Invasive “crazy ants” are rapidly displacing fire ants in areas
across the southeastern US by secreting a compound that neutralizes the
other’s venom.
It’s the first known example of an insect having the ability to detoxify another insect’s venom, researchers say.
The crazy ant invasion is the latest in a series from the southern
hemisphere and, like its predecessors, will likely have dramatic effects
on the region’s ecosystems. Known for their painful stings on humans
and other animals, fire ants dominate most ant species by dabbing them
with powerful, usually fatal venom. A topical insecticide, the venom is
two to three times as toxic as DDT on a per weight basis.invasive files
But when a crazy ant is smeared with the venom, it begins an
elaborate detoxification procedure—it secretes formic acid from a
specialized gland at the tip of its abdomen, transfers it to its mouth,
and then smears it on its body.
In lab experiments, exposed crazy ants that were allowed to detoxify
themselves had a 98 percent survival rate. This chemical counter-weapon
makes crazy ants nearly invincible in skirmishes with fire ants over
food resources and nesting sites. The research is published in the
journal science express.
“As this plays out, unless something new and different happens, crazy
ants are going to displace fire ants from much of the southeastern US
and become the new ecologically dominant invasive ant species,” says Ed
LeBrun, a research associate with the Texas invasive species research
program at the Brackenridge Field Laboratory at the University of Texas
at Austin.
Researchers have previously reported that where crazy ants take hold,
the numbers and types of arthropods—insects, spiders, centipedes, and
crustaceans—decrease, which is likely to have a ripple effect on
ecosystems by reducing food sources for birds, reptiles, and other
animals. They also nest in people’s homes and damage electrical
equipment.
