Scientists Find How Density of Ants Relates to Ecosystem

Scientists at the University of Exeter found that ants have two great effects on the environment, by being both ‘ecosystem engineers' and predators. The scientists studied the impact of different combinations and densities of black garden ants (Lasius niger) and common red ants (Myrmica rubra). They found the ants affect the nutrients within the soil as they move the soil for colony construction and the ants prey on a wide range of other animals, including larger animals. These scientists found that a low population of ants within an area, increased the diversity and density of other animals, particularly herbivores and decomposers. However when the ants were at higher populations, they had no or opposite effects on the presence of other animals. This demonstrates the possibility that ant predation could cause a decrease in other animal species, which could have a negative effect on the ecosystem.

Photo of fire ants. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Subterranean Termite Swarming Season

For one subterranean termite genus, Reticultermes, the months of February through May means swarming season in Texas. These winged reproductive swarmers emerge from the colony in order to fly and begin a new colony. Subterranean termites are social insects that live in colonies underground, in order to avoid sunshine and outside air. Their caste system consists of workers, soldiers, and reproductives. The workers build shelter tubes from tiny pieces of soil, wood, and debris that are glued together using secretions and fecal material. These shelter tubes form an extensive tunneling system underground that allows them to carry resources back into the colony. The soldier termites protect the colony from other insect intruders and the reproductives are responsible for starting a new colony.
Termites feed on cellulose material, including roots, paper, and cardboard. They are important to our ecosystem, since they decompose cellulose; however, they become economic pests when they invade structures. Termite damage may be detected by the presence of mud tubes, damaged wood, and the swarming of winged reproductive termites.

Some Preventative Practices:
1) Any stumps, scrap wood, grade stakes, cardboard boxes, and newspapers found around structures should be removed.
2) Firewood, landscape timbers, and compost piles should not be stored around foundations of structures.
3) Minimize moist areas by grading the soil and installing gutters to allow water to drain away from the building.

Some Chemical Approaches to Termite Control:
If termites are found around structures, some measures can be taken, such as applying liquid insecticides and/or installing baiting systems. When soil insecticides are applied, they provide a continuous chemical barrier around the structure. There are both repellent and non-repellant liquid insecticides that can be applied around structures. The termites attempting to tunnel into the chemically treated area will either be killed or repelled, thus preventing them from entering the structure. Termite baiting systems can also be installed above ground and/or in the ground around structures. The bait stations usually contain a piece of untreated wood until termite activity is detected. Once termite activity is observed, then the untreated wood is replaced with a plastic tube containing an insecticide within a cellulose matrix. The worker termites feed on the cellulose matrix and then exchange it with other members of the colony. This results in death of the colony members.

Photo of termite damage. Photo by Center for Urban and Structural Entomology, Texas A&M University.