Pesticide and metabolites residues in honeybees: A 2014-2017 Greek compendium

Abstract

In the period between 2014 mid-2017, more than 200 samples of honeybees were sent by authorities and individuals in Benaki Phytopathological Institute after incidents of unexpected deaths of bees in various parts of Greece. The samples were analyzed for pesticides and breakdown products, by two multi-residue methods based on an expanded HPLC-ESI-MS/MS and a newly developed GC-MS/MS method. Sample preparation was optimized and based on modified QuEChERS using for clean-up C18 and PSA. Until mid-2017, 293 detections were registered in a total of 205 honeybee samples, resulting in a 76% percent of positive samples, to at least one active substance. Concentrations’ range varied from 1 to 160000 ng/g bee body weight . In some cases, these levels surpassed LD 50 values indicating intoxication events. Predominant substances were clothianidin, coumaphos, imidacloprid, acetamiprid and dimethoate. In less extent, other acaricides such as amitraz (mostly its breakdown products DMF, DMPF), tau-fluvalinate and certain pyrethroids exemplified by cyhalothrin, cypermethrin and deltamethrin were also recorded. In several samples, more than one active substance was detected. Overall, this work aspires to provide valuable insight to pesticides and metabolites occurrence in honeybees in Greece between 2014-2017 and in parallel assist research community and apiculturists in this pivotal Mediterranean region that bee health and pollination services have prolific importance.