Honey Bees and the Mediterranean Fruit Fly Spray Program

Abstract

Since the start of the Mediterranean fruit fly spray program, we have received several inquiries from beekeepers and entomologists concerning the hazards of the bait sprays to honey bees in the sprayed areas. In this paper we are attempting to present all the information we have gathered during the eight months the spraying operations have been under way. The first question confronting us was whether or not the baits being used in the sprays would attract honey bees. Five pounds of the N.B.C. yeast hydrolysate, and five pints of Staley's Sauce Base No. 2 were obtained from the Florida State Plant Board and tests made to determine whether they were attractive to honey bees. The yeast bait was mixed with a 50 percent sugar solution at the rate of 2 pints per gallon of syrup and the mixture was sprayed on rows of cantaloupe plants. Other rows were sprayed with a 50 percent sugar solution, without the bait. Observations and counts were made of the number of honey bees visiting the treated plants. No difference in numbers of bees was observed, and it was concluded that the yeast bait did not attract honey bees to any significant extent. Staley's Sauce Base No. 2 was mixed with sugar syrup at the rate of two pints per gallon of syrup. Two feeders, one containing plain sugar syrup and one containing syrup with the sauce bait added, were placed in each of several colonies of bees. In all cases, the feeder containing the plain sugar syrup was emptied in a shorter time than the one containing syrup plus sauce bait. Tests also were made with open pans of sugar syrup and sugar syrup plus sauce bait placed fifty yards away from a hive of bees. Here again there was no significant difference in the time it took the bees to find the pans or in the number of bees attracted to them. From these tests it was concluded that the sauce bait does not have any attraction for honey bees. After it was determined that these baits did not attract honey bees, the information was passed on to beekeepers with the prediction that any damage which might occur to honey bees would not be serious and probably would be confined to those bees which happened to fly through the spray as it was being applied. With possibly one exception, this was correct, only seven or eight complaints having been received from beekeepers claiming damage from the aerial sprays. Of these reports, only four have been definitely confirmed as spray injury, and in only one case was the loss great enough to be considered important. The first reported injury came from a beekeeper who had three colonies located within the city limits of Miami. The area in which the bees were located was sprayed four times with the malathion bait spray (1 qt. sauce bait, 2 pounds of 25% malathion wettable powder per 1 gallon of water applied at the rate of one gallon per acre). All bee loss occurred from