Differences in colony phenotypes across different origins and locations: evidence for genotype by environment interactions in the Italian honeybee (Apis mellifera ligustica)?

International audienceThe aim of this study was to reveal the existence of locally adapted populations of Apis mellifera ligustica. To this end, the spring development and honey production of three sources of A. mellifera ligustica were compared in three Italian habitats differing in flora and climate, in order to investigate interactions between origin of the bees and test environment (GxE). The results from a total of 165 colonies showed significant GxE for the considered traits. Interestingly, for two of the considered origins, colonies produced most when kept in their region of origin. Honey production can be considered a measure of adaptation to environment as it reflects the ability of a colony to make the most profit of the plant nectar sources present in its surroundings. Thereby, this study shows that populations of locally adapted honeybees still exist in Italy, despite widespread use of commercially produced honeybee queens