Did You Hear That?
High-Tech Device Detects Weevils in Nursery Crops
Adult black vine weevil, Otiorhynchus sulcatus;
actual size about 7 mm or
3/8 inch. (K11135-1)
Like a reporter sticking a microphone up to the mouth
of a celebrity, ARS entomologist
James R. Fisher sticks a specially designed microphone in the pots of
nursery crops to hear black vine weevils.
The nursery industry in Oregon is huge, raking in sales
of more than $600 million, with 80 percent of the crops shipped to other
states. Black vine weevils want to eat awayliterallyat that
industry by munching on the roots of those crops.
"There is zero tolerance for these insects, with
quarantines imposed by other states and buyers," says Fisher, who
works in the ARS Horticultural Crops Research Laboratory, in Corvallis,
Oregon. If state inspectors find even one weevil, the shipment can't
be sold. The nursery industry spends more money ($3 million) on controlling
these weevils than on all other insect pests combined.
Entomologist Jim Fisher
uses a portable acoustic
detector and amplifier
(AED-2000) connected to
a detection probe placed
into a pot among the roots
of a bird's nest spruce,
a popular woody ornamental. (K11131-1)
Nurseries hire pest scouts to hunt for black vine weevils
in an effort to limit insecticide use. But the scouts can search only
about 5 to 8 pots per hour. So Fisher teamed up with Richard W. Mankin,
of ARS's Center for Medical, Agricultural, and Veterinary Entomology
in Gainesville, Florida, and Acoustic Emission Consulting (AEC) of Fair
Oaks, California, to develop a portable listening device that can evaluate
15 to 25 pots per hour.
AEC and other corporations previously worked with ARS
to listen in on non-root-feeding pests such as termites, ants, and Asian
longhorned beetles. But Fisher believes this new device will revolutionize
detection of root-feeding pests like the weevil.
While technology to measure insect noises has been around
since the early 1900s, it did not become reliable until the 1980s. This
invention is one of the first that can easily be used in the field.
Full-grown larva of
black vine weevil, Otiorhynchus sulcatus;
actual size about 6 mm
or 1/4 inch. (K11132-1)
Previous versions weighed 15 pounds and could not be used
in the rain. The new one is lighter, can filter unnecessary noise, and
is more durable. Unlike other models, this one doesn't need a professional
technician to operate it. "The device is very user friendly,"
The person doing the listening wears headphones and places
a wand-like device on a very large nail that has been placed in the
root ball of the plant. Another handheld component then amplifies and
measures the sounds. The weevil makes a distinctive clicking noise as
its body vibrates off the soil.
Fisher is still working with the instrument to see which
time of year is best to do the tests.By David Elstein, Agricultural
Research Service Information Staff.
This research is part of Crop Protection and Quarantine,
an ARS National Program (#304) described on the World Wide Web at www.nps.ars.usda.gov.