Americas agricultural landscape is now 48 times more toxic to honeybees, and likely other insects, than it was 25 years ago, almost entirely due to widespread use of so-called neonicotinoid pesticides, according to a new study published today in the journal PLOS One. This enormous rise in toxicity matches the sharp declines in bees, butterflies, and other pollinators as well as birds, says co-author Kendra Klein. This is the second Silent Spring. Neonics are like a new DDT, except they are a thousand times more toxic to bees than DDT was, Klein says. Using a new tool that measures toxicity to honey bees, the length of time a pesticide remains toxic, and the amount used in a year, Klein and researchers from three other institutions determined that the new generation of pesticides has made agriculture far more toxic to insects. Honey bees are used as a proxy for all insects. The study found that neonics accounted for 92 percent of this increased toxicity. Neonics are not only incredibly toxic to honeybees, they can remain toxic for more than 1,000 days in the environment, said Klein. Some scientists have been warning that there is an insect apocalypse underway. A global analysis of 452 species in 2014 estimated that insect abundance had declined 45 percent over 40 years. Not only do bees, butterflies, and other insects pollinate one-third of all food crops, declining insect numbers can also have catastrophic ecological repercussions.