When researchers collected honey samples from around the world, they found that three-quarters of them had a common type of pesticide suspected of playing a role in the decline of bees. That demonstrates how pervasive a problem the much-debated pesticide is for honeybees, said authors of a study published ... in the journal Science. "What this shows is the magnitude of the contamination," said study lead author Edward Mitchell ... adding that there are "relatively few places where we did not find any." Over the past few years, several studies - in the lab and the field - link insecticides called neonicotinoids ... or neonics, to reduced and weakened honeybee hives. Neonics work by attacking an insect's central nervous system. As part of a citizen science project, the Swiss researchers asked other experts, friends and relatives to ship them honey samples. More than 300 samples arrived and researchers tested 198 of them for five of the most common types of neonics. Overall, 75 percent of the samples had at least one neonic, 45 percent had two or more and 10 percent had four or more. Results varied by region. In North America, 86 percent of samples had the pesticide; Asia, 80 percent; Europe, where there's a partial ban, 79 percent; Africa 73 percent; the Australian region, 71 percent and South America, 57 percent. The study found that nearly half of the honey samples exceeded a level of the pesticide that some previous research said weakens bees.