- Animals: bees
- Crop Production: pollination, pollinator health
- Farm Business Management: business planning
One of the most challenging issues for present-day commercial agriculture is the recent dramatic loss of honeybee colonies, which are currently used as the main source of pollination for horticultural crops in the United States. A solution to this problem is encouraging farmers to shift their reliance from honeybees to native pollinators. One of the most efficient species of wild bee, the bumblebee (Bombus spp.), has many advantages. This project is based upon the premise found commonly in research relating to bumblebees that only a small number of overwintering, fertilized queens, create successful nests. Although the numbers vary somewhat, it is estimated that only 1% of emerging queens develop new colonies. Mice and ant depredation as well as loss of habitat are considered to be the primary culprits impacting colony success. In this project, we will examine various bumblebee nest box designs along with other variables relating to nest success in order to develop recommendations and plans for growers. This work should result in specific practices that growers can adopt in order to increase their native bumblebee pollinators, thus improving their overall fruit quality.
Project objectives from proposal:
For greenhouses crops, several commercial bumblebee breeding companies presently rear bumblebee colonies to sell to plant growers. Considering that the hives for sale have a lifespan ranging from four weeks to three months, at a price of $700 to $1000 for the multiple colonies necessary to pollinate a acre of crop, we believe that a more capable and inexpensive way of introducing long-term bumblebee colonies for the pollination of outdoor crops would be welcomed.
Some of the publicized research concerning methods of establishing bumble bee colonies, such as through the construction of nest boxes, includes the following: Frison, T.H. 1926, Fye, R.E. and J.T. Medler. 1954, Hobbs, G.A., Virostek, J.F., and W.O. Nummi. 1960, Prys-Jones & Corbert 1991, Munn 1998, Kearns & Thomson 2001.
Two main options for bumblebee nest box construction were gleaned from the research: one opinion is that the ideal nest box should have two chambers (one as a nest and the other as a vestibule where food can be provided and the bees can defecate), while the other opinion is that a one chamber box being perfectly sufficient.
Preceding research also tell us that bumblebees utilize their sense of smell and sight to hone in on ideal nesting places. Because of this, some researchers suggest that positioning the man-made nests near obvious land marks such as trees, posts, stumps, rocks, etc. will yield better results. Other studies have shown that drawing some type of pattern at the entrance helps the bees to locate their nest faster. For our project, we have taken into account the bumblebee’s perception of color as indicated by the research. Earlier studies have found that bumblebees can detect colors in the blue range (blue, indigo, violet and purple), and yellow range (yellow, red-yellow, green-yellow, yellow-green), and are most sensitive to hue discrimination in the violet range and the blue-green-to-green spectral range, and cannot make a distinction between black and red.
One of the unresolved issues in the literature is if the nesting height is of any significance to the bumblebee, and if so, what is the optimal height for above ground domiciles. The earlier research presents three main possibilities: 1) the best height for nest boxes is at least 15 inches above the ground, 2) height should be four feet above the ground, and 3) the height of the nest is not important as long the nest is protected from flooding, excessive humidity, wind and heat.
As there is no general consensus in previous research in standards for bumble bee nest boxes, and there is scant information on the success rate of different types of nests, we will test several models based on variations in design, color, and height to determine the most suitable conditions for a robust bumblebee colony. We also recognize that the previous research on bumblebees is not readily available to farmers and therefore, as extension educators, it is our duty to share with our cooperating farmers proven, practical, and user-friendly guidelines in how to install man-made nest boxes with the express purpose of creating and maintaining a system of crop pollination with the bumblebee population.