Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

See Moth submissions from National Moth Week 2023

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Previous events


Species Urophora quadrifasciata - Four-barred Knapweed Gall Fly

Tephritid fly, Urophora quadrifasciata - Urophora quadrifasciata Some type of Fruit Fly? - Urophora quadrifasciata Urophora quadrifasciata (Meigen)? - Urophora quadrifasciata Green Eyed Fly - Urophora quadrifasciata - male fly - Urophora quadrifasciata - male Four-barred Knapweed Gall Fly - NB - Urophora quadrifasciata - male tiny in a swarming group - Urophora quadrifasciata - female Unknown Fly - Urophora quadrifasciata - female
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon ("Acalyptratae")
Superfamily Tephritoidea
Family Tephritidae (Fruit Flies)
Subfamily Tephritinae
Tribe Myopitini
Genus Urophora
Species quadrifasciata (Four-barred Knapweed Gall Fly)
Explanation of Names
Urophora quadrifasciata (Meigen 1826)
quadrifasciata = 'four-banded' (refers to the wing pattern)
2-3 mm
Native to Europe, introduced in NA in 1988 to control knapweeds (now across most of the US)
Introduced to control knapweed (Centaurea spp.)
Life Cycle
Two generations a year. Overwintering generation emerges as adults from galls in the mature seedheads in the spring when new flower buds are beginning to form. Female fly uses her ovipositor to penetrate half grown flower buds it lays eggs among the developing stamens. May lay more than one egg per seedhead. Eggs hatch in three to four days and larvae chew down in a floret into the ovary causing the plant to start forming a gall about eight days after larvae hatched.
See Also
U. affinis has less extensive wing markings
Internet References
Fact sheets: R.F. Lang(1)M.B. Sacry(2)