Environmental Studies Program


Date of this Version

Fall 2016


Environmental Studies Undergraduate Student Thesis, University of Nebraska–Lincoln, 2016


Copyright © 2016 Ryan Becker


There are a number of different ways for the decline of Apis melifera or the honey bee. It could be a lack of flowers (food), pesticides, viruses and even parasites. There is an accumulation of things, but this study focuses on the synergism between the fungicide propiconazole and the insecticide chlorpyrifos. These two pesticides are used to dose around 2,100 honeybees with an LD50 test for chlorpyrifos and a relative dose test for propiconazole. The two pesticides are then mixed into a 1:1 mixture ratio of chlorpyrifos and propiconazole and diluted with acetone. The bees are dosed and looked after for 96 hours. Every 24 hours the dead bees are counted and recorded. In conclusion we found that the LD50 for chlorpyrifos may be higher than previous literature had described and when mixed together, the data suggests that propiconazole and chlorpyrifos do indeed create a synergistic effect on Apis melifera.