Dag, A., Institute of Animal Science, Volcani Center, Min. of Agric. and Rural Development, PO Box 6, Bet Dagan 50250, Israel
Fetscher, A.E., Department of Biology, University of California, Riverside, CA 92521, United States
Afik, O., B. Triwaks Bee Research Center, Department of Entomology, Hebrew University of Jerusalem, Rehovot 76100, Israel
Yeselson, Y., Department of Vegetable Crops, Volcani Center, Min. of Agric. and Rural Development, PO Box 6, Bet Dagan 50250, Israel
Schaffer, A., Department of Vegetable Crops, Volcani Center, Min. of Agric. and Rural Development, PO Box 6, Bet Dagan 50250, Israel
Kamer, Y., Institute of Animal Science, Volcani Center, Min. of Agric. and Rural Development, PO Box 6, Bet Dagan 50250, Israel
Waser, N.M., Department of Biology, University of California, Riverside, CA 92521, United States
Madore, M.A., Dept. of Botany and Plant Sciences, University of California, Riverside, CA 92521, United States
Arpaia, M.L., Dept. of Botany and Plant Sciences, University of California, Riverside, CA 92521, United States
Hofshi, R.
Shafir, S., B. Triwaks Bee Research Center, Department of Entomology, Hebrew University of Jerusalem, Rehovot 76100, Israel

Avocado nectar is unusual because it contains perseitol, a 7-carbon sugar alcohol. We compared avocado-nectar collection by commonly used Italian-based (IT) honey bee colonies and New World Carniolan (NWC) colonies introduced in avocado orchards in Israel (IS) and California (CA). In IS, NWC colonies had greater honey yields (1.2-4.3 fold), with a higher perseitol content (1.1-5.4 fold), than IT colonies. Overall, we calculated that NWC bees collected 1.4 to 18.1 times more avocado nectar than IT bees in the IS orchards. In CA, analyses of the crop contents of foragers revealed non-significant strainspecific trends in visitation to avocado flowers that were consistent with those indicated by data from IS. The genetic basis for honey bee differences in visitation to avocado flowers was further supported by the consistently high honey perseitol content of selected colonies over two years. The implications of possible strain-specific difference in avocado-nectar preference are discussed in relation to the use of honey bees for avocado pollination.