Higher developmental temperature increases queen production and decreases worker body size in the bumblebee Bombus terrestris

Climate change and increasing average temperatures are now affecting most ecosystems. Social insects such as bumblebees are especially impacted because these changes create spatial, temporal and morphological mismatches that could impede their ability to find food resources and mate. However, few studies have assessed how the colony and life cycle are affected when temperatures rise above optimal rearing temperature. It has become imperative to understand how heat stress affects the life history traits of insect pollinators as well as how changes in life history interact with other traits like morphology. For example, a decrease in the number of foraging workers could be balanced by producing larger workers, able to forage at longer distances and gather more resources. Here, we investigated the impact of temperature on colony production and body size in the bumblebee Bombus terrestris. Colonies were exposed to two temperatures: 25 °C, which is around the optimal temperature for larval development and 33 °C, which is slightly above the set-point that is considered stressful for bumblebees. Although the production of males and workers wasn’t significantly affected by these different temperatures, queen production and reproductive investment were much higher for colonies placed in 33 °C than in 25 °C. We also found that, in agreement with the temperature-size rule, workers were significantly smaller in the higher temperature. The decrease in worker body size could affect resource collection and pollination if their foraging distance and the quantity of food they are taking back to the colony decreases. While in our controlled conditions the bumblebees were fed ad libitum, the decrease of resource collection in field conditions could prevent colonies from producing as many queens as in our study. Together with the decrease of worker body size, our results suggest that elevated temperatures could ultimately have a negative impact on bumblebee colony fitness. Indeed, smaller workers are known to have weaker flight performance which could affect foraging performance and consequently colony development.

Honey Bee Queen Production: Canadian Costing Case Study and Profitability Analysis

The decline in managed honey bee (Hymenoptera: Apidae) colony health worldwide has had a significant impact on the beekeeping industry. To mitigate colony losses, beekeepers in Canada and around the world introduce queens into replacement colonies; however, Canada’s short queen rearing season has historically limited the production of early season queens. As a result, Canadian beekeepers rely on the importation of foreign bees, particularly queens from warmer climates. Importing a large proportion of (often mal-adapted) queens each year creates a dependency on foreign bee sources, putting beekeeping, and pollination sectors at risk in the event of border closures, transportation issues, and other restrictions as is currently happening due to the 2020 Covid-19 pandemic. Although traditional Canadian queen production is unable to fully meet early season demand, increasing domestic queen production to meet mid- and later season demand would reduce Canada’s dependency. As well, on-going studies exploring the potential for overwintering queens in Canada may offer a strategy to have early season domestic queens available. Increasing the local supply of queens could provide Canadian beekeepers, farmers, and consumers with a greater level of agricultural stability and food security. Our study is the first rigorous analysis of the economic feasibility of queen production. We present the costs of queen production for three Canadian operations over two years. Our results show that it can be profitable for a beekeeping operation in Canada to produce queen cells and mated queens and could be one viable strategy to increase the sustainability of the beekeeping industry.

Honey bee queen production: Canadian costing case study and profitability analysis

The recent decline in honey bee (Hymenoptera: Apidae) colony health worldwide has had a significant impact on the beekeeping industry as well as on pollination-dependent crop sectors in North America and Europe. The pollinator crisis has been attributed to many environmental and anthropological factors including less nutrient rich agricultural monocultures, pesticide exposure, new parasite and pathogen infestations as well as beekeeper management and weather. Canadian beekeepers have indicated that issues with honey bee queens are the most significant factor affecting their colony health. In Canada, beekeepers manage colony losses by relying on the importation of foreign bees, particularly queens from warmer climates, to lead new replacement colonies. Unfortunately, the risks associated with imported queens include the introduction of new and potentially resistant pests and diseases, undesirable genetics including bees with limited adaptations to Canada’s unique climate and bees negatively affected by transportation. Importing a large proportion of our queens each year also creates an unsustainable dependency on foreign bee sources, putting our beekeeping and pollination sectors at an even greater risk in the case of border closures and restrictions. Increasing the domestic supply of queens is one mitigation strategy that could provide Canadian beekeepers, farmers and consumers with a greater level of agricultural stability through locally bred, healthier queens. Our study is the first rigorous analysis of the economic feasibility of Canadian queen production. We present the costs of queen production for three case study operations across Canada over two years as well as the profitability implications. Our results show that for a small to medium sized queen production operation in Canada, producing queen cells and mated queens can be profitable. Using a mated queen market price ranging from $30 to $50, a producer selling mated queens could earn a profit of between $2 and $40 per queen depending on price and the cost structure of his operation. If the producer chose to rear queens for his own operation, the cost savings would also be significant as imported queen prices continue to rise. Our case studies reveal that there is potential for both skilled labour acquisition over time in queen production as well as cost savings from economies of scale. Our queen producers also reduced their production costs by re-using materials year to year. Domestic queen production could be one viable strategy to help address the current pollinator crisis in Canada.