NOVASezóna 5 Přidat obrázekČíslo epizody16Insect AlternativeOverviewIn a world that each year loses up to 40 percent of its crops to insects, some form of pest control is desperately needed. But chemical pesticides have backfired. Pesticide-resistant insects frequently develop, and previously harmless insects have become devastating infestations. Farmers have found themselves trapped on a "pesticide treadmill"—the more they spray, the more they have to spray. NOVA examines several alternatives for pest control.Air dateMay 24, 1978Runtime (min)60