As natural pollinators suffer, farmers are becoming more dependent on commercial species of bees—those bred and transported for agricultural purposes. Without them, we would no longer even have certain foods. For Pacific Standard, Josh Dzieza writes about the use of bees in commercial agriculture:

Without bees our supermarkets would be far blander and less nutritious places. There would still be grains, but fewer of the many fruits, nuts, and vegetables that need bees to pollinate them. The Department of Agriculture estimates that bees add about $15 billion in value to the crops they pollinate, and these days, they get driven to those crops on trucks. Avocados, plums, pears, cantaloupes, cucumbers: they all get pollinated by a migrant force of honeybees.

With all the honeybee deaths over the last decade, it seems like more bees would be an uncontroversial good. But one new study found that these expensive, hard-working commercial bees are killing off the ones who work for free.

The problem lies in the diseases and parasites commercial bees are introducing to their wild relatives. The BBC reports:

The study, published in the Journal of Applied Ecology, reviewed data from existing studies to look at the potential for diseases to jump from commercial bees to insects in the wild. "Our study highlights the importance of preventing the release of diseased commercial pollinators into the wild," said lead researcher Dr Lena Wilfert.

Wild honeybees, in numbers already significantly weakened, were found to be quite susceptible to these commercial bee maladies, causing major colony losses. And we aren’t talking one or two commercial bee diseases here—one previous study showed that about 77 percent of bees imported to the UK were infected with up to five parasites.

Bees aren’t the only insects affected; the populations of wasps, ants, and certain kinds of flies—all pollinators themselves—have also been adversely influenced by illnesses caught from commercial bees.

While there are plans for future research into which bee varieties are most likely to spread disease, experts say that the current study calls attention to the need to better monitor and manage the use and movement of commercial bees. It's one step towards avoding the one of the bleak possible futures the Dzieza imagines—"warehouses of Varroa-immune superbees plucked from an increasingly hostile landscape and kept alive for their agricultural utility."