This modification makes it much easier, and faster.
by Maryann Frazier, Elina Niño and Christina Grozinger
GRAFTING . . . a useful skill that many beekeepers would love to have in their beekeeping skills toolbox but for various reasons don’t. Picking up and moving a fragile 24-hour old larva from its cell and into an artificial queen cup is intimidating even if one has good eyesight and a steady hand. Many of us try it but understandably become frustrated and give up. BUT before throwing in the towel for good, read on and give this modification a try. It WILL make a difference. For those of you grafting thousands of cells a day, you also might want to consider this technique; it will likely shave precious seconds off of your grafting time allowing you more time to respond to those email requests for more queens!
Our (Penn State) Center for Pollinator Research held it’s 4th annual queen rearing workshop in June, 2014. In addition to traditional grafting we talk about and demonstrate alternative queen rearing methods, including the Hopkins Hopkins/Case method. One of the challenges with this technique is that the bees tend to rear too many queen cells and they are often connected to one another, making separation of individual cells difficult. So it is common to score the frame of young brood horizontally and vertically (think of making columns and rows) using a hive tool thus removing many of the cells but leaving small groups of cells with young larvae that will be reared as queen cells and later be cut out and relocated. In the process of demonstrating this, it just so happened that we were using plastic foundation (necessary for the modification about to be described) but it was also freshly drawn comb that had not previously contained brood. As the frame was scored, we were surprised by what we so CLEARLY saw; very young larvae, nestled unharmed in the “wells” of the plastic foundation but stripped naked of their wax cells! So easy to see, so easy to access!
The Pursuit of Evidence
Poor eyesight and/or an unsteady hand make grafting a challenge and more than a few students of the pursuit have given up after a single attempt. It certainly seemed to us that this little discovery should make the process easier… but would it? We wanted evidence!
We engaged eight of our undergraduates, graduates and technicians in a friendly but “controlled” grafting investigation! Each participant was asked to graft 10 cells using the traditional Doolittle grafting method and 10 cells using the modification of removing the comb cells. Their skill-level ranged from 1st timers to beginners (not their first attempt but not experienced) to experienced. The study was conducted in the Grozinger field lab, a regular beehive of activity.
Overall, the average time for grafting 10 larvae using the traditional Doolittle method was five min. 17 sec. and two min.51 sec. when using the modification of removing the comb cells. Acceptance in the cell builder colonies was 64% and 74% respectively. So our modified method was almost twice as fast as the traditional and resulted in better queen cell acceptance! Using our modification, the three first time grafters reduced their grafting time by an average of two min. 52 sec. but surprisingly had 67% acceptance regardless of the technique (see table 1). The three beginners reduced their time by an average of three min. eight sec. while increasing their acceptance by 20%. The two experienced grafters (including author Niño) reduced their grafting time by an average of only 18 seconds but still increased their acceptance by 10%.
You Too CAN do this.
So if you’ve given up on grafting or never got started because it just looked too difficult, give this modification a try. Of course, you’ll want to graft larvae from your “best” colony (the one whose traits you want to pass on to “daughter” colonies). You also need to get the bees to draw at least one frame of plastic foundation (from any disease-free colony). It is even easier to see the young larvae if you use black foundation. To get the bees to draw this foundation without putting brood in the cells place these frames in the honey supers. Once the frames are drawn, they will likely contain nectar or honey and will need to be extracted (honey) or left for the bees to rob out (nectar). Note, if you leave capped honey out for the bees to rob they will do more damage to your combs. If you are using last year’s drawn combs it is helpful to place them in the colony for a day to allow the bees to polish the cells in preparation for egg-laying. We found it best to use the freshly drawn out frames since removing the wax cells from old frames (especially those that had several generations of bees emerge from them) damages the larvae. We also use a frame cage designed and built by Craig Cella to confine the queen to a frame for 24 hrs so that we know the age of the brood within 24 hrs. You can also use a large push-in cage to do the same thing. Then once you are ready to graft just use your hive tool to scrape a small area of the comb containing young larvae. Make sure to scrape only a small area at a time to avoid larvae drying out.
We hope you’ll give this a try. If you do, drop us an email (firstname.lastname@example.org) and let us know how you make out; we’d enjoy hearing about your experience. Until then we wish you all Good Grafting!
Acknowledgements and resources: We are thankful to those who participated in our comparative grafting study; Philip Betz, Ryan Cray, Julia Fine, Marin McAuthor, Bernardo Niño, Ryan Raynolds, and Mario Padilla.
Frame cages are available from Craig Cella 867 E. Winter Road, Logantown, PA 17747, 570-725-3682