Environment: Days of Whine & Roses

Throughout the northeastern U.S., June's heavy rains greened the countryside in splendid style, creating luscious lawns, luxuriant sprays of roses —and a mosquito crop that is big, noisy and vicious enough to turn the average picnic into a Schuhplattler exhibition. Says Dr. Thomas Bast, associate medical entomologist of the New York state health department: "This year's overall count is at least 200% higher than any other over the past six years. Some traps that usually catch about 25 mosquitoes a night now catch anywhere from 400 to 500."

Bast places much of the blame on the deluges of Hurricane Agnes: "Eggs that...