Progress report for FNE23-050
Project Information
With this project, we seek to evaluate the benefits of overwintering honey bee colonies of two different sizes in climate controlled storage at four locations in Pennsylvania and compare this to colonies overwintered outdoors at each location.
We will compare:
- Survival: 1) Compare survival of nucleus colonies vs full size colonies inside cold storage. 2) compare survival of full size colonies in cold storage vs outdoor colonies.
- Feed consumption 1) Compare food consumption of nucleus colonies vs full size colonies inside cold storage. 2) Compare food consumption of full size colonies in cold storage vs outdoor colonies.
- Parasitic Varroa mite levels: Compare varroa mite levels in colonies wintered indoors to those wintered outdoors.
- Spring Colony Strength: Measure and compare the amount of brood and bees at the same time point of colonies wintered indoors vs outdoors.
- Economics: 1) Calculate the costs of overwintering indoors and outdoors. 2) Calculate the feasibility and profitability of overwintering nucleus colonies in cold storage.
- Differences between sites: Compare landscape effects across geographic regions.
Beekeepers in Pennsylvania are facing overwintering colony losses of 40% or more each year. These losses are commonly attributed to colony starvation, the parasitic varroa mite, and weather. New practices are needed to improve sustainability and profitability of beekeeping. Climate controlled storage of honey bees is a known and established practice in Canada, Minnesota and other regions that experience extreme low winter temperatures, but is increasingly being used in warmer climates, such as Texas, to improve health and profitability in beekeeping. Climate controlled storage of honey bees has rarely been recorded in Pennsylvania. We propose to study the benefits of climate controlled storage in four locations in Pennsylvania to determine if the practice is economically viable and beneficial to farmers in this region by reducing colony losses, food consumption, pest infestations, and energy inputs.
Honey bees forage on nectar from flowering plants to create honey which serves as their source of energy during the times of year when floral resources are not available. Honey bees do not hibernate, they regulate the temperature of their nest during winter by forming a cluster and vibrating their wing muscles to create heat. Temperatures inside the cluster are maintained between 82 and 94°F. At low temperatures, below 30°F, the cluster contracts to conserve heat while consuming more resources to generate heat. At extremely low temperatures the cluster is so contracted that the bees may not be able to access the food stores within the hive, which increases the risk of starvation if food stores are out of reach inside the hive. At temperatures above 50°F, the cluster expands and the bees become increasingly active and leave the colony in an attempt to forage. Foraging is energetically costly for the colony, reduces the lifespan of the individual bees, and requires the beekeeper to provide additional supplemental food sources. The cluster operates most efficiently when ambient temperatures are slightly above freezing.
Floral resources in Pennsylvania become scarce in the fall and honey bee colonies rely on stores of honey collected earlier in the year or on supplemental food provided by the beekeeper. As our landscape and weather change, there are increasingly fewer floral resources, particularly later in the year, which results in costly supplemental feed to maintain colonies. For example, 350 colonies in PA, owned by Extract and Box, LLC, require over 4000 lbs in liquid syrup during the fall and 1200 lbs of dry sugar over winter to mitigate resource losses from vast temperature fluctuations. Additionally, when outside temperatures are warm and floral resources are scarce, honey bees and other insects will attempt to steal honey from other hives in a behavior known as robbing. Robbing is detrimental to the colony that is being robbed, as it loses its food stores, and the colony that is doing the robbing may bring diseases and pests back to their hive. By placing colonies indoors, robbing behavior cannot occur.
Varroa mite infestations are a leading cause for disease transmission and negatively impact colony survival. Varroa mites damage honey bees by feeding on the developing bees and transmitting/activating harmful viruses. Exposure to mites and viruses reduces lifespans of winter bees that increase colony mortality. Because varroa mites can only reproduce when the bees are rearing young, a pause in brood production is a pause in mite development. Placement of colonies indoors in constant darkness and constant low temperatures result in the queen ceasing to lay eggs and the colony will become broodless. This added benefit of halting mite reproduction will likely lead to healthier colonies in the spring.
Additionally, climate controlled storage may offer beekeepers the ability to affordably overwinter very small colonies called nucleus colonies or nucs. Each spring Pennsylvania beekeepers import tens of thousands nucs and packages of bees from southern states. Some beekeepers transport their nucs to the south to overwinter, this comes at a high cost in labor, transportation, and carbon emission. Increased nuc sales are of interest to both the producer of these colonies and to consumers who are increasingly seeking locally available sources of bees.
Climate controlled storage of honey bees may offer Northeastern beekeepers an opportunity to adapt to a changing climate, reduce colony losses, decrease expenses, and increase profitability by overwintering small colonies which can be sold or used by the farmer the following spring. Understanding the benefits of this system and communicating the results of this research will empower farmers to make informed decisions to improve the sustainability and health of their bees while increasing profitability.
Cooperators
- (Researcher)
- (Researcher)
- - Technical Advisor
Research
In order to explore the benefits of climate controlled storage of honey bees we propose to lease four specially designed climate controlled storage units from HiveTech Solutions (https://www.hivetechsolutions.com/mica) to be placed at four farms in Pennsylvania. A total of 320 colonies of honey bees, 80 colonies from each farmer, will be dedicated to this project. At each location, each of the colonies will be managed and prepared for winter using standard practices. 160 of the colonies will be configured in standard single deep hives or “singles” (8-10 frames each) and 160 will be configured in single nucleus hives or “nucs” (5 frames each). For each beekeeper, that is a total of 40 singles(20 inside, 20 outside) and 40 nucs (all inside).
During the spring and summer of 2023, each beekeeping operation will prepare for the experiment by ensuring that honey bee colonies are strong, healthy, and the needed hive equipment is in working order. In August, the colonies for the experiment will be chosen and a standard protocol for preparation will be practiced by all participants. Parasitic mites will be controlled using chemical miticides. During the months of September and October the colonies will be fed supplemental sugar syrup, as needed, to reach the weight necessary for overwintering. In November, the colonies will be placed inside the unit and the outside colonies will be placed just outside of the storage unit and monitored through the winter.
We will compare:
1. Survival: 1) Compare survival of nucleus colonies vs full size colonies inside cold storage. 2) compare survival of full size colonies in cold storage vs outdoor colonies.
The number of colonies that go into the winter will be compared to the number of colonies that come out of winter.
2. Feed consumption 1) Compare food consumption of nucleus colonies vs full size colonies inside cold storage. 2) Compare food consumption of full size colonies in cold storage vs outdoor colonies.
Based on data shared with us from beekeepers who have kept colonies indoors, we will ensure that sufficient food is stored in the hives prior to the start of overwintering. Each hive will be individually numbered and assessed for weight and bee population size just prior to movement into the unit. In March, when hives are removed from the storage unit, the same assessment will occur, so we can determine how much food was consumed and how well the bee populations were maintained. Each hive will be weighed using a standard scale. Adult bee population will be assessed by visualizing the bees on each frame. The area of bees will be estimated as the number of frames covered with bees.
3. Parasitic Varroa mite levels: Compare varroa mite levels in colonies wintered indoors to those wintered outdoors.
Each hive will be individually numbered and assessed for parasitic mite population size just prior to movement into the unit. Parasitic mite levels are assessed using a standard alcohol wash. From each colony, ½ cup (300 individuals) of bees is collected into a pint glass jar containing alcohol. The jar is shaken for one minute to dislodge the mites from the bees. The alcohol is poured through a fine sieve to catch the mites, which are counted. The number of mites per 100 bees is then determined. In March, when hives are removed from the storage unit, the same assessment will occur, so we can determine how the mite population changed, or was maintained, over the winter.
4. Spring Colony Strength: Measure and compare the amount of brood and bees at the same time point of colonies wintered indoors vs outdoors.
In March, when the hives are removed from the storage unit, their brood population will be estimated. Each frame will be lifted from the hive and the brood will be visualized. The area of brood on each side of each frame will be recorded and ¼, ¼, ¾ or 1 frame of brood. When all frames are added together, we will have an estimate of the total amount of brood in the hive, which is a determination of the future population size of the colony. More brood will mean a larger colony and subsequently more bees to sell and/or more honey production.
5. Economics: 1) Calculate the cost of overwintering indoors and outdoors. 2) Calculate the profitability of overwintering nucleus indoors compared to indoor and outdoor overwintering of standard colonies.
Throughout the project expenses and income will be recorded. Costs including labor, transportation, supplemental feed, electricity, and miticide application will be recorded for both indoor and outdoor storage. We will use data from the economic inputs and survival to model the profitability of each treatment type by using anova t-test and use that analysis to generate a formula that will demonstrate predicted outcomes at various operational scales.
6. Differences between sites: Compare landscape effects across geographic regions.
The comparison will occur at multiple locations in Pennsylvania, each beekeeper will overwinter colonies both indoors and outdoors. Because we will be working together, and following the same protocol, the experiment will have four replicates that will account for differing landscapes and climates. Each beekeeper will set up a weather station alongside the outdoor-wintering bees to monitor the temperature, humidity, precipitation, and wind to document the environmental condition at each apiary.
As planned, Bernie, Christina, Kate, Mark, and Tim spent the month of September preparing the (320) colonies that were dedicated for this cold storage research colonies. The colonies were fed supplemental sugar syrup, as needed, to equalize and reach the weight necessary for overwintering.
On 10/6/23 our HiveTech units arrived without incident. They were placed, leveled, and started to ensure proper operation before loading them.
Our Data has been consistently logged and monitored using a dashboard provided by HiveTech. This live dashboard allows each principal to see his or her current and historical data. Temperature, inside and outside, relative humidity inside and outside and internal CO2 levels were constantly monitored and recorded.
We are scheduled to move the colonies out the week of March 27, 2024. We plan to put them in place nearby and let them fly for about 3 days. The bees must orient themselves and defecate before doing the following assessments. We will measure, preferably all on one day: Which colonies survived, and which did not, hive weight, Colony size defined by an estimated number of frames of bees, Varroa mite levels using an alcohol wash, and total brood area in each colony (percent brood area on each frame, then added all together). Lastly and later, we will discuss the economics of the work and look at the weather data that was collected.