B and G May Not Spray Ivy

Harvard may drastically reduce its pollution of the local environment this spring. It may decide to end the annual insecticide spraying of the ivy.

For the past six years, the ivy on a block of seven buildings north of the Yard has been left unsprayed, as an experiment to see whether nature could control pests better than chemicals. The study is now complete and indicates that after a few years unsprayed ivy can be as pest-free as sprayed ivy.

The primary danger to Harvard's ivy is from the larvae of a small black and white moth. This moth, known as the Eight Spotted Forester (Alypia Octomaculata). emerges in early May and its caterpillars feed on the ivy for several months.

Forty Years

Buildings and Grounds has been spraying the ivy to combat this normally rare pest for some 40 years. Several biologists thought that the insecticides had been killing the moth's parasites more than the moths themselves. The biologists then asked B and G to test their hypothesis by leaving several buildings unsprayed.

B and G started the trial in 1965 and for the first two years, huge numbers of caterpillars devastated the un-sprayed ivy. But now all ivy appears to be equally healthy.

Last spring, after only a year of healthy unsprayed ivy, Philip J. Darlington Jr., Agassiz Professor of Zoology said, "We need one more good summer before we know where we really stand."

Last summer was the good summer the anti-spraying biologists were looking for. They are now ready to present the results of the six-year project and to make their recommendations to B and G.

B and G will meet on Tuesday, March 9 to plan for the spring and will take up the proposal then.

Despite the saving in time and energy the spraying halt would mean, B and G planners are reluctant to stop, because not spraying might mean several years of defoliated ivy in June when the alumni are around. Darlington believes the spraying should stop and said, "It's a matter of principle not to spray if we don't have to."