Behaviour Mating Behaviour		"A-Z" INDEX &   SEARCH Evolution of Multiple Mating Behaviour, in Honey Bees... A Speculation

The multiple mating of a queen honeybees has long been controversial, because of ideas on human morality propagated by religeonists. This page seeks to indicate the current range of ideas on how the trait has become part of honey bee behaviour.

What follows is published with the permission of the authors, it is not a complete reproduction of the original text, but has been mainly extracted, in order to give a broad view, from a paper by Kellie Palmer and Ben Oldroyd Entitled...

Evolution of multiple mating in the genus Apis

Apart from the omission of much of the fine detail, the only alterations are due to page structure and re-numbering of references. For full details... Please consult the original paper.

The main arguments
The following arguments are as listed in Crozier and Page ^[1], with certain modifications:

1. Multiple mating increases effective population size and therefore is selected for, because it increases population longevity ^[2].
   
   
2. Multiple mating is favored because it increases the genetic variation within broods.
   This may be beneficial because:
   1. it increases genetic variation between founding queens and between workers;
   2. it forms a basis for caste differentiation;
   3. a mixture of genotypes is 'useful' in a variable environment.
      
      
3. Females mate a number of times because:
       a,  of selection favoring sperm competition within their spermathecae;
       b,  competition between worker sub-groups favors a more rapid colony division rate, favoring multiple mating which intensifies such competition ^[3].
   
   
4. Multiple mating is favored by queens because it increases their genetic output relative to that of their worker progeny ^[4].
   
   
5. Multiple mating by queens is favored because it selects for worker adjustment of the sex ratio to be closer to that selected for at the queen level ^[4], ^[5], ^[6], ^[7], ^[8].
   
   
6. Multiple mating is easier for queens than resisting the mating attempts of males ^[9], ^[10].
   
   
7. Multiple mating by queens is favored because it enables queens to store sufficient sperm to build up large and long-lived colonies ^[1], ^[11], ^[12], ^[13].
   
   
8. Multiple mating by queens is selected under certain conditions of colony growth because, when accompanied by a sex determination system based on heterozygosity, it leads to higher colony reproductive success than single mating ^[14], ^[15], ^[16].
   
   
9. The following arguments have been put forward since Crozier and Page ^[1]: mitigates against the effects of parasitism ^[17], ^[18], ^[19], ^[20], ^[21].
   
   
10. Multiple mating is selected for because it increases the probability that an important specialist trait in a population is rare ^[22].
    
    
11. Polyandry increases the chance that the proportions of the paternity array will produce workers having increased fitness through heterosis [23].

ACKNOWLEDGMENTS

The authors wish to thank the Bee Laboratory at Sydney University and Robin Moritz for constructive comments.
The authors were financially supported by the Australian Research Council.

Kellie A. PALMER, Benjamin P. OLDROYD
School of Biological Sciences A12, University of Sydney, New South Wales 2006, Australia

Abstract
Multiple mating by social insect queens is a widespread phenomenon. Because of the apparent inclusive fitness benefits of monandry, and the potential costs of polyandry, explanations for the evolution of multiple mating have been frequently sought.

Current leading explanations are collectively known as 'genetic variance' hypotheses which posit that both queen and colony fitness are increased by an increase in the intracolonial genetic diversity that accrues from multiple mating.

However, the precise way in which genetic diversity acts to increase colony fitness is not clear. Furthermore, some of these hypotheses are probably insufficient to explain extreme levels of polyandry observed in the genus Apis.

REFERENCES