Tiny Ants Wield Mighty Clout
In West Germany, stringent laws and ant-protection societies watch over Formica Polyctena
BIELEFELD, WEST GERMANY
EIGHT hikers move slowly through a forest in central Germany, quietly searching. They could easily be mistaken for bird watchers. But instead of gazing up through binoculars, this group peers down through tiny magnifying glasses. ``Watch out! Ant road!,'' calls out someone ahead, and the group takes one giant step to the left. A closer look at the footpath shows it to be a miniature, bustling autobahn. Ants cruise determinedly along a path cleared not by thick-soled hiking shoes but by a near-constant ant sweeping and cleaning campaign. The hikers, members of the German Ant Protection Society (DASW is its German acronym) have found what they are looking for.
In West Germany, some species of ants are protected by law. Josef Kissener, the DASW's chairman for the state of Rhineland-Pfalz in south-central Germany, says 85 laws at the state and federal levels protect various types of ants and their habitats. Forest ants are among the most protected: Anyone convicted of damaging one of their huge nest mounds, or moving a colony without permission, could be fined up to DM 500,000 ($312,000).
Endangered ants? Voluminous legislation? Steep fines? The casual observer may be tempted to dismiss ant protectors as a crank fringe group. But certain species of wood ants - such as the Formica Polyetena - are threatened. Efforts to stem the destruction of their mounds and habitat have increased as scientists discover more about their key role in improving the health and balance of forest life.
``There is no question that the Polyetenae are beneficial to a forest,'' says Dr. Bert H"olldobler, professor of zoology at W"urzburg University. This rather ordinary looking reddish-brown ant has the nickname ``policeman of the woods.'' It wipes out nearly all insects that are harmful to trees.
``One ant mound can get rid of up to 100,000 caterpillars in a single day,'' claims Dr. H"olldobler. Polyetena colonies are typically made up of many nest mounds scattered throughout a forest. They act as a check against tree parasites. They also begin a chain reaction of events that attract more life into a forest.
The Polyetena ants maintain herds of tree sap-sucking aphids, which they milk. The aphids in turn stimulate the trees to produce sap. Trees produce more sap than the aphids can use, and other insects - up to 250 species - live off the excess. The bumper crop of insects attracts spiders, birds, and bats - all necessary for the ecological health of a forest.
The Polyetena ants have very few natural enemies. Insects and birds are repelled by the formic acid the ants spray in self-defense. What is there, then, to disrupt this well-ordered ant system?
``A great deal of the damage to Polyetena? mounds comes from negligence,'' says H"olldobler. Many of the nest mounds are located near pathways or woodland roads. A carelessly placed walking stick, boot, or tire can seriously damage the large, but delicate, nests. The warm nests protect the ants during their winter hibernation. In the later part of summer, much of the ants' activity is devoted to making their mounds watertight. If nests are disturbed, it can ruin the ants' chances to survive the winter. But it's not just negligence that causes damage.
``People used to plunder ant mounds for larvae,'' says Mr. Kissener of the Rhineland-Pfalz DASW chapter. ``Fishermen would use them for bait and pet owners would use them for birdseed.''
But even if absent-minded and deliberate destruction of ant mounds were to completely stop, ants would still need the help of an ant protection campaign, say members of the DASW.
The German Ant Protection Society was formed 22 years ago by Karl G"osswald, a professor of zoology at the University of W"urzburg. The DASW - an organization operating mostly on volunteer help of its members - works to protect existing ant colonies and their habitats.
Members erect what look like chicken-wire tepees over ant nests. The ants easily crawl through the wire but birds and burrowing animals are kept out. The wire shelters make the nests more noticeable and less likely to be walked on accidentally.
Some of the older mounds can grow very large - up to several feet high and 10 ft. around.
The more ambitious DASW activities involve transplanting colonies of ants to new woods. More than 30 years ago DASW founder Dr. G"osswald experimented with moving ants into woods with no ants. The intent was to increase the number of ants and use them as a natural form of pest control.
``Only a third of the ant mounds survived,'' says current DASW president Mr. Premper. But something was learned: Colonies moved into groves planted with just one type of tree did not do as well as colonies in areas with varied vegetation.
The work of DASW members and many ant specialists seems to suggest that because they are good for ants, mixed culture forests - woods with many different types of trees in them - may be healthier for trees as well. In the long run, ant protection may also equal forest protection.