Text Size:   A+ A- A   •   Text Only
Site Image
Pecan weevil regulations
Curculio caryae, commonly known as pecan weevil, is an insect pest to fruit (nuts) of pecan, hickory (Carya spp.), and walnut (Juglans regia). Adult weevils emerge from soil in late August through early September and begin feeding on developing nuts. Eggs are deposited in the nuts by female adult weevils. Developing weevil larvae (grubs) will feed on the meat of the nut (kernel). During late fall through early winter, the grub will chew an exit hole in the nut and burrow into the soil. Pecan weevils will remain in the soil for approximately two to three years. The cycle continues with the emergence of adult weevils. Damage to nuts is twofold, caused by adults feeding on immature nuts and weevil larvae feeding on nut kernels. Symptoms of infection include destruction of the kernel, premature nut drop, and exit holes in nut. Pecan weevil infestation can cause devastating losses in nut yield.

C. caryae distribution is not well documented and unconfirmed in most areas. Unconfirmed records of pecan weevils are reported in the following regions: China and Georgia in Asia, Ontario in Canada, Mexico, and in the United States;Florida, Georgia, New Mexico, South Carolina, and Texas. The weevil is not known to occur in Oregon

The New Mexico Department of Agriculture (NMDA) has in established a state exterior quarantine to prevent the spread of pecan weevil to the state’s nut industry. This exterior quarantine prohibits hosts of Curculio caryae to be shipped from Oregon and other states with the exception of Arizona, California, and portions of Texas (El Paso, Hudspeth, and parts of Culberson counties). Regulated articles include hickory and pecan nuts, plants and associated soil, and equipment used in nut production, harvesting and storage. Extracted nut meat is exempt.

Nurseries wanting to ship regulated articles must present a certificate of quarantine compliance (CQC) issued by an authorized official from the state of Oregon. The CQC must state that the regulated articles have been treated by approved methods determined by the NMDA and an official has supervised such treatment.

The following treatment options are approved by the NMDA:
  • Nuts- stored in an approved cold storage chamber at or below 0° F for a period of 7 consecutive days or immersed in water at a temperature of 140° F for a period of 5 minutes.
  • Plants or plant parts- methyl bromide or aluminum phosphide as specified in the quarantine.
  • Equipment- steam cleaned.

For additional certification information, contact the horticulturist in your area or the Oregon Department of Agriculture at 503-986-4640.