Hutchison applauds fight against invasive species on Texas lakes
U.S. Sen. Kay Bailey Hutchison told a group gathered Aug. 10 at Caddo
Lake National Wildlife Refuge near Karnack that invasive species such as
the giant salvinia are a threat to the refuge.
“While Caddo Lake is home to hundreds of animal, fish and
plant species, invasive species threaten this magnificent resource,”
said Hutchison. “We are proud to work with the Caddo Lake Institute and
Texas A&M University on creating a center of excellence focused on
eradicating invasive species.”
Hutchison’s remarks were preceded by a tour of the Center
for Invasive Species Eradication’s salvinia weevil-rearing facility
located at the wildlife refuge.
The center was developed through support from Hutchison and
is funded by Congress through the U.S. Department of Agriculture’s
Natural Resources Conservation Service. It is administered by Texas
AgriLife Research and the Texas AgriLife Extension Service and managed
by the Texas Water Resources Institute.
Giant salvinia is a free-floating aquatic fern that has
aggressively invaded Caddo Lake and other lakes in Texas. Since its
appearance on Caddo Lake in 2006, giant salvinia has been an aggressive
invader that can double in size in four to 10 days under favorable
In the center’s first project, AgriLife Research and
AgriLife Extension scientists are evaluating and demonstrating multiple
control methods—biological and chemical—and assessing their
effectiveness in killing giant salvinia, according to Lucas Gregory, the
center’s project manager.
The salvinia weevil is the plant’s only biological enemy,
according to the researchers. Scientists are raising the tropical weevil
at the rearing facility to supply weevils for release on Caddo Lake and
to serve as a living weevil laboratory, Gregory said.
“We have released more than 100,000 weevils and 300,000
weevil larvae at four locations on the lake, to date and will be
releasing more this afternoon,” he said.
Gregory said the scientists are also evaluating several new
herbicides to determine their effectiveness in controlling giant
“We plan to begin large-scale chemical treatments in late
August using proven chemicals and hope to treat upwards of 300 acres,”
Other plans include collaborating with USDA’s Agricultural
Research Service’s Biological Control Lab in Argentina to obtain
cold-tolerant weevils to see if they fare better in Caddo Lake and
establishing a weevil nursery in the upper portions of the lake that
will naturally disperse during flooding.
Scientists involved in the project are Dr. Allen Knutson,
AgriLife Extension entomologist; Dr. Michael Masser, AgriLife Extension
fisheries specialist; Dr. Paul Baumann, AgriLife Extension weed
specialist; Howard Elder, Texas Parks and Wildlife Department aquatic
habitat biologist; and Patrick Ireland, AgriLife Extension assistant and
project coordinator for the center.
Collaborators include the Caddo Lake Institute, Caddo
National Wildlife Refuge, Cypress Valley Navigation District, Texas
Parks and Wildlife Department, U.S. Fish and Wildlife Service, U.S. Army
Corps of Engineers, Natural Resources Conservation Service, Cypress
Valley Navigation District, Louisiana Department of Wildlife and
Fisheries, and Louisiana State University.
More information is available at http://cise.tamu.edu .