Bee Instrumental Insemination Group

Why use instrumental insemination for honey bees?

Beekeepers have strived to control the mating of queens so as to conserve or improve stocks. As queens naturally mate on the wing, it is impossible to be certain as to which drones she has mated with. The best that can be achieved using free mating, is by swamping an isolated area with colonies containing the desired drones and hoping that the queen mates with these.

During recent years, equipment and techniques have been developed that are capable of achieving high success rates. It is now possible to rear instrumentally inseminated queens who's performance now matches that of naturally mated queens.

Purity of mating... Isolation using an Island mating Station can be used, but this often requires considerable travel. The degree of isolation achieved is also suspect and in recent times many stray drones have been found, in spite of stringent quality control. This has happened both by accident and due to deliberate sabotage.

For absolute control we can use Instrumental Insemination, but this is a mechanical system of mating and only gives results that depend on the quality of the queens and drones fed into the program, it is not a magic bullet, all it really says is that one particular queen was mated with the semen of the drones used... It is still up to you to get the quality control right so that the genetics of both queens and drones is what you want.

Special techniques

There are some tricks that we can play using II, these are not very commonly used, but they do have a minor place within a breeding program.

Single drone crosses... This can be helpful in transplanting characteristics from one strain to another, but requires an enormous amount of evaluation of the queen's colony and the daughters of such a colony, the life of single drone queens is very limited (usually about 3 months), so you need to more raise queens quickly from the inseminated one.

This technique can be extended by dilution of semen so that the single drone's output can be inseminated into several queens, this is also very labour intensive in observation and evaluation of the progeny and the laying life is again very limited owing to small numbers of sperm used to inseminate each queen.

Selfing... We can keep a queen unmated and dose her a couple of times with CO2, this results in her becoming a drone layer. We raise these drones and then use their semen to inseminate their drone laying mother. This is a difficult and time consuming exercise, but has a place in 'fixing' particular genes... This is almost a genetic bottleneck and should not be used unless you have done much analysis of the DNA.

Increasing diversity... Depending on race, naturally mated queens will mate with between seven and thirty drones (up to 70 for some African species). The queen holds about one micro litre of semen in her spermatheca, each drone produces about one micro litre, in multiple mating the queen expels the unwanted volume of semen after homogenizing the loads from each drone into a mixture. This is not a true mixture but is lumpy, It used to be thought that each drone's semen was kept separate, but then it was discovered that the mixture is more like a bag of marbles, today we are leaning towards considering it more like a sack of peas or even a bag of sand.

We can use the II techniques to increase the diversity further than in nature. The semen can be collected from up to several hundred drones, diluted, mixed and centrifuged to remove the diluent. This means that the number of patrilines in the II queen's colony will be equal to the number of drones whose semen was harvested, so in such a queen's daughters there will be up to several hundred patrilines that are genetically different. There is a downside to this centrifuging, which damages many of the spermatozoa (by breaking off tails) although Anita Collins in Beltsville USA is working on some improvements, you cannot expect normal life out of such queens. The limits being a few weeks to one season.

So why do ordinary beekeepers practice II ?

It may look at first sight as if this technique should be confined to the laboratory, but it can be performed in a garden shed or even the back of a van. There are moves afoot to refine a version of the equipment that will fit in a pocket and be usable in the apiary, so you can expect II to be mentioned more frequently in the future. A common reason to use II is if you are interested in breeding Apis Mellifera Mellifera strains and you have many mongrel colonies around your apiary, including direct Italian and Carniolan imports. As a result your breeding work will be an up hill struggle without II.

Some are interested in un-picking some of the hybridization that has taken place among British bees in the last century or so, II plays a part in this and now that DNA analysis is becoming more widespread we are better able to know what to cross with what in order to do so.

There are many beekeepers that wish to keep foreign strains against a background of UK mongrels and the only way to keep these pure is by II.