Economic aspects of the use of honeybees as pollinators for many agricultural crops are nowadays receiving more attention. In several countries beekeepers and scientists have tried to estimate the real value of honeybees and other pollinating insects. It is difficult to estimate the impact of pollinators in open field situations, but it is easier to calculate the benefit of honeybee pollination for greenhouse crops since fewer parameters playa role. In addition, the use of hand pollination for certain greenhouse crops is very expensive. The cost of hand pollinating 1600 ha of tomatoes in the Netherlands is roughly US$18 million. Honeybees have been used in the Netherlands for the pollination of several horticultural crops in greenhouses for more than 40 years, e.g. strawberries, gherkins, melons and plums. For seed production, plant breeding companies use honeybees for carrot, onion, leek, brassicas, beans, radish and asparagus.