SUPER INVADER. A flea beetle is seen at the United States
Department of Agriculture (USDA)/Agricultural Research Service (ARS)
Invasive Plant Research Laboratory in Ft. Lauderdale, Florida.
The insect is a potential biocontrol agent that may be released
as early as next year to combat the spread of the Chinese tallow
tree. The tallow is a highly invasive tree rapidly overtaking
forests from Texas to Florida. (Gregory Wheeler/USDA via AP)
From The Asian Reporter, V27, #23 (December 4, 2017),
Flea beetle from China may help against "super
By Stacey Plaisance
The Associated Press
NEW ORLEANS — The tallow tree, a "super invader" with toxic
leaves and no natural enemies in North America, is conquering
Overtaking forests from Texas to Florida, tallows grow three
times faster than most native hardwoods, and each one casts off
100,000 seeds per year. Controlled burns haven’t stopped their
spread, nor have herbicide sprays from helicopters. Cutting them
down works only when each stump is immediately doused with
chemicals. Harvesting them for biofuel remains more a promise
than a practical solution.
Some scientists say introducing a flea beetle from the
tallow’s native habitat in eastern China may be the best
Yes, they’re aware of "nightmare scenarios" with other
non-native plants and bugs, environmental scientist Michael
But he also points to success stories, such as the aquatic
weevil that munches on giant salvinia, a floating fern from
Brazil that had been clogging waterways in Florida and Texas
until its insect enemy was brought in. The weevil underwent a
similar line of testing through the U.S. Department of
Agriculture (USDA), and like the flea beetle, the weevil spends
its entire lifecycle on one plant, he said.
"Importing an organism to help control another organism right
off the bat doesn’t sound very intuitively smart to do, but it
turns out that especially with insects and plants, they’ve
co-evolved over many millions of years, and in a lot of cases,
the insect is very host-specific," said Massimi, the invasive
species coordinator for the Barataria-Terrebonne National
Estuary Program along the Louisiana Gulf Coast.
In this case, the flea beetle (Bikasha collaris)
generally ignores other plants as it eats the roots and leaves
of the tallow (Triadica sebifera), a host-specific
tendency tested on about 150 other plant species in a decade of
laboratory work in the U.S. and China, researchers said.
The USDA’s Animal and Plant Health Inspection Service has
been working on an environmental impact assessment, which will
include a public comment period. If approved, the bugs could be
released sometime in 2018. Meanwhile, researchers in Louisiana
are studying tallows to gain a better understanding of the
beetle’s effectiveness once they are let loose.
Benjamin Franklin sent tallow seeds from London to a friend
in Georgia in the 1700s, but genetic testing cleared the
founding father of blame for the kind of tallows growing so
aggressively today — those trees were apparently introduced by
federal biologists around 1905, according to research led by
Evan Siemann, an evolutionary biologist at Rice University, that
was published in The American Journal of Botany in 2011.
U.S. Forest Service data show tallow now spreading across 10
states. Its growth nearly tripled in Texas in the last two
decades, and increased 500 percent in Louisiana, where its
higher tolerance for salinity enables it to crowd out
moss-covered bald cypress in swamps and bayous. Populations also
are up along the Atlantic coast, from Florida to the Carolinas.
"Tallows take advantage of disturbances," said Nancy
Loewenstein, an invasive plant specialist at Auburn University.
"Storms, floods, construction sites, logging sites, anything
that disrupts the environment will give an invasive like tallow
an opportunity to take over."
The help can’t come too soon for the keepers of America’s
suffering forests. Tallows grow into fully mature trees in just
three years, far outpacing native maples, oaks, cypress, and
elms. Their leaves are toxic to some animals, and they cast off
litter that changes soil chemistry and disadvantages
"Chinese tallows are very competitive, and they have no
natural predators here like in their native China," said Karan
Rawlins, an invasive species specialist at the University of
Georgia’s Center for Invasive Species & Ecosystem Health. "Very
few if any insects recognize it as a food source, so it has
basically become a super invader."
Also known as the popcorn tree and candleberry tree, tallows
have been planted widely since their first seeds arrived.
Coveted as ornamentals for their vibrant fall foliage, they have
seeds encased in small green capsules that split when ripe,
revealing a small cluster resembling a puffy kernel of popcorn.
Their oils have been used in candle and soap-making, and
beekeepers like their bountiful nectar.
But ecologists say they do more harm than good, decreasing
the diversity of plants, trees, and insects, and weakening the
food chain for birds and animals. At least one study found that
frog eggs are less likely to hatch into tadpoles in water
littered with tallow. And since the seeds don’t provide much
nutrition, Massimi said they’re like "junk food" for migrating
It’s taken more than a decade to clear tallow from just half
the 86-acre Audubon Louisiana Nature Center after floods from
Hurricanes Katrina and Rita.
"We still have 40-plus acres that are 95 percent Chinese
tallow, so we have a lot of work to do, and it’s going to be a
long, long haul," said Llewellyn Everage, who directs volunteers
and interns at the site. "This is not a quick problem to fix."