Research on Garden Bees
At least 213 bee species have been collected from a garden. Urban areas often have more bee species than natural or agriculture areas. In urban areas, gardens promote bee abundance and diversity.
- Gardens may filter bees: gardens have fewer andrenids (spring-foraging bees), fewer soil-nesting bees, more cavity nesting bees.
- Urban areas filter bees: favors larger bees with increased dispersal ability, higher physiological stress tolerance, broader diet breadth, wider regional distribution.
- Bees have thick 3 leg. Wasps have thin 3 leg. Bees and wasps have long antennae. Flies have stubby antennae. Bees have branched hairs. Flies and wasps have straight hairs. Only bees collect pollen!
- Most gardeners are interested in pollinator conservation: 91% surveyed plant for pollinators and dedicate an estimated 515-681 acres to pollinator habitat (1,386 gardeners surveyed). Gardeners vary in their ability to identify bees and bee-friendly flowers. Oregon Bee Atlas Volunteers are the best. Master Gardeners tied for last with the general public.
Pollinator-Friendly Plants
- Most pollinator plant lists are based upon anecdotal observations. No research-based list exists for the Pacific Northwest.
- Our Study Plants: counted pollinators, vacuum-sampled plants for insects; 2017-2019 at field plots (1m2, separated by 6 m of turf on all sides) in Aurora, OR
| Common Name | Scientific Name | Perennial/Annual | Notes |
|---|---|---|---|
| Farewell-to-spring | Clarkia amoena | Annual | #4 native bee D-vac (2017); #4 Bee Species Richness (2017) |
| Giant blue eyed Mary | Collinsia grandiflora | Annual | |
| Globe gilia | Gilia capitata | Annual | #1 All Bees & Native Bees counts (2017); #2 All Bees counts (2018); #1 native bee D-vac (2017); #2 Bee Species Richness (2017); #5 Ranked by Gardeners |
| Miniature lupine | Lupinus polycarpus | Annual | |
| Common madia | Madia elegans | Annual | #2 All Bees & Native Bees counts (2017); #3 native bee D-vac (2017); #3 Bee Species Richness (2017) |
| Baby blue eyes | Nemophila menziesii | Annual | |
| California Poppy | Eschscholzia californica | Annual | #5 Native Bees counts (2017), #5 All Bees counts (2018), #1 Native Bees counts (2018), #3 Native Bee D-vac (2018); #1 Bee Species Richness (2018) |
| Common sunflower | Helianthus annuus | Annual | |
| Varied-leaf phacelia | Phacelia heterophylla | Annual | #3 Native Bees counts (2018), #1 Native Bee D- vac (2018); #2 Bee Species Richness (2018) |
| Desert deervetch | Acmispon (Lotus) parviflorus | Annual | |
| Yarrow | Achillea millefolium | Perennial | #2 Native Bee D-vac (2018); #5 Bee Species Richness (2018) |
| Pearly everlasting | Anaphalis margaritacea | Perennial | #3 Bee Species Richness (2018) |
| Showy milkweed | Asclepias speciosa | Perennial | |
| Western red columbine | Aquilegia formosa | Perennial | #1 Ranked by Gardeners |
| Douglas' aster | Aster subspicatus | Perennial | #3 All Bees & Native Bees counts (2017), #2 Native Bees counts (2018); #2 native bee D-vac (2017); #1 Bee Species Richness (2017) |
| Common camas | Camassia leichtlinii | Perennial | #3 Ranked by Gardeners |
| Oregon sunshine | Eriophyllum lanatum | Perennial | #4 Bee Species Richness (2018) |
| Wild strawberry | Fragaria vesca | Perennial | |
| Oregon iris | Iris tenax | Perennial | #2 Ranked by Gardeners |
| Cream Stonecrop | Sedum oregonense | Perennial | #5 Bee Species Richness (2017) |
| Blue-eyed grass | Sisyrinchium idahoense | Perennial | #4 Ranked by Gardeners |
| Goldenrod | Solidago canadensis | Perennial | #4 All Bees & #5 Native Bees counts (2017); #4 Native Bee D-vac (2018) |
| Italian oregano 1 | Origanum vulgare | Perennial | #1 All Bees counts (2018); #5 native bee D-vac (2017) |
| Catnip 1 | Nepita cataria | Perennial | #5 All Bees Counts (2017& 2018) |
| Pineapple Sage 1 | Salvia elegans | Perennial | |
| Lavender 1 | Lavandula intermedia | Perennial | #3 All Bees Counts (2018); #4 Native Bee D-vac (2018) |
Garden Bees
- Sampled 22-24 gardens around the Portland Metro area, 2017 and 2018.
- 2017 bees have been identified
- 36 bee species identified from 2017 samples
| Family | Species | Flight Season | Native Status | Floral Specificity | Nesting Substrate | Sociality |
|---|---|---|---|---|---|---|
| Andrenidae (Mining Bees) | Panurginus sp. 1 | ? | Non-native | Specialist | Soil | Solitary |
| Apidae (Cuckoo, Carpenter, Digger, Bumble, and Honey Bees) | Apis mellifera | Year round | Native | Generalist | Above-ground | Eusocial |
| Bombus calignosus 2 | April - October | Native | Generalist | Above-ground cavity | Eusocial | |
| Bombus flavifrons | April - September | Native | Generalist | Above-ground cavity | Eusocial | |
| Bombus fervidus / californicus | February - October | Native | Generalist | Above-ground cavity | Eusocial | |
| Bombus griseocollis | March - November | Native | Generalist | Above-ground cavity | Eusocial | |
| Bombus mixtus | February - August | Native | Generalist | Above-ground, above-ground cavity | Eusocial | |
| Bombus sitkensis | March - September | Native | Generalist | Above-ground cavity | Eusocial | |
| Bombus vandykei | April - September | Native | Generalist | Above-ground cavity | Eusocial | |
| Bombus vosnosenskii | February - October | Native | Generalist | Above-ground cavity | Eusocial | |
| Ceratina sp. 1 | April - September | Native | Generalist | Wood | Subsocial | |
| Ceratina sp. 2 | April - September | Native | Generalist | Wood | Subsocial | |
| Melissodes sp. 1 | May - September | ? | Specialist | Soil | Social parasite | |
| Halictidae (Sweat Bees) | Agopostemon virescens | April - October | Native | Generalist | Soil | Solitary |
| Agopostemon angelicus / texanum | May - October | Native | Generalist | Soil | Solitary | |
| Agopostemon texanum | May - October | Native | Generalist | Soil | Solitary | |
| Lasioglossum pacificum | February - November | Native | Generalist | Soil | Subsocial | |
| Lasioglossum sisymbrii | January - November | Native | Generalist | Soil | Solitary | |
| Lasioglossum titusi | Year round | Native | Specialist | Soil | Solitary | |
| Lasioglossum zonulum | May - November | Non-native | Generalist | Soil | Eusocial | |
| Lasioglossum sp. 1 | ? | ? | Generalist | Soil | ? | |
| Lasioglossum sp. 2 | ? | ? | Generalist | Soil | ? | |
| Halictus ligatus | April - October | Native | Generalist | Soil | Subsocial | |
| Halictus tripartitus | April - October | Native | Generalist | Soil | Subsocial | |
| Halictus rubicundus | March -October | Native | Generalist | Soil | Subsocial | |
| Halictus farinosus | April - October | Native | Generalist | Soil | Subsocial | |
| Sphecodes sp. | ? | Native | Specialist | Social parasite | Social parasite | |
| Megachilidae (Leafcutter and Mason Bees) | Anthidium manicatum | May - September | Non-native | Generalist | Below-ground cavity | Solitary |
| Anthidium sp. 1 | Summer - Early Fall | ? | Generalist | Below-ground cavity | Solitary | |
| Anthidium sp. 2 | Summer - Early Fall | ? | Generalist | Below-ground cavity | Solitary | |
| Megachile rotundata | June - August | Non-native | Generalist | Below-ground cavity | Solitary | |
| Megachile angelarum | June - September | Native | Generalist | Below-ground cavity | Solitary | |
| Megachile perihirta | May - October | Native | Generalist | Below-ground cavity | Solitary | |
| Megachile sp. 1 | Summer - Early Fall | ? | Generalist | Below-ground cavity, Wood, Soil | Solitary | |
| Osmia sp. 1 | Spring - Fall | ? | Varies | Below-ground cavity, Soil | Solitary |
Results:
- Taxon: 3% Andrenidae; 36% Apidae; 39% Halictidae; 22% Megachilidae
- Native Status: 89% native; 11% nonnative
- Floral Specificity: 96% generalists; 4% specialists
- Nesting Habit: 22% above-ground cavity nesters; 44% soil nesters; 6% social parasites; 8% wood nesters; 17% below-ground cavity nesters; 8% above-ground nesters (e.g. grass or trees)
- Sociality: 28% Eusocial; 19% Subsocial; 36% Solitary; 6% Social Parasites
Initial impressions:
- Sunnier, flower-rich gardens have more bees
- Soil nesting bees were rarer than expected. More similar to NYC bees community than to other garden bee communities.
- Ligated sweat bees, honey bees and yellow-faced bumblebees are in every garden
- Overhead irrigation seems to depress bee abundance (and diversity)
- If you plant it, they will come
Want to learn more about this topic? Explore more resources from OSU Extension:
Bees and Pollinators
