Image Number K7722-1

A Brazilian fly makes fire ants literally lose their heads. ARS scientists hope to import it for tests in the United States, where fire ants lack natural enemies. They feed on crops and sting people and animals in 11 states. Beheading a live host-a rarity among parasitic flies-is standard procedure for Pseudacteon flies. And they attack only fire ants. The female deposits an egg on or in a fire ant's body. Weeks later, a maggot has moved through the unlucky ant's neck into its head-and eaten the contents. The head falls off after an enzyme-made by ant or maggot (scientists don't know which)-dissolves its connecting tissue.

Photo by Sanford Porter.

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