Improvement of almond production using Bombus terrestris (Hymenoptera: Apidae) in Mediterranean conditions

Abstract

[eng] The pollination of almond trees strongly depends upon insects. The current decline of honeybees and wild bees’ populations is leading to the search of alternatives to increase the almond production. In this study, we examined the effect of introducing Bombus terrestris colonies in almond orchards of Mallorca (Spain). We compared one plot with introduced bumblebees and another as a control without bumblebees. In each plot, we monitored fruit set and the spatial distribution of FS. We modelled the visitation rate of the main pollinators, B. terrestris and A. mellifera, as well as the foraging behaviour of B. terrestris under different climatic conditions. We found that FS was statistically significantly higher in Bb plot. The activity and behaviour of B. terrestris is conditioned by temperature, whereas that of A. mellifera is more influenced by global radiation and relative humidity. Our study confirms that the use of B. terrestris increases almond production and its foraging activity and behaviour depends on temperature.