Eric Asare

Date of Award


Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)


Resource Economics and Policy


George Criner

Second Committee Member

Francis Drummond

Third Committee Member

Greg White


The present study investigates the impact that bees, specifically native and honey bees, have on the yield of lowbush blueberries and subsequently the net profits of enterprises in Maine. The study focus on bees due to their extreme importance to the yield of blueberries. Research shows that blueberries are about 100 percent dependent on bee pollination. In Maine, blueberry farms rely heavily on honey bees for their farm pollination needs. In recent years there have been bee ‘die-offs’, caused by disease as well as known and unknown stressors. Over the years, the number of native bees and honey bees have been declining. At the same time, the demand for their pollination services have risen. This is especially true for honey bees, which are rented by farmers and are a crucial input for production. The high demand for pollination services has helped increase the price of honey bee hives over the years, putting an economic burden on blueberry growers, especially high and medium input farms that rely more on honey bees, than native bees, for their pollination needs. Research shows that native bees are very efficient pollinators compared to honey bees, and they could provide insurance against rising prices of honey bee hives. This study models some of the uncertainty associated with the numbers of native bees and honey bees, and how they impact the profit of blueberry enterprises in Maine. Specifically, the following objectives are pursued: 1) To quantify the relative contributions of honey bees and native bees to fruit set, 2) To quantify the effect of fruit set on the yield of blueberry farms in Maine, 3) To simulate and quantify the effect of the state of bees (specifically, honey bee collapse and native bee abundance) in Maine on the profitability of different types of blueberry farms in Maine, and 4) To estimate the monetary values of honey bee and native bee densities as pollinators of lowbush blueberries. The results of the study show that fruit set has a positive and statistically significant effect on the yield of blueberries, at the 1 percent level. Additionally, native bee and honey bee densities also have positive and statistically significant effects on fruit set (both at the 1 percent level). Native bees have a greater marginal impact on fruit set than honey bees, measured using their densities (bees/m2/minute). The study estimates the value of native bee and honey bee densities (bees/m2/minute) on an organic lowbush blueberry farm to be $29 and $3, respectively. For a low input farm, the values of the densities (bees/m2 /minute) of native bees and honey bees are $54 and $6, respectively. The high input farm has the greatest values for the densities (bees/m2/minute) of native bees and honey bees at $449 and $49, respectively. This study also found out that native bees have a greater impact on the profit of three different farming systems (organic, low input and high input), compared to honey bees. In summary, native bees have been found to be more effective pollinators than honey bees, on a per bee density basis. This result is consistent with other studies in the blueberry literature. This research supports calls for the promotion and conservation of populations of native bees to help agricultural enterprises, both in general and in this case for Maine blueberry farms in particular.