Bug FAQSagebrush Woolly Stem Gall Midge
Rhopalomyia floccosa · Order: Diptera · Family: Cecidomyiidae
The Sagebrush Woolly Stem Gall Midge makes white, woolly galls about 5 mm across on California sagebrush (Artemisia californica).
Source: Wikipedia
How to recognize it
The insect creates white, woolly, single-chambered bud galls.
Source: Wikipedia
Size
Each gall is about 5 mm (0.20 in) in diameter.
Source: Wikipedia
Where it lives
It lives on California sagebrush, Artemisia californica.
Source: Wikipedia
What it eats
The midge feeds by inducing galls on the sagebrush plant.
Source: Wikipedia
Life cycle
Its life cycle revolves around forming galls on the host plant.
Source: Wikipedia
Where it comes from
Its range is tied to the distribution of its host, California sagebrush.
Source: Wikipedia
Where it is found in the US
Recorded in 1 of 51 states and DC. Most records: California.
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
Same family (Cecidomyiidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Rhopalomyia_floccosa
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.