| Bombus sitkensis | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Apidae |
| Genus: | Bombus |
| Subgenus: | Pyrobombus |
| Species: | B. sitkensis |
| Binomial name | |
| Bombus sitkensis | |
Bombus sitkensis, the Sitka bumblebee, is a species of bumblebee common in western North America from Alaska to California.
The Sitka bumblebee has an oblong head with a medium-length proboscis. The females (queens and workers) have black and yellow hairs intermixed on the face and forward part of the thorax and a black patch in the middle of the thorax, while their sides are yellowish. [2] Terga (abdominal segments) 1 and 2 are yellow, and 3 and 4 black, the latter with a yellow posterior rim. The two last terga are brownish-red. [3] The male has the face and forward parts of the thorax yellow, and only the posterior parts are darker (black and yellow intermixed). On the abdomen terga 1 and 2 are yellow, [2] and terga 3 to 5 yellow on the anterior part, black on the posterior. The tail (terga 6 to 7) is brownish-red. [3]
The species is a common bumblebee found in the western North America from Alaska and British Columbia, and Washington, to northern Idaho, western Montana, and the coastal parts of California. [2] [4] The Sitka bumblebee has experienced mild population declines in parks in California due to competition with the yellow-faced bumblebee (B. vosnesenskii) for nesting sites, such as rodent holes. [5]
The Sitka bumblebee forages on flowering plants from several families, including the Ericaceae, Asteraceae, Saxifragaceae, and Rhamnaceae. The flight period for the queen is very long, from the end of January to the beginning of December. The first workers emerge in early March, while males appear in early April. Both the latter castes have disappeared by the end of September. [4]
Bombus fraternus is an endangered species of bumblebee known commonly as the Southern Plains bumblebee. It is native to the United States east of the Rocky Mountains. It is most often encountered in the southern Great Plains and along the Gulf Coastal Plain. This species has been found as far north as New Jersey and North Dakota, and as far south as Florida along the Gulf Coastal Plain into the state of Chihuahua in Mexico. This species was uncommon historically, but having faced declines in population; its estimated abundance is less than 15% of historical numbers.
Bombus campestris is a very common cuckoo bumblebee found in most of Europe.
Bombus insularis is a species of bumblebee in the subgenus Psithyrus, the cuckoo bumblebees. It is native to northern and western North America, where it occurs throughout Canada, Alaska, the northern United States, and some western states. It is known commonly as the indiscriminate cuckoo bumblebee.
Bombus variabilis is a critically endangered species of cuckoo bumblebee that occurs in North America. It has not been observed in the United States in at least 20 years and is potentially extirpated or extinct.
Bombus suckleyi is a species of bumblebee known commonly as Suckley's cuckoo bumblebee, named after biologist George Suckley. Suckley's bumble bee is a generalist pollinator and represents a rare group of obligate, parasitic bumble bees. Suckley's bumble bee is a social-parasite because it invades the nests of the host bumble bees, including the western bumble bee, and relies on host species workers to provision its larvae. It is native to northwestern North America, including Alaska and parts of western and central Canada and the western United States.
Bombus nevadensis, the Nevada bumblebee, is a species of bumblebee. It is native to North America, where it occurs from Alaska to California in the west, and east to Wisconsin, and in Arizona, New Mexico, and Mexico.
The two-spotted bumble bee is a species of social bumble bee found in the eastern half of the United States and the adjacent south-eastern part of Canada. In older literature this bee is often referred to as Bremus bimaculatus, Bremus being a synonym for Bombus. The bee's common name comes from the two yellow spots on its abdomen. Unlike many of the other species of bee in the genus Bombus,B. bimaculatus is not on the decline, but instead is very stable. They are abundant pollinators that forage at a variety of plants.
Bombus vosnesenskii, the yellow-faced bumblebee, is a species of bumblebee native to the west coast of North America, where it is distributed from British Columbia to Baja California. It is the most abundant species of bee in this range, and can be found in both urban and agricultural areas. Additionally, B. vosnesenskii is utilized as an important pollinator in commercial agriculture, especially for greenhouse tomatoes. Though the species is not currently experiencing population decline, urbanization has affected its nesting densities, and early emergence of the B. vosnesenskii has been implicated in the increasing lack of bee diversity on the West coast.
Bombus occidentalis, the western bumble bee, is one of around 30 bumble bee species present in the western United States and western Canada. A recent review of all of its close relatives worldwide appears to have confirmed its status as a separate species.
Franklin's bumblebee is one of the most narrowly distributed bumblebee species, making it a critically endangered bee of the western United States. It lives only in a 190-by-70-mile area in southern Oregon and northern California, between the Coast and Sierra-Cascade mountain ranges. It was last seen in 2006. Franklin's bumblebee collects nectar and pollen from several wildflowers, such as lupine, California poppy, and horsemint, which causes it to be classified as a generalist forager.
Bombus centralis, the central bumblebee, is a species of bumble bee found in parts of Canada and the western United States. The species was first described by Ezra Townsend Cresson in 1864.
Bombus caliginosus, the obscure bumblebee, is a species of bumblebee native to the West Coast of the United States, where its distribution extends from Washington through Oregon to Southern California.
Bombus flavifrons, the yellow-fronted bumble bee or yellowhead bumblebee, is a species of bumblebee. It is native to North America, where it is distributed across much of Canada, Alaska, and the western contiguous United States.
The half-black bumblebee is a small bumblebee with a wide distribution in North America, its range extending from Ontario to Nova Scotia and southward to Georgia.
Bombus bifarius, the two-form bumblebee, is a species of eusocial bumblebee of the subgenus Pyrobombus. B. bifarius inhabits mountainous regions of western North America, primarily the states of Colorado and Utah. Its common name refers to a historical artifact, in that it was believed that this species had a color polymorphism, with a red-tailed nominate form and a black-tailed nearcticus form, present in the species. This polymorphism has recently been shown to belong instead to a cryptic sister species, Bombus vancouverensis, that occupies almost the entirety of the range of what was formerly classified as bifarius; true bifarius only has a red form, so it is not "two-formed" at all.
Bombus crotchii, commonly called Crotch's 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.
Bombus griseocollis is a species of bumblebee known commonly as the brown-belted bumblebee. It is native to much of the United States except for the Southwest, and to the southernmost regions of several of the provinces of Canada.
Bombus rufocinctus is a species of bumblebee known commonly as the "red-belted bumblebee". It is native to North America where it has a wide distribution across Canada and the western, midwestern, and northeastern United States. It may occur in Mexico.
Bombus vancouverensis, the Vancouver Island Bumblebee, is a common species of eusocial bumblebee of the subgenus Pyrobombus. B. vancouverensis inhabits mountainous regions of western North America, where it has long been considered as a synonym of Bombus bifarius, and essentially all of the literature on bifarius refers instead to vancouverensis. B. vancouverensis has been identified as one of the two species of bumblebee observed to use pheromones in kin recognition. The other is the frigid bumblebee, Bombus frigidus.
