  The decline in extent of wild pollinators in recent years has been partly
associated with changing farm practices and in particular with increasing
pesticide use. In this paper we combine ecological modelling with economic
analysis of a single farm output under the as- sumption that both pollination
and pest control are essential inputs. We show that the drive to increase farm
output can lead to a local decline in the wild bee population. Commercial bees
are often considered an alternative to wild pollinators, but we show that their
intro- duction can lead to further decline and finally local extinction of wild
bees. The transitions between different outcomes are characterised by threshold
behaviour and are potentially difficult to predict and detect in advance. Small
changes in economic parameters (input prices) and ecological parameters (wild
bees carrying capacity and effect of pesticides on bees) can move the
economic-ecological system beyond the extinction threshold. We also show that
increasing the pesticide price or decreasing the commercial bee price might
lead to re-establishment of wild bees following their local extinction. Thus,
we demonstrate the importance of combining ecological modelling with economics
to study the provision of ecosystem services and to inform sustainable
management of ecosystem service providers.
