Tortoise Beetle Might Do the Trick
At the South American Biological Control
Laboratory in Buenos Aires, Argentina, ARS
researchers led by Daniel Gandolfo think
they may have a way to halt the dramatic
spread of tropical soda apple (TSA). The
Gratiana boliviana, 5- to 6-millimeter-long
tortoise beetle, appears to have the fecundity,
longevity, and host-specificity to make
it an ideal natural control agent.
In both larval and adult stages, G.
boliviana beetles chew holes in the
upper leaves of the plant, significantly
reducing the weed's survivability.
However, before researchers could apply
for U.S. release they had to make sure that
G. boliviana would not devour nontarget
“Since TSA is related to several
widespread crops, a risk assessment had
to be performed for them, particularly eggplant,
Solanum melongena, the most defenseless
crop in the family,” says Gandolfo.
Recent studies in Argentina and quarantine
facilities in Gainesville, Florida, have
eliminated eggplant as a suitable host for
The tiny, iridescent beetles—of turquoise
and gold—will soon be put to the test
in rangelands and improved pastures across
Pennsylvania, the southern United States,
and Puerto Rico. — By Jesús
García, formerly with ARS.
NOTE: The TSA leaf beetle was approved
for field release in Florida on May 7, 2003.
The initial release of G. boliviana in Florida
began in May 14 in Polk County. Subsequent
releases were made on June 17 in Alachua
County, September 5 in Hendry County, and
November 11 in Sumter County. – University
of Florida, Cooperative Extension Service
JASPER, Texas, July 8, 2004 (ENS):
A thorny weed some call the "plant from hell"
has been found on a private ranch in East Texas. The
plant, known as the tropical soda apple, is on the federal
noxious weed list.
It can quickly take over pastures, first displacing
the grass, then the cattle, said Dr. Mary Ketchersid,
Texas Cooperative Extension pesticide safety specialist.
Ketchersid said she does not want to sound like an
alarmist, but the weed has caused economic disaster
for agricultural producers in other states.
Native to Argentina and central Brazil, the perennial
weed produces small fruit about inch in diameter, dark
green with light green stripes.
When mature, tropical soda apple can reach 6 feet in
height and have a stem 1 inch in diameter.
Resembling small striped watermelons, the fruit or
"apples" contain more than 100 seeds and are
readily eaten by cattle and wildlife, including deer,
wild hogs, raccoons and birds. The seeds, which are
not digested, may be quickly distributed over a wide
In the United States, it was first found in Florida
and infested areas there increased from a couple of
thousand acres to more than a million in six years.
The weed has taken over hundreds of thousands of acres
in Florida, Alabama, Arkansas, Georgia and Louisiana.
"I think we need to be scared," Ketchersid
said. "People need to be watching for it,"
The hope is, Ketchersid said, to contain the weed to
the original site. But she warns that since it is a
perennial, eradicating it is not likely to be easy.
"We have been trying to eradicate mesquite since
before the 1960s, and it is still the subject of brush
control programs," she said.
Landowners are advised to act promptly and enlist the
help of specialists if they suspected they have the
"The landowner told us in a meeting that he had
probably brought it in with a load of Louisiana hay
in 1998," Ketchersid said. "He has been trying
to control it himself for years, and now it is a real
Many treatments are likely to look good at first, killing
most of the weed's foliage. But with perennials, if
the herbicide isn't carried to the roots, the plant
may soon recover by the next growing season.
"The control can look really good right now, but
in the next year, if the roots have not died, the plant
can come back," Ketchersid said.
By the time the task force learned about the Jasper
infestation, it was too late in the season to follow
these recommendations, said Dr. Paul Baumann, Extension
weed control specialist and another member of the task
"We know what works in other states, but we do
not know for certain what works here on our soils and
environment," he said. "We want to find the
most economical solution, one that uses the least amount