Meeting Abstract
On Lesvos (GREECE), we studied the temporal foraging behavior of two primary bee pollinators of field bindweed (Convolvulus arvensis), a native weed of the Mediterranean region. We observed Lasioglossum malachurum, a eusocial generalist, and Systropha curvicornis, a solitary specialist, to be abundant pollinators of C. arvensis on the island. Knowing both species compete for C. arvensis, we hypothesized the bees have different temporal foraging niches. Visitation in quadrats at two field sites revealed temporal niche separation, wherein L. malachurum visited C. arvensis early while S. curvicornis visitation peaked later in the morning. To further understand the niches of these two species, we used multiple linear regression to test for relationships between visitation and five environmental variables: the number of partially open C. arvensis flowers, the number of fully open C. arvensis flowers, relative humidity, temperature, and light intensity. S. curvicornis visitation was positively related with the number of fully open C. arvensis flowers. L. malachurum was positively related with the number of partially open C. arvensis flowers and the number of fully open C. arvensis flowers. Visitation by L. malachurum was negatively associated with light intensity. These results confirm our observations that L. malachurum visited C. arvensis early in the morning when the flowers were only beginning to open while S. curvicornis visited the flowers only when they were fully open.
