Honey Bee Breeding Program Design: Varroa Sensitive Hygiene

[Music] Veroa sensitive hygiene or VSH occurs when honeybee workers identify cells with reproducing veroamites and remove them. Breeders use a VSH test to select bees with strong might removal traits, helping increase these behaviors in their colonies and reducing the need for chemical applications to control veroamites. To ensure the test accurately measures the current queen's score, she must have been present for 7 weeks. So all brood and workers are her offspring and the colony must remain untreated with mitoides as well. To perform the test, you will need a grafting stand, magnification, a light source, sharp forceps, paper towels, and a notebook or data sheet. Prepare to record the results of the test by creating a data table. Create columns for colony ID, the number of reproducing mites, the number of non-reproducing mites, and the total number of cells opened. You can also include columns for calculations, the colony score, and any comments you want to add about the colony or the test. To start the testing process on a colony of interest, open the hive and look for a frame with emerging bees. On the same frame near where bees are emerging from their cells, you should find brood at the appropriate age for this test. We're looking for bees that are 4 to 6 days post capping. When you open the cells, you should see white pupy with dark purple eyes. Brush the bees off the frame and take it to the location where you will perform the test. Place the frame on a grafting rack. Extra lighting and magnification can be helpful, but are not required. Using fine forceps, pierce the capping of a cell and move the forceps in a circular motion. Then grab the pupa Keep your eyes on the cell and check the inside for mites. A non-reproducing mite will be in the cell alone. A reproducing might have a small white male and various stages of immature females in the cell with her. After you have checked the cell, check the bee that you are holding in your forceps. A foundress might be seen running over the pupa. The immature mites may also be found adhering to her body. As you test, place the bees that you removed into piles of five for ease of counting. As you open cells, write down when you see a non-reproducing female might or a veroamite family. Continue removing pupy and looking in cells until you have completed 100. As you continue to open cells, if you count five reproducing mites, you can stop the test even if you have not opened 100 cells. If you open a 100 cells and have not found any mites, you must open an additional 100 cells for the test to be valid. Once you have finished the test, return the frame to the hive it came from. You can now calculate the queen's VSH score. Let's look at the data. In nature, approximately 15% of veroamites are non-reproductive. So, you're looking for a higher number than 15% to show that might reproduction is being suppressed. Look at the data you collected earlier. We'll be using this chart developed by John Harbo to convert your data to a VSSH score. Let's look at some examples. We looked at 100 cells and found one reproducing might and one non-reproducing might. According to Harbo's chart, this gives us a score of two because 50% of infested worker cells For this one, again, we looked at 100 cells. This time, we found zero reproducing mites and five non-reproducing mites. So, this one gets a score of four. In another test, we found five cells containing reproductive mites and stop the test even after we only opened 60 cells. Here, the colony score is a zero because they're allowing the mites to reproduce unchecked. To breed for bees with the veroa sensitive hygiene trait, select from those that have a score of four to breed from. With proper care and testing, the number of colonies with high scores will increase over time, resulting in more might resistant honeybees. [Music]