Balbuena et al. (2015) perform a catch and release experiment to determine the effect of glyphosate on honeybees. The bees ate 10mg/L, 5mg/L, and 2.5mg/L of glyphosate. Exposure to glyphosate slows the bees’ return trip to the hive. Flight paths are also affected. Bees fed with the higher concentrations took more time returning to the hive and had more indirect flights. The bees that ate 2.5mg/L and 5mg/L had indirect flights after the first release, but had normal flights after second. This affects their homing behavior. Memory retrieval is impaired because the probability of bees taking a shorter route to the hive is lower, therefore, longer flights and lack of improved homing behavior is increased. Exposure to glyphosate at non-lethal levels cause sublethal effects and, in turn, changes bees’ foraging behavior.
Another study by Frazier et al. (2015) looks at the effects of pesticides on foraging bees. They calculate 53 different pesticide residues on 8 crops and number of dead and dying bees. Frazier et al. (2015) finds a decrease in number of forager bees in cotton. Fungicide levels are higher than insecticides. The bees collect residues beyond target crop. The author concludes bees are in coming into contact with agrochemicals. Bee deaths are highest in cotton, pumpkin and