In some areas almost a third of adult males are blinded. We are, however, no longer entirely defenseless against this scourge. Deet and permethrin enhanced sprays offer better, but far from complete, protection. More important, a bacterium originally gathered in the Negev Desert called Bti, a version of the Bt insecticide widely used by gardeners, is almost instantaneously effective against blackfly larvae in streams. Despite these defenses, I still won t venture north for another week.
Old memories die hard.