Amid the continuing decline of pollinators worldwide, U.S. lawmakers recently revived a perennially struggling bill that aims to save these helpful species. However, pollinator loss is more complicated than many headlines suggest. And curbing it, some scientists say, requires more than just stricter pesticide regulation—a major focus of the bill.

This is the fifth iteration of the Save America’s Pollinators Act, which was introduced by Democratic Representatives Earl Blumenauer of Oregon and John Conyers Jr. of Michigan in 2013 but has never been put to a vote. It was initially intended to address colony collapse disorder—the sudden disappearance of millions of honey bees from commercial hives that was first widely noted around 2006, and which peaked nearly a decade ago. The bill’s latest form calls for a joint initiative by the U.S. Department of Agriculture, Environmental Protection Agency and Department of the Interior to monitor wild bee species, including bumble and mason bees. It also proposes changes to the EPA’s pesticide review process—namely, establishing a board of beekeepers, scientists and farmers who would review research on pesticides’ effects on pollinators before the chemicals could be approved for use on agricultural plants.

The bill—which is currently with a subcommittee that will decide if and when to move it toward a vote before the House of Representatives—could spur work to fill in gaps in scientists’ understanding of the health of both honeybee and wild bee species. But it appears unlikely to address the paucity of data on environmental threats to other wild pollinators—such as moths, butterflies, beetles, flies, wasps and bats.

The bill’s revival also raises a question that tends to make headlines at least once a year: Is there really a “beepocalypse,” or have honeybees recovered?

The collapse of commercial honeybee hives is definitely still an issue, according to Christina Grozinger, an entomology professor at the Pennsylvania State University Center for Pollinator Research. The USDA estimates 1.5 million hives were lost in the U.S. from January 2017 to January 2018. Grozinger says beekeepers are simply propagating new hives—splitting large hives into two, and ordering new queens to start new ones entirely—fast enough to keep pace with the losses.

Particularly troubling to entomologist Dennis vanEngelsdorp, project director for the nonprofit Bee Informed Partnership (BIP), is that since 2006, summer losses have approached those occurring in winter—which had long been the deadliest time of year for bees because of the cold weather, minimal honey reserves and parasites. “Colonies are [now] dying at a constant rate, all year round,” VanEngelsdorp says. Honey bees are not in danger of extinction by a long shot, says University of Illinois entomologist May Berenbaum—“but beekeeping, as an industry, is still under threat.”

Canary in the Beehive?

Honeybees are often looked to as proxies for the status of pollinators as a whole, but that concept seems imperfect. Data from the largest federal survey on domestic honeybee mortality only date back to 2015; data on wild bees are far less comprehensive, and those on other wild pollinators are scarcer still. The factors that threaten honeybees also frequently differ from those threatening wild bees and other wild pollinators. For example, BIP beekeepers consistently cite parasitic varroa mites—which entomologists frequently list as honeybees’ greatest stressor—as a top cause of hive mortality. But these mites do not infect wild bumblebees or mason bees.

Pesticides, the chief issue that the Save America’s Pollinators Act hopes to address, appear to affect honeybees, wild bees and other wild pollinators all quite differently. Most research covering pesticides’ effects on pollinators has focused on those of specific chemicals (particularly on a type called neonicotinoids) on individual honeybees. In response to these pesticides, bees routinely develop impaired immune systems and become more susceptible to pathogens such as Nosema and deformed wing virus. But field studies, which have many more variables, suggest neonicotinoids have far milder effects on honeybees.

Unlike wasps, bumblebees or solitary bee species, honeybees live in large hives—and these massive, malleable complexes can buffer them against stressors, Berenbaum says. As a colony, they share one “stomach”: a communal reserve of nectar and pollen harvested from kilometers around, from a mix of agricultural, wild, pesticide-treated and untreated flowers. Although every bee may be exposed to pesticides, the dose is diluted by nectar or pollen samples from millions of other flowers.

In contrast, bumblebees have fewer workers, smaller foraging ranges and less diverse food reserves. They also nest in the ground, where some pesticides can persist for months to years. Around treated areas, this translates to higher doses of neonicotinoids and fungicides—compounds that have both been shown to compromise bumblebee nesting behavior and reduce the production of both new workers and queens. Solitary bees live under similar, albeit more extreme, conditions than bumblebees, depending on the nectar they can individually gather from nearby areas. “You can lose 30 percent of the bees in a [honeybee] colony, and not have a huge effect on that colony’s health or productivity. However, if you kill solitary bees … you not only kill that [individual] but all her subsequent offspring,” vanEngelsdorp says.

The Save America’s Pollinators Act would collect more data on the health of wild bees—which would be a major asset to scientists, Berenbaum says. The act’s proposed pesticides review board would also generally consider native bees and other wild pollinators more in regulating the chemicals.

Many species of bees make wax or food stores that can be tested for pesticide exposure, and the insects return to nests, making them easy to track. But other wild pollinators, such as moths, butterflies, wasps, flies and beetles, do not reliably return to a central nest or produce material that can be easily tested. As a result, there is comparatively little research on how neonicotinoids affect these insects. Some critics believe the proposed legislation would be unlikely to remedy the imbalance between the troves of research on honeybees and the comparatively scarce data on wild pollinators as a whole. And realistically, when the pesticide review board evaluates how chemicals affect pollinators, it will have to base many of its conclusions on research done on honey bees.

“The Saving America’s Pollinators Act was developed in consultation with scientists, beekeepers and the environmental community to combat one of the most prominent threats to pollinator health,” Blumenauer says. “I’m always open to discussing improvements to this bill as it moves through the legislative process.”

But Berenbaum says the legislation will not fix problems she thinks far outstrip neonicotinoids, varroa and disease—namely climate change, habitat loss and the diminishing diversity of forage that pollinators have access to, as fields and native plants are replaced by monocultures such as lawns and agricultural areas. “There’s a natural human tendency to focus on what’s immediately fixable,” she says. But the more existential issues of the American lifestyle—that is something a single bill cannot address.