California almond trees are in bloom from February through early March. To produce an almond, each flower must be visited by a honey bee or other pollinator. It is estimated that as many as two thirds of all the commercial bee hives in the US are now located in the almond orchids. The bees contribute so much to the almond crop that growers pay between $100 and $200 per hive. Large commercial beekeepers sign contracts to deliver bees. They shut their bees in at night, stack the hives on pallets and drive the hives to almond country on flatbed trucks. At the orchard, pallets are removed by fork lifts and spread through out the orchard. The bees are released in a sea of almond pollen and nectar. In March when the almonds finish blooming, beekeepers pack up their bees and transport them to other locations where pollen and nectar are available.
This system of pollination is needed because almond orchards are kept clean of “weeds” that could harbor tree pests. Alternative sources of pollen and nectar are not available in large enough quantities to maintain the numbers of pollinators needed at peak almond bloom. The bees must leave in March because there is no longer enough food.
This system is economically lucrative, but places stress on the bee colonies. Bringing bees to a small area allows diseases and parasites to spread among the hive. Insecticides are not used during pollination season to protect the bees. However, the areas where bees go after almond pollination are not uniform or uniformly managed. Some crops within a mile radius of a bee hive may be treated with insecticides that could harm bees that visit there. This system has incurred substantial losses of bee colonies every year that most be replenished to maintain the system. There are many challenges to keeping bee colonies healthy under these conditions. Bee biologists are studying when, where and why colonies are lost, hoping to reduce the losses of bee colonies.