Listening for Weevils in Nursery Crops

By David Elstein
March 31, 2004

A new, lightweight device that can magnify the noises of tiny, black vine weevils will be an asset to nursery growers.

Agricultural Research Service scientists working with Acoustic Emission Consulting (AEC) of Fair Oaks, Calif., have made improvements to AEC's machines that can detect insects by the sounds they make. The new device is lighter and more durable and won't pick up distracting noises. The biggest advantage may be that this system, unlike other models, does not need a professional technician to operate it.

The nursery industry is big business in the United States, especially in Oregon where it's worth more than $600 million annually. But the black vine weevil continues to threaten many nursery crops. More than $3 million is spent each year to control these pests, because of strict quarantine regulations that require plant inspectors to reject shipments of nursery crops from other states if just one weevil is found. The new device will allow inspectors to search 15-25 plant pots an hour, compared to five to eight pots without it.

The instrument was refined and tested by entomologist James R. Fisher of the ARS Horticultural Crops Research Laboratory in Corvallis, Ore., and Richard W. Mankin, an ARS entomologist at the agency's Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Fla.

To use the device, the listener wears headphones and sticks a wandlike device on a very large nail that has been placed in the root ball of the plant in the soil. The listener holds a small, computerlike device that amplifies and measures the sound. The weevil makes a distinctive noise while traveling through the soil.

More information about this research is in the April 2004 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's chief scientific research agency.