EFFECT OF SYNTHETIC QUEEN MANDIBULAR PHEROMONE SPRAYS ON POLLINATION OF FRUIT CROPS BY HONEY-BEES (HYMENOPTERA, APIDAE)

Three different concentrations of honeybee, Apis mellifera L., queen mandibular pheromone were applied to 0.4-ha blocks of apple, Malus domestica Borkh., and pear, Pyrus communis L., by air-blast sprayer. Concentrations of 1,000 queen equivalents (QEQ) (AI)/ha increased the number of honey bees foraging on both apple and pear under a wide range of environmental conditions, orchard management systems, and geographical locations. Bee activity on plots sprayed with pheromone concentrations of 0.1 or 10 QEQ (AI)/ha did not differ significantly from controls. The pheromone was most effective on the day of application and declined to the level of control plots by the third day. The pheromone did not improve any yield or fruit quality parameters in apple. However, fruit diameter in pear was increased by the pheromone, resulting in an estimated average increase in return of $1,055/ha.