Bug FAQYellow-legged Wood Fly
Blera humeralis · Order: Diptera · Family: Syrphidae
The yellow-legged wood fly has a shiny black thorax with orange-yellowish hairs and four copper-colored stripes, and a black abdomen marked by wide yellow stripes. Its larvae are rat-tailed types that live in tree sap or rot holes, while adults visit flowers for nectar and pollen. It is a Nearctic species found along the western coast of North America.
Source: Wikipedia
How to recognize it
The thorax is glossy black, covered with orange-yellowish pile and four copper-colored stripes. The abdomen is black with broad yellow stripes.
Source: Wikipedia
Where it lives
Larvae develop in sap-exuding wounds or rot holes of trees.
Source: Wikipedia
What it eats
Adults feed on flower nectar and pollen. Larvae are rat-tailed and consume sap or decaying material in tree holes.
Source: Wikipedia
Life cycle
Hoverflies, including this species, can hover almost motionless in flight.
Source: Wikipedia
Where it comes from
This species occurs along the western coast of North America.
Source: Wikipedia
Where it is found in the US
Recorded in 3 of 51 states and DC. Most records: California, Oregon, Washington.
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 yellow-legged wood fly look like?
It has a shiny black thorax with orange-yellowish hairs and four copper-colored stripes, and a black abdomen with wide yellow bands.
Source: Wikipedia
What do the larvae eat?
The rat-tailed larvae feed on sap that seeps from trees or on material in rot holes.
Source: Wikipedia
Do these flies visit flowers?
Yes, adult yellow-legged wood flies gather nectar and pollen from flowers.
Source: Wikipedia
Same family (Syrphidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Blera_humeralis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-29 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-29.