I find the Fuzzy-horned bumble bee, Bombus mixtus, to be a common species in Thurston County and much of the west side. It is also found in the north central of the state, and the mountainous areas in eastern Washington.
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
Field ID tips
The relatively bright red rear of the abdomen is a prominent field mark I see on this species. The abdomen feels three (3) toned. Yellow transitioning into black and then into orange.
T1 = yellow
T2 = yellow with some/ a lot of black possible
T3 = black, possibly with some orange
T4 = orange
T5 = orange
Similar Species
My ID challenge with the Fuzzy-horned bumble bee, B. mixtus is that there are some other, less common species with similar color patterns, such as theSikta bumble bee, the High country bumble bee and the Frigid bumble bee. Recognizing that an individual with red at the end of the abdomen is NOT mixtus is the larger challenge.
Let me restate: assume you are looking at a Fuzzy-horned bumble bee and then decide if one of the other species may be a better match.
Having said that, Sitka can be ruled out easily because the colors at the end of the abdomen are not as bright and often do not extend up to T3 or even the front portion of T4.
The other two are easily ruled out in most circumstances based on location. Those two species, are high alpine specialists and are not routinely encountered unless extremely lucky or on a targeted mission. A key field mark for separating Bombus mixtus from the other two is color of the scutum. The Fuzzy-horned bumble bee has a cloudy scutum (yellow with black hairs also). The scutum on both the High country bumble bee and the Frigid bumble bee is yellow.
Fuzzy-horned bumble, B. mixtus
Fuzzy-horned bumble, B. mixtus
Fuzzy-horned bumble, B. mixtus
Fuzzy-horned bumble, B. mixtus
Fuzzy-horned bumble, B. mixtus
Showing that the majority of the orange is T4 and T5.
The Black tail bumble bee, Bombus melanopygus, can be encountered in many areas around Washington state: Lowlands like Tumwater on the west side, in the mountains and over across the top of the state and beyond.
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
When I first started taking pictures of bumbles this species was one of the first I submitted to Bumble Bee Watch. It was also the species that taught me the bumble bee term “cloudy“. Cloudy is the term to describe bumble patterns that have a mixture of black and yellow hairs. On the Black tail bumble bee, the area in front of the wings (scutum) and behind the head is such a mixture of black and yellow. And on the Black tail bumble that cloudiness is very obvious.
Black tail bumble bee, B. melanopygus
Note the cloudy (black hairs mixed in) scutum (area of thorax in front of wings).
Field ID tips
Abdomen pattern is similar in many respects to the Hunt bumble bee, with the big difference at T4.
The Black tail bumble bee
Anterior thorax = cloudy (area in front of wings)
T1 = yellow
T2 = orange
T3 = orange
T4 = black with some white hairs
T5 = black
T4 is black with some white hairs rather than cloudy because the white hairs are in a distinctive line rather than mixed in among the black hairs.
As might be surmised by the common name, this species is not native to Washington state or the west coast of North America. Fertilized queens of this species can be commercially purchased.
Tomato plants require “buzz” pollination to maximize their yields. Bumble bees can buzz pollinate, honeybees can’t. For this reason greenhouse growers of tomatoes in British Columbia purchased impatiens queens and raised them in the tomato greenhouses. Some queens escaped and got established in the wild in British Columia. The BC population is expanding and has now been detected in Washington state.
It was just three springs back (2017) that Chris Looney and I documented their presence at Peace Arch International Park, on the Canadian border in Whatcom County, WA. Just this summer (2020) I heard that Bombus impatiens had been detected as far south as King County.
The Common eastern bumble bee currently is restricted to areas west of the mountains with the current (but spreading) population centered near Blaine but now documented as far south as King County. It is not expected to expand into the east side, based on some preliminary “suitable range” analysis done by the excellent team of invasive species entomologists at the Washington state Department of Agriculture. Their modeling suggests impatiens may rapidly spread south through western Washington and into Oregon and California.
Keep your eyes peeled. New county record for your list!
Field ID tips
The Common eastern bumble bee abdomen shows a color pattern of:
T1 yellow T2 black T3 black T4 black T5 black
Similar species
The Common eastern bumble bee is the only species of bumble bee with a black end of abdomen in Washington state that has:
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
I have never seen Bombus suckleyi in the wild. I have grave concerns that I never will. Suckley cuckoo bumble bees seemed to prefer the Western bumble bee, Bombus occidentalis. When occidentalis populations crashed, the preferred target species was no longer available to suckleyi.
Predator/prey ratios suggest a smaller population of suckleyi relative to their occidentalist hosts. Suckleyi numbers probably also plummeted, but their population base level had never been estimated so we have no baseline. What we do have is years of increased bumble bee sampling and very few detections of suckleyi since the late 1990s.
If you think you see one, please get good pictures but give serious consideration to NOT COLLECTING IT. Any individual you encounter is a sexually active one. As cuckoos, there are no workers, only queens and drones. At the current population level we need to help all survivors bee successful.
Looking at the color forms for Suckleyi shown in Bumble Bees of the Western United States, all forms of the Suckley bumble bee have a solid yellow T4. That easily separates it from the Indiscriminate cuckoo bumble bee.
Also, male B. suckleyiare all or mainly yellow. Other cuckoo males are not. So if you see a yellow cuckoo you have something special! Get that picture!
The key distinguishing photographically useful feature for separating B. suckleyi from B. insularis and B. fervidus, according to the key in Bumble Bees of the Western United States, by Koch, et al, 2012, is the color of the hairs on the back of the head (Occiput). I have used this in a key, with a handlens, but may be a challenge with just a camera photo.
If the hairs on the occiput are predominantly black it is B. suckleyi.
Both B. flavidus and B. insularis have mainly yellows hairs on the back of their heads. This is important to remember, as far as capturing the key elements needed for photographic identification. Make that shot!
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
Field ID tips
We have three species of cuckoo bumbles in Washington state.
Out of the three cuckoo queens, within Washington, only the Indiscriminate cuckoo bumble bee will show a black notch on T4.
Similar Species
At least in Washington,Fernald cuckoo bumble beesB. fernaldae and Indiscriminate cuckoo bumble bee. B. insularis are somewhat easy to distinguish between. As seen in the picture above and below, the Indiscriminate cuckoo has black up the center of tergites T3, T4 and T5 that break up the yellow bands. The Fernald cuckoo bumble bee will have a continuous yellow band on T4 (no black interruption).
The Suckley cuckoo bumblee bee queen also has a solid yellow T4, so the presence of black on T4 is a strong indicator what you have is Bombus insularis. The key distinguishing feature for separating the Indiscriminate cuckoo bumble bee, B. insularis from Suckley cuckoo bumble bee, B. suckleyi, according to the key in Bumble Bees of the Western United States, by Koch, et al, 2012, is the color of the hairs on the back of the head (Occiput). If the hairs on the back of the head are predominantly black it is B. suckleyi.
Both B. flavidus / fernaldae and B. insularis have mainly yellows hairs on the back of their heads. This is important to remember, as far as capturing the key elements needed for photographic identification.
The Fernald cuckoo bumble has a continuous yellow band on T4 (no black interruption).
T1 = black
T2 = black
T3 = black
T4 = yellow ( insularis, would show a black area in the center)
T5 = black (drones may show some orange or pale hairs)
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
Fernald cuckoo bumble bee, B. flavidus
Similar Species
We have three species of cuckoo bumbles in Washington state.
The Fernald cuckoo bumble bee can be distinguished from the Indiscriminate cuckoo bumble bee because the Indiscriminate bumble has a yellow face and a black notch on T4 while the Fernald cuckoo has a black face and a solid yellow T4
The Fernald cuckoo bumble bee, in the west, is a dark bumble. T3 is black. If T1 is yellow or cloudy, then this is not a reliable field mark.
In the Suckley cuckoo bumble bee, T3 is yellow with a black notch. In the case of B. suckleyi, T1 is always black on a queen. So, if T1 and T3 are black, it is most likely a Fernald cuckoo. If T1 is black and T3 shows some yellow, it may well be a Suckley cuckoo bumble bee. If T1 is cloudy, not black or yellow, it suggests Fernald not Suckley.
The key distinguishing feature for separating B. flavidus from B. suckleyi, the Suckley bumble bee, according to the key in Bumble Bees of the Western United States, by Koch, et al, 2012, is the color of the hairs on the back of the head (Occiput). If the hairs on the back of the head are predominantly black it is B. suckleyi. Bombus fernaldae has mainly yellows hairs on the back of the head. This is important to remember, as far as capturing the key elements needed for photographic identification. Make that shot!
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
The Morrison bumble bee, Bombus morrisoni is very rare in Washington state. There is evidence that the range of B morrisoni’s has been strongly contracting over the last decade or so. There is at least one population of morrisoni remaining in Washington and we hope we can locate others. Similar to what is being seen in Oregon, bumble bees in central Washington seem to be utilizing the urban areas. This may be climate change related, in that it has been so hot and dry many fewer nectar and pollen resources are available in the native landscapes so the urban centers with planted mints and other pollinator plants offer a greater diversity of flowering resources, throughout the full season.
If you encounter a suspected morrisoni in the field, please get good pictures. A positive ID can be made just from photographs for this species, so it would be better to use a non-lethal approach to documenting any individuals you encounter.
Field ID tips
This is a good sized bumble bee, similar to the Nevada bumble bee.
The Morrison bumble bee has a yellow scutum, alar and scutellum
T1 & T2 are yellow. T3 is mainly yellow but may show some black on the sides.
It has a short cheek.
Similar Species
The Nevada bumble bee is the most similar species. It will show a black dot between the wings and T3 will be all yellow. Relative to the Morrison bumble, nevadensis has a long cheek and therefor a very different face shape.
The yellow form of the California bumble bee will be very similar to the Yellow bumble bee, but shows some black on T2 and T3. There is disagreement about whether the California bumble bee is a subspecies of the Yellow. The two distinct forms come together in the Willamette Valley of Oregon, and you can see some of the mixed patterns that result.
The Brown-belted bumble bee is very much an east side species. It is not that partial to mountainous areas either, more often found in drier lowland areas. I have picked it up near the Canadian border near Sinlaheiken WMA, on a USFWS Milkweed field that is grown for monarch butterflies. That area is very hot and dry, so it fits within the expected habitat preferences.
Field ID tips
From an identification perspective, this species is relatively easy, with just a possible couple of gotcha’s. The worker is distinctive, with a yellow thorax (small to medium spot between the wings), a yellow T1 and a brown T2. T3 thru T6 are all black
Queens, which fly early in the season and again as summer wanes, have a slightly different appearance. T2 is not brown, instead it is similar in color to T1, but with black on each side. See picture above.
Thorax yellow with very small to medium black spot
T1 = yellow
T2 = yellow with black on edges for queen T2 = brown for workers
T3 = black
T4 = black
T5 = black
Similar Species
Similar species include the Nevada bumble beeBombus nevadensis,Half-black bumble beeB. vagans and the Eastern common bumble beeB. impatiens.
The Nevada bumble bee has a yellow T3 and a distinctive thorax spot.
Half-black bumble bee is generally smaller and has a more delicate feel. The two species feel very dissimilar in body shape and behavior. Once you have identified one, when you encounter the other species it will feel like a very different species.
The Common eastern bumble bee currently is restricted to areas west of the mountains with the current (but spreading) population documented as far south as King County. It is not expected to expand into the east side, based on some preliminary “suitable range” analysis done by the excellent team of entomologists at the Washington state Department of Agriculture. The Common eastern bumble bee has a black T2
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
The Nevada bumble bee, Bombus nevadensis, may well be our largest bumble bee in Washington state. Notice in the picture above its size relative to a native Iris. When I give talks I describe it as being “as large as my thumb”. That may be a bit of an exaggeration, but it is definitely a distinct presence when present.
Field ID tips
The Nevada bumble bee is identified by its larger size, the golden thorax with a black spot in the center, and T1 thru T3 a similar golden brown to the thorax. In some places, T1 may show some black (as in the photo below) but in general T1 is golden/yellow.
Nevada bumble bee, Bombus nevadensis
Similar Species
Similar species include Brown-belted bumble bee, Bombus griseocollis and the Morrison bumble bee, Bombus morrisoni.
The Brown belted bumble bee has brown on T2 or if yellow (queen) has black on the edges of the yellow on T2. T3 is black.
Morrison bumble bee lacks a black dot on the center of the abdomen. It also shows some yellow on T3. Relative to the long cheek of nevadensis, morrisoni has a short cheek.. If in doubt, look at the shape of the face. Hand lens can be handy. Once you have seen them both, you should feel confident in distinguishing between them.
Please reference the Embedded Range Maps page to better interpret # of observations per ecoregion.
Nevada bumble bee is an east side species. There are a few records on the west side, but it is not regularly seen there (that I am aware). I found it at the Turnbull NWR on a couple of separate occasions.
