The Pollination Ecology of Showy Vernal Pool Annuals: A Pilot Survey of Visitors to Three Endangered Plant Kandis Gilmore, Christina M. Sloop, Hattie K. Brown Laguna de Santa Rosa Foundation, Santa Rosa, CA, [email protected], www.lagunafoundation.org

Introduction Methods Preliminary Results The Santa Rosa Plain is home to both natural and Half-meter square observation quadrats were For B. bakeri, visitation rates of all observed created vernal pools and swales that harbor the placed randomly within each vernal pool and were were higher at naturally occurring pools than cre- endangered annual plants Blennosperma bakeri, assigned to a cover class standardized by the Cali- ated pools and the insect visitors included solitary Limnanthes vinculans, and Lasthenia burkei. Ques- fornia Native Plant Society (CNPS). The area with- bees, cuckoo bees, , syrphid flies, and beetles. For tions to be answered to promote the recovery of in the quadrat was observed over five replicates of L. burkei, visitation rates were slightly higher for ob- these species are: five minute intervals. Insect visits were recorded served insects in natural pools. 1. What pollinators do plants rely on to reproduce? each time contact was made with a new inflores- We were unable to compare pollinator visits at a 2. What is the ecology and distribution of these in- cence. Short visits (less than 5 seconds) and long constructed pool containing L. vinculans, but did sur- sect pollinators? visits (5 seconds or longer) were noted in an at- vey pollinator activity between two natural sites, one During the spring of 2009, we conducted a pilot tempt to differentiate quick perching from actual grazed by horses and another ungrazed. We ob- study to observe insect visitors to floral popula- manipulation of floral parts. Time of day, tempera- served higher visitation rates at the grazed site. tions of each species at both naturally occurring ture, and weather were recorded for each set of Specialist ground-nesting solitary bees were ob- and man-made or created pools across the bloom- five replicates. We surveyed several flower cohorts served at all sites. ing season. We performed timed observations throughout the blooming season to capture sea- across different flower cohorts and cover class sonal variability. densities.

Average visitsAverage to B. bakeri Visits per to 5B. minute bakeri interval Average visitsAverage to L. burkei Visits per to 5 L.minute burkei interval AverageAverage visits to Visits L. vinculans to L. vinculans per 5 minute throughout flowering season interval throughout flowering season

throughout flowering season Houghton photo R. 9 1.8 7 1.6 8 6 1.4 7 5 1.2 6 4 5 1 Created Created Natural Grazed Natural Natural Ungrazed 0.8 3 Natural 4

0.6 3 2 0.4 2 1 0.2 1 0 0 0 Solitary bees Cuckoo bees Small black flies Syrphid flies Beetles Solitary bees Bombaliid flies Syrphid flies Honey bees Beetles Solitary bees Syrphid flies Small black flies Honey bees Beetles Solitary bee Cuckoo bee Small black OtherOther fliesflies Syphid flies Beetles Solitary bee Bombaliid fly Syrphid fly Honey bee Beetle Solitary bee Syrphid fly Small black fly Honey bee Beetle

Objectives Insect Community Next Steps 1. Identify the common pollinators of the three The following insects, identified to family, were the most common visitors of: In the following years we plan to further examine the relative role of specialist solitary bees and other flow- plants. B. bakeri: L. vinculans: L. burkei: er visitors in the reproductive success of these endan- 2. Assess the insect community in natural and bees bees bees gered plant species. We will correlate successful seed created vernal pool sites. Andrenidae Andrenidae Andrenidae Apidae Apidae beetles set with insect visitation and test the efficacy of polli- beetles beetles Cantharidae

3. Assess flower-visitation rates of insects in natu- Houghton photo R. Chrysomelidae Chrysomelidae Chrysomelidae nation of the various flower visitors. Syrphidae in L. burkei ral vs. created sites and align this with seed Melyridae Melyridae Coccinellinae Our findings will help promote systematic manage- set data. flies flies Melyridae Anthomyiidae Muscidae flies ment and ultimately foster species recovery. 4. Inform endangered species management and Syrphidae Bombyliidae Muscidae Muscidae help promote recovery. Syrphidae Syrphidae Acknowledgements N. Rank, B. Black, W. St. John, B. Sabo, C. Cummings, D. Martinez, A. Lowe, A. photo R. Houghton photo R. Andrenidae in L. vinculans Dyer, K. Britsch, S. Francis, R. Crowe, S. Boaz. This work was funded in part by a grant from the California Dept. of Fish and Game.