Selection and breeding of honey bees for higher or lower collection of avocado nectar.

Intensive activity of honey bees, Apis mellifera L., is essential for high fruit set in avocado, Persea americana Mill., orchards, but even when hives are located inside the orchard, many bees still search for alternative blooms. We tested for a possible genetic component for a preference of avocado bloom relative to competing bloom. The honey from each hive was extracted at the end of the avocado bloom and the concentration of perseitol, a carbohydrate that is unique to avocado, was analyzed as a measure for avocado foraging. During the first year, five bee strains were compared in three different sites in Israel. Significant differences were found between strains in honey perseitol concentrations, suggesting differences in their efficiency as avocado pollinators, although these differences were site dependent. At two sites, colonies with the highest and lowest perseitol concentrations were selected as parental "high" and "low" lines. Queens were raised from the selected colonies and were instrumentally inseminated by drones from other colonies of this line. During the second and third years, colonies with inseminated queens were introduced to the avocado orchards, together with the selected colonies still surviving from the previous year. Colonies of the high line had greater perseitol concentrations than those of the low line. Selected colonies that survived from the previous year performed consistently vis-à-vis perseitol concentration, in the second year of testing. Heritability value of 0.22 was estimated based on regression of offspring on midparent. The results reveal a heritable component for willingness of honey bees to collect avocado nectar.