National Park Service U.S. Department of the Interior

Klamath Network Featured Creature January 2010

Rat-Tailed Maggot ( tenax)

Reproduction and Adult Stage: Reproduction of the rat-tailed maggots FIELD NOTES: occurs in the adult stage, where they have

much more aesthetically pleasing common General Description: names: “Flower ,” “Hover Flies,” or The “rat-tailed maggots” are the aquatic “Drone Flies.” As adults, the flower flies larvae of certain genera of the Dipteran are important as , second only to family Syrphidae. This apt, imaginative and . common name is an appropriate description of a long, telescoping The adult stage of Eristalis tenax is an respiratory siphon which can extend excellent example of , closely several times their body length. Another resembling the honey in color, size, common name for them is “mousies,” and behavior. However, as a “True ” of and they are common live bait for ice the order Diptera, they only have two fishing in the Midwest. wings, whereas bees and wasps will have

four wings. The rat-tailed maggot is an air breather, using their namesake organ to access open air, even though the body is fully Distribution: submerged. Since their respiration is not Eristalis tenax is wide spread, from dependent on the oxygen content of the northern regions in Alaska, south to water, they can survive anoxic, and Florida. World-wide, it can anaerobic conditions. even be found in .

Habitat: Where to see it in the Klamath Descriptions of the favored of Parks: rat-tailed maggots generally include The aerial dispersal, ability to live in such colorful words as: Putrid, Filthy, marginal , and cosmopolitan Stagnant, Liquid Manure, and distribution suggest that these could be Excrement-laden. In short, these larvae found in all of our Klamath Network are so tough, that they can live in very Parks, even in our park not normally marginal habitats, which few other associated with aquatic , the arid invertebrates can colonize. They have Lava Beds National Monument. even been reported in petroleum-laden pools, where their siphon can penetrate More Information: the oil layers, allowing them to breathe. Swan, L.A. and C.S. Papp. 1972. The common insects of . Harper Although the above habitat descriptors and Row, Publishers. New York, NY. give us a sense of pollution, note that many naturally occurring marginal Usinger, R.L. 1956. Aquatic insects of habitats can fit the requirements of the California. University of California Press, rat-tailed maggots, such as temporary Berkeley, CA. pools in the middle of the forest, or moist decaying wood. However, when Bonus section: NOT FOR THE FAINT we find them in ecosystems not OF HEART: This species is also reported normally expected to be “putrid,” they to have infected the intestinal tracks of serve as excellent indicators of Images of Eristalis sp. Top photo from collection and humans, somehow passing through the courtesy of Dr. Mark Vinson, USGS. Middle images ecosystem impairment. digestive tract unharmed. When getting to from http://bugguide.net/node/view/26679/bgimage. Bottom image of adult from the colon, the respiratory siphon allows http://nathistoc.bio.uci.edu/diptera/Eristalis.htm them access to an “airway.”