Predispersal seed predation of Wyethia amplexicaule, Crepis 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 insect 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 Lepidoptera 24 Seed damage 60 40 # samples 20 average=39.0% 0 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% % seed damage 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% More 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 Phycitodes 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 floweringBee plant and phenology 3.5 3 2.5 2 abundance log10(x+1)1.5 1 0.5 0 24 Apr 8 May 90 80 22 May 70 5 Jun 60 50 19 Jun # species40 total bee abundance 3 Jul richness 30 20 17 Jul 10 31 Jul 0 14 Aug mean flowering plants/hectare2 24 Apr 28 Aug 8 May 11 Sep 22 May 25 Sep 5 Jun 9 Oct 19 Jun 23 Oct 3 Jul bee richness17 Jul 31 Jul 14 Aug plant richness28 Aug 11 Sep 25 Sep 9 Oct 23 Oct 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.