spinosad®); carbaryl; malathion; or a formulation with Bacillus thuringiensis.
Commercial - Many insecticides are labeled for controlling pecan nut casebearer on pecan. Insecticide labels can change from year to year so it is the user’s responsibility to follow current label directions for worker safety, grazing restrictions and application rates for target pests. Commercial growers should refer to E-215, “Managing Insect and Mite Pests of Commercial Pecan in Texas,” (link); or MP144 2012 Insecticides Recommended for Arkansas (click here for the pages specific to pecans).
Note: The use of pyrethroid (e.g., Asana®, Ammo®, Warrior®) or carbaryl (e.g., Sevin®) insecticides has sometimes been followed by outbreaks of aphids or spider mites in pecans.
from Donn Johnson, Professor
AGRI 320 Department of Entomology
University of Arkansas
Fayetteville, AR 72701