Progress 10/01/11 to 09/30/16
Outputs
Target Audience:Bee biologists; conservation organizations; Federal agencies (USFWS, APHIS, USFS; BLM; NPS; NRCS); State agencies (CDFA; CDFW, CDPR); Farmers; Beekeepers; Gardeners; School groups Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Instructed a 5-day workshop on pollinators for (Jepson Herbarium Workshops); a 3-day course for (Siskiyou Field Inst., OR); in a 10-day course on bees for academic pollination biologists (The Bee Course); a 1-day training sessions for assistants on a BLM grant; a 1-day bumble bee ID workshop for BLM and other agency personnel. I was an Instructor in a 3-day workshop on bee biology and ID (Siskiyou Field Institute); a 5-day workshop on pollinators for (Jepson Herbarium Workshops); and I was an instructor in a 10-day course on bees for academic pollination biologists (The Bee Course). I continue to serve as Co-coordinator for North America (USA) for the Bumble Bee Specialist Group of IUCN and have collaborated in submitting Red List Assessments for all 46 species of bumble bees of NA north of Mexico. How have the results been disseminated to communities of interest?Results of my research were disseminated via: invited presentations and abstracts at meetings (12); tours and bioblitz days (16); news articles (1); phone and radio interviews (8). What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Farmers, gardeners, and school groups are putting into practice bee friendly habitat using guidelines provided. US Fish and Wildlife Service is currently considering petition I coauthored to protect Franklin's Bumble Bee, BOMBUS FRANKLINI, under the National Endangered Species Act. USDA-APHIS is currently considering a petition submitted by Xerces Society, NRDC, Defenders of Wildlife and me regarding regulation of interstate movement of commercial bumble bees to protect local bumble bees and honey bees. USFWS just listed the Rusty Patched Bumble Bee, BOMBUS AFFINIS as endangered under the ESA, based on a petition that I coauthored with the Xerces Society in 2013.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Leong, M., L. Ponisio, C. Kremen, R. Thorp, G. Roderick. 2016. Temporal dynamics of global change: bee community phenology in urban, agricultural, and natural landscapes. Global Change Biology 22:1046-1053.
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Ponisio, LC, K Wilkin, LK MGonigle, K Kulhanek, L Cook, R. Thorp, T Griswold, and C Kremen. 2016 Pyrodiversity begets pollinator community diversity. Global Change Biology (2016) 1-15 [doi: 10.1111/gcb.13236]
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Cameron, SA, HC Lim, JD Lozier, MA Duennes, and R Thorp. 2016. Test of the invasive pathogen hypothesis of bumble bee decline in North America. PNAS Early Edition [doi/10.1073/pnas.1525266113].
- Type:
Book Chapters
Status:
Published
Year Published:
2016
Citation:
Reade, C., K. Goka, R. Thorp, M. Mitsuhata, and M. Wasbauer. 2016. CSR, Biodiversity and Japans stakeholder approach to the global bumble bee trade. In: J Atkins and B Atkins, eds. The Business of Bees, Greenleaf Publishing. Chapter 4, pp 69-88.
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Target audiences for my research efforts include: Bee Biologists; Conservation Organizations; Federal Agencies (US FWS, APHIS, USFS); Farmers; Gardeners and school groups Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?I mentor graduate students and employees of colleagues on basics of bee genera and species IDs. How have the results been disseminated to communities of interest?Results of my research were disseminated via: invited presentations at meetings (5); tours (23); news articles (5) and radio and TV interviews (3) in addition to the scientific journal articles listed above. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Farmers, gardeners, and school groups are putting into practice bee friendly habitat using guidelines provided and US Fish and Wildlife Service is currently considering a petition I coauthored to protect the Rusty-Patched Bumble Bee, BOMBUS AFFINIS, under the National Endangered Species Act and has recently given it a positive 90-day finding.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Kleijn, D. et al. (Winfree, Bartomeus, Carvalheiro, Henry, Isaacs, Klein, Kremen, MGonigle, Rader, Ricketts, Williams, Adamson, Ascher, Baldi, Batary, Benjamin, Biesmeijer, Blitzer, Bommarco, Brand, Bretagnolle, Button, Cariveau, Chifflet, Colville, Danforth, Elle, Garratt, Herzog, Holzschuh, Howlett, Jauker, Jha, Knop, Krewenka, Le Feon, Mandelik, May, Park, Pisanty, Reemer, Riedinger, Rollin, Rundlof, Sardinas, Scheper, Sciligo, Smith, Steffan-Dewenter, Thorp, Tscharntke, Verhulst, Viana, Vaissiere, Veldtman, Ward, Westphal, Potts). (2015). Delivery of pollination services is an insufficient argument for pollinator conservation. Nature Communications 6:7414
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Forrest, JRK, RW Thorp, C Kremen, NM Williams. (2015). Contrasting patterns in species and functional-trait diversity of bees in an agricultural landscape. J Applied Ecol. 52:706-715
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Reade, C. W., R. Thorp, K. Goka, M. Wasbauer, M. R. McKenna. [2015]. Invisible compromises: Global business, local ecosystems, and the commercial bumble bee trade. Organization & Enviromnent 1-22
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Bee biologists; conservation organizations; Federal agencies (USFWS, APHIS, USFS; BLM; NPS; NRCS); State agencies (CDFA; CDFW, CDPR); Farmers; Beekeepers; Gardeners; School groups Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Instructor in a 5-day workshop on pollinators for (Jepson Herbarium Workshops); in a 10-day course on bees for academic pollination biologists (The Bee Course); and in two bumble bee ID workshops. How have the results been disseminated to communities of interest? Results of my research were disseminated via: invited presentations at meetings (9); tours (20); news articles (1) and radio interviews (2). What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Farmers, gardeners, and school groups are putting into practice bee friendly habitat using guidelines provided. US Fish and Wildlife Service is currently considering a petition I coauthored to protect Franklin's Bumble Bee, BOMBUS FRANKLINI, under the National Endangered Species Act. USDA-APHIS is currently considering a petition submitted by Xerces Society, NRDC, Defenders of Wildlife and me regarding regulation of interstate movement of commercial bumble bees to protect local bumble bees and honey bees.
Publications
- Type:
Books
Status:
Published
Year Published:
2014
Citation:
Williams, PH., RW Thorp, LL Richardson, & SR Colla. 2014. Bumble Bees of North America: An Identification Guide. Princeton Univ. Press. 208pp.
- Type:
Books
Status:
Published
Year Published:
2014
Citation:
Frankie, GW, RW Thorp, R Coville, and B. Ertter. 2014. California Bees & Blooms. A Guide for Gardeners and Naturalists. Heyday Press 296 pp.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Reade, C., K. Goka, R. Thorp, M. Mitsuhata, M Wasbauer. 2014. CSR, biodiversity and Japans stakeholder approach to the global bumble bee trade. J Corporate Citizenship 56:53-66.
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: Target audiences for my research efforts include: Bee Biologists; Conservation Organizations; Federal Agencies (US FWS, APHIS, USFS); Farmers; Gardeners and school groups Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? My studies of bees in urban gardens and restored farmlands in California were in collaboration with the lab groups of GW Frankie (UC Berkeley); C Kremen (UC Berkeley); and NM Williams (UC Davis). How have the results been disseminated to communities of interest? Results of my research were disseminated via: invited presentations at meetings (7); tours (9), video interview (3); and radio interviews (1). I was an instructor in a 2-day workshop on pollinators for the UC Santa Cruz Arboretum; and I was an instructor in a 10-day course on bees for academic pollination biologists (The Bee Course). I continue to serve as Co-coordinator for North America (USA) for the Bumble Bee Specialist Group of IUCN. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Farmers, gardeners, and school groups are putting into practice bee friendly habitat using guidelines provided. US Fish and Wildlife Service is currently considering a petition I coauthored to protect Franklin’s Bumble Bee, BOMBUS FRANKLINI, under the National Endangered Species Act. USDA-APHIS is currently considering a petition submitted by Xerces Society, NRDC, Defenders of Wildlife and me regarding regulation of interstate movement of commercial bumble bees.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Results of my research were disseminated via: invited presentations at meetings (2); tours (10); video interview (1); and audio interviews (3). I was an instructor in a 2-day workshop on pollinators for the Jepson Herbarium, UC Berkeley; and I was an instructor in a 10-day course on bees for academic pollination biologists (The Bee Course). I continue to serve as Co-coordinator for North America (USA) for the Bumble Bee Specialist Group of IUCN. PARTICIPANTS: My studies of bees in urban gardens and restored farmlands in California were in collaboration with the lab groups of GW Frankie (UC Berkeley); C Kremen (UC Berkeley); and NM Williams (UC Davis). TARGET AUDIENCES: Target audiences for my research efforts include: Bee Biologists; Conservation Organizations; Federal Agencies (US FWS, APHIS); Farmers; Gardeners and school groups PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Farmers, gardeners, and school groups are putting into practice bee friendly habitat using guidelines provided. US Fish and Wildlife Service is currently considering a petition I coauthored to protect Franklin's Bumble Bee, BOMBUS FRANKLINI, under the National Endangered Species Act. In September 2012 BOMBUS FRANKLINI was put on the IUCN list of the "100 most threatened species."
Publications
- Thorp, R. W. 2012. Native bees and flowers in California prairies and grasslands. Fremontia 39 (2&3):40 2011. Publication date October 2012.
- Kimoto, C., S. J. DeBano, R. W. Thorp, R. V. Taylor, H. Schmalz, T. DelCurto, T. Johnson, P. L. Kennedy, and S. Rao. 2012. Short-term responses of native bees to livestock and implications for managing ecosystem services in grasslands. Ecosphere 3(10):88.(pp 1-19) http://dx.doi.org/10.1890/ES12-00118.1
- Kimoto C, DeBano SJ, Thorp RW, Rao S, Stephen WP. 2012. Investigating temporal patterns of a native bee community in a remnant North American bunchgrass prairie using blue vane traps. Journal of Insect Science 12:108. Available online: http://www.insectscience.org/12.108 Published: 6 September 2012 ISSN: 1536-2442 Volume 12, Article 108, Pages 1-23.
- Klein, A-M., C. Brittain, S. D. Hendrix, N. Williams, R. Thorp, and C. Kremen. 2012. Wild pollination services for California almond rely on semi-natural habitat. Journal of Applied Ecology 49:723-732.
- Thorp, R. W. 2012. Biodiversity of native bees and crop pollination with emphasis on California. Pp. 526-537. In: Gepts, P., T. R. Famula, R. L. Bettinger, S. B. Brush, A. B. Damania, P. E. McGuire, and C. O. Qualset, eds. Biodiversity in Agriculture. Domestication, Evolution, and Sustainability. Cambridge University Press. 606 pp.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Results of my research were disseminated via: invited presentation at meetings (10); tours (10); video interview (1); audio interviews (3); and interviews published in newspapers and magazines (6). I was an instructor in a 2-day workshop for Citizen Science pollinator monitoring; and I was an instructor in a 10-day course on bees for academic pollination biologists (The Bee Course). I was coauthor on a poster presentation at the International Pollination Symposium in Mexico. I am the Co-coordinator for North America (USA) for the newly established Bumble Bee Specialist Group of IUCN. PARTICIPANTS: My studies of bees in urban gardens and restored farmlands in California were in collaboration with the lab groups of GW Frankie (UC Berkeley); C Kremen (UC Berkeley); and NM Williams (UC Davis). TARGET AUDIENCES: Target audiences for my research efforts include: Bee Biologists; Conservation Organizations; Federal Agencies (US FWS, APHIS); Farmers; Gardeners and school groups PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Farmers, gardeners, and school groups are putting into practice bee friendly habitat using guidelines provided. US Fish and Wildlife Service is currently considering a petition I coauthored to protect Franklin's Bumble Bee, BOMBUS FRANKLINI, under the National Endangered Species Act.
Publications
- Frankie, G. W, R. W. Thorp, J. Pawelek, B. Ertter, J. Hernandez and M. Ponder. 2011. California native bees and native flowering plants: How close is the relationship pp. 78-81. In: Willoughby Et Al. Eds, Strategies & Solutions. Proceedings CNPS Conservation Conference, 17-19 Jan 2009 Sacramento, CA
Kissinger, C. N., S. A. Cameron, R. W. Thorp, B. White, and L F. Solter. 2011. Survey of bumble bees (Bombus) pathogens and parasites of in Illinois and selected areas of northern California and southern Oregon. Journal of Invertebrate Pathology. 107:220-224.
Kreman, C., K. S. Ullman and R. W. Thorp. 2011. Evaluating the quality of citizen-science data on pollinator communities. Conservation Biology 25(3):607-617 (June 2011)
Wolf, A. T. and R. Thorp. 2011. Plant-pollinator interactions in naturally fragmented habitats. Pp. 275-296. In: Harrison S. and N. Rajakaruna. Serpentine. The Evolution and Ecology of a Model System. University of California Press. 446 pp.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Results of my research were disseminated via: invited presentations at meetings (12); tours (2); video interviews (2); interviews published in newspapers and magazines (5); and a poster at the ESA Annual Meeting, San Diego. I was an instructor in 3 workshops of 2 to 10 days on bees and other pollinators for federal agency (NRCS, US Forest Service) and academic pollination biologists (The Bee Course). I coauthored 3 petitions to federal agencies (US FWS; and USDA/APHIS) regarding conservation of bumble bees. PARTICIPANTS: My studies of bees in urban gardens and restored farmlands in California were in collaboration with the lab groups of GW Frankie (UC Berkeley) and C Kremen (UC Berkeley). TARGET AUDIENCES: Target audiences for my research efforts include: Bee Biologists; Conservation Organizations; Federal Agencies (US FWS, APHIS); Farmers; and Gardeners. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Farmers and gardeners are putting into practice bee friendly habitat using guidelines provided. US Fish and Wildlife Service is currently considering a petition to protect Franklin's Bumble Bee, BOMBUS FRANKLINI, under the National Endangered Species Act. USDA/APHIS is currently considering petitions to provide specific protections to native bumble bees.
Publications
- Pawelek, J., G. Frankie, R. Thorp, and R. Coville. 2010. Starting your native bee sanctuary. Pacific Horticulture [Apr/May/Jun 2010] 71 (2): 16-19.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: CROP POLLINATION: Identified over 5,600 bees in 5 families, 27 genera and 68 species for collaborative studies on almond pollination by native bees and farm habitat restorations to enhance bee populations for crop pollination. URBAN BEES: Over 1,550 bees identified in 5 families, 41 genera, and 189 species for collaborative studies on urban gardens as habitat for native bees. Bee diversity prior to planting Honey Bee Haven Garden at UC Davis was: 5 families, 19 genera, and 44 species. BIODIVERSITY AND ECOLOGY: Surveys of historic sites located no BOMBUS FRANKLINI in 2009, but did find four workers and one male of B. OCCIDENTALIS, a closely related species that had declined severely in the same areas. INVASIVES: No honey bees were found on Santa Cruz Island in 2009 five years since the last one seen confirming removal success. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Farm restoration and urban gardens provide can suitable habitat for bees. Both floral resources (pollen and nectar) as food, and nesting substrates enable reproductive success and enhance diversity and abundance of native bees. These bees provide essential pollination services to crops, gardens and wildflowers in surrounding landscapes.
Publications
- 1. Hranitz, J. M., J. F. Barthell, R. W. Thorp, L. M. Overall, and J. L. Griffith. 2009. Nest site selection, influences mortality and stress in developmental stages of Megachile apicalis Spinola (Hymenoptera: Megachilidae). Environmental Entomology 38(2).:484-492. (April 2009) 2. McIver, J., R. Thorp, and K. Erickson. 2009. Pollinators of the invasive plant yellow starthistle in northeastern Oregon. Weed Biology and Management. 9(2):137-145. 3. Frankie, G. W., R. W. Thorp, J. Hernandez, M. Rizzardi, B. Ertter, J. C. Pawelek, S. L. Witt, M. Schindler, R. Coville, and V. Wojcik. 2009. Native bees are a rich natural resource in urban California gardens. California Agriculture. 63(3):113-120 (July-Sept. 2009). 4. Barthell, J. F., M. L. Clement, D. S. Song, A. N. Savitski, J. M Hranitz, T. Petanidou, R. W. Thorp, A. M. Wenner, T. L. Griswold and H. Wells. 2009. Nectar secretion and bee guild characteristics of yellow star-thistle on Santa Cruz Island and Lesvos: Where have all the honey bees gone Uludag Bee Journal. 9(3):109-121. 5. Frankie, G. W., R. W. Thorp, J. C. Pawelek, J. Hernandez and R. Coville. 2009. Urban bee diversity in a small residential garden in northern California. Journal of Hymenoptera Research. 18(2):368-379. 6. Wenner, A. M., R. W. Thorp, J. F. Barthell. 2009. Biocontrol and eradication of feral honey bee colonies from Santa Cruz Island, California: A summary. Proceedings 7th California Islands Symposium. Institute for Wildlife Studies, Arcata, CA. pp. 327-335. 7. Hernandez, J., G. W. Frankie and R. W. Thorp. 2009. Ecology of Urban Bees: A review of current knowledge and directions for future study. Cities and the Environment vol 2, issue 1, article 3, 15 pp. http://escholarship.bc.edu/cate/vol2/iss1/3/ 8. Pawelek, J., G. W. Frankie, R. W. Thorp, M. Przbylski. 2009. Modification of a community garden to attract native bee pollinators in urban San Luis Obispo, California. Cities and the Environment vol 2, issue 1, article 7, 20 pp. http://escholarship.bc.edu/cate/vol2/iss1/7/
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: CROP POLLINATION: Identified over 15,000 bees in 5 families, 22 genera and 60 species for studies on farm restoration to enhance native bee populations for crop pollination. URBAN BEES: Identified over 1,000 bees in 5 families, 35 genera, and 140 species for studies on gardens as habitat for native bees. BIODIVERSITY AND ECOLOGY: Surveys of historic sites found no BOMBUS FRANKLINI in 2008 and only one worker of B. OCCIDENTALIS. The latter species had not been seen in the area since 2002. Added 5 species to bee biodiversity survey of Santa Cruz Island. BEE BIOLOGY: Nest of BOMBUS MELANOPYGUS in a bird house successfully transferred 30 miles. INVASIVES: No honey bees were found Santa Cruz Island in 2008. It has now been four years since the last honey bee was found confirming the success of our efforts to remove this exotic species from the island. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Farm restoration and carefully designed urban gardens that provide suitable habitat for bees including floral resources (pollen and nectar) as food and nesting substrates enabling them to complete their reproduction enhance diversity and abundance of native bees. These bees provide important pollination services to crops, gardens and wildflowers in the surrounding environs.
Publications
- Wojcik, V. A., G. W. Frankie, R. W. Thorp, and J. L. Hernandez. 2008. Seasonality in bees and their floral resource plants at a constructed urban bee habitat in Berkeley, California. Journal of the Kansas Entomological Society 81(1):15-28.
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Progress 01/01/07 to 12/31/07
Outputs
CROP POLLINATION: Identified over 3200 bees in 5 families, 21 genera and 50 species for studies on farm restoration to enhance native bee populations for crop pollination. URBAN BEES: Identified over 700 bees in 5 families 38 genera and 145 species for studies on gardens as habitat for native bees. BIODIVERSITY AND ECOLOGY: Surveys of historic sites found no BOMBUS FRANKLINI in 2007. Only two B. OCCIDENTALIS were confirmed from collections by cooperators east of areas surveyed in northern California and southern Oregon. In 2007, added three generalist native bee species to the guild of pollinators of the endangered Suisun Thistle found in 2005. BEE BIOLOGY: Nests of ANDRENA BLENNOSPERMATIS, a solitary bee that specializes in pollen of a vernal pool plant were found along the edge of a road about 100 meters from the nearest host plants. INVASIVES: No honey bees were found Santa Cruz Island in 2007. It has now been three years since the last honey bee was found
confirming the success of our efforts to remove this exotic species from the island. A petition by a commercial producer to introduce exotic bumble bees to California for open field crop pollination was denied as the result of a collaborative responses that emphasized the environmental risks and suggested use of native bumble bees instead.
Impacts
The diversity of native bees can be enhanced by farm restoration and carefully designed urban gardens that provide suitable floral resources (pollen and nectar) as food for bees and nesting substrates for them to complete their reproduction. These bee populations provide an important ecological service, pollination, to crops, gardens and wildflowers in the surrounding environs.
Publications
- Peter G. Kevan, Dan Eisikowitch, Wanja Kinuthia, Peter Martin, E. C. Mussen, Uma Partap, O. R. Taylor, Vernon G. Thomas, R. W. Thorp, Carlos H. Vergara, & Kimberly Winter. 2007. High quality bee products are important to agriculture: why, and what needs to be done. J Apicultural Research 46(1):59-64.
- Thorp, R. W. 2007. Biology of specialist bees and conservation of showy vernal pool flowers. A review. Pages 51-57. in R. A. Schlising and D. G. Alexander (Editors), The Vernal Pool Landscapes. Studies from the Herbarium, Number 14. California State University, Chico, CA.
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Progress 01/01/06 to 12/31/06
Outputs
CROP POLLINATION: Cooperated on farm restoration project to enhance native bees as crop pollinators. URBAN BEES: Cooperated in evaluating urban gardens as habitat for native bees. BIODIVERSITY AND ECOLOGY: No BOMBUS OCCIDENTALIS and only one worker of B. FRANKLINI were seen in 2006. BEE BIOLOGY: Nest sites of several specialist vernal pool bees were found in bare soil adjacent to patches of the endangered plant, Contra Costa Goldfields, in Fairfield, California. A fungus feeding nematode, BURSAPHELENCHUS KEVINI, phoretic in the sweat bee, HALICTUS FARINOSUS, collected on Santa Cruz Island, CA provided DNA for phylogenetic studies. INVASIVES: Removal of honey bees from Santa Cruz Island appears successful. None were seen in 2006 and it has been more than two years since the last sighting. A white paper was produced evaluating risks of importing exotic bumble bees to North America.
Impacts
Farm land set aside or restored to provide habitat for native bees can enhance crop pollination. Urban gardens can provide habitat for native bees to offset declining pollinator populations. Native bumble bee population declines are of increasing concern. Commercial trafficking in bumble bees has risks as well as benefits. Native bumble bees reared locally should be used whenever possible.
Publications
- Giblin-Davis, R.M., H. Selcuk, B.J. Center, W. Ye, N. Keskin, R. Thorp, and W.K. Thomas. 2005. Bursaphelenchus anatolius n. sp. (Nematoda: Parasitaphelenchidae), an Associate of Bees in the Genus Halictus. J. Nematology 37(3):336-342.
- Winter, K, L. Adams, R. Thorp, D. Inouye, L. Day, J. Ascher, S. Buchmann. 2006. Importation of non-native bumble bees to North America: Potential consequences of using Bombus terrestris and other non-native bumble bees for greenhouse crop pollination in Canada, Mexico and the United States. A White Paper of the North American Pollinator Protection Campaign (NAPPC) (August 2006). 35 pp. http://www.pollinator.org/Resources/BEEIMPORTATION_AUG2006.pdf
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Progress 01/01/05 to 12/31/05
Outputs
CROP POLLINATION: In addition to proximity to wild land areas, urban areas and farm restorations provide and may enhance native bee populations for pollination of nearby crops. BIODIVERSITY AND ECOLOGY: The narrow endemic BOMBUS FRANKLINI and widespread B. OCCIDENTALIS were not found during intensive searches in CA and OR in 2005. Related eastern bumble bee species are also declining. Declines appear due to an exotic strain of pathogen, NOSEMA BOMBI. Five new species of ANDRENA were described in two subgenera. BEE BIOLOGY: Small bees avoid MALACOTHAMNUS stigmas when foraging for nectar. INVASIVES: No honey bees were found on Santa Cruz Island in 2005. Tests showed that invasive yellow star-thistle reduced native bee visits to native gumplant.
Impacts
In addition to the importance of adjacent wild land areas, crops may benefit from enhanced native bee habitat in urban gardens and farm restorations. Decline of bumble bee populations is of increasing concern. Investigations are needed to determine causes and remedies. Invasive pollinators enhance reproduction of invasive plants. These invasive plants may reduce visits of native pollinators to native plants via competition.
Publications
- Frankie, G. W., R. W. Thorp, M. Schindler, J. Hernandez, B. Ertter, M. Rizzardi. 2005. Ecological patterns of bees and their host ornamental flowers in urban Berkeley, California. J. Kansas Entomol. Soc. 78(3):227-246.
- Barthell, J. F., R. W. Thorp, A. M. Wenner, J. M. Randall, and D. S. Mitchell. 2005. Seed set in a non-native self-compatible thistle on Santa Cruz Island: implications for the invasion of an island ecosystem. pp. 185-191. In: Garcelon, D. K. and C. A. Schwemm (Eds.) Proc. 6th California Islands Symposium, Ventura, December 1-3, 2003. National Park Service Technical Publication CHIS-05-01, Institute for Wildlife Studies, Arcata, CA.
- W. E. LaBerge and R. W. Thorp. 2005. A Revision of the Bees of the Genus Andrena of the Western Hemisphere. Part XIV. Subgenus Onagrandrena. Illinois Natural History Survey, Bulletin 37 (1):1-63.
- R. W. Thorp and W. E. LaBerge. 2005. A Revision of the Bees of the Genus Andrena of the Western Hemisphere. Part XV. Subgenus Hesperandrena. Illinois Natural History Survey, Bulletin 37 (2):65-93.
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Progress 01/01/04 to 12/31/04
Outputs
CROP POLLINATION: Collections of native bees from sustainable ag farms and adjacent wild land areas in Yolo and Butte counties, CA include over 55 not previously recorded and bring the total to nearly 350 species and morphospecies. BIODIVERSITY AND ECOLOGY: The narrow endemic BOMBUS FRANKLINI continues to decline. None were found in 2004 nor were any of the related, formerly common and widespread B. OCCIDENTALIS. Decline appears due to a strain of pathogen, NOSEMA BOMBI. Morphology of male genitalia suggests B.FRANKLINI is most closely related to B. AFFINIS of eastern North America. BEE BIOLOGY: A fungus feeding nematode, BURSAPHELENCHUS KEVINI, phoretic associate of the sweat bee, HALICTUS FARINOSUS, found on Santa Cruz Island, CA provided DNA for phylogenetic studies. INVASIVE MUTUALISTS: Honey bee removal from Santa Cruz Island appears nearly complete. Less than 20 were seen at one site in July/August and none were seen in September 2004. Combined with increased
numbers of seed predatory teprtitid flies, has resulted in decreased seed set in yellow star-thistle.
Impacts
We continue to expand our knowledge of diversity, resource use and pollination services provided by native bees to sustainable ag farm crops and the contribution of adjacent wild land habitats to the system. Decline of bumble bee populations is of increasing concern and in need of investigation as to cause(s). Reduced pollination and increased seed predation may effectively reduce reproduction of some weeds.
Publications
- Kremen, C., N.M. Williams, R.L. Bugg, J.P. Fay, and R.W. Thorp. 2004. The area requirements of an ecosystem service: Crop pollination by native bee communities in California. Ecology Letters 7(11):1109-1119.
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Progress 01/01/03 to 12/31/03
Outputs
CROP POLLINATION: Collections of native bees from sustainable ag farms and adjacent wild land areas in Yolo County, CA include over 80 not previously recorded and bring the total to just over 300 species and morphospecies. VERNAL POOL POLLINATORS: A new western record of PANURGINUS n sp, an oligolege of DOWNINGIA is near Livermore, CA. Observations at three sites suggest that nests of this bee may be inundated for a month or more during the winter. BIODIVERSITY AND ECOLOGY: The narrowly endemic BOMBUS FRANKLILNI continues to decline. DNA sequencing of one male suggests a relationship with B. LUCORUM. Collections of bees on yellow star-thistle and cinquefoil in eastern OR include 66 new records for a total of 108 species. Bees in a newly established garden in Berkeley include 17 species, 4 new to the area. BEE BIOLOGY: Long curved genal hairs of female OSMIA GLAUCA are used in mud collection and transportation for nest construction, not for pollen collection as
previously suggested. INVASIVE MUTUALISTS: On Santa Cruz Island, CA, reduction in honey bee populations and increased seed predation by tephritid flies combine to reduce overall seed set in control heads of yellow star-thistle in contrast to experiments conducted 10 years ago.
Impacts
We continue to expand our knowledge of diversity and resource use by native bees on sustainable ag farms, adjacent wildlands, and urban gardens. Newly established gardens attract bees as soon as bloom is available. Reduced pollination and increased seed predation may effectively reduce reproduction of some weeds.
Publications
- Barthell, J. F., J. M. Hranitz, R. W. Thorp, and M. K. Shue. 2003 High temperature responses in two exotic leafcutting bee species : Megachile apicalis and M. rotundata (Hymenoptera: Megachilidae). Pan-Pacific Entomologist 78(4):235-246 [2002].
- Frankie, G. W., and R. W. Thorp. 2003. Pollination and pollinators. pp. 919-926 In Resh, V. H. and R. T. Carde (eds). Encyclopedia of Insects. Academic Press, Elsevier Science, St. Louis MI 1205pp.
- Thorp, R. W., P. C. Schroeder, and C. S. Ferguson. 2003. Bumble bees: Boisterous pollinators of native California flowers. Fremontia 30(3-4):26-31 [Jul/Oct 2002 distributed May 2003].
- Kremen, C., R. L. Bugg, N. Nicola, S. A. Smith, R. W. Thorp, and N. M. Williams. 2003. Native bees, native plants and crop pollination in California. Fremontia 30(3-4):41-49 [Jul/Oct 2002 distributed May 2003].
- Frankie, G. W., R. W. Thorp, M. H. Schindler, B. Ertter, M. Przybylski. 2003. Bees in Berkeley? Fremontia 30(3-4):50-58 [Jul/Oct 2002 distributed May 2003].
- Thorp, R. W. 2003. Bumble bees (Hymenoptea: Apidae): commercial use and environmental concerns. Pp. 21-40. In: K. Strickler and J. H. Cane (eds.). For nonnative crops, whence pollinators of the future? Thomas Say Publications in Entomology: Proceedings. Entomological Society of Amererica, Lanham, MD. (204pp.)
- Barthell, J. F., R. W. Thorp, G. W. Frankie, J.-y. Kim, and J. M Hranitz. 2003. Impacts of introduced solitary bees on natural and agricultural systems: the case of the leaf-cutting bee, Megachile apicalis (Hymenoptera: Megachilidae). Pp. 151-162. In: K. Strickler and J. H. Cane (eds.). For nonnative crops, whence pollinators of the future? Thomas Say Publications in Entomology: Proceedings. Entomological Society of Amererica, Lanham, MD. (204pp.)
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Progress 01/01/02 to 12/31/02
Outputs
CROP POLLINATION: Collections of bees on sustainable ag farms and adjacent wildland areas of the Capay Valley include 31 species beyond the 196 already identified. VERNAL POOL POLLINATORS: An undescribed species of PANURGINUS, a specialist that collects pollen from short anther column species of DOWNINGIA was also found to collect pollen from D. INSIGNIS, a long anther column species. BIODIVERSITY AND ECOLOGY: Populations of the narrowly endemic BOMBUS FRANKLINI remain rare. A few workers and at least one autumn queen were seen at three historic sites in southern Oregon. One spring queen of its more widespread relative B. OCCIDENTALIS was seen in Oregon. About 80 species of bees were found in urban Berkeley gardens. BEE BIOLOGY: Levels of stress protein Hsp 70 were significantly higher in MEGACHILE APICALIS eggs and larvae in nests exposed to sun versus shaded sites.
Impacts
We are expanding knowledge of diversity and resource use by native bees on sustainable ag farms, adjacent wildlands, and in urban gardens. Vernal pool ecosystems house undescribed native bees with poorly known biologies. Female MEGACHILE APICALIS that place their offspring in thermally extreme microhabitats facilitate invasion into habitats with otherwise unoccupied nesting niches.
Publications
- Frankie, G. W., S. B. Vinson, R. W. Thorp, M. A. Rizzardi, N. Zamora, and P. Ronchi. 2002. Coexistence of Africanized honey bees and native bees in the Costa Rican seasonal dry forest. pp. 327-339 In: Erickson, E. H., Jr., R. E. Page, Jr., and A. A. Hanna, eds. Proceedings of the Second International Conference on Africanized Honey Bees and Bee Mites. Tucson, AZ April 2000 A. I. Root Co. Medina, OH
- Wenner, A. M. and R. W. Thorp. 2002. Collapse and resurgence of feral colonies after Varroa arrival. pp. 159-166. In: Erickson, E. H., Jr., R. E. Page, Jr., and A. A. Hanna, eds. Proceedings of the Second International Conference on Africanized Honey Bees and Bee Mites. Tucson, AZ April 2000 A. I. Root Co. Medina, OH
- Frankie, G. W., S. B. Vinson, R. W. Thorp, M. A. Rizzardi, M. Tomkins, L. E. Newstrom-Lloyd. 2002. Monitoring: An essential tool in bee ecology and conservation. pp. 187-198. In: Kevan, P. G. and V. L. Imperatriz-Fonseca (eds.), Pollinating bees. The conservation link between agriculture and nature. Proceedings Workshop Conservation and Sustainable Use of Pollinators in Agriculture, with Emphasis on Bees. Sao Paulo, Brazil (October 1998). Brasilia: Ministry of Environment, 2002. 313 pp.
- Kremen, C., N. M. Williams, and R. W. Thorp. 2002. Crop pollination from native bees at risk from agricultural intensification. Proceedings National Academy of Sciences. 99(26):16812-16816.
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Progress 01/01/01 to 12/31/01
Outputs
CROP POLLINATION: All important native bee pollinators of watermelon on sustainable ag farms were also found in adjacent wildlands. VERNAL POOL POLLINATORS: Nests of ANDRENA BLENNOSPERMATIS were found in upland bare soil areas within 50m of their pollen host plants. BIODIVERSITY AND ECOLOGY: Populations of the narrowly endemic BOMBUS FRANKLINI continue to decline from 1998 through 2001. Its more widespread relative B. OCCIDENTALIS, once reared commercially for hothouse tomato pollination, has virtually disappeared from the Pacific Coast states since 1998. BEE BIOLOGY: Mortality and quantities of stress protein "heat shock 70" were significantly higher in MEGACHILE ROTUNDATA than in its close relative M. APICALIS at several high temperature exposures indicating more pronounced heat stress in the former.
Impacts
Wildlands adjacent to sustainable ag farms provide habitat for all the important pollinators of watermelon. This demonstrates the importance of maintaining healthy wildland ecosystems near farms. Declines in populations of some native bumble bees threatens some crop pollination systems. More pronounced heat stress helps explain differences in spread, distribution, and habitat selection between two invasive learcutting bee species.
Publications
- Dag, A., S. A. Weinbaum, R. W. Thorp, and D. Eisikowitch. 2000. Pollen dispensers (inserts) increase fruit set and yields in almonds under some commercial conditions. J Apicultural Research 39(3-4): 117-123.
- Kim, J-y. and R. W. Thorp. 2001. Maternal investment and size-number trade-off in a bee, Megachile apicalis, in seasonal environments. Oecologia 126:451-456.
- Barthell, J. F., J. M. Randall, R. W. Thorp, and A. M. Wenner. 2001. Promotion of seed set in yellow star-thistle by honey bees: evidence of an invasive mutualism. Ecological Applications 11(6): 1870-1883.
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Progress 01/01/00 to 12/31/00
Outputs
CROP POLLINATION: We identified over 20 species of native bees visiting a variety of crops in Yolo and Solano counties. Native bees provide 81% of watermelon pollination on farms near wildlands, versus 9% on farms distant from wildlands. VERNAL POOL POLLINATORS: A bee that specializes on DOWNINGIA pollen was determined to be an undescribed species. BIODIVERSITY AND ECOLOGY: Populations of BOMBUS FRANKLINI, a narrow endemic in northern California and southern Oregon, continued to decline from 1998 through 2000. BOMBUS OCCIDENTALIS, formerly a common bumble bee at Bodega Reserve, has not been found during the past two years. Flower visits by honey bees show a disproportionate use of introduced plants.
Impacts
Native bees that pollinate crops and wildlands as sources of native bees are overlooked resources. An unnamed vernal pool bee shows how little we know about wildlands. These affirm our need to preserve wildland ecosystems to keep ecological services intact. This is important since honey bee availability is threatened, and there are worldwide concerns of pollinator declines, e.g., bumble bees.
Publications
- Barthell, J. F., Thorp, R. W., Wenner, A. M. and Randal, J. M. 2000. Yellow star-thistle, gumplant and feral honey bees on Santa Cruz Island: A case of invaders assisting invaders. pp. 269-273. In: Proceedings 5th Channel Islands Symposium [on CD Feb. 2000].
- Thorp, R. W., Wenner, A. M., and Barthell, J. F. 2000. Pollen and nectar resource overlap among bees on Santa Cruz Island. pp. 261-268. In: Proceedings 5th Channel Islands Symposium [on CD Feb. 2000].
- Mussen, E. C. and Thorp, R. W. 2000. Beekeeping in California. Honeybee Science 21(1):1-8. [In Japanese with English summary]
- Wenner, A. M., Thorp, R. W., and Barthell, J. F. 2000. Removal of European honey bees from the Santa Cruz Island Ecosystem. pp. 256-260. In: Proceedings 5th Channel Islands Symposium [on CD Feb. 2000].
- Thorp, R. W. 2000. The collection of pollen by bees. Plant Systematics and Evolution 222:211-223.
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Progress 01/01/99 to 12/31/99
Outputs
ALMOND POLLINATION: Experiments with hive inserts for pollen distribution by honey bees showed significant increases in fruit set and yield in Nonpareil at 50 meters from colonies with pollen inserts in a 1:2:1 planting design, but not at 150 meters. VERNAL POOL POLLINATORS: Females of a PANURGINUS bee that are pollen specialists on DOWNINGIA were found to have modified facial hairs that are used in conjunction with head rubbing behavior to remove pollen from the nototribic flowers. BEE IDENTIFICATIONS: Bees were identified for cooperative studies of biodiversity on serpentine versus non-serpentine soils and sustainable agriculture farms near and away from wildlands. SYSTEMATICS AND ECOLOGY: Populations of BOMBUS FRANKLINI in northern California and southern Oregon showed a dramatic decrease in abundance in 1999 compared with the preceding El Nino year.
Impacts
These studies help determine how to best manage bees for effective pollination of crops such as almond; how to measure pollination efficiency based on understanding structures and behaviors for pollen removal by bees; how biodiversity of bees relates to managed and non-managed ecosystems; and how populations of a narrow endemic bumble bee fluctuate.
Publications
- Barthell, J. F., D. M. Bromberger, H. V. Daly, and R. W. Thorp. 1999. Nesting biology of the solitary digger bee, Habropoda depressa (Hymenoptera: Anthophoridae) in urban and island environments. J. Kansas Entomol. Soc. 71(2):116-136.
- Leong, J. M. and R. W. Thorp. 1999. Colour-coded sampling: The pan trap colour preferences of oligolectic and nonoligolectic bees associated with a vernal pool plant. Ecological Entomology. 24:329-335.
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Progress 01/01/98 to 12/31/98
Outputs
ALMOND POLLINATION: Our 9-year database shows high production is typically in years with warm dry weather for good bee flight, high buds per meter, and late starting bloom. In 1998, El Nino rain and cold conditions prevailed through peak bloom of NePlus and again at late peak of Nonpareil and peak of Mission. Temperatures for honey bee flight were above threshold at peak Nonpareil bloom, but below through peak bloom for NePlus, and again at peak Mission bloom. All cultivars, except Nonpareil had light bud production. Fruit set was best from mid Nonpareil and early Mission flowers, and poorest from early NePlus flowers. Mid cohort flowers of Nonpareil seem to have compensated for lack of pollination of the early cohort which suffered from rain and cold. Pollen foragers visited younger flowers and contacted stigmas more frequently, spent more time in contact with stigmas and had more loose pollen on their bodies than did nectar foragers. These data support our
hypothesis that pollen foragers are the more efficient pollinators of almond. SYSTEMATICS AND ECOLOGY: Keys and descriptions, including five new species, for a revision of bees of the subgenus HESPERANDRENA were prepared in cooperation with Dr. W. E. LaBerge. Field studies of BOMBUS FRANKLINI extended its known range, and confirmed its narrow endemism in northern California and southern Oregon.
Impacts
(N/A)
Publications
- THORP, R.W. AND LEONG, J.M. 1998. Specialist bee pollinators of showy vernal pool flowers. Pp. 169-179 IN Ecology, Conservation and Management of Vernal Pool Ecosystems - Proc. 1996 Conf., C.W. Witham, E.T. Bauder, D. Belk, W.R. Ferren, Jr. and R. Ornduff (eds.), California Native Plant Society, Sacramento, CA.
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Progress 01/01/97 to 12/01/97
Outputs
ALMOND POLLINATION: In 1997, bloom started in early February. There was good overlap of early and mid blooming cultivars, but Mission did not have significant bloom until the other cultivars were in decline. Bud production was unexpectedly greater than in 1996 for four of the five cultivars. Nonpareil was the only one to continue strong alternate bearing over an eight-year period. Fruit set was highest for early flowers and lowest for late flowers of mid and late blooming cultivars. Early flowers of the earliest cultivar lacked adequate cross-pollen, but mid and late opening flowers provided some compensation. Weather for bee pollination was good throughout bloom. A post-treatment evaluation of fruit set in areas supplied with bumble bees in 1995 and 1996 showed no orchard effect, supporting prior indications that bumble bees are effective pollinators of almond. During incubation, emergence of males and females of OSMIA LIGNARIA started on days 2 and 4; 50% had
emerged by days 6 and 10, respectively. VERNAL POOL BEES: ANDRENA (DIANDRENA) BLENNOSPERMATIS was found over 100 miles north of previous records. SYSTEMATICS AND ECOLOGY: Systematic studies continue on ANDRENA and BOMBUS. A field survey of bumble bees of eastern Turkey was made in July-August 1997. Ecological studies continue on Andrenidae, Megachilidae, Anthophoridae.
Impacts
(N/A)
Publications
- BARTHELL, J.F., BROMBERGER, D.M., DALY, H.V. AND THORP, R.W. 1997. Nesting biology of urban and island populations of a ground-nesting solitary bee. Central States Entomol. Soc., Fayetteville, AR (April
- THORP, R.W. 1997. Pollination. Proc. 25th Almond Industry Conf., pp. 98-99, Modesto, CA (3 December 1997). Abstract.
- MUSSEN, E.C. AND THORP, R.W. 1997. Honey bee pollination of cantaloupe, cucumber and watermelon. UC DANR Publ. 7224. 3 pp.
- THORP, R.W. 1997. Vernal pool specialists: bees. P. 113 IN FABER, P.M. (Ed.), California's Wild Gardens: A Living Legend. California Native Plant Society for California Department of Fish and Game.
- THORP, R.W. 1997. Research Project: Almond Pollination. Pp. 171-173 IN MONASTRA, F. and RAPARELLI, E. (Eds.), Inventory of Almond Research, Germplasm and References. FAO REUR Tech. Ser. 51. roject
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Progress 01/01/96 to 12/30/96
Outputs
ALMOND POLLINATION: In 1996, bloom started in mid February and progressed steadily into mid March. Mission did not have significant bloom until early March when other cultivars were in decline. Bud production was greater than in 1995, but somewhat less than in 1994 for five cultivars. NePlus, Nonpareil, and Price exhibited strong alternate bearing over a seven-year period. Percent fruit set continued to be inverse of bud production. Only Butte among three cultivars showed significant increase in fruit set near versus away from 16 hives of BOMBUS OCCIDENTALIS in a reversal of position from our 1995 test. In a larger scale test near Ripon, we failed to find any direct correlation with fruit set or yield with density of hives of BOMBUS OCCIDENTALIS at rates of 2, 4, and 6 hives per acre. VERNAL POOL BEES: In LIMNANTHES, pan-trap samples of oligolectic bees, ANDRENA (HESPERANDRENA) LIMNANTHIS, show that females prefer white and blue equally, but discriminate against
yellow. SYSTEMATICS AND ECOLOGY: Systematic studies continue of ANDRENA and BOMBUS. Ecological studies continue on Andrenidae, Megachilidae, Anthophoridae.
Impacts
(N/A)
Publications
- THORP, R.W. 1996. Bee management for pollination. Pp. 132-138, 143 IN Micke, W.C. (ed.), Almond Production Manual. University of California DANR Publication 3364, 289 pp. DeGRANDI-HOFFMAN, G.
- R., THORP, R. W., LOPER, G., and EISIKOWITCH, D. 1996. Describing the progression of almond bloom using accumulated heat units. J. Appl. Ecol. 33(4):812-818.
- THORP, R.W. and LEONG, J. 1996. Specialist bee pollinators of showy vernal pool flowers. Conf. Abstracts, p. 19: Ecol., Conserv., & Mngmnt.--Vernal Pool Ecosystems. CNPS/Soc. Ecol. Restor./Wildlife Soc., June 96, Sacramento, CA Abstract
- LEONG, J.M. and THORP, R.W. 1996. Pan traps and oligolectic bees: using the color preferences of specialist bee pollinators. Suppl. Bull. Ecol. Soc. Amer. 77(3):260 Abstract
- THORP, R.W. 1996. Biology of specialist bees and conservation of showy vernal pool flowers. Conf. Abstracts, p. 6: Vernal Pool Complex of the North State: Biol., Conserv., and Mngmnt. Butte Environ. Council, Nov. 96, Chico, CA Abstract
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Progress 01/01/95 to 12/30/95
Outputs
ALMOND POLLINATION: Almond bloom started early, but progressed rapidly. Most cultivars overlapped well, but fog limited flight hours for bees. Rains in January caused colony losses and delayed movement of colonies into orchards. Rains and strong winds in March caused widespread losses of trees, especially large mature ones. Two applications of Queen Mandibular Pheromone (QMP) at 400 queen equivalents produced some increase in honey bee visits, especially pollen foragers during the following two afternoons. There was no increase in fruit set or yield. Trees of three cultivars nearest 16 hives of BOMBUS OCCIDENTALIS produced significantly higher fruit-set than trees of the same cultivars 20 rows away. VERNAL POOL BEES: Surveys of natural and created pools demonstrated that oligolectic bees were present in restored and created pools when viable natural pools were in the same habitat. Comparisons of yellow, white, and blue pan-traps established that they are useful tools
for monitoring oligolectic bees in the vernal pool habitat. SYSTEMATICS AND ECOLOGY: Systematic studies continue on ANDRENA and BOMBUS. Ecological studies continue on Andrenidae, Megachilidae, Anthophoridae.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
Almond Pollination: Almond bloom started late and progressed rapidly. Most cultivars overlapped well providing excellent conditions for cross pollination. Spray applications of four doses of Queen Mandibular Pheromone (QMP) showed no statistically significant differences in honey bee activity, fruit set, harvest yield, or individual nut weights. There were trends that suggested some effect: the highest dose had the most bee activity, the control had the least fruit set and yield, and the second highest dose had the most fruit set and yield. Three of five cultivars showed strong alternate bearing in buds per meter and fruit set over five years. OSMIA LIGNARIA females did not complete nests during the brief bloom, but continued to nest after almond blossom. BOMBUS OCCIDENTALIS workers visit more flowers over more area per unit time, collect more pollen, leave trees more frequently, and have a higher ratio of pollen foragers than do hone,yr bees, confirming our findings
in 1993. Vernal Pool Bees: Nesting female ANDRENA were moved about one mile. Only one of over 90 marked bees was recovered collecting pollen in the new area. Oligolectic bees were attracted to yellow pan traps, suggesting this may be a useful monitoring tool. Systematics/Ecology: Systematic studies continue on ANDRENA and BOMBUS. Ecological studies continue on Andrenidae, Megachilidae, and Anthophoridae.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
Almond Pollination: High pollen hoarding selections of honey bees had significantly more bees than similarly managed commercial colonies in February prior to almond pollen. These larger populations produce more pollen foragers and thus are well suited from almond pollination. Bud production data continue to suggest biennial bearing in some almond cultivars and is inversely related to fruit set. OSMIA LIGNARIA females continued to forage after almonds ceased blooming. Incubation and release methods need improvement. Evaluations of BOMBUS OCCIDENTALIS from commercial colonies showed that: bumble bees work faster, cover more area of bloom per unit time and have a higher ratio of pollen foragers than do honey bees. However, bumble bee colonies have only hundreds of workers versus thousands of workers in honey bee colonies. Vernal Pool Bees: In Fresno and Madera counties, host-specific bees are rare on vernal pool plants at both source and creation sites. Experiments showed
that seed set of a vernal pool plant, BLENNOSPERMA NANUM, in a mitigation site was significantly lower than that in a natural site that had greater quantity and quality of pollinators. Bee Systematics/Ecology: Systematic studies continue on BOMBUS, TRACHUSA, ONAGRANDRENA, and HESPERANDRENA. Ecological studies continue on these and on MEGACHILE, ANTHOPHORA and CENTRIS. Electrophoresis shows BOMBUS ALBOANALIS is a species distinct from B. FRIGIDUS.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
ALMOND POLLINATION: High pollen hoarding selections of honey bees collected about 1.8 times more pollen than commercial colonies. Buds per meter of branch were greater in 1992 than in 1991. Bud production data from 1990-92 suggest biennial bearing. Percent fruit set again showed an inverse relation with buds per meter. OSMIA LIGNARIA produced broad cells, but reproduction was poor due to the compact (3 week) almond bloom season. Brood of Sierran foothill bees survived summer temperatures in Davis in 1992. ALFALFA LEAFCUTTING BEES (ALCB): ALCB emerged and reproduced successfully in San Joaquin Valley alfalfa in 1992. ALCB foraging drops off rapidly beyond 50 m from their domiciles. Significant increases in brood mortality occurred at temperatures above 40 degrees C (104 degrees F) for 4 hr x 4 d. It is important to keep ALCB nests shaded and well ventilated in California alfalfa fields. BEES OF BODEGA RESERVE: BOMBUS spp. dominated visits to 3 LUPINUS spp. Bees visited
L. NANUS, VARICOLOR, ARBOREUS and all had fewer bee visits than many other flowering plants. Pod and seed yield were lowest in L. ARBOREUS suggesting pollinator limitation. BEES OF THE CHANNEL ISLANDS: Long-term biodiversity and floral association databases continue. Previously unrecorded species of native bees continue to be found. BEE SYSTEMATICS/ECOLOGY: Systematic studies continue on BOMBUS, TRACHUSA, ONAGRANDRENA AND HESPERANDRENA. Ecological studies continue on TRACHUSA, BOMBUS, MEGACHILE, ANTHOPHORA, AND CENTRIS.
Impacts
(N/A)
Publications
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Progress 01/01/91 to 12/30/91
Outputs
ALMOND POLLINATION: High pollen hoarding selections of honey bees had more pollen per total foragers returning to hives than did low lines. Buds per meter of branch were fewer in 1991 than in 1990. Proportions of pistils with pollen tubes penetrating to the ovule increased directly with the numbers of cross-compatible pollen grains applied to stigmas. This dose response shows the need for adequate pollen. OSMIA LIGNARIA from Sierran foothills survived milder than usual summer temperatures in Davis in 1991. ALFALFA LEAFCUTTING BEES (ALCB): ALCB emerged and reproduced successfully in San Joaquin Valley alfalfa in 1991. Increases of 200 pounds of seed per acre were obtained with ALCB in addition to honey bees. Laboratory tests showed that high temperatures that can occur in the area may be lethal to ALCB. Thus, it is important that ALCB nests not exceed ambient temperatures. BEES OF BODEGA RESERVE: Late rains and colder than normal weather from March into May
produced delayed initiation of bee activity, especially spring flying species. Many flowers seem pollinator limited based on low bee activity and seed set. BEES OF THE CHANNEL ISLANDS: Long-term biodiversity and floral association databases continue. Unrecorded species of native bees continue to be found. BEE SYSTEMATICS/ECOLOGY: Systematic studies continue on BOMBUS, TRACHUSA, ONAGRANDRENA and HESPERANDRENA. Ecological studies continue on TRACHUSA, BOMBUS, MEGACHILE, ANTHOPHORA, and CENTRIS.
Impacts
(N/A)
Publications
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Progress 01/01/90 to 12/30/90
Outputs
ALMOND POLLINATION: Most APIS colonies lost population in February due to cold weather and lack of almond bloom, but increased rapidly with the onset of bloom. During peak bloom, 90% or more of the pollen trapped at colonies was almond pollen. Movement of bees between trees of the same versus different cultivars did not differ in a hexagonal planting during most overlap of bloom. Less than 20% of returning bees on average, carry pollen. ALMOPOL model accurately predicted initial nut set for 4 of 5 cultivars. BEES OF BODEGA RESERVE: Many spring annuals, especially LUPINUS BICOLOR, were less abundant in 1990 than in 1987-1989. Flower visitation by bees and other pollinating insects was less than 1/100 flowers per minute. Females of HABROPODA visit more than two times as many LUPINUS ARBOREUS flowers per minute than do workers of BOMBUS. BEES OF THE CHANNEL ISLANDS: Long-term biodiversity and floral association databases continue. The introduced MEGACHILE APICALIS and at
least 10 unrecorded native bees have been found on Santa Cruz Island and seven unrecorded bee species have been found on Santa Rosa Island. APIS are most abundant on introduced weeds. They have been observed foraging on 41 plant species, of which 36.6% are introduced. BEE SYSTEMATICS/ECOLOGY: Systematic studies continue on BOMBUS, TRACHUSA, ONAGRANDRENA and HESPERANDRENA. Ecological studies continue on TRACHUSA, BOMBUS, MEGACHILE, ANTHOPHORA, and CENTRIS.
Impacts
(N/A)
Publications
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Progress 01/01/89 to 12/30/89
Outputs
Almond Pollination: Colonies treated with methanol used for tracheal mite control had significantly reduced pollen foraging and population increase. Significant differences were not found for late spring and fall treatments. Bee visitation was positively correlated with reward production per meter of branch. ALMOPOL predictions were within the 95% confidence interval of average actual nut set for four of five cultivars. Bees of Bodega Reserve: Spring flowering started later and flowers were less abundant than in 1987 and 1988. Pollinator limitation was suggested by few bee visits during good flight weather. Anthophora californica pupate in spring and females construt multiple nests. Bees emerged 2-4 weeks later than in previous two years. Bees of the Channel Islands: No swarms entered baited hives, suggesting reproduction of feral colonies was inhibited by three consecutive drought years. Acceptance of drilled sticks by cavity nesting bees was low and
predominantly in early spring. No honey bees were found on Santa Rosa Island, thus it may be compared with Santa Cruz Island for studies of ecological impact of Apis. Bee Systematics/Ecology: Bombus nevadensis and auricomus are separated by more isozymes than closely related species of Pyro- and Fervidobombus. Male genitalia support separation at the species level. Dark forms of coastal California are enzymatically nevadensis. Bees sampled from putative areas of hybridization are enzymatically and morphologically auricomus.
Impacts
(N/A)
Publications
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Progress 01/01/88 to 12/30/88
Outputs
Almond Pollination: No significant differences occurred in nectar and pollen production from individual flowers of 5 cultivars. Significant differences occurred in blossom density. Bee visits were correlated with density of resource. Honey bee colonies with 8 frames of worker bees had significantly more flight than weaker or stronger colonies. Cluster and frame by frame strength evaluations are highly correlated. Bees of Bodega Reserve: Nest sites of 30% of 46 bee species on the Reserve have been mapped. Females of Anthophora californica and A. bomboides excavate nests at similar rates in sandstone cliffs although the former do not moisten the soil with water. Females of Anthidium palliventre accept drilled sticks for nests although they are adapted for digging burrows in sand. Male Melissodes pallidisignata remain faithful to limited cruising areas over nest sites. Bees of Santa Cruz Island: Feral honey bee colonies in the center of the island are uniformly
distributed. Apis visit 30 species of flowers, 43% of which are introduced. Of 60 plant species not visited by Apis, 18% are introduced. Over 10 species of native bees not previously recorded from the island were found. Earwigs compete with native bees for nest holes. Honey Bee Ecology: Baseline data on feral colonies and their impact on solitary bees and flora are being gathered for comparison with Africanized bees. Feral colonies on exposed combs, even with large autumn populations, or in shallow ground holes have low overwinter survival rates.
Impacts
(N/A)
Publications
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Progress 01/01/87 to 12/30/87
Outputs
Almond Pollination: Correlation between cluster versus frame by frame (FOB) counts of worker bees was high. There were no significant differences in estimates by two experienced and one inexperienced observers. Hives with 4 FOB had significantly less flight activity than hives with 6-10 FOB. Height of stigma relative to anthers differed between cultivars. Validation of Gloria DeGrandi-Hoffman's ALMOPOL model showed good fit of equations for bloom progression and bee foraging population. Nut set predictions underestimated 2 of 5 cultivars. Kiwifruit Pollination: A regression equation produced by counting the number of seeds in both halves of cross & longitudinal sections and adding fruit weight predicted seeds per fruit within a 5% confidence interval. Liquid spray applications of pollen showed no significant increases in fruit weight or seed number. Bee hives moved in late had higher percent kiwifruit pollen income than did early ones. Bumble bees buzz
pollinate kiwifruit flowers. This is probably the original method of pollination for Actinidia. Bees of Bodega Reserve: Six families, 24 genera, and 45 species of bees occur at the Reserve. The peak of diversity occurs in May. Nests of 10 species were located and mapped. Phenologies and floral associations were recorded. Africanized Honey Bees: The impact of honey bees on other bees in population abundance, reproductive success, and floral preferences is being studied in central California with G. W.
Impacts
(N/A)
Publications
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Progress 01/01/86 to 12/30/86
Outputs
Almond Pollination: Pollen traps increase pollination efficiency of honey bee colonies by significantly increasing numbers of pollen collecting bees and their ratio to nectar foragers in most years. Feeding sugar syrup during bloom increases pollen foraging somewhat, especially during years with prolonged periods of rainy weather. Cluster size correlates well with frame by frame counts of worker bees for evaluating colony strength, is less disruptive and more rapid. Osmia cornuta emerged in synchrony with bloom, but females remained active 6 weeks beyond bloom. Both O. cornuta and lignaria produced fewer bees than released. Kiwifruit Pollination: Neither pollen traps nor feeding sugar syrup during bloom increased pollen or total foraging by honey bees. When hives were introduced in successive waves, a higher percent of kiwifruit pollen was found in traps of the latest introduction. Syrphid flies were more common than honey bees on flowers. Osmia lignaria
emerged in synchrony with bloom. provisioned nests with some kiwifruit pollen, but produced fewer bees than released. Alfalfa Pollination: The primary response of honey bees to increased reward of a high nectar producing genotype was an increase in numbers of foragers. The tendency for bees other than the honey bee for higher visitation to the low nectar genotype may reflect a pollen preference as noted in previous studies.
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Progress 01/01/85 to 12/30/85
Outputs
Almond Pollintion: Pollen traps increased pollination efficiency of honey bee colonies by increasing numbers of pollen collecting bees and their ratio to nectar foragers. Feeding sugar syrup during bloom did not. Labelled pollen transferred from returning foragers to bees at the hive entrance, and some to newly emerged bees in the hive. Labelled pollen in entrance dispensers quickly dispersed throughout the colony. Pollen remained viable on bees and entrance obstructions up to 24 hours. Pollen in entrance dispensers tested viable, but produced no increase in yield in a test orchard. Osmia lignaria and O. cornuta emerged at almond bloom, provisioned nests, but produced fewer bees than released. Kiwifruit Pollination: Neither pollen traps nor feeding sugar syrup during bloom increased pollen or total foraging by honey bees. Percent kiwifruit pollen as highest in traps at colonies fed syrup or moved in a mid bloom. Syrphidae were sometimes more abundant than honey
bees at female flowers. Native bees: Andrena, Halictus and Bombus also visited flowers. Pollen from female flowers was found to lack cytoplasm. Alfalfa Pollination: Bee density was significantly greater on high vs. low nectar producing alfalfa with both planted on the same soil type. Pollen foragers were least numerous in alfalfa in June when traps showed safflower pollen competing for bees.
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Progress 01/01/84 to 12/30/84
Outputs
Almond pollination: A factorial experiment tested effects of colony strengths in relation to: pollen traps, sugar syrup feeding, solar heating with plastic covers, and extra space in strongest colonies on flight and pollen income. Solar heating did not affect bee cluster temperatures, but did elevate peripheral hive temperatures, and had a depressing effect on bee flight and pollen income during the good weather in 1984. Feeding syrup did not increase flight or pollen income as in 1983. Extra space in colonies with >12 frames of bees had no effect on bee flight. Pollen traps increased bee flight and pollen income, but the two traps tested differed in amount of this positive affect. Hand pollinations showed a direct correlation between average numbers of pollen grains per stigma and percent fruit set. This relationship should be more carefully defined and attention should be given to amounts of pollen deposited in each bee visit. Stigmas of seven cultivars differ
in spatial relation to anthers at dehiscence influencing amounts of self deposited pollen. Alfalfa pollination; Honey bee foraging and colony changes were compared in alfalfa selected for high vs. low nectar. Despite differences in soil type, significantly more bees foraged at high nectar flowers, in early season. Nectar loads of bees were higher on high nectar flowers early, but reversed later. Bees collected more pollen from low nectar flowers. Optimal foraging, changes in colony strength and food stores were not different.
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Progress 01/01/83 to 12/30/83
Outputs
Almond pollination: Our previous studies have shown that pollen foraging honey bees are more efficient than nectar foragers for pollination of almonds, and that pollen traps increase pollen foraging, but may decrease colony growth. We compared effects of traps on colonies of different strengths and found colonies with less than 8 frames of bees showed significant increases in brood and pollen stores, but larger colonies did not. Feeding colonies with sugar syrup during bloom was found to be another means of increasing pollen foraging from colonies, especially those with less than 10 frames of bees. Sugar syrup feeding also increased population size of colonies with 6 to 10 frames of bees. In these studies of colony management to increase pollination efficiency we compared colonies of different strengths and found that colonies of less than 10 frames of bees responded differently from those with more bees. This may in part be due to lack of space in larger colonies.
Our cluster count had closely correlated with colony strength based on intensive counts of frames of bees and a conversion table has been constructed. The cluster counts have the advantages of being quicker, less hazzard to the queen and less exposure to ambient temperatures. The main disadvantages is that cluster counts provide no information on the status of the queen or brood (important stimuli for pollen foraging).
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Progress 01/01/82 to 12/30/82
Outputs
Almonds: Adding pollen traps increased numbers and proportions of pollen collectors, but reduced population growth rates with prolonged (48 day) use on honey bee colonies. Since we have shown greater pollination efficiency for pollen versus nectar foragers in almonds, this technique may benefit the grower. We derived a table to convert cluster counts to estimates of frames of bees for rapid evaluation of honey bee colony strength with less than 8 frames of bees. This table needs to be expanded for stronger colonies and other methods (e.g. hive entrance activity) need to be developed so grower can assess pollinator needs without having to open beehives. A survey of grower production problems showed bee colony strength or strength times numbers was best correlated with yield. Fruit set in South Australia dropped rapidly beyond 170m. from sites where honey bee colonies were during bloom confirming earlier measures of foraging patterns during predominating marginal
flight conditions. Prunes: Counts of bees foraging in trees and correlated percent fruit set are being analyzed. Alfalfa (=lucerne): In South Australia honey bee density did not differ significantly across a 60 hectare field, although bee marking experiments showed that they tend to forage close to their hives. More honey bees (7-13%) were collecting pollen than do so in California. A few native leaf-cutting bees were trap nested.
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Progress 01/01/81 to 12/30/81
Outputs
Almond pollination-California--Honey bees do not fly as far in cool, damp weather. Bees drift from high bee density to low bee density orchards. 90% of surveyed colonies were above the minimum strength, and increased an average of 2.6 frames of bees during the pollination period. Strong colonies procude more total forager, but fewer foragers per frame than weak colonies. Pollen traps caused a slight increase in percentage of pollen foragers, but a decrease in total foragers. Aerial photography combined with image analysis shows promise as a technique for assessing total bloom on an area-wide basis. In a 1980 crop survey slightly over half of growers perceived weather as their most important pollination problem. Almond pollination-South Australia--In marginal weather conditions, significant reductions in the number of foraging bees were observed at about 200 m. versus at less than 35 m. for hives. Bees select the shortest distance when flying between trees and tend
to visit trees in the same stage of bloom. Bee colonies in study orchards were of better than the average quality of the previous year. Fluorescent Nectar--Honey bees appear to be using both visual cues (florescence) and odor cues to determine if nectar is available in flowers.
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Progress 01/01/80 to 12/30/80
Outputs
Almond Pollination--Flowers opening just before or during rains set less fruit than those opening after rains. Fruit set is highest near compatible bouquets placed in crotches of trees, and decreases with distance from the bouquet even within the same tree. Bees tend to fly from a tree to the nearest tree in the most similar bloom stage. Pollen collecting bees carry more viable pollen and produce more fruit set than do nectar collectors. Fluorescent Nectar--Apis (UDC Arboretum) and Xylocopa and other native pollinators (Tulare Co.) were able to discriminate fluorescent nectar from sugar syrup and nectar volatiles and other fluorescing materials in syrup in experimentally modified Fremontodendron flowers. Sunflower pollination--In a hybrid seed field with 6 males fertile and 30 male sterile rows, measurements from nearest (row 1) to furthest (row 15) from male fertile rows showed: increases in receptive heads and decreases in bees per head and pollen grains per bee
venter. Aristolochia Pollination--Blossoms open and hand pollinated in late January-early February with pollen from the same population produced 54% and 42% initial fruit set by early March respectively, while unpollinated flowers produced only 6% set. None of the tagged fruits developed to maturity by early July, when only 3 fruits were noted in the entire population. Low final fruit set may be due to self-incompatibility with most of the vines vegetatively reproducing and therefore the same genotype.
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Progress 01/01/79 to 12/30/79
Outputs
Almond Pollination--Application of supplemental pollen in an orchard with sufficient honey bees and 4 rows Nonpareil with row of NePlus or Mission on either side did not increase yields in 1979, (some increase was noted in 1978). Reciprocol bouquet tests and determination of bee foraging behavior in relation to percent bloom indicates bees respond more to phenological than varietal characterists. Orchardists should select varieties with maximum overlap in bloom period. Nectar Fluorescence--Tests with experimentally modified flowers of Fremontodendron support our hypothesis that bees visualize and utilize fluorescent nectar as a recognition cue. Meadowfoam Pollination--Bee mediated pollen in populations of Limnanthes is restricted to small neighborhoods. Most central populations in the distribution of the genus are pollinated by specialist bees, while L. striata and peripheral populations tend to be pollinated by generalists. Aristolochia Pollination--A.
californica appears to provide the flies that visit its flowers with a good reward (a secretion from a band of glandular hairs just below the sexual column) and thus, is not a typical trap flower as are many of its relatives. Sunflower Pollination--Honey bees tend to forage only for nectar in male sterile rows and carry no detectable pollen even in the row adjacent to male fertile rows.
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Progress 01/01/78 to 12/30/78
Outputs
Almond Pollination- The application of supplemental pollen to be redistributed by honey bees was tested in an orchard with four rows of Nonpareil bordered by NePlus and Mission. Most bees visit flowers with more than 50% anthers dehissed, but nectar collecting bees tend to visit older flowers than do pollen foragers. The earliest flowers of each variety tend to set more fruit than do the later flowers. Nectar Fluorescence- Chi Square analyses of 1977 and 1978 honey been training experiment data were significant and support our hypothesis that bees can see the fluorescence and/or UV abservance and use this visual cue among others to detect the presence of nectar in flowers. Meadefoam Pollination- Among several methods tested to detect patterns of bee-mediated pollen flow in Limnanthes populations the most useful were marking bees with acrylic paint or dusting groups of flowers and examining pollen loads of bees taken at intervals from the marked plots for the
colored dusts. These showed most pollen flowe to be restricted to small neighborhoods even within large continuous patches of flowers. Only rarely were individual bees found over 10-20 m from the point of marking. Most species and populations of Limnanthes have specialist pollinators, but peripheral isolated ones such as L. douglasii sulphurea were visited by generalists only. Pollen Collecting Behavior of Bees- During studies of grooming and pollen packing behavior we found that bees collect pollen directly from the scopae of other bees.
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Progress 01/01/77 to 12/30/77
Outputs
Almonds--Applications of Beeline registered trademark did not attract bees nor increase yield. A fruit set study indicated bees need not be in orchards before mid bloom of the earliest variety, but time of colony removal needs further definition since late bloom of the latest variety had significant set. Floral phenology stages were identified as a base furture pollination studies. Pollen morphology differs between Nonpareil and Mission under the scanning electron microscope and can be useful in bee foraging studies. Preliminary tests indicate bouquet pollination and pollen tube growth analysis can help evaluate varietal discrimination and preferences by bees. Nectar fluorescence--Honey bee training experiments using models with artificial liquid nectar supported our hypothesis that bees see the fluorescence or UV absorption of certain nectars, thus increasing their foraging efficiency. Chalkbrood of Megachile--Heat or formalin treatments for disinfection of old
straw nests for reuse sustained lowest amounts of disease. Maneb dusted into active nests three times a week did not give control. New straws treated with heat, bleach, and solutions of alfalfa leaves or pollen were nmost acceptable to bees. Tumbled, rolled and bleached loose bee nests had 27% more unattached cells, but 18% less emergence. Vernal pools--Bees foraged nototribically on Downingia with short columns, but sternotribically on species with long columns.
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Progress 01/01/76 to 12/30/76
Outputs
Almond Pollination: A field trial of effects of spraying "Beeline", a reputed bee food attractant, on blooming almonds in an attempt to increase bee activity and pollination was conducted. The test orchard consisted of 24 rows of 2 varieties, 1/2 of which were treated with "Beeline". Bee visitation counts weremade before and after treatment. No apparent differences were noted between beeactivity on treated versus non-treated trees. Counts of pollinated fruits on tagged limbs were compared with previous flower counts and no increase in % fruit set was found in treated trees. Harvest data also showed no increase in yield in treated trees of either variety. Nectar Fluorescence: We tested our hypothesis that fluorescent or ultraviolet absorbance characteristics of nectar from some bee-visited flowers is perceived and utilized by bees. Honey bees were trained to visit artificial flowers stained centrally with fluorescing, UV-absorbing materials. Tests revealed these
bees could distinguish treated models from untreated ones with a high degree of proficiency, thus confirming our hypothesis. This could aid in foraging efficiency of bees, enhance pollination of flowers, and serve as a potential tool for understanding and improving pollination. Chalk Brood: This fungus disease continues to increase in alfalfa leafcutting bee populations in the western U.S. Infection was reducedby separating healthy cells and disinfecting them with bleach. Sanitation and loose cell culture are important regulators.
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Progress 01/01/75 to 12/30/75
Outputs
Almond pollination: Honey bees in disposable pollination units (3 lbs. of bees with caged queen in a styrofoam box) and overwintered colonies with 2 to 3 frames of bees were placed in cages over Nonpareil trees each intergrafted 1/3 to the compatible variety 1248. Each treatment, DPU or colony involved 4 replicate cages. Over 1400 flowers were counted on branches of each variety and for each treatment giving fruit sets of 48.7% on 1248 vs 34% on Nonpareil; and 46.3% with CPU's vs 36.6% with colonies. Virtually all the variation between DPU's & colonies was on Nonpareil with 43.3% set with DPU's vs 26.4% set with colonies. Since bees in DPU's collect little pollen relative to bees in colonies, these differences may be due to varietal preferences of nectar vs pollen gathering bees. Nectar samples were collected from different varieties, root-stocks, and orchards for analyses of fluorescence and other chemical constituents relative to attractiveness to bees. Alfalfa
leafcutting bees: Chaldbrood, a fungus disease, has been found to cause up to 50-60% mortality in commercial bee populations in the western United States. Differences between it and the fungus causing disease in honey bees were found using the scanning electron microscope. Artifical infection was effected with spores from cadavers,but not from cultures, thus providing a technique for determining whether it andthe honey bee chalk brood are cross-infective.
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Progress 01/01/74 to 12/30/74
Outputs
Intrafloral behavior of honey bees in almonds: bees collecting pollen contact stigmas more frequently and spend less time per flower than bees collecting nectar, or pollen and nectar; more bees collect nectar than pollen on Peerless, but not on other varieties. Nectar from 20 of 85 plant species fluoresces and absorbs ultra violet in flowers coevolved with bees. Reproductive ecology of native flowers: Aristolochia californica is a self-compatible primitive trap flower, pollinated by fungus gnats; Entomophilous plants in vernal pools are pollinated principally by oligolectic bees; Interfloral flights of bees on Agoseris statistically coincide with the distance between nearest-neighbor flowers, minimizing energy outputs; Ludwigia peploides in California is a generalist differing from L. p. glabrescens in Oklahoma only in species of pollinators. The alfalfa leafcutter bee: prefers to use old nests before new ones; produces a higher male sex ratio early in the first
generation; diapauses from eggs laid in late July and early August; is severely infested with megachile chalk brood disease, an Ascosphaera fungus, in parts of California andNevada with mortality ranging from 4 to 64%. Ecology of native bees: Mt. DiabloState Park contains the most northern populations of Trachusa perdita and Centris hoffmanseggiae; the gregarious nests of Trachusa are typical for the species; the previously unknown nests of Centris are scattered, shallow, branching, and contain overwintering
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