WASHINGTON, D.C. — EPA has approved a previously registered pesticide for use against a parasite that harms bees, a move the agency calls critical to protecting bees and consistent with President Obama’s memo on improving pollinator health, though a beekeeper group says targeting parasites is insufficient and limits on bee-toxic pesticides are also needed. On March 10, the EPA registered oxalic acid to target varroa mites, which it calls “a serious and devastating pest of honeybee colonies,” according to EPA’s registration document.

The U.S. Department of Agriculture (USDA) requested the registration of oxalic acid, which is currently used in Canada and Europe to target varroa mites and which EPA had previously registered as an anti-microbial pesticide until registrants voluntarily canceled their registrations in 1994.

The registration comes as EPA and USDA are investigating the massive decline of honeybees and other pollinators seen since 2006 and have named both the varroa mite and pesticides as among the factors in the decline, spurring debate between environmentalists and pesticide producers over which is the primary culprit. The two agencies are leading a federal Pollinator Health Task Force that is expected to soon release a new strategy for implementing Obama’s June 20 memo on stemming declines in pollinators by improving habitat, assessing how pesticides and other stressors contribute to pollinator declines and taking action where appropriate. The executive memo also instructs EPA to expedite review of registration applications for new products targeting pests that harm pollinators, and includes a call for EPA to assess potential risks of neonicotinoid pesticides to pollinators.

In the March 10 registration document, EPA says varroa mites feed on developing bees and reduce their life span, and that if an infested bee colony is not treated, it will likely die. Varroa mites also transmit numerous honeybee viruses, and have quickly developed resistance to registered chemicals.

Although beekeeper advocates are backing the registration, they argue that restrictions on bee-toxic pesticides are also needed. In comments posted to a federal website March 11, the Pollinator Stewardship Council (PSC) calls oxalic acid an “important tool in managing the health of honeybees” but says bees also need pesticide-free forage for a diverse and natural food supply.

The group reiterated its call for expedited study and restrictions on neonicotinoid pesticides in a March 12 letter to the federal task force, which is expected to issue a strategy for implementing the president’s memo in the coming days or weeks. Industry groups, meanwhile, have argued that varroa mites are the primary culprit in bee declines and that scientific evidence that neonicotinoids harm bees through sub-lethal adverse effects comes from poorly designed studies that rely on unrealistic doses and exposure scenarios.