The frequency of thelytokous parthenogenesis in European-derived Apis mellifera virgin queens

Rosalyn Gloag,Emily J Remnant,Benjamin P Oldroyd

doi:10.1007/s13592-019-00649-0

Abstract

Thelytokous parthenogenesis is the asexual production of female progeny. In the honey bee, Apis mellifera, thelytoky is unknown from mated queens, but can occur in virgin queens that have been induced to lay. We used microsatellite markers to quantify theltyoky in virgin A. mellifera queens of European origin that were sham inseminated with saline and/or narcotised with carbon dioxide. Of 20 queens, 17 (85%) produced at least one daughter thelytokously during an 8-week period. One exceptional queen produced 19% thelytokous progeny, though few total offspring (20 daughters in 107 pupae). The average proportion of thelytokous progeny among the remaining queens was 0.9% (range 0–3.5%), with the balance being males. These results are consistent with observations from the pre-molecular biology era that virgin honey bee queens of non-African subspecies regularly produce thelytokous offspring at low frequency and indicate that there is significant natural variation in the capacity for thelytoky among these queens.

Highlights

Male Hymenopterans typically arise from unfertilised eggs (Dzierzon 1845) by arrhenotokous parthenogenesis and are haploid (White 1973)
Of the four queens sham-inseminated with saline prior to a second CO2 narcosis, one died shortly after insemination, and two produced only phenotypically male brood and were not considered further
Of 14 queens sham-inseminated with saline prior to a second CO2 narcosis, 8 survived beyond the first week posttreatment and laid eggs

Summary

Introduction

Male Hymenopterans typically arise from unfertilised eggs (Dzierzon 1845) by arrhenotokous parthenogenesis and are haploid (White 1973). In some populations or species, females can arise via automictic thelytokous parthenogenesis (Rabeling and Kronauer 2013) (Figure 1). Other African lineage subspecies, such as those from Tunisia (Anonymous 1892), may have high frequencies of worker thelytoky. These differences across lineages are consistent with a genetic basis of thelytoky in honey bees. In Capensis workers, thelytokous reproduction is thought to be controlled by a single locus in a simple Mendelian manner (Lattorff et al 2005; Aumer et al 2017; but see Chapman et al 2015)

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Conclusion