Symbiotic Relationships

• Ant/Ant: Some species of ants are extreme in their dependence upon other ant species. For example, the ant Tuleutomyrmex schneidere spends almost its entire life riding on the backs of host ant species. They seem to contribute nothing to the hosts, but are tolerated and even fed. Slavemaker ants (Formica subintegra, for example) steal brood from other colonies and return the brood to develop and serve the Slavemaker colony. The slaves are absolutely dependent in that if they don't work, they don't get fed. Other ants work together as with the Crematogaster limata parabiotica and Monacis debilis. These ants have their nests close together and share the same foraging trails. Camponotus has also been seen giving food to the Monacis workers.
  
  
• Ant/Other Insect: These relationships are many and diverse, ranging from commensual to parasitic. Aphids and ants have many species relationships where both the ants and aphids benefit (mutualism). Aphids secrete honeydew and amino acids through their anus. The ants eat or store the honeydew. The ants sometimes incorporate the aphid territory into their own territory, which allows easier access to the aphids and affords the aphids protection by a greater number of ants. The honeydew sometimes contains chemicals that are purposely directed at attracting ants. The aphids sometimes release chemical signals that warn other aphids of a predatorial attack and also alert the ants so they can attack the invader.
  
  
• Ant/Plant: These relationships are also known to be abundant. Some carnivorous plants allow ants to hunt herbivores on them. In turn, the ant protects the plant from the herbivores eating their plant tissue. Many plants have extrafloral nectaries on various parts of the plant. These are nectar- producing structures not associated with flowers. The ants are attracted to the plant where they can obtain small amounts of sugar and, in turn, defend the plant from other insects. Ants provide this same service of eliminating herbivores to many plants. Other ants confiscate plant parts to grow fungus on in fungus gardens deep with colonies. These leaf cutter ants process the leaves and use the fungus grown upon the leaf material for food. Sometimes ants live in tree hollows and have no effect on the plant at all. Harvester ants do a great service to plants by collecting and transporting seeds. In one case, the ants eat a small part of the seed and leave the rest of the still- viable seed to germinate.

Science Education Connection Department of Biochemistry The University of Arizona Tuesday, April 29, 1997 warder@u.arizona.edu http://biology.arizona.edu/sciconn/lessons/shindelman/ All contents copyright © 1997. All rights reserved.