Predispersal seed predation of Wyethia amplexicaule, acuminata, and Agoseris glauca

Robert L. Johnson and Val Jo Anderson Brigham Young University

project

• Document seed predation in select forb species • Document occurrence of pest parasitoids • Effect of treatment with imidacloprid methods

• 3 plant populations • 20 plants – nearest plant to point on transect bisecting population • 5 random plants per imidacloprid treatment – soil drench – spray – control • Seed heads harvested following anthesis and reared in the lab • Following emergence, individual seed were examined for damage

Imidacloprid treatment

Soil drench: 0.5 gallons solution = 1.2 grams active ingredient

Spray: foliar spray until solution begins dripping from foliage

Wyethia amplexicaulis

Reared capitula 2,256 Neotephritis finalis 2256 Trupanea nigricornis 186 Melanagromyza sp. 15 24 Seed damage

average=39.0% 60

40 # samples # samples

20

0

e 0% 5% 0% 0% or 1 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 8 85% 90% 95% M % seed damage Agoseris glauca

Reared capitula 575 Campiglossa sp. 155 Diptera (unknown) 18 Seed damage

600

500

400

average=8.1

300 # samples 200

100

0 0% 1-20% 21-40% 41-60% 61-80% 81-99% More % seed damage Imidacloprid treatment: site x treatment (p<0.01)

18.0% b 16.0%

14.0%

12.0%

10.0%

8.0% a a 6.0% a

percent seed damage 4.0% a a 2.0% a a a 0.0% Manti Ridge Teat Mountain Willow Creek habitat

control spray drench Crepis acuminata

Reared capitula: 2859 Campiglossa sp 52 albatella 133 subsp. mucidella

Seed damage

220

200

180

160 average=12.4% 140

120

100

# samples 80

60

40

20

0 0% 1-20% 21-40% 41-60% 61-80% More % seed damage Imidacloprid treatment: habitat x site x year (p<0.01)

10.0%

9.0%

8.0%

7.0%

6.0%

5.0%

4.0%

percent seed damage 3.0%

2.0%

1.0%

0.0% Squaw Peak Sheep Creek West Mountain Squaw Peak Sheep Creek West Mountain

2006 2007

control spray drench conclusions

• Significant seed damage can occur in wild plant populations – Year and site influence percent damage • A new seed predator, host associations, and parasitoids were discovered • Capitulum size of W. amplexicaulis influences pest abundance per capitulum but not total percent seed damage • Imidacloprid treatment can reduce seed damage – soil drench provides greater pest control but was not significant most of the time at the 95% confidence level. Impact of Habitat Alterations to Bee Diversity in Sagebrush and Pinyon/Juniper Communities of the Eastern Great Basin

Robert L. Johnson and Val Jo Anderson Brigham Young University

project

Hypothesis: introduced grassland habitats support lower bee diversity than neighboring native habitats

• quantify the differences/similarities in bee diversity between natural and altered habitats – 3 sites x 4 habitats x 3 traps per = 36 traps – Malaise traps – Continuous sampling – two week intervals • quantify vegetation in each habitat – flowering plant density – plant cover sagebrush pinyon/juniper cheatgrass crested wheatgrass Results

• 162 taxa • 44 singletons • 21 doubletons – 40.1 % rare Bee abundance – site x year (p=0.04)

100.0 b

90.0

80.0

70.0

60.0 ab 50.0 aa 40.0 a a 30.0

average bee abundance/trap 20.0

10.0

0.0 Antelope Valley Tintic Valley Yuba site

2006 2007 Bee abundance by habitat (p<0.01)

120 c 100

80

60

40 a a 20 average bee abundance per trap b

0 cheatgrass crested wheatgrass juniper sagebrush habitat Bee richness by habitat (p<0.01)

35 c

30

25

20

a 15 a

10 b

average bee bee richness per trap 5

0 cheatgrass crested wheatgrass juniper sagebrush habitat 3D MDS of bee diversity by habitat

Transform: Log(X+1) Resemblance: S17 Bray Curtis similarity 3D Stress: 0.19 Habitat Cheatgrass Crested Juniper Sagebrush Prevalent and modal bee species

Cheatgrass modal habitat bee species % frequency rank species specific Lasioglossum (Dialictus) hyalinum 88.9% 1 x Lasioglossum (Lasioglossum) sisymbrii 83.3% 2 x Lasioglossum (Dialictus) incompletum 77.8% 3 x Eucera actuosa Cresson 1878 50.0% 4 Lasioglossum (Dialictus) albohirtum 50.0% 5 x x Lasioglossum (Dialictus) sed i 50.0% 6 Eucera lutziana (Cockerell) 1933 44.4% 7 Agapostemon angelicus Cockerell 1924 38.9% 8 x x Lasioglossum (Dialictus) pruinosiforme 38.9% 9 x x Lasioglossum (Evylaeus) pulveris 38.9% 10 x Lasioglossum (Dialictus) sp. 33.3% 11 Melissodes sp. 33.3% 12 Anthophora urbana Cresson 1878 27.8% 13 Lasioglossum (Dialictus) sp. 19 27.8% 14 Lasioglossum (Evylaeus) incompletum 27.8% 15 Perdita albonotata Timberlake 1954 27.8% 16 x x

Sagebrush modal habitat bee species % frequency rank species specific Eucera actuosa Cresson, 1878 55.6% 1 Eucera lutziana (Cockerell, 1933) 55.6% 2 Osmia sp. 55.6% 3 Lasioglossum (Dialictus) sp. K1 44.4% 4 Lasioglossum (Dialictus) hyalinum 38.9% 5 Lasioglossum (Lasioglossum) sisymbrii 38.9% 6 Eucera fulvitarsis Cresson, 1878 33.3% 7 Lasioglossum (Dialictus) sp. 33.3% 8 Andrena piperi Viereck, 1904 27.8% 9 x x Anthophora ursina Cresson, 1869 27.8% 10 Lasioglossum (Dialictus) sedi 27.8% 11 45 40 40

35

30 28

25 21 20 # species#

15 11 9 9 9 10 8 77

5 1 0 0 cheatgrass crested wheatgrass juniper sagebrush habitat

singletons habitat specific modal Plant richness – habitat x site (p=0.04)

14

12

10

8

6

4

2

0 Antelope Valley Tintic Valley Yuba site x habitat interaction

cheatgrass crested w heatgrass juniper sagebrush 3D MDS of flowering plant diversity by habitat

Transform: Log(X+1) Resemblance: S17 Bray Curtis similarity 3D Stress: 0.13 Habitat type Cheatgrass Crested Juniper Sagebrush Herbaceous cover

30%

25%

20%

15% % cover

10%

5%

0% Cheatgrass Crested wheatgrass Sagebrush Juniper habitat

3.5

Bee and 3 flowering plant 2.5 phenology 2

1.5 log10(x+1)

1

0.5

0

y l t a ct Apr Jul Oc M Jun Ju Aug Aug 4 8 5 Jun 3 4 8 9 O 3 abundance 2 22 May 19 17 31 Jul 1 2 11 Sep 25 Sep 2 total bee abundance mean flowering plants/hectare2

90

80

70

60

50

40 # species

30

20

10

0

l ay u ul Jun J Jul M Jun J Aug Aug Sep Sep 8 May 5 9 3 7 1 4 8 1 5 9 Oct 24 Apr 22 1 1 3 1 2 1 2 23 Oct

richness bee richness plant richness Conclusions

1. Bee diversity is influenced by habitat, site, and year 2. A strong relationship exists between flowering plant diversity and bee diversity 3. Pinyon/juniper habitat generally supports the greatest flowering plant and bee diversity 4. Crested wheatgrass supports the lowest bee abundance and diversity 5. Mature pinyon/juniper stands have high conservation value for bee populations 6. Metrics for restoration success should factor in forb abundance