Kim Hageman, an associate professor at the university, also found out back in 2013 just how far the chemical can travel. She and her team discovered very small amounts of chlorpyrifos in the water, air and plant life in parts of the country where the pesticide isn't even sprayed. For this study, the group led by Dr. Elodie Urlacher fed lab bees a slightly lower dose than what Hageman found in her samples. Note that the chemical's lethal dose is around 100 billionths of a gram, and the team used an amount a thousand times lower than that.
They've determined that despite ingesting what's considered a "safe" and extremely small dosage, the lab bees couldn't learn or remember odors as well as specimens that weren't exposed to the chemical could. According to Dr. Urlacher, this means exposure to the pesticide may be stunting honeybees' "effectiveness as nectar foragers and pollinators" since they "rely on such memory mechanisms to target flowers." That is a big issue, because many crops -- a number of which are kept insect-free using this particular pesticide -- rely on honeybees for pollination.
She believes that the group's findings now raise questions about how the pesticide should be regulated. "It's [...] clear that it is not just the lethal effects on bees that need to be taken into account," she said, "but also the serious sub-lethal ones at minute doses."