Latshaw Apiaries 

Instrumental Insemination – Performed Using the Flexible Insemination Technique

By Joseph S. Latshaw

Beekeepers, in general, are a collection of highly skilled and innovative people who are constantly developing new ideas and improving existing designs.  Within the beekeeping community there is a small group of people devoted to selective breeding through the use of instrumental insemination.  With such diversity and creativity it should then come as no surprise to expect such a vast array of instrumental insemination techniques and instruments around the world, which can be traced back to the early work of Dr. Lloyd Watson.  Dr. Watson is the researcher accredited with providing the first evidence of a successful attempt to instrumentally inseminate queen honey bees in 1926 (Cale 1926).  His success was achieved using a highly simplified “instrument” that employed a technique which is very similar to the flexible insemination technique practiced today.  In this article I will illustrate some of the advances made in the practice of instrumental insemination using the flexible insemination technique with modern improvements in instrument design.   

The flexible insemination technique was first developed by Dr. Lloyd Watson and in its most basic form involves a device used to restrain the queen, a device to hold the syringe used for delivering drone semen and a pair of forceps for grasping the queen’s sting to expose the opening of the reproductive system.  In Dr. Watson’s work, he used a small wooden block to which he secured the queen using a thin thread.  Then with the aid of a microscope, Dr. Watson grasped the sting with a pair of fine forceps to open the vaginal chamber into which he inserted the tip of a small glass syringe containing honey bee semen.  Dr. Watson’s apparatus and technique laid the groundwork for those who would follow in his footsteps of perfecting the instrumental insemination technique as we know it today.

The basic process of instrumental insemination is essentially the same as that of Dr. Watson, however advancements in equipment design have made the flexible insemination technique easier to learn and more efficient (Kuhnert and Laidlaw 1994) than other techniques currently practiced.  Instrument design has advanced since the invention of Dr. Watson’s apparatus.  Some changes include the use of a queen tube to secure the queen, as well as a source for carbon dioxide to flow through the instrument to anesthetize the queen during the insemination procedure, which reduces injury caused by struggling queens.  Carbon dioxide was also found to induce egg production in newly inseminated queens (Mackensen 1947).  Additionally, you will notice the use of what is termed a “ventral hook” in Figure 2 that attaches to the queen tube.  The purpose of the ventral hook is to stabilize the ventral side of the abdomen (last abdominal sternite).  Some instrument designs also incorporate the use of a larger capacity syringe designed by Dr. Harbo, that enables the collection of larger volumes of semen at one time for the purpose of storage or inseminating larger quantities of queens during a single sitting (Harbo 1985).

To begin the insemination process, the first objective is to collect a sufficient volume of semen to inseminate the desired number of queens.  A benefit of many instruments that employ the use of the flexible insemination technique is a great deal of maneuverability associated with simplified instrument design.  An example of such a benefit is evident with the process of semen collection which can be performed with the glass tip away from the main portion of the instrument.  Simplified instruments often feature reduced mechanical fixtures, which allow for more working space.  When collecting semen, the everted drone is placed under the field of view of a dissecting microscope and the semen is collected from a bed of mucus.  The marbled tan semen can be gently vacuumed off of the bed of mucus upon which it rests.  For insemination purposes, the semen is the essential portion and it is best to leave the bed of mucus intact as it presents problems with obstructing the flow of semen within the glass tip.  A single drone may yield approximately one microliter of semen and a standard dose for a single queen is eight microliters. 

Once the desired amount of semen has been collected, it is time to prepare the queens for instrumental insemination.  To begin this portion of the process, I first position the instrument under the microscope and adjust the flow of carbon dioxide used to anesthetize the queen during the insemination procedure.  Once the equipment has been prepared, the first step is to remove the virgin queen from her cage and insert her into the queen holding tube that consists of a piece of tubing with an approximate inside diameter of a quarter inch by approximately one inch in length.  This will securely hold the queen during the insemination procedure, provided, a slow and steady flow of carbon dioxide is directed through the tube during the procedure.  An anesthetized queen is much easier to manipulate, a luxury Dr. Watson did not have during his early work.

With the queen anesthetized, carefully position the ventral hook, just lightly touching the last abdominal sternite of the queen.  Upon stabilizing the queen with the ventral hook, gently grasp the queen’s sting and raise the sting structure vertically and dorsally to expose the vaginal opening.  The folds of tissue surrounding the vaginal opening are indicated by three black dots.  The proper insertion place of the glass insemination tip is in approximately the center of the three dots.  Once the glass insemination tip has been inserted it is then advisable to release the sting, thus allowing the surrounding tissue to form a “seal” around the glass tip.  The ability to easily release the sting once the glass tip has been inserted is an advantage over other insemination techniques because the formation of a tight seal reduces the likelihood of semen leakage around the glass tip, thus delivering a greater quantity to the queen, reducing waste and the potential for contamination.

After releasing the sting and insuring the glass tip is properly positioned, a standard dose of eight mircoliters is delivered to the queen.  While delivering the semen it is important to view the movement of semen inside the tip as this insures the glass tip was inserted properly and that there are no obstructions within the glass tip.  Once the queen has been inseminated, the queen holding tube is removed from the instrument and the queen is released from the tube.  While still anesthetized, it is possible to clip and mark the queen before the effects of the carbon dioxide wear off, usually within a couple of minutes following the procedure.

The instrumental insemination procedure is relatively straightforward once one learns the basic technique.  Then it is a matter of practice to perfect ones skill and concentrate on improving efficiency and success.  Compared to other insemination techniques, the flexible insemination technique requires approximately 20% less time (Kuhnert and Laidlaw 1994).  During the past seven seasons, I have used the flexible insemination technique to inseminate nearly 6000 queens.  Based upon my experience with the flexible insemination technique and other insemination techniques, the advantages associated with a reduction in the amount of time required to perform the insemination and ease at which the procedure is learned are associated with instrument design and technique.  As previously stated, instruments that employ the flexible insemination technique are often simplified with respect to complexity of instrument design and the number of movements controlled by mechanical adjustments.  Simply put, many people have the experience and hand coordination to control a pair of forceps or “tweezers”, if you will, as opposed to learning the coordination required to manipulate a more mechanized instrument.  Additionally, using forceps provides great maneuverability without cluttering the working space, which translates into greater efficiency.

Hopefully I have successfully illustrated the basics of instrumental insemination using the flexible insemination technique.  As I have described in this article, instrumental insemination of honey bee queens is a relatively simple procedure in itself, however, it does require a certain amount of time and practice to master the technique.  The time and effort involved are well worth the rewards when one realizes the potential to be achieved with regard to genetic improvement of honey bee stock through the use of instrumental insemination and selective breeding.        

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Last modified: 02/29/08

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