Fire Ants by Stephen Welton Taber, Texas A&M University Press,
$29.95, ISBN 0890969450
EACH sting from a fire ant feels like a burning match held against your skin.
That鈥檚 how they got their name. But an encounter with these creatures could
involve more than a few nasty bites. Fire ants live in huge earth mounds.
Stumble into one of these, and the dozens or hundreds of stings can cause
anaphylactic shock in sensitive victims, even death.
The world swarms with invasive species, from the dread zebra mussel infesting
North American lakes to the brown tree snake that devastated the birds of
Pacific Islands. But the fire ant is in a class of its own, as Stephen Taber
graphically reveals in Fire Ants.
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It鈥檚 the first creature to force a major sport to change its rules. Golfers
in some parts of Texas are now permitted to move the ball if it lands too close
to a fire ant mound. Its venom is unique among animals. It is composed of a
group of alkaloids鈥攖he solenopsins鈥攚ith only a tiny protein element.
This mixture zaps through insect exoskeletons like nobody鈥檚 business, but is
also extremely effective against mammals, fish and birds.
This makes Solenopsis invicta, the red imported fire ant, otherwise
known as RIFA, the deadliest invasive insect in the US. Of the 14 million
Americans stung in 1984, a hundred died. And the problem is getting worse as the
fire ants increase their range. They have already captured the South, and are
moving west and north at roughly 50 kilometres a year. The ant may eventually
cover about half the US and much of Mexico.
Destructive they may be. But looking at fire ants from a less human-centred
perspective reveals a very different creature鈥攐ne that has adapted
splendidly to human disruption of the environment, displays interesting
evolutionary traits, and is a salutary rebuke to our pretensions to control our
surroundings through chemistry.
The first invading fire ants鈥攖he black imported fire ant, or
BIFA鈥攑robably arrived in Mobile, Alabama, in 1918. At the time it came
ashore, probably from a ship loaded with lumber or fruit from Argentina, it
found hundreds of species of native ants, including three fire ant species
native to North America. But BIFA quickly outcompeted its rivals, expanding east
to Florida, and west to Texas.
Taber speculates that this success was due to BIFA鈥檚 tolerance for disturbed
land found beside roads, in cities and pastures. Native ants were adapted to the
forests that had covered the American South until Europeans came. And they were
not equipped to see off invaders.
BIFA got lots of attention from farmers and entomologists, but around the
Second World War, several colonies of RIFA landed in Mobile. More prolific,
bellicose and adaptable than their cousins, RIFA wiped the floor with BIFA. Now
confined to a small remnant of its range, BIFA and all the native fire ant
species are now 鈥渆ndangered鈥�, as Taber ironically notes.
Fire Ants offers encyclopedic coverage of all the species known in
North America, and some good chapters on the species native to both North and
South America, as well as their little-known origins and evolution. But for many
readers, the most riveting parts of the book will no doubt be those devoted to
their 鈥渕edical importance鈥� and the failure of 鈥渃hemical control鈥�.
Taber summarises the voluminous literature on attempts to control fire ants
with chemicals. It makes for sobering reading. Nothing worked鈥攆rom the
arsenic, DDT and leaded gasoline of early years, to the hormone analogues and
species-specific toxins of today. Harvard entomologist E. O. Wilson called the
massive campaign in the 1960s against the fire ant 鈥渢he Vietnam of entomology鈥�,
a reference to the poison Mirex that was dumped on the ants from the air.
Although each new pesticide would wipe out 98 per cent of fire ants in an area,
it would kill every other ant, too. Five years later the place would be
recolonised, this time by fire ants alone.
Inevitably, other wildlife was affected by the pesticides, forcing an end to
their use. RIFA, Taber concludes, is here to stay.
Fire Ants boasts dozens of black and white photos, several maps,
many line drawings of ants and other insects, an index, a long bibliography, a
glossary of terms and a key to species. Know your enemy is, after all, an
imperative in any war.