As Colony Collapse Disorder reduces honey bee (Apis mellifera) populations in many countries around the world the attractiveness of native pollinators garners attention for agriculture. Mason bees (Osmia lignaria) are early spring bees that have been used successfully to pollinate orchard crops. In this work, mason bees were added to six small strawberry farms in 2014 and three small farms in 2015. All farms were large enough to be split into a control (no bees added) and an experimental plot (mason bees added). The size and growth rate of strawberries from the treatment and control plots were compared and bee homes were deployed to determine whether they would be colonized.
Statistical analysis (non-parametric, rank-based ANCOVA) demonstrated that mean fruit volume of berries on treatment plots (4,419 mm3) was larger than volume of berries on control plots (2,919 mm3; F(1,762) 21.836, p<0.001). Mean daily growth rate of berries on treatment plots (220 mm3/day) was also faster than growth of berries on control plots (151 mm3/day; F(1,762)21.342, p<0.001). Bee homes were colonized at a rate that varied by home type (from 4-20%). This is the first work to demonstrate that mason bees can successfully be used to pollinate, and improve fruit production, of a non woody crop.