Olfactometer Tests of Insecticides for Repellency to Honey Bees, 1982

In the laboratory, premeasured amounts of insecticides diluted to various concentrations were sprayed uniformly onto 25 cm sq filter-paper sheets. After air drying,the sheets were cut into 5 cm sq pieces, and one piece was loosely rolled and slipped into an 8 cm length of 15 mm 10 glass tubing. An identical tube was loaded with a paper which had been sprayed with dilutant only. The tubes were attached to 2 branches of a 9 mm ID glass Y-tube. Air lines connected to the opposite ends of the 8 cm residue-holding tubes provided airflow (5.0 ml/min) across the residue papers and down the Y-tube branches. Worker honey bees from a laboratory-held colony were introduced into the stem of the Y-tube, allowed to walk to the branch junction and make a directional choice, and travel up the chosen branch 7 cm before being removed and retested. The treated branch was alternately placed to the right and left for successive tests. After 5 such runs, the olfactometer parts were cleaned, new filter papers inserted, and a new bee tested. Five bees were tested per spray batch, and 4 spray batches (with 20 bees making 100 runs) completed each chemical dosage trial.