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Ants And Aphids

An intimate, symbiotic relationship exists between ants and aphids. They are often compared to cattle, with the ants acting as protectors and ranchers. What aphids have that ants want is something called honeydew, a sweet substance that is excreted by aphids through their anus and contains surplus sugar from the aphid's diet. Ants protect aphid eggs during the winter, and carry the newly hatched aphids to new host plants, where the aphids feed on the leaves and the ants get a supply of honeydew.

Because of their ability to reproduce rapidly and grow large colonies, their feeding on plants causes yellowing, stunting, mottling, browning, and curling of leaves, as well as inhibiting the ability of the host plant to produce crops. Infestations by aphids can cause plants to die, and the insects can carry other diseases, such as plant viruses, from one plant to another. Their saliva is also toxic to plant tissues. Among the biological controls of aphid infestations in agriculture and horticulture are lacewings, sometimes called "aphid lions," lady beetles or ladybird beetles (ladybugs), and syrphid flies. Pesticides, including diazinon, disyston, malathion, nicotine sulfate, and others, are also used to control aphids. On a smaller scale, some gardeners control aphids by simply washing them off with a spray of soapy water.



Arnett, Ross H. American Insects. New York: CRC Publishing, 2000.

Hubbell, Sue. Broadsides from the Other Orders: A Book of Bugs. New York: Random House, 1993.

Imes, Rick. The Practical Entomologist. New York: Simon & Schuster, 1992.

McGavin, George C. Bugs of the World. Blandford Press, 1999.

Vita Richman Neil Cumberlidge


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—A hard, shell-like structure that serves both to protect the vital organs of animals without an internal skeleton and to support their muscle systems.


—A sweet substance excreted by aphids that ants need.


—Asexual reproduction without the fertilization of eggs.


—Openings that lead to a system of tubes that supply air to insects.


—A biological relationship between two or more organisms that is mutually beneficial. The relationship is obligate, meaning that the partners cannot successfully live apart in nature.

Additional topics

Science EncyclopediaScience & Philosophy: Anticolonialism in Southeast Asia - Categories And Features Of Anticolonialism to Ascorbic acidAphids - Reproductive Habits, Ants And Aphids