The chronic effect of the botanical insecticide Neem EC on the pollen forage of the bumble bee Bombus terrestris L.
¹Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences,Kreutzwaldi Str. 1, Tartu 51014, Estonia; phone: +372 7313396;fax +372 7313351; e-mail: firstname.lastname@example.org
²Jõgeva Plant Breeding Institute, Aamisepa 1, Jõgeva alevik 48 309, Jõgeva, Estonia
The botanical insecticide Neem EC is allowed for use as a pest control agent in organic farming. Although the preparation is considered safe for honey bees, its effect on bumble bees has been less studied. The aim of this study was to investigate the effect of sublethal chronic doses of the botanical insecticide Neem EC (1% azadirachtin) on the pollen forage of the bumble bee Bombus terrestris L. Four pairs of colonies (one pair consisting of a test and a control colony) were placed at 0, 400, 800 and 1200 m from leguminous fields. Prior to taking the colonies to the field the test colonies were fed with a sublethal dose of Neem EC (0.01 ppm azadirachtin in the food) for a three-week period, whereas the control colonies were fed untreated food. Pollen loads of homing bees were removed and analysed. Our results show that sublethal doses of Neem EC may affect the pollen forage of bumble bees.