Stegophylla essigi
In 3 days ~10%
Stegophylla essigi, also known as the California woolly oak aphid, is a species of North American aphid. It had been found on many California oaks, including blue oaks, valley oaks, Oregon white oaks, coast live oaks, interior live oaks, California black oaks, and scrub oaks.
Woolly oak aphids overwinter as eggs. Several generations develop each year. In the spring, females reproduce parthenogenically (without mating). In the fall, male and female aphids are produced. Adult males may be either winged or wingless. For S. essigi, oviparae and both wingless and winged males are produced in November. Populations of S. essigi may continue to reproduce parthenogenically on evergreen oaks such as coast live oak, especially in leaves tied together by caterpillar silk. A visible sign of the presence of California woolly oak aphid is oak leaf margins that are folded upward and become reddish. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Portland | 🇺🇸 United States | |
| 2 | Sacramento | 🇺🇸 United States | |
| 3 | San Francisco | 🇺🇸 United States | |
| 4 | Los Angeles | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Californian Woolly Oak Aphid sighting in Los Angeles on a given day, based on 6 verified sightings from GBIF citizen-science data. It is the 715th most-seen of the 851 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 Californian Woolly Oak Aphid in Los Angeles on a given day, so our monthly data shows no clear season.
Among the best
Of the 4 cities where we can rate Californian Woolly Oak Aphid sightings, Los Angeles ranks 4th at under 5%, level with the leaders once rounded. The best odds are in Portland (United States, under 5%), Sacramento (United States, under 5%) and San Francisco (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Californian Woolly Oak Aphid is recorded against all the insects logged in Los Angeles (6 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.
