Comparison of conventional and tweezer techniques of instrumentally inseminating honey bees
Three possible methods are compared... Conventional, Perforated sting hook and manual use of tweezers... Safety and damage limitation favours the tweezer method.
The conventional insemination method is illustrated in the sketch at right and shows the difficulty in entry past the valvefold.
Syringe tip entry is also made more difficult due to folds in the queen's vagina... With an inherent risk of injury to the queen.
The difficulties are not insurmountable and much II work is successfully done by this method.
A 0.15 mm hole in the hook can be threaded over the sting which is then pulled upwards and sideways. Depending on the model of apparatus in use there may be a lack of sensitivity to this action.
The angular motion traps the sting itself as the parallel bore of the hole become out of parallel with the sting shaft and binds against the side of the sting. The serrated nature of the sting shaft ensures a non slip grip. The tension in the sting both opens the vagina and reduces the wrinkling to allow easy penetration.
I am of the opinion that holes of this size can be produced by spark erosion. Research undertaken during January 2003, concluded that it was possible to use this method, but the cost of having the job done commercially was prohibitive, unless you took the trouble to set up your own tooling and learned the technique yourself (in which case costs become very low).
During 2005 the perforated sting hook was taken a little further... Sue Cobey of Ohio State University developed a jeweled sting hook that uses a ruby watch bearing jewel instead of having to drill the very small diameter hole.
Peter Schley has a spring loaded clasping device that can perform a similar job by gripping the sides of the sting.
Whilst requiring a steady hand, this method, that uses fine quality light weight tweezers, straightens out the natural folds in the vagina and, therefore, gives easier quicker and safer entry. The manual use of tweezers gives feedback on the tension applied to the sting, which in turn limits any possible damage.
This method gives the easiest entry into the vagina and after a little practice it is very quick.
The tweezers need to be fine and well polished... Ideally they should only be used on one queen, so a large number of freshly autoclaved instruments should be available. The insides of the jaws are polished smooth by dragging the tweezers over a folded piece of 800 'wet and dry' abrasive paper that is used in preparation of motor cars for spraying.
While at Gormanston, during 2003, John Pollard and I sorted out a design of tweezer that had spring, as well as a profiled grip on the sting. There are several unusual points in this design and I feel sure it could be taken further and be manufactured all in one piece from stainless steel. In honor of the event we called it the "Gormanston Tweezer".