Bug FAQGoldenrod Gall Fly
Eurosta solidaginis · Order: Diptera · Family: Tephritidae
The fly is best known for the round galls it makes on goldenrod stems. Adults emerge in spring, mate on the plants, and females lay eggs in the buds; the larvae then induce the plant to form a protective gall where they feed and develop.
Source: Wikipedia
How to recognize it
It creates a hard, bulbous gall on several goldenrod species.
Source: Wikipedia
Where it lives
The female inserts her eggs near the developing buds of the goldenrod plant.
Source: Wikipedia
What it eats
Parasitic wasps lay eggs in or on the gallmaker’s larvae, consuming them.
Source: Wikipedia
Life cycle
After hatching, the larva moves to the area below the bud and triggers the plant to form a gall. Inside the gall the larva feeds, molts twice, and later chews an exit tunnel in mid-September.
Source: Wikipedia
When you see it
Adults emerge from the galls in spring. Mating occurs on goldenrod, and females lay fertilized eggs into the buds.
Source: Wikipedia
Where it comes from
It is native to North America.
Source: Wikipedia
Where it is found in the US
Recorded in 40 of 51 states and DC. Most records: Minnesota, New York, Vermont, Wisconsin, Pennsylvania, Michigan, Illinois, Ohio.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When are the adults active?
Adults appear in the spring, mate on the plants, and lay eggs in the buds.
Source: Wikipedia
Are there natural enemies that control them?
Parasitic wasps target the larvae inside the galls, killing them.
Source: Wikipedia
Same family (Tephritidae)
Thistle Stem Gall FlyUrophora cardui
Goldenrod Brussels Sprout Gall FlyProcecidochares atra
Mediterranean Fruit FlyCeratitis capitataDamages trees, gardens or crops
Cotton-gall TephritidAciurina bigeloviae
Oriental Fruit FlyBactrocera dorsalisDamages trees, gardens or crops
Mottled Thistle FlyXyphosia miliariaSources
- Wikipedia: https://en.wikipedia.org/wiki/Goldenrod_gall_fly
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.