Frigid bumble bee, Bombus frigidus

Field ID tips

The Frigid bumble bee, Bombus frigidus is a very rarely encountered bumble bee species in Washington. That may be because it is rarely looked for by individuals who go into the high country. That trend seems to be changing. I expect we will be adding additional locations to the map above. It has recently been detected at Harts Pass, by Rich Hatfield.

Key field marks are:

  • the yellow scutum and scutellum,
  • T1 & T2 yellow
  • T3 black (no white hairs)
  • T4 & T5 red/orange
  • high elevation

Similar Species

The Frigid bumble bee, Bombus frigidus is often found in association with two other high alpine specialists: the Forest bumble bee, Bombus sylvicola and the High country bumble bee, Bombus kirbiellus. All three show red on the abdomen.

The Frigid bumble bee, Bombus frigidus is easily distinguished from the Forest bumble bee because the red on a frigidus is at the end of the abdomen while the red on a sylvicola is on T2 and T3.

It is more of a challenge to visually separate the High country bumble bee from the Frigid bumble bee. They both have T1 and T2 yellow. The High country bumble bee, B. kirbiellus has black on the front half of T3, and yellow on the rear portion of T3. T4 and T5 are orange. Visually, this puts a break (yellow) between the black and red segments. This is in contrast with the Frigid bumble bee where black and red meet directly with no yellow line of separation.

Fuzzy-horned bumble bee, B. mixtus, and Sitka bumble bee, B. sitkensis are other similar species. A couple of key differences between kirbiellus and mixtus/sitkensis include:

  • Cloudy scutum on mixtus amd sitkensis /yellow on kirbiellus
  • Range (elevation)-one might find B. mixtus and sitkensis pretty high but you will not find frigidus in the lowlands

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