A New England Town Sprays Its Elm Trees with DDT

The robin was twitching, tremoring, convulsing uncontrollably, and peeping occasionally. The student handed the bird to me, and in a few minutes it was dead in my hands. It was April 23, 1963, and I was in my laboratory at Dartmouth College in Hanover, New Hampshire, when the student walked in with the bird. A week earlier the elm trees of Hanover had been sprayed with the insecticide DDT to control the spread of Dutch elm disease by elm bark beetles. In the following weeks 151 dead birds filled my freezer, many of them exhibiting before they died the tremors that we later learned were typical of DDT poisoning. Four of us were conducting a small-scale study of the effects, if any, of the DDT spray program in Hanover. We were shocked by what was happening to the local birds, but we would have expected this reaction to DDT if we had read the scientific literature on earlier DDT spray programs on elm trees. We had not. We soon realized that we had rediscovered what other ornithologists had already reported from DDT spray programs in the American Midwest. We also soon learned that DDT was ineffective in preventing the spread of Dutch elm disease and that another procedure, sanitation without insecticides, effectively protected the elms. This DDT spray procedure was all costs and no benefits. Hundreds of towns were killing thousands or millions of birds while not protecting their elms. The whole thing struck me as absurd and tragic. It became a life-changing event for me. I decided that DDT was a chemical that had to be stopped, although I hadn’t the slightest idea where such a conclusion was going to lead. I was 33 years old and had become what in those days was usually called a conservationist. Now such people have been renamed “environmentalists.” I had a dubious beginning as such a person. When I was about seven and living in a northern suburb of Philadelphia, I came across a couple of snakes.

A Mark-recapture Technique for the Dutch Elm Disease Vector the Native Elm Bark Beetle, Hylurgopinus rufipes (Coleoptera: Scolytidae)

Six mark-recapture experiments were conducted in Manitoba, Canada, to determine the effectiveness of fluorescent powder to mark emerging native elm bark beetle adults, Hylurgopinus rufipes (Eichoff) (Coleoptera: Scolytidae), the vector of Dutch elm disease, Ophiostoma novo-ulmi (Brazier), after departure from overwintering sites in spring and emergence from broodwood in summer. Native elm bark beetles marked themselves on emergence from overwintering sites and summer trap logs. The spring and summer periods of flight activity for unmarked and marked beetles were similar. Marked beetles were captured over 1 month after peak emergence in the spring and 2 months after emergence from trap logs in the summer. Marked beetles were captured up to 1 km (0.6 mi) from release sites. Where integrated Dutch elm disease management activities are implemented in buffer zones to minimize the number of elm bark beetles entering community urban forests, buffer zones should be a minimum of 1 km (0.6 mi) in width.