Diptera - Fruit flies

Eutreta rotundipennis (Loew)

Photograph by Jeffry Lotz - FDACS/DPI

Kingdom:	Phylum:	Class:	Order:	Family:
Animalia	Arthropoda	Insecta	Diptera	Tephritidae
Animals	Arthropods	Insects	Flies	Fruit flies

SPECIES DESCRIPTION

Size: 6.5-7.5 mm from antennae to tip of wings.
Wing pattern and shape: brownish-black with numerous, fine, clear speckles throughout and a narrow, unpigmented arc at wing tip broken by narrow dark rays. Wing very broad relative to length, giving rise to the specific epithet.
Body color: brownish-black.
Oviscape: similar color as body, about 0.6 mm long, tapered to a broadly truncate tip.

 Photographs:

Eutreta rotundipennis, Adult, Cades Cove, Photograph by Jeffry Lotz - FDACS/DPI.
Eutreta rotundipennis, Early season apical stem gall in Verbesina alternifolia, Cades Cove, May 2002, Photograph by Gary J. Steck.
Eutreta rotundipennis, Late season upper stem gall in Verbesina alternifolia, Cades Cove, August 2002, Photograph by Gary J. Steck.
Eutreta rotundipennis, Late season gall at leaf axial in Verbesina alternifolia, Cades Cove, August 2002, Photograph by Gary J. Steck.
Eutreta rotundipennis, Late season inflorescence gall in Verbesina alternifolia, Cades Cove, August 2002, Photograph by Gary J. Steck.
Eutreta rotundipennis, Gall in Verbesina alternifolia opened to show puparium, Cades Cove, May 2002, Photograph by Gary J. Steck.
Verbesina alternifolia, Host for Eutreta rotundipennis, Cades Cove, Photograph by Gary J. Steck.

Similar species:

 At least three other species of this distinctive genus occur within GSMNP. Eutreta rotundipennis can be easily differentiated by the broken apical hyaline area of the wing and broadly oval wing shape.

DISTRIBUTION:
(GSMNP in green, red star indicates state record only-distribution may be localized in that state)

 Pennsylvania, Maryland, Kansas, Texas (state record only), Tennessee (GSMNP) and North Carolina (GSMNP).

 

 In Park:

Cades Cove and Oconaluftee.

 

 HOST PLANTS:

 Verbesina alternifolia (L.) Britt ex Kearney and V. occidentalis (L.) Walter (Asteraceae).

 
Verbesina alternifolia
Photograph by Gary J. Steck

 NATURAL HISTORY

 Habitat:

 Open fields and peripheral woodlands containing the host(s). Generally at the lower elevations such as Cades Cove.

Phenology

 Multivoltine. Overwinters in galls in the host. By mid-May the spring generation has reached the late instar and/or pupal stage in stem/apical galls of V. alternifolia. At least one more or less distinct additional generation follows until the overwintering generation forms galls in the upper portions of V. alternifolia and V. occidentalis in August-September.

 Breeding and Courtship:

 Not observed.

 Oviposition and Immature Stages:

 Oviposition has been observed to take place during late afternoon into the upper portions of the host stem.

 Predators and Parasites:

 Heavily parasitized by hymenopteran endoparasites.

 Community Ecology:

 Other tephritid flies such as Strauzia verbesinae may share the same host plant (Verbesina occidentalis) but the relationships are unknown.

 CONSERVATION BIOLOGY:

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.

ACKNOWLEDGMENTS

 Text:

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

Photographs:

Jeffry 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

REFERENCES

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.
Steck, G. J. and B. D. Sutton. 2000. New records for Tephritidae (Diptera: Tephritidae) in Great Smoky Mountains National Park. Insecta Mundi 14: 256.
Stoltzfus, W. B. 1977. The taxonomy and biology of Eutreta (Diptera: Tephritidae). Iowa State Journal of Research 51: 369-438.

GLOSSARY

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.
multivoltine - Having several generations per year.
hyaline - Clear or transparent.

Last Updated: October 3, 2002