# Effect of Honey Bee Colony Strength on Foraging Productivity and Its Application to Precision Pollination

## TL;DR

Stronger honey bee colonies are more productive and resilient for pollination, suggesting fewer strong colonies can replace many weak ones, reducing costs and environmental impact.

## Contribution

Demonstrates that stronger colonies provide disproportionately higher productivity and resilience, enabling precision pollination strategies.

## Key findings

- Stronger colonies showed higher weight gains per frame of bees compared to weaker colonies.
- Strong colonies experienced lower weight losses during forage dearth periods.
- Fewer strong colonies can replace multiple weak ones, improving pollination outcomes and reducing transport.

## Abstract

Commercial pollination services are a multi-million dollar industry in the United States and are growing in other regions of the world as the intensive cultivation of high value crops such as almonds and blueberries increases. This growth has prompted research into precision pollination approaches, analogous to those used in precision agriculture, with the aim of optimising the use of honey bee colonies and other resources. Honey bee colonies are often transported across large geographical distances to crops and this practice impacts both the economics of pollination service and the environment. In this study, we examined whether pollination services can be streamlined by using strong colonies rather than larger numbers of weaker colonies. We found that strong colonies consistently and disproportionately outperform weak colonies during pollination and are also more resilient in periods of dearth. Prioritising the deployment of stronger colonies is proposed in order to improve pollination outcomes and beekeepers’ revenues and to reduce the number of colonies that are transported, thus also lowering the environmental impact of the transhumance.

Honey bee pollination of entomophilous commercial crops is a major input in agricultural management yet unlike irrigation, fertilisation and plant protection have yet to be integrated into precision agriculture practices. This study examines colony strength as a key determinant of efficient pollination. Over three years and across two study sites, we evaluated the relationship between colony strength (frames of bees, FOBs) and colony productivity using continuous hive weight monitoring. Hive weight data were analysed for both absolute gains and relative gains normalised per FOB across colony strengths. In all study periods, stronger colonies showed disproportionately higher weight gains compared to weaker colonies. For each additional FOB, the average increase in normalised weight gain ranged from 0.1 to 0.41 kg per colony, indicating a non-linear relationship between colony strength and productivity. An efficiency factor calculated for groups of strong and weak colonies ranged from 1.2 to 2.6, depending on the season and crop. Moreover, during periods of forage dearth, strong colonies exhibited lower weight losses than the weak colonies per FOB, making them more efficient under resource limited conditions. Our findings demonstrate that colony strength significantly influences foraging efficiency and colony resilience, ultimately supporting the conclusion that fewer stronger colonies will improve pollination outcomes while reducing the economic and environmental costs associated with commercial pollination services.