In the summers of 2017-2019, we’re sampling Portland area gardens for pollinators.  You can learn more about our work, here.

  • Garden Selection:  Our goal was to sample 20-30 Portland area home and community gardens over three years.  We advertised our project at the Fall 2016 Metro Master Gardener re-certification, which was attended by ~250 Master Gardener volunteers.  At that event, 123 folks registered their interest in participating.  After circulating a follow-up survey, with more details about the study, 56 folks noted that they remained interested in participating in the study.  From these 56 potential study sites, I chose three transects with 31 potential study sites:
    • the Urban Core:  gardens located within Portland, in highly populated neighborhoods
    • the Forest Edge: gardens located within Portland, located adjacent to Forest Park
    • the Portland Suburbs:  gardens located outside of Portland, in a peri-urban landscape

We contacted these 31 potential study sites, and heard back from 25 people.  In April 2017, we visited each of these 25 potential study sites, to ensure that they are suitable sites for this study.  We ultimately settled on 24 study sites for our 2017 sample. In 2018, we scaled back to 22 sites, to make the study easier to manage.

  • Bee Sampling Methods:  we use a modification of the standardized method for monitoring bee populations, developed by LeBuhn, Griswold, McKinley, Droege, Roulston, Cane, Parker, Buchmann, Tepedino, Williams, Kremen and Messenger. Specifically, we use colored bowl traps to passively sample bees from home gardens. Following Fetridge et al. (2008), we focus our collections in flowerbeds, rather than lawns.  We place six water pan traps into each garden (two blue, two yellow and two white), and allow the traps to passively sample bees, for 24 hours.  We also hand collect bees, allocating 10 minutes of collection time within each garden. Across all gardens, and across the three years of this study, we will have allocated nearly 2,000 hours of hand-collecting time, and will have set 1,188 pan traps.
  • Preliminary Results: (more will be added, as they are identified to species)
  • Latin Name (Common Name); Ecological Characteristics
    1. Apis mellifera
    2. Anthidium manicatum; Wool Carder BeeExotic, Cavity-Nesting, Generalist, Solitary
    3. Anthidium sp1; Cavity-Nesting, Generalist, Solitary
    4. Anthidium sp2; ; Cavity-Nesting, Generalist, Solitary
    5. Bombus flavifrons dimidiatus: Native, Hive-nesting, Generalist, Eusocial
    6. Bombus californicus: Native, Hive-nesting, Generalist, Eusocial
    7. Bombus mixtus: Native, Hive-nesting, Generalist, Eusocial
    8. Bombus vosnosenskii: Native, Hive-nesting, Generalist, Eusocial
    9. Bombus caligunosus (one male and one female)
    10. Bombus griseocollis, Native, Hive-nesting, Generalist, Eusocial
    11. Bombus sitkensis (1 male)
    12. Bombus vandykei (1 male)
    13. Melissodes sp.
    14. Agopostemon virescens (Bi-colored Striped-Sweat Bee); Native, Soil, Generalist, Solitary
    15. Agopostemon angelicus/texanus ; Native, Soil, Generalist, Solitary
    16. Agopostemon texanus (Texas Striped-Sweat Bee); Native, Soil, Generalist, Solitary
    17. Lasioglossum pacificum ; limited information available about this species. Broussard et al. 2011 recorded this 39 specimens (~3% of total bee catch) of this species across all four cranberry sites that were sampled for native bees. Distribution known to be SE corner of BC (including Vancouver Island), through coastal and subcoastal regions of OR, WA, CA, down to Santa Barbara County. Generalist feeder (48 flower records in 14 families and 22 genera). Distribution in Oregon is widespread: Benton, Clackamas, Clatsop, Columbia, Curry, Lane, Lincoln, Jackson, Douglas, Washington, Yamhill, Multnomah, Polk (McGinley 1986). Females fly Feb. to late November, with a peak in late May and June. Males fly late June to early October. Information from McGinley (1986). Studies of Halictinae (Apoidea: Halictidae), I: Revision of New World Lasioglossum Curtis. Smithsonian Contributions to Zoology. Number 429.
    18. Lasioglossum sisymbrii
    19. Lasioglossum zonulum
    20. Lasioglossum titusi
    21. Lasioglossum sp1
    22. Lasioglossum sp2
    23. Megachile rotundata
    24. Megachile angelarum
    25. Megachile perihirta
    26. Megachile sp.
    27. Ceratina (subgenus Zadontomerus) sp1
    28. Ceratina sp2
    29. Halictus ligatus
    30. Halictus tripartitus
    31. Panurginus sp.
    32. Osmia sp.
    33. Triepeolus sp.
    34. Sphecodes sp.
  • Butterflies
    • Cabbage white
    • Woodland Skipper
    • Grey Hairstreak
    • Western Tiger Swallowtail
    • California Tortoiseshell