A Farewell Party for Corn Earworm Pests
February 11, 1999
Like catnip that tantalizes cats, scents from plant flowers lure corn
earworm or bollworm moths into a partying mood. The moths are attracted to
their favorite foods by zeroing in on plant scents. In the South, the feast
begins with corn but soon the moths move into cotton. Each year, these pests
cost farmers nearly $2 billion in losses and chemical control expenses.
Now scientists are throwing a farewell party for the moths. In a field
study, entomologist Juan Lopez and agricultural engineer Kenneth R. Beerwinkle
at College Station, Texas, gave the insects a lethal dish that killed 730 moths
in a 54-foot row of corn. Lopez and Beerwinkle work for the
Agricultural Research Service, chief
research agency of the U.S. Department of
In search of food, the insects were drawn to the artificial smell of the
night-blooming Gaura plant. The moths feasted at sunset for a few hours
and ate a fatal dose of carbaryl, a commonly used household insecticide. More
dead moths were found on the second night after treatment.
Not all the insects that died were found intact. On the morning after
treatment, the researchers found wings without bodies, which they estimated to
represent another 150 moths. These insects were likely eaten by predators. The
second night after treatment, the researchers found more dead moths.
Females ready to lay eggs in the silks of sweet corn or in cotton are
especially attracted to the aroma. But in this study, both sexes of several
insect species were attracted. Other ARS researchers at Charleston, S.C., and
Ames, Iowa, have tested the attractant against melonworm, pickleworm, cabbage
and soybean looper, and European corn borer.
ARS has applied for a patent on the attractant, which can be used optionally
with a feeding stimulant and insecticide. The researchers are developing a
cooperative research and development agreement with an industry partner to
commercialize the technology.
Scientific contact: Juan D. Lopez, Jr., ARS
Areawide Pest Management Research
Unit, College Station, Texas, phone (409) 260-9530, fax (409) 260-9386,