Cross and longitudinal sections of
the granulovirus, a pathogen of potato tuber moths.
Insect Virus Could Spell Doom for Potato
Pest By Jan
Suszkiw August 25, 2006
The potato tuber moth is quickly earning a bad reputation among potato
growers in Washington, Oregon and other Northwest states. But like an
over-exposed Hollywood star, this pest is destined for a serious meltdown.
It won't come from fame, though, but from exposure to a type of insect
pathogen called a granulovirus. In July, Agricultural Research Service (ARS)
scientists in Wapato, Wash., began testing the granulovirus' potential to
biologically control the moth's caterpillar stage, which feeds on both the
potato plant and its tubers.
Once ingested, the granulovirus could put a stop to such feeding by
liquefying the caterpillar's tissuesstarting from the inside outin
10 to 20 days. Except for a few other potato-tuber-moth relatives, this highly
specific pathogen doesn't infect other insects, or humans and other mammals,
Lacey. He's an entomologist with the ARS
Agricultural Research Laboratory, Wapato.
There, Lacey and ARS colleague entomologist Steven Arthurs are
studying ways to biologically produce and formulate the granulovirus as a
biopesticide product that potato growers could spray on their crops before
harvest, when synthetic insecticides aren't used. Another potential use is on
stored potatoes. Lacey is leading the studies as part of a three-year
cooperative agreement involving scientists at Oregon State University's
Research and Extension Center, and the
Center in Lima, Peru. The Washington
State Potato Commission is helping fund the effort.
Although the granulovirus is already used in other countries to
protect stored potatoes from infestation, it's not commercially available to
U.S. growers, and limited research has been done investigating the pathogen's
Besides the granulovirus, which is now being field-tested under a
federal experimental-use permit, Lacey's group is also examining the biological
control potential of the bacterium Bacillus thuringiensis, two species
of insect-specific nematodes, and the fungus Muscodor albus. In earlier
potato-storage studies at Wapato, Muscador's release of natural volatile
compounds killed both adult potato tuber moths and their larvae.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.