All Taxa Biodiversity Inventory - Great Smoky Mountains National Park


Diptera - Fruit flies

Euaresta festiva (Loew)

Photograph by Jeffrey Lotz - FDACS/DPI















Fruit flies




Size: Approximately 6-7 mm long from antennae to tip of wings.
Wing pattern: Black background with thin black rays radiating to the edges and variously shaped and sized hyaline areas interiorly and posteriorly.
Body color: Thorax and abdomen orangish to reddish-brown with numerous, fine, yellowish setae.
Male genitalia: Black, broader than preceding abdominal segment.
Oviscape: Black, relatively long at about 0.95-1.2 mm, weakly to strongly tapered to blunt tip.


 Euaresta festiva Adult female, Oconaluftee, August 2002, Photograph by Jeffrey Lotz - FDACS/DPI.

Similar species:

 The only other species in this genus found to date in GSMNP, E. bella, is considerably smaller than E. festiva and not so brightly colored. These species may occur together where their hosts co-exist, for example near Metcalf Bottoms. Other mottled-wing tephritid flies such as Neotephritis and Tephritis are superficially similar.

(GSMNP in green; red dots indicate localized distribution in state)

Widespread in northern and central United States west to Idaho; in the eastern U.S. Euaresta festiva reaches its southernmost distribution in the southern Appalachian Mountains.



 In Park:

Metcalf Bottoms and Oconaluftee.



 Restricted to Ambrosia trifida L. (Asteraceae).



 Low to high elevation, open and sunny old fields, grassy balds, meadows, and streamsides wherever the host occurs.


 Adults present during mid to late summer in GSMNP. A similar flight time was reported in Ohio, where populations are univoltine and larvae develop and overwinter in the seeds, followed by pupariation in the spring (Foote 1965).

 Breeding and Courtship:

Reproductive behaviors are complex. Activities take place on the host plant, and they include male territoriality and elaborate courtship activities such as wing-waving and "kissing" (Batra 1979).

 Oviposition and Immature Stages:

Females oviposit into female flowers. Larvae complete development and pupate within a single achene (Novak et al. 1967). Up to 24% of seeds in host populations in Ohio were reported destroyed by larval feeding (Foote 1984). Immature stages were described by Foote (1965).

 Predators and Parasites:

 No specific information.

 Community Ecology:

 Numerous insects are associated with giant ragweed, but their interactions with E. festiva have not been investigated.


Populations of this fly depend on maintenance of its host plant populations, which, in turn, require regular disturbances to maintain open meadows and edges along forests and roadsides.

 Special Protection Status:

- Rangewide: None

- In Park: All plants and animals are protected within the Great Smoky Mountains National Park. Collection requires a permit which is usually granted only for research or educational purposes.



Gary J. Steck, Ph.D., Florida State Collection of Arthropods, Gainesville
Bruce D. Sutton, Florida State Collection of Arthropods, Gainesville


Jeff Lotz, Division of Plant Industry, Florida Department of Agriculture & Consumer Services, Gainesville
Gary J. Steck, Ph.D., Florida State Collection of Arthropods, Gainesville

Web Page Development:

Bruce D. Sutton, Florida State Collection of Arthropods, Gainesville



Batra, S.W.T. 1979. Reproductive behavior of Euaresta bella and E. festiva (Diptera: Tephritidae), potential agents for the biological control of adventive North American ragweeds (Ambrosia spp.) in Eurasia. New York Entomological Society 87: 118-125.
Foote, B.A. 1965. Biology and immature stages of eastern ragweed flies. Proceedings North Central Branch, Entomological Society of America 20: 105-106.
Foote, B.A. 1984. Host plant records for North American ragweed flies (Diptera: Tephritidae). Entomological News 95: 51-54.
Foote, R. H., F. L. Blanc, and A. L. Norrbom. 1993. Handbook of the fruit flies (Diptera: Tephritidae) of America north of Mexico. Cornell University Press, Ithaca, New York, 571 pp.
Novak, J.A., W.B. Stoltzfus, E.J. Allen, and B.A. Foote. 1967. New host records for North American fruit flies (Diptera: Tephritidae). Proceedings Entomological Society Washington 69: 146-148.

For further information visit the Euaresta festiva page at the Systematic Entomology Laboratory, USDA.


hyaline - Clear or transparent.
oviposition - The act of laying eggs.
oviscape - The hardened sheath enclosing the needle-like ovipositor, or egg-laying structure, of female tephritid flies.
puparium - The hardened, cocoon-like structure, unique to Diptera, which develops from the cast 3rd instar skin, within which metamorphosis from pupa to adult takes place.
univoltine - Having one generation per year.

Please send any questions or comments to G. J. Steck or B. D. Sutton

Last Updated: October 18, 2002