Bug FAQBibio articulatus
Bibio articulatus · Order: Diptera · Family: Bibionidae
Bibio articulatus is a small fly about 6 mm across with a dark body that can be black or deep red and bright orange-red legs. It lives in rotting wood, on plant leaves, and in loose soil, mainly east of the Rocky Mountains in the United States. Adults appear in March, are most active in April and May, then become dormant by June.
Source: Wikipedia
How to recognize it
The bug has a dark exoskeleton ranging from black to deep red and its legs are orange or red. Its femora and tibiae are orange/red, the foretibial spurs are equal in length, and the foretibia is brown.
Source: Wikipedia
Size
Wingspan averages about 6 mm.
Source: Wikipedia
Where it lives
Found in rotting trees and feeding on plant leaves without causing major damage. Also occurs in loose soil during its reproductive phase.
Source: Wikipedia
What it eats
Feeds on decaying wood and plant leaves, but does not significantly harm the plants.
Source: Wikipedia
Life cycle
Adults emerge in March, are most active in April and May, then go dormant in June. Females lay eggs in soil or decaying material; larvae look like small worms and later pupate into winged adults.
Source: Wikipedia
When you see it
Active period is March through May, with dormancy starting in June.
Source: Wikipedia
Where it is found in the US
Recorded in 34 of 51 states and DC. Most records: Virginia, Pennsylvania, Maryland, Alabama, New York, Ohio, Wisconsin, North Carolina.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When will Bibio articulatus be seen?
Adults start appearing in March, peak in April and May, and become dormant by June.
Source: Wikipedia
What does Bibio articulatus look like?
It is about 6 mm wide, has a dark body that can be black or deep red, and bright orange-red legs.
Source: Wikipedia
Where does Bibio articulatus live?
It lives in rotting trees, on plant leaves, and in loose soil, mainly east of the Rocky Mountains in the U.S..
Source: Wikipedia
Same family (Bibionidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Bibio_articulatus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.