Objective 1: Determine how artificial homeostatic control of colony temperature affects pollination services to greenhouse tomatoes relative to a traditional commercial colony box, for healthy and infected bumblebee colonies.
Objective 2: Quantify how much time workers spend wing fanning or brood incubating in temperature-controlled colonies compared to a traditional commercial colony box, for healthy and infected bumblebee colonies.
Pollinator populations are declining worldwide, while food and crop demand continually increase. Therefore, growers have to rely more heavily on commercially available pollinator colonies. While honey bees are a popular choice, some crops can only be pollinated through buzz pollination, or need pollination service across a wider range of environmental temperatures than honey bees can supply. Commercially available bumblebees provide these features, and to help meet food and crop demand increases, there is therefore a need to examine ways in which we can optimize the efficacy and health of bumble bee colonies
Bumble bees are increasingly used to fulfill pollination needs, as they provide a less labor-intensive process compared to mechanical pollination. Bumble bees are highly effective pollinators, but have interests that compete with foraging (and therefore pollination) associated with colony survival. One of these is the need to regulate brood temperature within a specific range to ensure proper development of larvae. Bumble bees task switch between colony maintenance and foraging so any worker occupied with brood thermoregulation will not forage, resulting in decreased pollination service. Because brood thermoregulation is an energetically costly process, any additional energetic demands, such as mounting an immune response, will likely further reduce the number of foraging workers.
Parasitic infections impair bumblebee health and are thought to be major contributors to native bee population declines. Although commercial colonies used in greenhouses may start out infection-free, there is often pathogen spill-over from native pollinators. Managing infections is thought to be energetically costly to bees, and will thus divert precious energetic resources away from fueling colony maintenance and foraging. Since few treatments are available to cure infected bumblebee colonies, mitigating these energetic costs of infection is a priority.
My work looks to examine if by enhancing brood thermoregulation artificially, it will enhance the number of foraging workers and increase pollination service. I additionally examine if externally controlling the colonies temperature can mitigate infection effects, allowing for better pollination services.
We are currently in the process of building and optimizing the temperature controlled colony box. We have ordered a circulating water bath which both heats and cools. This is being connected to copper tubing shaped to fit around the outside of the commercial colony box, but is not obtruding upon the entrance of the colony, or the sugar box stored underneath. Cooper was chosen as it has a high conductance to allow rapid heat transfer. Further testing will be done to determine the best temperature to set the water bath to, so that the temperature inside of the colony stays around 29 C.
A digital camera has been obtained to record the images of the colony. These images will be analyzed to examine the proportion of bees wing fanning. Optimization of the camera settings, and the amount of red light necessary to obtain images are currently underway. Once finalized, a box will be constructed to encase the colony. The purpose of the box is so that the colony is in constant shade or red light (wired into the box), thus preventing stressing the bees out further.This box will have two holes at the top in which the camera lens can fit into and will be plugged when cameras are not in use. The holes will be approximately 1 meter away from the colony, as both the digital camera and the thermal camera record colony pictures at this distance. There will be one hole on the side in which plastic tubing will be utilized to connect the colony to outside of the box. This will allow bumble bees the ability to forage, while maintaining that no bees enter into the box and could potentially hit the camera lenses.
Planting of the tomatoes will begin in about a month.
At present, it is too soon to asses impacts of the project. However, if pollination services can be improved, it could lessen the amount of colonies needed to be purchase, thus financially helping farmers.
At current it is too soon into the project to comment much. However, my future direction of eventually becoming an educator have not changed.