Diptera - Fruit flies

Paracantha culta (Wiedemann)

Photograph by Jeffrey Lotz - FDACS/DPI

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

SPECIES DESCRIPTION

Size: Approximately 9-10 mm from antennae to tip of wings.
Wing pattern: solid brown centrally punctuated by several small, round, clear spots and one black spot; thin brown rays radiating out to forward and apical edges.
Body color: brown, same as wings.
Oviscape: orange-brown, about 1.5 mm long, tapered to a blunt tip.

Photographs:

Paracantha culta, Adult, Cades Cove, August 2002, Photograph by Jeffrey Lotz - FDACS/DPI.
Paracantha culta, Adults in field, Cades Cove, August 2002, Photograph by Gary J. Steck.
Paracantha culta, Adult in field, Cades Cove, August 2002, Photograph by Gary J. Steck.
Cirsium vulgare, Cades Cove, August 2002, Photograph by Gary J. Steck.

Similar species:

No other species of Paracantha has been recorded from GSMNP. This distinctive species is unlikely to be confused with any other tephritid fly in GSMNP. 

DISTRIBUTION:
(GSMNP in green)

 Paracantha culta is widespread throughout the southeastern coastal plain/piedmont and Mississippi River valley west into the Great Plains but is largely absent from the northeastern US/Appalachian Mountains, presumably due to a lack of suitable host.

 

 In Park:

Cades Cove and Oconaluftee.

 

 HOST PLANTS:

 Paracantha culta is restricted to the genus Cirsium (Asteraceae). In GSMNP we have collected adults on C. vulgare (Savi) Ten. (Cades Cove) and Cirsium. sp. (Oconaluftee); however, larvae/pupae have not been located. These Cirsium species may not be optimal hosts. Cirsium vulgare was introduced into North America in historical times, so any association with P. culta would be only recently developed.

Cirsium vulgare
Cades Cove, August 2002
Photograph by Gary J. Steck

 NATURAL HISTORY

 Habitat:

 Sunny open old fields and meadows at lower elevations containing Cirsium species.

Phenology

Adults have been collected June to August in GSMNP. In Nebraska, at least two generations of P. culta occur yearly on at least two different species of Cirsium. There the first generation adults appear in mid-May and second generation adults appear in late June (Lamp & McCarty 1982).

 Breeding and Courtship:

 Courtship occurs on or near the host and has been observed during late afternoon on sunny days in June in GSMNP.

 Oviposition and Immature Stages:

Oviposition takes place on unopened flower heads through the phyllaries. Immatures have not yet been recorded in GSMNP, but they have been described from Florida and Nebraska specimens. Eggs are distinctive - they are white with an elongate body about 1 mm long and an equal or longer tail (Benjamin 1934, Phillips 1946). One to 12 larvae per seed head have been reported in Florida thistles (Benjamin 1934) and up to 37 larvae have been found feeding on developing seeds in C. canescens in Nebraska (Lamp & McCarty 1982).

 Predators and Parasites:

 No information for GSMNP. Up to 40% of P. culta pupae in Nebraska are parasitized by a pteromalid wasp (Lamp & McCarty 1982).

 Community Ecology:

There is no information on relationships with other insects in GSMNP. In other parts of the U.S., other tephritid species and lepidoptera larvae co-occur and interact in Cirsium seed heads.

 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:

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

REFERENCES

Benjamin, F.H. 1934. Descriptions of some native trypetid flies with notes on their habits. USDA Technical Bulletin No. 401, 96 pp.
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.
Lamp, W.O. and M.K. McCarty 1982. Biology of predispersal seed predators of the Platte thistle, Cirsium canescens. J. Kansas Entom. Soc. 55: 305-316.
Phillips, V. T. 1946. The biology and identification of trypetid larvae (Diptera: Tephritidae). American Entomol. Soc., Mem. No. 12, 161 pp + XVI plates.

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.
univoltine - Having one generation per year.

Last Updated: October 10, 2002