(2014) experimentally measured changes in honey bee colony performance and fitness due to chronic sublethal neonicotinoids, thiamethoxam and clothianidin, and dietary exposure. The study consisted of 24 honey bee colonies with two different queen sisters from different breeding populations, one from Germany (A. m. carnica) and another from Switzerland (A. m. mellifera). Bees were fed pollen with a concentration of 5.0 ppb thiamethoxam and 2.0 ppb clothianidin (Sandrock et al., 2014). The results of the study were such that: there was a decrease in the total adult bee population by 28%, in brood by 13%, a decrease in total honey production by 29% and in the total amount of pollen collected by 19%. , in two 1.5-month brood cycles Honey bee colonies were able to successfully recover and survive through the 3.5-month winter. However, over the course of a year, colony growth decreased significantly due to increased queen replacement and decreased swarming during the following spring (Sandrock et al., 2014). Overall, A. m. mellifera were more vulnerable to exposure than A. m. carnica. These different results were most likely due to the different ecotypes of honey bees and differences in their genetics (Sandrock et al., 2014). Therefore, the study suggests that neonicotinoids have negative effects on bee colony performance due to their sub-lethal activity