UGA Pecan Extension

INSECT UPDATE: PECAN WEEVIL

It is that time of the year again when we expect pecan weevils to be present in the orchards. Peak emergence is expected to be between August 10 and September 20 in Georgia. Therefore, the last week of July would be the ideal time to start monitoring for these weevils by deploying pecan weevil traps (e.g., Circle traps or pyramid/Tedder’s traps). Choose blocks that have known history of pecan weevil infestations for monitoring.

Before shell hardening, treat if high numbers of weevils are seen or if nut drop caused by weevil feeding is high. After shell hardening, treat when weevils begin to emerge and continue spraying at 7-10 days interval especially following rainy days. Wet soil makes it easier for the weevils to dig through the soil and emerge, and extended dry weather may prevent emergence entirely.

For low weevil population, pyrethroids and Imidan can be used to prevent feeding injury from weevils emerging prior to shell hardening but may not be as effective under high weevil pressure after shell hardening.

For high weevil infestation, Carbaryl (Sevin) may be used. Just be aware that aphid and mite populations can flare up if Carbaryl is sprayed, the same is true if pyrethroids are sprayed. If aphids and mites become problematic and their populations warrant control, you can use products recommended for mites and aphids listed on the Commercial Pecan Spray Guide. Nexter has been shown to work for both of these pests.

 

Authors: A. Acebes-Doria and W. Hudson