Figure 1. Thresholds for sticky board types. Threshold of 60 varroa mites. Threshold of 120 varroa mites. Research by the beekeeper for the beekeeper

Transcription

1

2 Bees have a close-knit relationship with people. They have accompanied us on many of our major migrations over time and are found all over the globe. The domestication of bees and the practice of beekeeping have been traced back to ancient Egyptian times about 26 BCE. Beekeeping spread throughout Europe, adopted by the Romans in 56 BCE and quickly spread throughout the Americas with the arrival of Europeans. Colony management has gone through dramatic changes over the years, most recently due to a suite of pests and viruses that were introduced to North America in the 198 s. The effects of these pests and viruses were not felt until ~26 when beekeepers experienced a dramatic decline in honey bee colonies nationwide. Honey bee decline has been shown to be an accumulated result of multiple factors including chemicals, limited nutrition and environmental conditions, small hive beetles, tracheal mites, varroa mites, viruses, fungi and bacterial diseases. An accumulation of these stress factors weakens a colony and makes it more vulnerable to pests and pathogens, particularly Varroa destructor, and associated viruses. Varroa are responsible for the physical damage to individual bees while also serving as a pathway for viruses. There are many cultural and chemical varroa control tactics that are practiced in beekeeping, but few have yielded long term success. Consistent annual losses in honey bee colonies has created a strong interest in developing alternative approaches to apiary management that are accessible to the public. Integrated pest management (IPM) is a widely known concept throughout agriculture and is commonly used for pest control in urban and agricultural environments. IPM is a multifaceted approach to pest management that combines biological, cultural, mechanical and chemical tools into a program that will reduce pests while decreasing the use of chemicals. A chemical approach may be necessary but IPM focuses on monitoring a pest s population and foregoing chemical treatment until a pest threshold or a specific pest s population level is reached. Our goal is not to eradicate varroa because they are here to stay, but to maintain varroa at sustainable levels and prevent them from reaching their threshold. Once varroa reach their threshold they are considered damaging to a colony and the colony has a difficult time recovering. Monitoring pest levels is

3 important in determining pest levels, and also in determining when to treat with miticides. The goal of my project is to build an IPM management program to decrease varroa and varroa-vectored viruses that incorporates not only the cultural and mechanical methods of varroa control but also colony behavior, specifically splitting colonies and using mite monitoring techniques to dictate when to use miticides. Our hopes are that by using various non-chemical control methods we will be able to reduce chemical treatments. In recent years, research has noted strong correlations between natural swarming behaviors of honey bees and the long term survival of honey bee populations accompanied with parasitic pressures of varroa mites. Swarming is an acquired evolutionary technique in which colonies reproduce while indirectly reducing pests and diseases. Research has supported the development of the co-existence of the European honey bee and varroa among feral and isolated apiaries. A split (i.e. an artificial swarm) is the division of one colony into two colonies resulting in the parental colony and daughter colony. It is predicted that long term effects of splitting colonies will result in the development of a stable co-existence between the host and parasite (bees and mites) in managed colonies. The goal here is to become sustainable beekeepers. Colonies will still be lost each season due to viruses, pests, weather or a combination of stressors, but by splitting colonies you will be able to increase and keep sustainable numbers of colonies in your apiary. I am using varroa control methods that are familiar to the beekeeping community, for example drone brood removal, screen bottom boards, splitting of colonies and hygienic stock selection. The long-term goals of this project are 1). To better understand the relationship between varroa and honey bees 2). To provide a basis for sustainable apiary management and 3). To understand how splitting and swarming affect the population dynamics among varroa mites, varroa-vectored viruses and honey bees. As pesticides are becoming less effective there is a need to explore alternative beekeeping management strategies. There are many methods of varroa control, but none alone have been successful at preventing the buildup of pests and diseases while increasing the long term survival of

4 a colony. I am focusing my efforts in the mid-atlantic region. The baseline data that I am collecting from this study will assist in developing a final program that will be useful to beekeepers throughout the region. This project is a citizen science project. Beekeepers will assist in collecting data that will be available online allowing them to track their results and compare their findings against results in their area. Bugonia is the online database in which beekeepers will enter data about their hives and track their progress. Bugonia will be launched in mid-late May. You will remain anonymous to others throughout the study. Research by the beekeeper for the beekeeper It is important to follow the protocol that I am providing below. The goal is to maintain varroa populations at reduced levels using nonchemical tactics. However, if the varroa mite threshold is reached then chemical control methods are acceptable. It is important that if you do use chemicals or medications that they are NOT used until the varroa threshold is reached and all information is recorded and given to me (the names of the chemicals or medications, how much is being applied and how often). Any information you provide will be kept confidential. There are two groups in this study. You must pick one to participate in: the control group or the treatment group. The control group will be preventing the colonies from swarming. The treatment group will be splitting the colonies. You must sign up for one OR the other and specify which swarm preventative tactics you are applying. There is one mandatory monitoring method for control and treatment apiaries, the sticky board. There are two styles of sticky boards and they have different thresholds. The checkered sticky board has a mite threshold of 6 mites; the full white sticky board has a threshold of 12 mites (figure 1). IPM thresholds are specific to the region and so it may be difficult to compare thresholds to colonies in the south, Midwest or west coast. All personal information you share with me will also be kept confidential (for example name and ). Uniformity is important for comparing results across samples so please follow the protocol. Figure 1. Thresholds for sticky board types Threshold of 6 varroa mites Threshold of 12 varroa mites

5 The strength of each colony is based upon 6 variables: adult bee population and brood population, brood pattern quality, and the amount of pollen, nectar and honey in each colony. Each frame must be assessed individually. It will take approximately 15 minutes to assess 1 colony with 2 hive bodies. Each variable will be measured by estimating its frame coverage to the nearest quarter, (, ¼, ½, ¾, 1). The quality of the colony s brood pattern is based upon a 1-3 scale, 3 being the strongest and 1 being the weakest. Temperament is estimated on a 1-3 scale, 1 being docile and 3 being aggressive. Varroa are monitored on average every 3 days using the sticky board method. Monthly assessments include: Mite population estimates via sticky boards Symptoms of disease Hive productivity based on quantifying the amount of honey, nectar and pollen Adult bee and brood estimates. Each frame side divided into fourths, 1 full frame divided into eighths (see figure 2). Temperament and brood pattern quality Queen status: present and laying, no queen, virgin ect. Queen cells tallied and their status (either a cup, charged (with an egg or larvae) or capped) Supply list: Sticky boards Vegetable or canola oil (pam) Drone frame 1. Assessments (below is an example of a data entry that shows the general format and what data to collect during each assessment period, figure 3). Specify frame type (shallow, medium or deep) Split each side of the frame into quadrants and estimate bee, brood, pollen, honey and nectar to the nearest quarter Side A ¼ bees ¼ pollen nectar honey Side B ¼ bees pollen nectar honey Figure 2: how a frame is divided, each side of the frame is divided into quarters

6 Figure 3. Data entry sheet that will be provided to record monthly assessment estimates. If eggs or larvae are present check mark the frame colony ID 4 temperament frame 1 frame 2 frame 3 frame 4 frame 5 frame 6 frame 7 frame 8 frame 9 frame 1 brood box brood pattern side A Adult bee type 1/2 1 1/2 1/2 1/2 3 medium 3/4 1/2 1/2 3/4 1/2 1 3/4 1 side A Sealed Q cups Q charge Brood 3/ /2 3/4 pollen nectar honey 1/2 3/4 1/2 3/4 1 3/4 3/4 3/4 1/2 1.5 Q capped 2 Q status queen laying eggs larvae notes 2. Brood patterns Brood pattern is not measured for each frame. It is an overall estimate of the colony. Brood guidelines Brood pattern quality does not depend on the amount of the frame that is covered in brood, but on the total amount and consistency of the pattern of brood, larvae or eggs throughout the entire colony The number of empty cells (not containing eggs, larvae nor brood) and the shape of the brood area define a pattern The inner frames will have more brood typically than the outer frames that are reserved for pollen, nectar and honey Brood pattern is based upon a scale of 1-3 A score of (3) will have minimal empty cells; a score of (1) the brood, eggs or larvae will be scattered and inconsistent Below I have provided a recommended guideline for splitting, although you may have your own method that you feel more comfortable with following. However, it is important to follow the natural pattern of colony swarming. There are two requirements: (1) the parent queen must be given to the daughter colony (the split) and you must allow the parental colony to rear a new queen; (2) the splits must mimic the natural timing and behavior of a swarming colony. It is also important to remember that you do not need to split every colony in your apiary, for example if the colony is not showing signs of swarming then it is better not to split them.

7 When to split: When you notice signs that a colony is making preparation to swarm Over five charged queen cells At least five or more frames of brood in the colony and 3-5 frames of honey (more or less running out of room), although it can vary Colony division At least 2/3 of the brood frames with clinging bees should be given to the daughter colony and 1/3 left in the parental colony, replacing the frames in the parental colony with drawn comb The queen is given to the daughter colony and the parental colony will be left to rear a new queen Split the honey and nectar frames between the colonies and feed the daughter colony It is recommended to not split after the end of June because the colony may not be able to properly build up and store enough honey for winter use If you decide to host a control apiary you must prevent your colonies from swarming. Swarming is related to the space availability; here are several techniques that can keep the incidence of swarming low: 1). removing queen cells 2). providing ample room for queen egg laying and expansion of the brood nest 3). providing ample room for pollen, nectar and honey storage. Varroa counts should be done at 3 day intervals. They are performed typically one day after the hive assessment. One day at minimum must be allocated between assessment and sticky board insertion because it will give the bees time to calm down. Sticky board monitoring 1. The sticky board is covered with a sticky substance (vegetable oil or petroleum jelly) 2. Insert the board sticky-side up below the screen bottom board or in the hive entrance 3. As mites are dislodged during grooming or removal from the capped cells they will fall through the screen cover and adhere to the board 4. The board is removed after 72 hours (3 days) 5. The mites are counted

8 The final control method of the project is drone brood removal. Place one drone frame in the brood area of the colony and remove it when there is capped brood in the frame. Timing of removal is essential because waiting too long will result in drones emergence and release of mites. It is important to place the drone frame in the colony early in the season to catch the first mite reproductive cycle. This will assist in reducing the mites throughout the season and is an important component of this IPM management. The program I am developing is an IPM managerial plan to maintain sustainable levels of varroa mites while reducing reliance on chemicals and medications. It will reduce the amount of time and costs beekeepers must spend on varroa control treatments, while overall increasing colony health and survivorship long term. Thank you for your support. If you have any questions or concerns please contact me, kciola@udel.edu United States Environmental Protection Agency Region III, Regional Agricultural Environmental Protection Agency, (EPA-OPP-11-3) University of Delaware

9 Sample sheet 214 Date colony ID temperament frame 1 frame 2 frame 3 frame 4 frame 5 frame 6 frame 7 frame 8 frame 9 frame 1 brood box brood pattern side A Adult bee type medium side A Sealed Q cups Q charge Brood pollen Q capped Q status nectar honey eggs larvae notes Date colony ID temperament frame 1 frame 2 frame 3 frame 4 frame 5 frame 6 frame 7 frame 8 frame 9 frame 1 brood box brood pattern side A Adult bee type medium side A Sealed Q cups Q charge Brood pollen Q capped Q status nectar honey eggs larvae notes