All Taxa Biodiversity Inventory - Great Smoky Mountains National Park


Diptera - Fruit flies

Euaresta bella (Loew)

Photograph by Jeffrey Lotz - FDACS/DPI















Fruit flies



Size: Small, about 4-5 mm long from antennae to tip of wings.
Wing pattern: Black background with thin black rays radiating to the edges and variously
Body color: Thorax with brown to grayish or black background with numerous, fine, golden setae. Abdomen reddish-brown.
Oviscape: Black, 0.5-0.6 mm long, weakly tapered to blunt tip.
Male genitalia: Black, conspicuously broader than preceding abdominal segment.


 Euaresta bella, Adult, The Purchase, August 2002, Photograph by Jeffrey Lotz - FDACS/DPI.

Similar species:

Euaresta festiva is larger and more yellowish in body color than E. bella. These species may occur together where their hosts co-exist, for example near Metcalf Bottoms.

(GSMNP in green)

Widespread throughout the U.S.



 In Park:

Metcalf Bottoms and The Purchase. A previous record from Smokemont (Blanc 1995).



 Ambrosia artemisiifolia L. (Asteraceae) (common ragweed) is the only known host.



 Old fields and disturbed areas over a wide range of elevation. Generally distributed wherever the host is found.


Adults present during late summer to early fall in GSMNP. A summer-fall flight time was also 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. Often they probe without laying eggs and 30% of probed flowers are damaged and sterilized (Batra 1979). Larvae complete development and pupate within a single achene (Novak et al. 1967). Up to 8% 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 information.

 Community Ecology:

 Numerous insects are associated with common ragweed, but their interactions with E. bella 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


Jeffrey 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.
Blanc, F. L. 1995. Accumulated collection data on the Tephritidae of North America north of Mexico. Unpublished database. Part of data used for distribution maps in Foote et al. 1993.
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 additional information on this species visit the Euaresta bella page at the USDA Systematic Entomology Laboratory website.


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: September 3, 2002