From buds to seeds: bees are key
James H. Cane
U.S. Department of Agriculture
Agricultural Research Service
Pollinating Insect Research Unit
Utah State University, Logan, Utah, USA
Wind-pollinated
"The management
implications are that
sustainability of these
[sagebrush eco-]systems
will depend on maintaining or restoring the
perennial herbaceous
species.”
Chambers et al. 2007.
Ecological Monographs
77:117-145.
Penstemon
Hedysarumcyaneus
boreale seed field
seed production field
Crepis
(Asteracae)
Hedysarum
(Fabaceae)
Astragalus
Lupinus
 Asteraceae (Compositae)
 Apiaceae (Umbelliferae)
 Fabaceae (Leguminosae)
 Malvaceae
Eriogonum
Cleome
Chaenactis
Penstemon
Cleome serrulata
Cleome lutea
Eriogonum umbellatum
Dalea searlsiae
Penstemon speciosus
Balsamorhiza sagittata
Astragalus filipes
Sphaeralcea munroana
Lomatium dissectum
Hedysarum boreale
0
20
40
60
80
100
120 x
Reproductive Gain With Pollinators
Hedysarum boreale
Cleome lutea
Cleome serrulata
Balsamorhiza sagittata
Penstemon speciosus
Astragalus filipes
Dalea ornata
Dalea searlsiae
Sphaeralcea grossularifolia
Sphaeralcea munroana
Sphaeralcea concinnea
0
5x
10 x
15x
20 x
Reproductive Gain With Cross-Pollination
Cleome
serrulata
Penstemon
speciosus
Self-fertile
Self-incompatible
Autogamy
Autopollination
Pollination Treatment
b
Geitonogamy
a
Xenogamy
a
Freely Visited
a
Self-Pollen
Outcross
Freely-Visited
0
10
20
30
40
50
60
Seeds per Silique (pod) (Mean + 1 std dev.)
0.0
0.2
0.4
0.6
0.8
Sum Seeds per Raceme (gms)
1.0
Pseudomasaris pollen
wasps at Penstemon
Syrphids, other flies
at Lomatium
bee
Hedysarum
boreale
Astragalus filipes
Phlox longifolia
Balsamorhiza
Eucera
frater
Area of circle= sum of individuals
sampled across sites
Diadasia
5
(to be based on plants)
Median Abundance
6
Diadasia
4
3
Halictus
Colletes
2
Agapostemon
Agapostemon
1
2
4
6
8
Sites Occupied (of 17)
10
12
Diadasia diminuta at
Sphaeralcea
Sphaeralcea
Deliver 3345 pollen
grains per
stigma
Osmia cyanella
Nesting
shelter
with
nesting
holes
Osmia sanrafaelae nest in straw
Hived honeybees,
useful for
pollinating several
wildflower species
 Often not best, but
usually much
better than no
bees


Alfalfa leafcutting bees
useful for several
summerblooming species
 Other Osmia
bees can be
managed to
pollinate various
Fabaceae,
Asteraceae and
more
Osmia sanrafaelae nest in straw
Osmia
cyanella
Nesting
shelter
with
nesting
holes

Stewardship
of wild bees
that you can’t
manage
 May multiply
on other
cultivated
flowering
species
Weevil exit
hole in seed
of Hedysarum
adults
egg
Weevils that attack Dalea seed
larvae
larva
cocoon
Twig nest of the bee Hoplitis sambuci
>85% of bee
species
nest in the
ground
100
80
60
1 min
3 min
9 min
27 min
Du
ra
tio
20
54
°C
°C
50
°C
46
°C
42
°C
0
Temp
n
40
38
l (%)
Larval Surviva
Survival of Megachile rotundata larvae following
heating in damp sand
eratu
re
600 km
Intact Burned
‘08
Bees sampled 40
39
Plants
surveyed
% Osmia
71
70%
65
77%
- 54 native bee species in total
- 20 other paired sites in 5 state region
- fire chronosequence of 20 years
Osmia
californica
SAFE
Fates of Bees after Fire
Osmia integra nest
?
 Dominant wildflowers need bees for pollination
 Cannot predict pollination needs or pollinators
 Seed growers need bees
 honey bee
 managed cavity-nesting Osmia
 wild bees
 Ground-nesting bees predominate, survive fire

Bee communities need bloom year after fire
 Stephanie Miller
 Melissa Weber
 Glen Trostle
 Katie Swoboda
 Kristal Watrous
 Byron Love
 Summer students