Survey of bees in the Judean Foothills and the Rift Valley

Yael Mandelik, Gideon Pisanty, Ariella Gotlieb, Tomer Koznichki

The survey of bees (wild and managed bees) was conducted in the Judean Foothills and the Rift Valley – representing the two major ecosystem types in Israel. In each region the survey was conducted in main bee habitats – natural habitats (chaparral and batha in the Judean Foothills, streams in the Rift Valley), agricultural habitat (almonds, sunflowers and watermelon fields in the Judean Foothills, a variety of crops in the Rift Valley), and in the Judean Foothills – also in planted pine forests. We conducted 5-6 samplings rounds along the year (2010) using both netting and water traps (pan-traps). Each of these methods emphasizes different groups of bees. In each sampling day two sampling rounds were conducted, in the morning and afternoon, under standard favorable weather conditions. Specimens sampled were classified to genus/morph-type and sent abroad for species-level identification. We are now starting to receive the identified bees (winter 2011). In the Judean Foothills in the agricultural areas 4400 bees were sampled, of ca. 225 morphotypes. The dominant genera were Lasioglossum, Andrena and Eucera. In the planted pine forest and the nearby natural habitats 536 bees were sampled of 14 genera. The species L. pseudosphecodimorphumwas dominant. In the planted pine forest and natural habitats diversity was maximal in the spring, and minimal in the summer and autumn. In the Rift Valley abundances were very low in the summer and autumn compared to the spring. In the spring, diversity and abundance were not affected by distance from agriculture, but changed along the season following concurrent changes in floral abundance. In all samples there were significant differences in bee composition between the two sampling methods applied.