gdsfg

If you find Bombus occidentalis, please contact bum

blebees@xerces.org

Visit ww

w.xerces.org/bum

blebees for more inform

ation.

Bom

bus bifarius (nearcticus)

Bom

bus morrisoni

Bom

bus melanopygus

Bom

bus nevadensis

Bom

bus mixtus

Bom

bus griseocollis

Bom

bus huntii

po

ck

et

gu

ide

to

ide

nt

ify

ing

th

e w

est

er

n

bu

mb

le

be

e

Bo

mb

us o

cc

ide

nta

lis

Photo by Derrick Ditchburn

Bom

bus bifarius

Bom

bus melanopygus

(edwardsii)

Found in the mountains and northern areas

Found in coastal areas

The western bum

ble bee was once com

monly found

in the western U

nited States and Canada. They can

still be found in northern and eastern parts of their historic range, but populations from

southern British

Colum

bia to central California have nearly disappeared

in recent years. Your efforts to search for this bee w

ill help document their current range. The Xerces

Society and scientists studying bumble bee decline

will use this inform

ation to promote conservation of

remaining B

. occidentalis populations.

Bom

bus appositus

Map based on Milliron 1971, A Monographof the Western Hemisphere Bumblebees.

other com

mon bum

ble bees of western n

orth Am

erica

There are around 30 bumble bee species present in w

estern North Am

erica. Females of som

e of the most

comm

only found bees are pictured here. Some species pictured have varieties w

ith different coloration.

For more identification inform

ation, visit ww

w.discoverlife.org and w

ww

.bugguide.net

ww

w.xerces.org/bum

blebees

TH

E XE

RC

ES S

OC

IET

Y F

OR

INV

ER

TE

BR

AT

E C

ON

SER

VA

TIO

N

Funding for bumble bee conservation provided by the C

S Fund.G

uide developed and illustrated by Elaine Evans, The Xerces Society.Thanks to D

r. Robbin Thorp, UC

Davis.

Bom

bus

calif

orni

cus

com

mon

fem

ale

Bom

bus o

ccid

enta

lis v

arie

ties

Bom

bus

suck

leyi

(cuc

koo

bee)

Bom

bus

fern

alda

e(c

ucko

o be

e)

sim

ilar

fem

ale

bees

wit

h ye

llow

on

the

4th

abdo

min

al s

egm

ent

Bom

bus

vosn

esen

skii

Bom

bus

insu

lari

s(c

ucko

o be

e)

Bom

bus

calig

inos

usB

ombu

s va

ndyk

ei

Thes

e lo

ok-a

-like

bee

s ha

ve y

ello

w h

air

on th

e 4t

h

abdo

min

al s

egm

ent,

as o

ppos

ed to

B. o

ccid

enta

lis

with

bla

ck o

r w

hite

hai

r on

the

4th

abd

omin

al

segm

ent.

Thes

e th

ree

varie

ties

of B

. occ

iden

talis

repr

esen

t the

m

ost

com

mon

ly f

ound

col

or p

atte

rns.

Som

e be

es

are

inte

rmed

iate

bet

wee

n th

ese

varie

ties.

sim

ilar

fem

ale

bees

wit

h y

ello

w o

n th

e he

ad

Nor

ther

n C

alifo

rnia

to

Brit

ish

Col

umbi

a,

east

to

Mon

tana

Rock

y M

ount

ains

to

Alas

ka

Cen

tral

coa

stal

C

alifo

rnia

Yello

w-h

eade

d be

eB

lack

-hea

ded

bee

Thes

e lo

ok-a

-like

bee

s ha

ve p

rom

inen

t ye

llow

hai

r on

the

fac

e, a

s op

pose

d to

B. o

ccid

enta

lis w

ith a

ll bl

ack

hair

on t

he f

ace.

Fem

ales

hav

e 6

abdo

min

al s

egm

ents

ver

sus

7 in

mal

es.

Fem

ales

hav

e 12

ant

enna

l seg

men

ts v

ersu

s 13

in m

ales

. Fe

mal

e hi

nd le

gs a

re w

ider

tha

n m

ale

hind

legs

.

Fem

ales

are

foun

d th

roug

h sp

ring,

sum

mer

and

ear

ly fa

ll.

Wor

kers

and

que

ens

are

both

fem

ale.

Mal

es c

an b

e co

mm

on i

n la

te s

umm

er a

nd e

arly

fal

l. Fe

mal

es h

ave

polle

n ba

sket

s (a

n in

dent

atio

n on

to w

hich

the

y so

met

imes

pa

ck p

olle

n) o

n th

eir

hind

leg

s, a

nd s

hort

er a

nten

nae

and

abdo

men

s. M

ales

som

etim

es h

ave

larg

er e

yes

and

long

er h

air.

Bum

ble

bees

pic

ture

d an

d de

scrib

ed i

n th

is

guid

e ar

e al

l fem

ale

bees

.

mal

e ab

dom

en7

segm

ents

fem

ale

abdo

men

6 se

gmen

ts

mal

e hi

nd le

g th

inne

r

mal

e an

tenn

a13

seg

men

tsfe

mal

e an

tenn

a12

seg

men

ts

fem

ale

hind

leg

wid

er

mal

e or

fem

ale

?h

istoric range of Bom

bus occidentalis