The Asian chestnut gall wasp (Dryocosmus kuriphilus Yasumatsu, Hymenoptera, Cynipidae) is considered as one of the most dangerous pests of the genus Castanea. In southern Switzerland repeated heavy Asian chestnut gall wasp attacks prevented chestnut trees from vegetating normally for years before the arrival and spread of the biological control agent Torymus sinensis Kamijo (Hymenoptera, Torymidae). This resulted in a greatly reduced green biomass and flower production. In this paper, we analyse the impact of such an ecosystem alteration of the environment on the composition of produced honey. Six beekeepers were chosen from sites with different densities of chestnut trees, each of which providing series of honey samples from 2010 to 2016. We determined the chestnut component in the honeys via a combined chemical and sensory approach, and correlated the obtained results with the degree of yearly Asian chestnut gall wasp-induced crown damage and weather conditions during the period in question in the surrounding chestnut stands. The chestnut component in the analysed honey sample series showed a strong correlation with the degree of Asian chestnut gall wasp-induced crown damage, whereas meteorological conditions of the corresponding year had a very marginal effect. Decreases in the chestnut component of the honey were statistically significant starting from a Asian chestnut gall wasp infestation level of 30%.
