Meeting Abstract
Field bindweed (Convolvulus arvensis) is an invasive weed, native to Europe and Asia, whose flowers reward diverse pollinators throughout midsummer. We examined foraging niche competition between two bee pollinators of C. arvensis, Systropha curvicornis (specialist) and Lasioglossum malachurum (generalist) in removal experiments on Lesvos, Greece. We recorded the natural visitation of these pollinators before and after removals. Before removal of bees, we measured natural visitation for one to three days. S. curvicornis and L. malachurum were removed in mass, each at a different site, for one day. We monitored the response one species to decreased presence of the opposing species over several days of visitation observations, as we continued removals so that catch per effort of each species increased at removal sites. At the site of S. curvicornis removal, the temporal foraging niche of L. malachurum was lengthened in response to reduced visitation by S. curvicornis. At the site L. malachurum was removed, the temporal foraging niche of S. curvicornis was unaffected by the removal of L. malachurum. The expanded foraging time by L. malachurum in the absence of S. curvicornis supports the hypothesis that these two pollinators display temporal niche partitioning on C. arvensis, wherein the generalist cedes time on C. arvensis to the specialist. These results are corroborated by our study of pollen loads extracted from L. malachurum at each site.
