Crotch's Bumble Bee

Crotch's Bumble Bee

Bombus crotchii

Daily sighting probability <5% · Rare
at San Diego

In 3 days ~10% in a week ~20%

40 Verified sightings at San Diego
April Best month

About the Crotch's Bumble Bee

Bombus crotchii, commonly called Crotch's bumble bee or the Golden State bumble bee, is a species of bumblebee named after the entomologist George Robert Crotch. It is classified as endangered due to the impacts of pesticides, climate change, and human development.

Crotch's bumble bee is characterized as a short- or medium- tongue length species. This species could be confused with Bombus californicus or Bombus occidentalis, as they have color patterns similar to Crotch's bumble bee.

Queens and workers (females) have a black head and thorax, with yellow on the dorsal anterior thorax, and sometimes yellow on the scutellum. The first metasomal tergum (T1) of the abdomen is all black or black in the middle portion. T2 is usually yellow, sometimes black medially. T3-5 are black or orange and T6 is black. Queens and workers have a similar appearance, with the main difference being their body size. Queens are 23–24mm long and workers are 14–18mm long.

Males have a slightly different appearance from queens and workers. Their eyes are very large, occupying much of the face. They display yellow hair on their faces, and a broad black stripe mid thorax. The front of the male... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability

More parks will be added in future updates.

Cities Where Found

# City Country Daily sighting probability
1 Los Angeles 🇺🇸 United States
<5%
2 Sacramento 🇺🇸 United States
<5%
3 San Diego 🇺🇸 United States
<5%

Before you go

What are the chances of seeing a Crotch's Bumble Bee in San Diego?

Rare

Under 5% of wildlife watchers report a Crotch's Bumble Bee sighting in San Diego on a given day, based on 40 verified sightings from GBIF citizen-science data. It is the 231st most-seen of the 693 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.

When is the best time to see a Crotch's Bumble Bee in San Diego?

Any time of year

In every month with enough records, under 5% of wildlife watchers report a Crotch's Bumble Bee in San Diego on a given day, so our monthly data shows no clear season.

Is San Diego the best place to see a Crotch's Bumble Bee?

Among the best

Of the 3 cities where we can rate Crotch's Bumble Bee sightings, San Diego ranks 3rd at under 5%, level with the leaders once rounded. The best odds are in Los Angeles (United States, under 5%) and Sacramento (United States, under 5%).

Where does the Crotch's Bumble Bee sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Crotch's Bumble Bee is recorded against all the insects logged in San Diego (40 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.

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