A class of widely used pesticides called neonicotinoids poses a bigger ecological threat than DDT, an environmental watchdog has warned.

Environmental Commissioner of Ontario Gord Miller issued the cautionary words Tuesday while speaking to press about his just-released annual report, which includes a section on the “Plight of Pollinators.”

Explaining the problems with neonicotinoids, also known as neonics, the report states: “Troubling questions are being raised about the broader environmental effects of these pesticides. Only a small portion of the active substance is taken up by plants in seed-treated crops, and the rest enters the environment. This is of concern because neonicotinoids are not only persistent in soil and water, but are also water soluble and highly mobile within ecosystems.”

Ontario, where use of neonics is extensive, has been experiencing higher than normal overwintering normal losses of bees, and increasing evidence has linked the pesticides to lethal and non-lethal harm to the pollinators. Facing economic hardship from these losses, beekeepers in the province sought last month to bring a class action suit against makers of neonics.

Bees “really are the canary in the coal mine,” Miller said.

“The impacts of neonicotinoids clearly are more wide-scale in the ecosystem. They are affecting the wild bees, other insects. They’re getting into the wild plants, they’re getting into the aquatic systems, and they’re affecting the food supply to our insect-eating birds.”

“We know that the impacts are extending into the ecosystem,” he said, “We don’t know at this time know the full magnitude.”