. >> mt expertagree th the single greatest threat to honeybee health is the varroa mi, an invive bloosucking pesthat bh directly rasitizesyoung anadult es and vectors bee diseases. where varroa mites are absent or well controlled, honeybees are thrivi. >> but jim says he knows why his bees are dying. >> we had a multitude of neonics that were showing up in our bees. it doesn't take much to kill a bee. >> neonicotinoids are a relatively new class of insecticide and coming on the scene in the 1990s. it is the fastest-growing group of insecticides in the united states. >> for the companies that make them, neonicotinoids, or neonics, are big business. they bring in over $2.6 billion a year in global sales. they are widely used as seed treatments, applied as soil drench, or sprayed onto foliage. in the u.s., they are used on some 200 million acres of cropland, on almostll corn, canola, and half of all soybean ops, asell as many fruits and vegetables. >> they are used in home and garden products, often at concentrations that are far higher than those you will find in the agricultural sector. >> mi