Carl A. Johansen

Digest on Bee Poisoning, its Effects and Prevention

Poisoning of bees by agricultural chemicals is a subject of continuing concern to beekeepers, and to farmers whose crops require the pollinating services of bees. The pattern of the poisoning hazard changes each year, as new pesticides are produced, and as legislation, education, and public opinion gradually deter some growers from practices which especially endanger bees.Dr. Carl Johansen has specialized in these problems for many years, and has now written an up-to-date appraisal of the situation as it affects honeybees; he has brought together also what little is known about the effects of pesticides on wild bees. Table 1 lists the laboratory and field toxicity of 92 pesticides applied as sprays or dusts. The effects of pesticides on bees depend on many circumstances, and the toxicity of any one material may therefore appear somewhat different in countries which have different agricultural and beekeeping techniques. Dr. Johansens results apply primarily to the western seaboard of North America, but th...