Relationship between toxicity of certain pesticides to the honey bee, Apis mellifera L. (Hymenoptera: Apidea) foragers and their hemolymph amino acids
In this research, certain pesticides, i.e. bio-pesticides and synthetics pesticides proved to be toxic against honey bee foragers. Laboratory evaluation of the pesticides cleared that both group of the insecticides showed highly toxicity to the workers. Both Vertimec®, Dipel2x® and Achook®as a bio-insecticides and the two synthetics pesticides (Sparkle® and Diazinox®) gave the mean number 50 (100%) with each of the recommended, half and quarter doses after 24, 48 and 72 h. On the other hand, Achook® and Dipel2x® (bio-pesticides) have the lowest toxicity among all treatments on the assigned insect. Moreover, the obtained results indicated those, for recommended, half and quarter doses, after 72 h. the mean numbers of mortality were 50 (100%), 47 (94%) and 29.66 (59.33%) for Achook®, and 43.66 (87.33%), 46.33 (92.66%) and 35.33 (70.66%) for Dipel2x®. In addition, the amino acids were evaluated after 24 h. in the heamolymph of all the treated individuals. The results cleared that all five pesticides have negative effect on the contents and amounts of amino acids. 15 amino acids were presented in untreated samples but the most of them disappeared in the recommended doses. For example Dipel2x® had the lowest effect among the other tested pesticides. The mean number of mortality started to be increased after long exposure time of 72 h. Although Dipel2x® had a negative effect on bees but it was the only one among the used pesticides, which presented the amino acid Proline. This is considered the most important constituent of honey bee protein. This phenomenon was due to the low toxicity of Dipel2x®.
