Progress report for FS24-364
Project Information
Varroa are currently responsible for greater losses of colonies than are any other biological threat, requiring commercial beekeepers to spend a substantial amount of time treating colonies with chemicals. Integrated pest management (IPM) is key to sustainable operations by reducing the labor associated with treating colonies, miticide costs, and loss of bees. Addressing these issues will result in increased profits and sustainability. A fundamental tenant of IPM is to use genetically resistant stock to improve productivity. This project focuses on the genetic aspect of IPM.
Some Florida queen producers actively select their own stock for local adaptation, overall hygiene, vigor and mite resistance. We plan to include these producers in this study. We will determine overall Varroa populations in approximately 500 colonies by performing standard alcohol washes on 300 worker bees, then collecting nurse bees for SNPs analysis, and finally rating vigor and defensiveness. The best 30 colonies with the lowest Varroa populations will be marked and set aside, then await the results of the SNPs assay; based these results further testing using MBB and PKB assay will occur.
This will aid Florida queen bee producers who, as a result of our scientific genetic data, can make more effective breeding decisions based on empirical information, rather than visual perception and instinct. As part of this process, the producers will be part of the field analysis and data collection. Thus they will be able to perform the screening tests themselves by the end of the study.
We plan to sample at least 500 colonies in operations managed by three different queen producers in Florida. After discussing stock selection methods with queen producers, we will inspect their colonies and assign them a unique number. First, we will assay these colonies for Varroa populations using a standard alcohol wash. The alcohol wash is generally accepted scientific method for accurately measuring the level of infestation by collecting 300 bees, placing them in a jar of alcohol, shaking them for 60 seconds, decanting off the liquid and counting the total number of mites that were washed off of the bees. Secondly, for genetic SNPs sampling, we will collect very young nurse bees, place them in tubes of ethanol. Then the samples will be sent to Harpur lab at Purdue. Lastly, based on this raw field data, we can immediately identify which are the best colonies that will be tested for MBB and PKB.
MBB is defined by a honey bee biting one or more legs off a Varroa.An assay has been developed by Dr. Greg Hunt at Purdue University (Hunt & Andino ABJ 2011) for accurately measuring the proportion of chewed mites in a colony. This will yield measurable results, and a potential tool for breeding selections. The method has two major components, collection of mites and evaluation of chewed legs. The collection of mites in the field by beekeepers is simple. (1) An oiled board is inserted over the bottom board (floor) of the hive. (2) The board is allowed to remain in the hive for 24-48 hours. (3) The mite boards are removed from the hives, and brought to safe processing area/lab. The second component is evaluation. (4) Sift through the contents and collect the dark mature mites. (5) Glue/set the mites "legs up" on a glass microscope slide/petri dish and count the total number of Varroa (6) View each mite on the slide under a low power microscope/15×-handlense and count how many mites have chewed/missing legs. (7) Calculate the MBB, as a percentage, example: 12 chewed mites/36 total mites = 33% of mites having chewed legs. The collection method is simple for beekeepers to perform in field with minimal training and tools. The evaluation component, steps 4-7, requires more skill and is labor intensive/time consuming. Fortunately, this can be done later, when beekeepers have more time.
Students at the University of Florida will be involved in counting the chewed mites, and some of the field work. Statistical analysis of the results will be performed and presented in the final report.
Pin-killed Brood assay is performed by using an entomological pin and piecing capped brood. A section of brood frame is marked so 50 cells are pieced, killing the pupae, the worker bees will remove the dead pupae. After 5-6 hours the frames are measured for the percentage removed. This is safer than the freeze killed methods which require the handling of dangerous liquid nitrogen. These results are a proxy for VSH hygienic behavior.
Cooperators
- - Producer
- - Producer
Research
This is research inspired project based findings at Purdue University, Dr. Greg Hunt (Professor Emeritus) and Mr. Krispin Given (Purdue Lab Senior Scientist) observed that some phenotypes of bees exhibited mite-biting behavior (Hunt et al. 2016). Worker bees were observed biting the legs off of a Varroa mite as way defend the colony from infestation. A video produced by Mr. Dwight Wells (citizen scientist) documents this type of grooming hygienic behavior (taken at Wright Patterson AFB in 2017-see below). Since a bee life cycle is 42 days, this hygienic behavior is inherited from generation to generation.
Dwight Wells frequently expounds “Bees out here in God’s country know how to bite the mites so they can survive, this in why Ohio feral swarms and survivor stock are our only hope!” To access the non-public video, click on the link, not the image: https://www.youtube.com/watch?v=CK1J9Hthj_Q
Purdue has an undertaken an exceptional agricultural extension effort to disseminate the leg-chewers genetics to bee breeding organizations across the USA. Dr. Hunt and Mr. Krispn Given worked hand-in-glove with commercial beekeepers and state organizations to distribute their genetics to anyone who wanted them. The annual “insemination fest” at the Purdue bee lab is an opportunity to inseminate breeder queens from across the nation with semen from mite biter workers and thus help our colonies to be healthier.
Dr. Harpur is currently serving an advisor for my MS project: Helping Florida Queen Producers to select for Mite-resistant Stock by Using Marker Assisted Selection, USDA Southern SARE FS24-364. My field work involves phenotyping Florida multi-generational bee stock looking for the strongest most mite-resistant colonies. The field measurement that indicates the overall ability to resist and survive mites is a simple alcohol wash. The alcohol wash is where one-half cup of bees is immersed in isopropyl alcohol, agitated and then the mites settle to the bottom for counting. Randy Oliver developed an improved method using Dawn detergent as a surfactant where the soap solution causes the mites to decouple from their honey bee host and are mechanically agitated to the bottom using a custom-made mechanical shaker. The bees are then collected for DNA testing and sent to Purdue for SNP analysis.
Shipped 296 samples of worker bees to Purdue University on January 15, 2025. These samples are currently in cold storage awaiting SNP analysis.
Watch a humorous video of my recent field data collection that is posted as a YouTube short. This video is not officially published so please click the link, not the image:
https://youtube.com/shorts/3qpXgibA6bE?si=euG2FfxjUfmX0C62
The next step is to perform mite-biting assays using sticky bottom boards. Some mites naturally fall to the bottom of the colony, alive and intact. Others are attacked by worker bees who chew the mite’s legs off and then fall to the bottom on the sticky board. The mites are counted and a simple percentage is calculated; chewed mites divided by total mites. This process is described in this brief video. Video link, you must use this link for private video, not the image which is a screen shot: https://youtu.be/h43jO21TXLE
Results:
The results of the field data collection are tabulated on the above excel spreadsheet.Field work included collecting 300 bees (half a cup), and washing in soapy water solution, and recording the number of bees on the bottom of the sample container.
Miksa Honey Farms: 2 beeyards sampled on January 11-12, 2025; 132 samples collected and recorded.
Cutts Tupelo Honey Farm: 4 beeyards sampled on January 14-15, 2025; 164 samples collected and recorded.
Data Analyses: There has been no statistical analysis performed on the data to date.
Discussion
For bee farmers in the USA have experienced 68% losses in 2024-25 (far exceeding to the Colony Collapse Disorder (CCD) event of 2007 (Lamas, 2025), this could not come at a worse time.) Press releases from Project Apis m. Jan+2025+Colony+Losses+Communication+Final and an updated report Colony+Loss+Survey_PR+(02) .
Many colonies in project yards have been impacted, colonies are very small, and possibly will be dead in weeks. the future is uncertain and it will slow to find a solution to this mass die-off any time soon. Trumps executive order to freeze spending at the USDA has paralyzed labs of the ARS, crippling our ability to solve this epidemic.
Unfortunately, at the time of this writing the USA bee-farmers are reeling from losing over 1.3 million colonies in the matter of months, and now finding funding freezes/cuts from the Trump and the DOGE. The ELAP program that was designed to help beekeepers recover from losses, has also been suspended. The future is uncertain as 100,000s of farm related business owner are scrambling just before Spring pollination contracts and planting.
Hopefully cooler heads will prevail, once they realize that you can’t eat cryptocurrency.
Further research
Mapping the genome of bees is imperative to identifying regions of the DNA that are germane to the hygienic behaviors and perhaps other as yet to be identified health traits.
Educational & Outreach Activities
Participation Summary:
We plan on having extensive outreach with this project. Currently, besides being a
commercial queen breeder, I am earning my MS Agroecology at UF via distance
learning. The operation is split between Slippery Rock, Pennsylvania in the
Summer/Fall and Chiefland/Otter Creek, Florida in Winter a early Spring. Cameron Jack
and Jamie Ellis are my academic advisors, and will help guide my outreach efforts with
the current undergrad students, participants in UF's Bee College, and the Florida State
Beekeepers Association (FSBA).
Artificially inseminated breeder queens will produced using the best stock identified in the study by me, these will be left with the queen producers, and UF and Purdue, daughters from these very valuable genetics may be made available on a limited basis to the public.
UF/IFAS has three, two-day Bee Colleges annually (>300 participants), which I plan to
attend at least one of these and set up a table with a portable digital microscope to
look at slides of chewed mites. Also the Pin-killed brood assay will be explained,
this way beekeepers will have hands-on experience
on how to perform this assay.
FSBA (>150 attendees) has their annual meeting in November, which I will have to
travel to from my Fall location in Pennsylvania to Florida. I plan to attend and set up a
table with a portable digital microscope to look at slides of chewed mites. This way
beekeepers will have hands-on experience on how to perform this assay.
Dr. Ellis agreed to interview me on UF's podcast: Two Bees in a Podcast (~3,000
listeners).
Also, I plan on writing at least one short article for either of the two national bee
journals (American Bee Journal or Bee Culture).
Plus, this project will involve several students under Dr. Jack's supervision in the Bee
Lab, and likely in the field as well (see letter of support in previous section).
Learning Outcomes
Learned an new and more cost effective way to sample for Varroa mites using Dawn dish soap instead of alcohol.