Stefanidou M., Pappas F., Methenitou G., Dona A., Koutselinis A.

Department of Forensic Medicine and Toxicology, University of Athens, Medical School, 75, M.Asias str., Goudi, Athens, Greece

All insecticides possess an inherent degree of toxicity to many non-target organisms, including the honeybees, that are frequently affected. Many honeybees are killed annually by the large quantities of insecticides used, leading to a financial loss of Greek apiarists' income and to the destruction of the ecosystem.
Since the detection of anticholinesterase insecticides in bees is difficult due to their rapid hydrolysis by the insect enzymes, the inhibition of acetylcholinesterase (AchE) or pseudocholinesterase (ChE) activity is a valid and sensitive biochemical indicator of exposure to these agents and is often mandatory of the agricultural use of anticholinesterase pesticides.
In the present work we have developed an easy and sensitive technique to detect the ChE inhibition, that meets the most important criteria of any analytical procedure. Small amounts of head tissue are needed and low concentrations of the enzyme can be detected.
We have estimated three different areas in the spectrum of exposure. Bees with enzymatic activity above 130 U/L had no insecticide exposure, whereas those with activity less than 80 U/L are definitely exposed to insecticides. Nonetheless, the exposure is questionable between 80 - 130 U/L and must be interpreted with other information beyond the biochemical results.
The determination of pseudocholinesterase inhibition is useful as a biomonitor of anticholinesterase pesticide exposure for bees.