For pesticide studies

Only a few studies report the use of supplemented syrup to study the influence of pesticide on the colonies maintained in field conditions. Faucon and collaborators (Faucon et al., 2005) studied the effect of imidacloprid exposure on colonies by feeding them with two concentrations of the pesticide diluted into syrup. One litre of syrup was given to each colony twice a week during two months. Bee activity, bee mortality, colony weight, honey production, observation of disease symptoms and pesticide repartition within the colony were assessed.

In 2007, the European Commission indicated that some guidelines related to setting maximum residue limits (MRL) should be produced for pesticides in honey within the EU regulation framework (EC- 396/2005) using colonies fed with supplemented syrup. The working group led by French Food Safety Agency - AFSSA (now incorporated in French Agency for Food, Environmental and Occupational Health Safety - ANSES) identified a gap in the regulation when pesticide residues may arise in honey through residues present in feeding stuffs. MRLs established in this case should in principle be set on the basis of appropriate supervised residue trials data. Therefore the group produced a document including a protocol to study the transfer of pesticide residues from syrup to honey (AFSSA, 2009). The principle of the test is based on spiked sugar syrup placed in a colony feeder. The honey bees collect it and store it in the cells of beehive frames. After transformation, the ripe honey is analysed to determine the “residue” of the tested AI. Control syrup is spiked with the solvent used to dilute the test compound. The quantity of syrup given to each colony depends on the strength of the tested colony. A quantity of 5l for a colony of 10 combs and 20,000 honey bees is considered sufficient. Syrup is distributed in the feeder all at once. In this protocol, only residues in honey are assessed. However, it is possible to adapt other observation concerning the biological traits of honey bees if needed.