The bees are going to court.

Three environmental groups sued the California Department of Pesticide Regulation on Tuesday, asking a judge to stop the agency from approving the use of agricultural chemicals linked to the mass die-off of honeybees that pollinate a third of the world’s food supply.

The Pesticide Action Network, the Center for Food Safety, and Beyond Pesticides argue in the suit that DPR violated state environmental laws by green-lighting a class of pesticides called neonicotinoids (neonics) before completing a reevaluation of whether those pesticides are safe to use. The agency has been conducting the review for more than five years, itself a violation of a two-year deadline to finish the work, according to the suit. (Disclosure: The plaintiffs are nonprofit partners in TakePart’s Save Our Bees campaign.)

“DPR’s foot-dragging is only part of the problem,” states the suit, which was filed in Alameda County Superior Court. “Pending its re-evaluation, DPR has not hesitated to make the existing problem worse by expanding the use of neonicotinoids without any meaningful analysis of the impact to bees or feasible alternatives.”

A DPR senior staff attorney, Marta Barlow, said in an email that the agency does not comment on pending litigation.

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The environmentalists allege that DPR has for years rubber-stamped approval of neonics, most recently on June 13 when it registered three pesticides for agricultural use.

If the case proceeds to trial, it could offer an inside look into the pesticide industry’s influence on regulators and why state officials have reacted so slowly to the apian apocalypse in the face of growing scientific evidence that pesticides have played a significant role in bee deaths.

The suit is the latest move in a legal campaign to restrict use of neonicotinoids. Last year, the Center for Food Safety and other environmental groups sued the U.S. Environmental Protection Agency over its approval of two neonics, arguing the government violated the federal Endangered Species Act by failing to consider the impact of the pesticides on not just the honeybee but a host of protected wildlife, from the Ohlone tiger beetle to the Quino checkerspot butterfly.

Neonics are so-called systemic pesticides, meaning the nerve agent is absorbed into all parts of a plant, from stems and leaves to the pollen and nectar bees depend on for food. Several studies have identified the spraying of neonics on crops and the use of neonic-treated seeds as among several interrelated factors—including disease, parasites, and poor nutrition—responsible for the loss of some 10 million beehives over the past seven years.

The California suit asks the court to halt the use of the three neonics DPR approved on June 13 and to prohibit the agency from registering any other pesticides potentially toxic to bees until the case goes to trial and DPR completes its review of neonics’ safety.

“The crisis is especially acute in California because we are the largest producers of crops that require pollination,” the suit noted.