Bug FAQThree-lined Falsehorn
Temnostoma trifasciatum · Order: Diptera · Family: Syrphidae
The Three-lined Falsehorn is a rare syrphid fly that mimics wasps and is often seen on flowers where it feeds on nectar and pollen. Its larvae live in moist, decayed wood, and the adults can hover almost motionlessly in flight. It occurs in the eastern and central United States and also in Canada.
Source: Wikipedia
How to recognize it
Adults look a lot like wasps, which helps them avoid predators.
Source: Wikipedia
Where it lives
Adults are commonly found on flowers.
Source: Wikipedia
What it eats
Larvae burrow in and feed on moist, decayed wood.
Source: Wikipedia
Life cycle
Adults can hover nearly motionless while flying.
Source: Wikipedia
Where it comes from
It is a rare species native to the eastern and central United States. Its range also includes Canada.
Source: Wikipedia
Lookalikes
Because they strongly mimic wasps, they may be mistaken for actual wasps.
Source: Wikipedia
Where it is found in the US
Recorded in 19 of 51 states and DC. Most records: Illinois, Maryland, Georgia, Pennsylvania, Tennessee, Virginia, Alabama, North Carolina.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What does the Three-lined Falsehorn look like?
It is a strong wasp mimic, looking much like a wasp.
Source: Wikipedia
Where can I find this fly?
Adults are usually seen on flowers in the eastern and central United States and Canada.
Source: Wikipedia
Same family (Syrphidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Temnostoma_trifasciatum
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-26 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-26.