Meeting Abstract
Convolvulus arvensis, field bindweed, is common in Mediterranean climates but we know little of the pollen dynamics of this flower. We studied the pollen dynamics of the flowers, and the pollinator’s foraging behaviors and foraging hours. We also studied how competition impacted pollen dynamics for Lasioglossum malachurum when the specialist competitor Systropha curvicornis was removed and present. For natural pollen decay, 10 flowers were monitored hourly and the anthers harvested for the pollen. C. arvensis pollen reward decayed rapidly from 6am to 9am and plateaued at about 10am, after visitation by early pollinators. Pollen dynamics and visitation show that, while S. curvicornis is a specialist, abundant L. malachurum remove most of the pollen during early foraging hours. To evaluate the C. arvensis pollen niches of the two bees, two sites were studied: one at which S. curvicornis was removed and one at which S. curvicornis was present. We collected 15 L. malachurum every hour from 7am to 9am, and their pollen was extracted and counted under a microscope. At the site with the competitor S. curvicornis present, the percentage of C. arvensis pollen on L. malachurum decreased at 9 am, when S. curvicornis foraging peaked on the flowers. Where the competitor was removed, C. arvensis pollen on L. malachurum remained high and constant throughout sampling. The two species display temporal niche partitioning of pollen by C. arvensis, for which the specialist S. curvicornis is a strong competitor against the generalist L. malachurum.
