Assessing the Toxic Effects of Insecticides on Honey Bees in the West Gonja District of the Savannah Region of Ghana

Abstract

Aims: To examine the toxic effects of insecticides on bees in farming communities in the Savannah Region of Ghana. Study Design:  The study employed five different doses of insecticides to 3 groups of 10 honey bees in each group using 3 types of insecticides. The number of dead bees were registered and used for the estimation of LC50 of each insecticide. Place and Duration of Study: The experiment was conducted at Damongo Agricultural Training College, Ghana, between August 2019 and September 2019. Methodology: We collected bees from farms in the West Gonja District of the Savannah Region of Ghana. Controller Super 2.5 EC, Pyrinex 48 EC and Golan SL were insecticides used for the experiment. Live adult bees were randomly obtained from beehives at 2:00 am from the farms when the bees were not aggressive. The bees were collected by hand and placed into a perforated plastic container and transported from the site of collection to the experimental site. They were allowed to acclimatize to the experimental conditions for a period of three hours under room temperature of 24 °C  and a relative humidity of 49 percent throughout the study. Results: Mortalities were recorded 10 minutes after administering the concentrations and thereafter at every 10 minutes continuously till 60 minutes. The LC50 was calculated using Where N is the number of honey bees in each group Controller Supper 2.5 EC at a concentration of 6.7 ml/L gave the highest mean mortality (10 bees) at the 50th minute while the concentration of 1.0 ml/L gave the lowest mean mortality (0.0 bees) in the same 50th minute. Conclusion: The LC50 for the three insecticides used were within the recommended concentrations provided by the Environmental Protection Agency of Ghana. The overall mortalities occurred when honey bees were exposed to different concentrations of all the three insecticides.