Evolution of multiple mating in the genus Apis

Abstract

Apis for which paternity frequency has been determined show high but extremely variable levels of polyandry [53].Kin selection is especially appealing as a contributing factor to the evolution of eusociality in Hymenopteran species because the haplo-diploid reproductive system of this order generates extremely high levels of relatedness among the workers in colonies in which the queen is mated only once. Intuitively, multiple mating by social insect queens is unexpected because multiple mating reduces nestmate relatedness within a INTRODUCTIONOne of the more intriguing questions of evolutionary biology is a plausible adaptive explanation for the widespread incidence of multiple queens (polygyny) or multiple mating (polyandry) by queens in the eusocial Hymenoptera. The frequency of mating varies substantially among species. While many species are monandrous and monogynous (e.g., the majority of the stingless bees [39]), a few have evolved extremely high levels of polyandry or polygyny [55,57,81]. In particular, all species of the genus 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.Apis / genetic variance / polyandry / task specialization / parasite Apidologie 31 (2000) 235-248 235

Paternity skew in seven species of honeybees (Hymenoptera: Apidae: Apis)

“…I). The data for A. dorsata are in agreement with the review of Palmer and Oldroyd (2000). The estimate for the western honeybee A. mellifera (16.0) is in good concordance with the classical population genetic study by Adams et al (1977), which yielded an average mating frequency of 17.25 with a maximum likelihood estimate based on the frequency of diploid males.…”

“…Likewise, mating frequencies exceeding 40 were recently reported for the medium sized cavity nesting honeybee A. nigrocincta Smith ). In the other Apis species the numbers of copulations are slightly lower (Palmer and Oldroyd, 2000;Tarpy et al, 2004) but still extraordinarily high compared to bees from closely related taxa (Strassmann, 2001).…”

“…As a consequence A. florea and A. andreniformis have a higher transfer efficiency with a lower percentage of expelled semen per drone: between 40 and 60% of spermatozoa per drone are retained in the queen, compared to only about 10% in the Asian cave-nesting species and less than 3% in A. mellifera L. . Likewise Palmer and Oldroyd (2000) estimated higher sperm transfer rates in the dwarf honeybees (A. florea 28%,A. andreniformis 74%,A.…”

“…We can confirm the extreme degree of polyandry in all seven Apis species (Palmer and Oldroyd, 2000). We found still significantly different mating frequencies among the species after applying the sample size calibration method despite of relatively small sample sizes.…”

Recruitment-dance signals draw larger audiences when honey bee colonies have multiple patrilines

“…Colonies of a minority of species of social bees, ants and wasps are comprised of genetically distinct patrilines of workers because the queens that head them have each mated with multiple males (polyandry). Extremely polyandrous mating behav-iour has evolved repeatedly in eusocial groups such as the army and driver ants (Eciton, Dorylus; Kronauer et al, 2004Kronauer et al, , 2006, leaf-cutter ants (Atta, Acromyrmex; Villesen et al, 2002), harvester ants (Pogonomyrmex; Wiernasz et al, 2004), yellow jacket wasps (Vespula; Foster and Ratnieks, 2001) and honey bees (Apis; Oldroyd and Wongsiri, 2006;Palmer and Oldroyd, 2000;Tarpy et al, 2004). Thus, extreme polyandry presents a fascinating challenge to the predicted scenario of high levels of intracolonial relatedness in eusocial hymenopteran colonies.…”