Data from: Pollination by wild bees yields larger strawberries than pollination by honey bees

1. A diverse array of wild bee species may provide more effective
pollination than the widely employed European honey bee (Apis mellifera
L.). High species richness within crop pollinator assemblages has been
linked to enhanced fruit and seed yields, but species richness is often
confounded with abundance in studies of pollinator communities. 2. We
investigated the effects of bee diversity and species identity on pollen
deposition and crop yield in the strawberry (Fragaria x ananassa) variety
Jewel through a field experiment that independently manipulated the
species richness and abundance of flower visitors. We used a new pollen
deposition measurement technique to determine the pollen contribution of
individual bees in an assemblage of flower visits. We compared the
performance of wild bee species and managed honey bees, as pollinators of
strawberry. We also calculated the influence of species richness, visit
frequency, and visitor identity on fruit mass, using the fruit that
developed from each sampled flower. 3. Species richness of flower visitors
did not influence floral pollen loads or strawberry mass. Honey bees and
wild bees deposited the same amount of pollen per visited flower. However,
strawberries that developed from flowers visited by wild bees were heavier
than flowers visited by honey bees. In addition, flowers visited by a
combination of wild and honey bees produced strawberries that weighed less
than flowers receiving purely wild bee visits. 4. Synthesis and
applications: Our findings show that honey bee pollination results in
lower yields than wild bee pollination in a strawberry crop. Consequently,
if managed honey bees in strawberry fields displace wild pollinators,
growers may obtain suboptimal yields. Management efforts aimed at the
maintenance or enhancement of wild pollinator populations may therefore be
a cost-effective way to increase both crop yield and biodiversity on
strawberry farms.