Keep the Good Bugs Down on the Farm
Sitting on Gwendolyn Ellen's desk among the stacks of papers, grant proposals,
and reference books is a silver dollar-sized black beetle with shiny antennae
and fang-like mandibles. "Isn't he beautiful," she says with an enthusiasm
that can't be faked.
Predatory ground beetles, like the Carabus on Ellen's desk, are beautiful—in
their own way. They fill a niche in the agricultural landscape where they prey
upon invertebrates, including many garden and farm pests. However, such beneficial
insects may be absent from farms where vital habitat is missing or where improper
use of pesticides has eradicated them.
"Just as it's important to preserve land for wildlife and bird populations,
it's also important to create habitat for beneficial insects," Ellen said.
To help keep good bugs on Oregon farms, researchers at Oregon State University
are working with farmers to encourage insects that pollinate crops or keep
pests in check. The OSU Farmscaping for Beneficials Project helps farmers work
their land in a more sustainable manner, which can mean everything from using
fewer pesticides to changing soil tilling practices. The researchers offer
options that can be individually tailored to each farm, said Ellen, who manages
the OSU project. Options could include growing a hedgerow on the edge of a
field or establishing a beetle bank.
Beetle banks are strips of land between cultivated rows that are left untilled
from year to year. Their matted and decomposing grasses provide hiding places
for many beneficial insects. "The bank acts as a beetle hotel, providing
a dry, undisturbed environment where predacious ground beetles can overwinter," said
Paul Jepson, director of OSU's Integrated Plant Protection Center, the project's
home base. In the spring, the beetles emerge from the banks and disperse into
the field, actively searching for prey. Without such refuge, beneficial beetles
can take longer to appear in the spring and may lag behind pest populations.
"Farming is very dynamic," said Ellen. Fields can change multiple
times through a season. And because large tracts of farmland can isolate crop
fields from the natural habitats for beneficial insects, places that are purposefully
built to provide stable refuge for good bugs can play an important role in
a farm's vitality and success.
"Without drastically changing how they grow their crops, both organic and
conventional farmers can create specific insect habitat that does not currently
exist on most farms," said Jepson.