Anniversary of a beekeeper’s discovery of thelytoky in Cape honey bees

Significance: The laying workers of the Cape honey bee continue to negatively affect the South African beekeeping industry, with more losses suffered in the northern regions of the country. The reproductive parasites enter susceptible host colonies, activate their ovaries, and lay diploid eggs, leading to colony dwindling and collapse. Diploidy in eggs produced by unmated laying workers arises from thelytokous parthenogenesis, first discovered in honey bees by a hobbyist beekeeper. We examine the consequences of thelytokous parthenogenesis and outline what is being done to understand and limit the spread of the laying workers of the Cape honey bee

The transcriptomic changes associated with the development of social parasitism in the honeybee Apis mellifera capensis

Social insects are characterized by the division of labor. Queens usually dominate reproduction, whereas workers fulfill non-reproductive age-dependent tasks to maintain the colony. Although workers are typically sterile, they can activate their ovaries to produce their own offspring. In the extreme, worker reproduction can turn into social parasitism as in Apis mellifera capensis. These intraspecific parasites occupy a host colony, kill the resident queen, and take over the reproductive monopoly. Because they exhibit a queenlike behavior and are also treated like queens by the fellow workers, they are so-called pseudoqueens. Here, we compare the development of parasitic pseudoqueens and social workers at different time points using fat body transcriptome data. Two complementary analysis methods—a principal component analysis and a time course analysis—led to the identification of a core set of genes involved in the transition from a social worker into a highly fecund parasitic pseudoqueen. Comparing our results on pseudoqueens with gene expression data of honeybee queens revealed many similarities. In addition, there was a set of specific transcriptomic changes in the parasitic pseudoqueens that differed from both, queens and social workers, which may be typical for the development of the social parasitism in A. m. capensis.Supplementary material: Online Resource 1 (XLSX 15 kb) Online Resource 2 (XLSX 13 kb) Online Resource 3 (PDF 268 kb) Online Resource 4 (XLSX 14 kb) Online Resource 5 (XLSX 29 kb)The Deutsche Forschungsgemeinschaft (RFAM).http://link.springer.com/journal/1142019-04-01hj2018Zoology and Entomolog

Reproductive parasitism by worker honey bees suppressed by queens through regulation of worker mandibular secretions

Social cohesion in social insect colonies can be achieved through the use of chemical signals whose production is caste-specific and regulated by social contexts. In honey bees, queen mandibular gland pheromones (QMP) maintain reproductive dominance by inhibiting ovary activation and production of queen-like mandibular gland signals in workers. We investigated whether honey bee queens can control reproductively active workers of the intraspecific social parasite Apis mellifera capensis, parasitising A. m. scutellata host colonies. Our results show that the queen’s QMP suppresses ovarian activation and inhibits the production of QMP pheromone signals by the parasitic workers, achieved through differential expression of enzymes involved in the biosynthesis of these pheromones at two points in the biosynthetic pathway. This is the first report showing that honey bee queens can regulate reproduction in intraspecific social parasites and deepens our understanding of the molecular mechanisms involved in the regulation of worker reproduction in social insects.The South African National Research Foundation (NRF) Thuthuka Grant No. TTK150703123061 to AAY, NRF Incentive funding and Competitive Research grant for rated scientists (CPR) to CWWP and RMC and an OWSD postgraduate bursary awarded to FNM.http://www.nature.com/srephj2018Zoology and Entomolog

Anniversary of a beekeeper’s discovery of thelytoky in Cape honey bees

SIGNIFICANCE: • The laying workers of the Cape honey bee continue to negatively affect the South African beekeeping industry, with more losses suffered in the northern regions of the country. • The reproductive parasites enter susceptible host colonies, activate their ovaries, and lay diploid eggs, leading to colony dwindling and collapse. • Diploidy in eggs produced by unmated laying workers arises from thelytokous parthenogenesis, first discovered in honey bees by a hobbyist beekeeper. • We examine the consequences of thelytokous parthenogenesis and outline what is being done to understand and limit the spread of the laying workers of the Cape honey bee.http://www.sajs.co.zahj2022Zoology and Entomolog

A single SNP turns a social honey bee (Apis mellifera) worker into a selfish parasite

The evolution of altruism in complex insect societies is arguably one of the major transitions in evolution and inclusive fitness theory plausibly explains why this is an evolutionary stable strategy. Yet, workers of the South African Cape honey bee (Apis mellifera capensis) can reverse to selfish behavior by becoming social parasites and parthenogenetically producing female offspring (thelytoky). Using a joint mapping and population genomics approach, in combination with a time-course transcript abundance dynamics analysis, we show that a single nucleotide polymorphism at the mapped thelytoky locus (Th) is associated with the iconic thelytokous phenotype. Th forms a linkage group with the ecdysis-triggering hormone receptor (Ethr) within a nonrecombining region under strong selection in the genome. A balanced detrimental allele system plausibly explains why the trait is specific to A. m. capensis and cannot easily establish itself into genomes of other honey bee subspecies.The Deutsche Forschungsgemeinschaft (to R.F.A.M.) and the National Research Foundation of South Africa (to C.W.W.P.)http://mbe.oxfordjournals.orghj2020Zoology and Entomolog

Hydroxylation patterns associated with pheromone synthesis and composition in two honey bee subspecies Apis mellifera scutellata and A. m. capensis laying workers

Colony losses due to social parasitism in the form of reproductive workers of the Apis mellifera capensis clones results from the production of queen-like pheromonal signals coupled with ovarian activation in these socially parasitic honey bees. While the behavioral attributes of these social parasites have been described, their genetic attributes require more detailed exploration. Here, we investigate the production of mandibular gland pheromones in queenless workers of two sub-species of African honey bees; A. m. scutellata (low reproductive potential) and A. m. capensis clones (high reproductive potential). We used standard techniques in gas chromatography to assess the amounts of various pheromone components present, and qPCR to assess the expression of cytochrome P450 genes cyp6bd1 and cyp6as8, thought to be involved in the caste-dependent hydroxylation of acylated stearic acid in queens and workers, respectively. We found that, for both subspecies, the quality and quantity of the individual pheromone components vary with age, and that from the onset, A. m. capensis parasites make use of gene pathways typically upregulated in queens in achieving reproductive dominance. Due to the high production of 9-hydroxy-decenoic acid (9-HDA) the precursor to the queen substance 9-oxo-decenoic acid (9-ODA) in newly emerged capensis clones, we argue that clones are primed for parasitism upon emergence and develop into fully fledged parasites depending on the colony's social environment.The South African National Research Foundation (NRF) Thutuka Grant No. 99286 to AAY, NRF Incentive funding to CWWP, AAY and RMC, a postgraduate bursary from the Organisation for women in Science for the Developing world (OWSD) and the Swedish International Development Agency (Sida) and the L’Oréal-UNESCO For Women in Science Fellowship for sub-Saharan Africa, awarded to FNM.http://www.elsevier.com/locate/ibmb2020-11-01hj2019Zoology and Entomolog

The biology of the Cape honey bee, Apis mellifera capensis (Hymenoptera: Apidae) : a review of thelytoky and its influence on social parasitism and worker reproduction

Cohesion in social insect colonies is maintained by use of chemical signals produced by the queen, workers, and brood. In honey bees in particular, signals from the queen and brood are crucial for the regulation of reproductive division of labor, ensuring that the only reproductive female individual in the colony is the queen, whereas the workers remain reproductively sterile. However, even given this strict level of control, workers can, in principle, activate their ovaries and lay eggs. Although much is known about the behavioral and physiological traits that accompany the switch from worker sterility to being reproductively active, much less is known regarding the molecular changes that accompany this switch. This review will explore what is known about the genes and molecular pathways involved in the making of laying workers/false queens in the Cape honey bee, Apis mellifera capensis Eschscholtz, through an analysis of the basis for thelytoky in this subspecies, the exocrine glandular chemistry of reproductively dominant workers and what is known about the biosynthesis of their pheromone components. This review will contribute to our understanding of the genetic regulation of thelytoky and the molecular mechanisms that govern reproductive division of labor in honey bees and provide generalizations that may be applicable to other social hymenoptera using this evolutionary fascinating example of worker reproduction.The South African National Research Foundation (NRF) Y-Rated Researchers Grant, NRF Incentive funding, a postgraduate bursary from the Organization for Women in Science for the Developing World (OWSD) and the Swedish International Development Agency (SIDA).https://academic.oup.com/aesahj2022Zoology and Entomolog

Changing scientific meetings for the better

Conferences are a pivotal part of the scientific enterprise, but large in-person meetings have several disadvantages. As the pandemic experience has shown, online meetings are a viable alternative. Accelerating efforts to improve conferences in virtual formats can lead to a more equitable and sustainable conference culture.Supplementary Information : Supplementary Figures 1–5, Supplementary Tables 1–14, Supplementary Methods and Data Visualization.https://www.nature.com/nathumbehav2021-09-15hj2021Zoology and Entomolog

Changing scientific meetings for the better

Conferences are a pivotal part of the scientific enterprise, but large in-person meetings have several disadvantages. As the pandemic experience has shown, online meetings are a viable alternative. Accelerating efforts to improve conferences in virtual formats can lead to a more equitable and sustainable conference culture.Supplementary Information : Supplementary Figures 1–5, Supplementary Tables 1–14, Supplementary Methods and Data Visualization.https://www.nature.com/nathumbehav2021-09-15hj2021Zoology and Entomolog