Swarming, defensive and hygienic behaviour in honey bee colonies of different genetic origin in a pan-European experiment

Summary

Honey bee colonies exhibit a wide range of variation in their behaviour, depending on their genetic origin and environmental factors. The COLOSS Genotype-Environment Interactions Experiment gave us the opportunity to investigate the phenotypic expression of the swarming, defensive and hygienic behaviour of 16 genotypes from five different honey bee subspecies in various environmental conditions. In 2010 and 2011, a total of 621 colonies were monitored and tested according to a standard protocol for estimation of expression of these three behavioural traits. The factors: year, genotype, location, origin (local vs. non-local) and season (only for hygienic behaviour) were considered in statistical analyses to estimate their effect on expression of these behaviours. The general outcome of our study is that genotype and location have a significant effect on the analysed traits. For all characters, the variability among locations was higher than the variability among genotypes. We also detected significant variability between the genotypes from different subspecies, generally confirming their known characteristics, although great variability within subspecies was noticed. Defensive and swarming behaviour were each positively correlated across the two years, confirming genetic control of these characters. Defensive behaviour was lower in colonies of local origin, and was negatively correlated with hygienic behaviour. Hygienic behaviour was strongly influenced by the season in which the test was performed. The results from our study demonstrate that there is great behavioural variation among different subspecies and strains. Sustainable protection of local genotypes can be promoted by combining conservation efforts with selection and breeding to improve the appreciation by beekeepers of native stock.

Resumen

Las colonias de abejas de la miel exhiben una amplia gama de variaciones en su comportamiento, en función de su origen genético y de factores ambientales. El estudio paneuropeo realizado en el marco de la acción COST “COLOSS” nos dio la oportunidad de investigar la expresión fenotípica de la enjambrazón, de los comportamientos defensivo e higiénico de 16 genotipos de 5 subespecies diferentes de abejas bajo distintas condiciones ambientales. En 2010 y 2011 un total de 621 colonias iniciales fueron controladas y examinadas de acuerdo con un protocolo estándar para la estimación de la expresión de estos tres rasgos de comportamiento. Los factores año, genotipo, ubicación, origen (local frente a no-local) y estación (sólo para el comportamiento higiénico) fueron considerados en los análisis estadísticos para estimar su efecto sobre la expresión de estos comportamientos. El resultado general de nuestro estudio es que el genotipo y la ubicación tienen un efecto significativo sobre las variables analizadas. Para todos los caracteres, la variabilidad entre las localidades fue mayor que la variabilidad entre los genotipos. Sin embargo, también se detectó una variabilidad significativa entre los genotipos de las diferentes subespecies, lo que en general confirma sus características conocidas. Los resultados de nuestro estudio demuestran la necesidad de apoyar los esfuerzos locales de cría para la conservación sostenible de las poblaciones europeas de la abeja de la miel.

Keywords:

• COLOSS
• Genotype-Environment Interactions Experiment
• Apis mellifera L.
• honey bee
• behaviour
• swarming
• defensive
• hygienic