ARTHROPODS OF FLORIDA
Florida State Collection of Arthropods
Museum of Entomology - Gainesville

Genus Eurosta Loew

INSECTA

Order: Diptera - True Flies

Family: Tephritidae - Fruit Flies

Adults are robust flies of medium size with dark brown to blackish bodies. Pinned specimens often greasy. Wings are also dark brown to blackish with few to numerous hyaline spots.

Larvae form galls in stems and roots of their hosts. Each species appear to be restricted to one or a few species of Solidago (Compositae), and each forms a characteristic gall on its host plant. The genus is restricted to the U.S.A. and Canada and contains seven species, of which four have been recorded from Florida. A fifth species, E. fenestrata Snow, was listed by Johnson (1913) from northeast Florida and mapped by Foote et al. (1993); however, this has not been verified and the record is considered dubious. Steyskal & Foote (1977), Ming (1989), and Foote et al. (1993) all provided keys to the adults of Eurosta.

 

Key to the Florida species of Eurosta

1 Scutum with a mixture of brown or black setulae among light-colored setulae; wing with numerous, regularly spaced hyaline markings along wing margin, appearing radiate at the apex - cribrata (Wulp)

1' Scutal setulae unicolorous, dark to golden or pale; wing with fewer or irregularly spaced hyaline markings along wing margin, without radiate pattern apically - 2

 

2 Wing with two prominent, triangular, hyaline areas on posterior margin; wing tip with extensive hyaline marking, but not radiate or crescentic - solidaginis (Fitch)

2' Wing with only a single prominent, triangular, hyaline area on posterior wing margin (basally), or diffuse or lacking; wing tip with narrow hyaline crescent or small spots - 3

 

3 Basal posterior margin of wing with extensive hyaline area, usually triangular to quadrangular but often in a diffuse pattern; apex of wing with narrow hyaline crescent or spots narrowly confined to wing margin - floridensis Foote

3' Basal posterior region of wing dark with only a small hyaline spot in cell cua1 that may narrowly attain posterior margin; spots at apex of wing not so narrow - lateralis (Wiedemann)

 

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 NY. 571 pp.

Johnson, C. W. 1913. Insects of Florida. I. Diptera. Bull. Am. Mus. Nat. Hist. 32:37-90.

Ming, Y. 1989. A revision of the genus Eurosta Loew, with a scanning electron microscope study of taxonomic characters (Diptera: Tephritidae). Thesis, Washington State University. xiv + 190 p.

Steyskal, G. C. and R. H. Foote. 1977. Revisionary notes on North American Tephritidae (Diptera), with keys and descriptions of new species. Proceedings of the Entomological Society of Washington 79: 146-155.