Brachyopa vacua
In 3 days ~10%
Brachyopa vacua (Osten Sacken, 1875), the Yellow-spotted Sapeater, is a rare, species of syrphid fly. It has been observed in Canada, Alaska and the northern United States. Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies for they are commonly found around and on flowers from which they get both energy-giving nectar and protein-rich pollen. Larvae for this genus are of the rat-tailed type. B.vacua larvae were collected from the juice of decaying fungi under dead bark.
7 to 10 mm. long Head a dirty yellow with a brown stripe on the cheek. Thorax with yellow hair and a double row of dark median lines. Scutellum with yellow hairs. Large yellow spots on the second abdominal segment. Wings, longer than last abdominal segment. Legs brown with light yellow at joints.
Larva. Length, 8 mm.x 3 mm., appears opaque yellow-ochre, brown, to black. Pointed anteriorly, widening in middle. Entirely wrinkled and covered with black spines ventrally. Puparium Length7 mm. cylindrical, wedge shaped in profile. The pupal spiracles are reddish-brown, conical, and curved outward, bearing... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Yellow-Spotted Sapeater sighting in Washington on a given day, based on 12 verified sightings from GBIF citizen-science data. It is the 1256th most-seen of the 1807 insects we can rate there. Over three days the chance rises to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Yellow-Spotted Sapeater in Washington on a given day, so our monthly data shows no clear season.
Only Washington, in our data
Washington is the only city on Wallace's Line with enough records to rate Yellow-Spotted Sapeater sightings: under 5% of wildlife watchers there report one on a given day.
Same family: Syrphidae
The closest relatives of the Yellow-Spotted Sapeater that you can see in Washington (family Syrphidae, Hover Flies) are Eastern Calligrapher (about 10%), Margined Calligrapher (about 10%) and Transverse-Banded Flower Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Yellow-Spotted Sapeater is recorded against all the insects logged in Washington (12 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
