Mutant Strain Of Deadly
Fire Ants On The
March Across America
The London Telegraph
DEADLY fire ants are on the march across America after developing a mutant strain that can survive winters. The ants, whose venom has killed dozens of people in the southern states, also cause damage to crops, lawns and electrical equipment estimated at £1.5 billion a year. In the past, they could survive only in the humidity of the American south. Now they are heading north.
Their most recent victim was a woman in a nursing home in Jackson, Mississippi who died in September after the ants swarmed over her body, riddling her with stings.
Children in the suburban south are regularly stung. Most come away with a painful blister which subsides after a few days. Two in every 100, however, need immediate hospital treatment or they die. In the American south-east, the ants have overtaken wasps and bees as the major source of allergic insect reactions.
A hybrid strain that seems able to withstand cold weather has now been found in California, far from the ants' traditional areas, which stretch from Florida to Texas. The insects, whose mounds pop up from the ground after rain, are believed to have crossed from South America to Alabama in the early part of this century.
They travel across country on livestock or bundle into giant balls that can float down flooded rivers. After swarming on to a human victim, they are believed to emit an alarm pheromone, at which point they all sting at once, causing maximum pain. Most fatalities occur in those who cannot escape: elderly people, babies in cribs or people who suffer from dementia.
Now scientists are commandeering the ants' natural enemies from South America. They have imported a parasitic fly that can wriggle inside the quarter-inch long ant and lay its egg. When the larvae hatch, they move into the ant's head where they feed until the head falls off. Faced with the fly, the normally fearless ant recoils and races towards its mound.
The scientists are also testing a micro-organism that occurs naturally in Brazil, which, if implanted into a fire ant nest, sickens the ants, slows their reproduction and causes the queen ant to produce fewer eggs.