Science: Just Us Girls

The desert locust (Schistocerca gregaria forsk) has made its name dread to generations of African and Middle Eastern farmers from Biblical times down to the recent destructive plague of locusts in Iran.

The locust's behavior is as unpredictable as the areas in which it appears. For years the Schistocerca lives a solitary, law-abiding life, the members of the clan thinly scattered over the countryside. Then, suddenly, what entomologists call the gregarious phase begins. The scattered insects somehow get together and converge in a huge, destroying swarm, leaving the land ruined wherever they pass.

Last week Dr. Andrew G. Hamilton, 46, head of the...