This Little-Known Parasite Is Killing America's Honeybees

Honeybees are disappearing at an alarming rate — and a bloodthirsty parasite is at least partially to blame.

Varroa destructor — otherwise known as the vampire mite — feeds on bees by drinking their blood. Its bite spreads infection and leaves unlucky pollinators the worse for wear. After an encounter with the destructor, honeybees are more likely to succumb to illness and disease, and eventually death.

"[It's] a modern honeybee plague," Jeff Pettis, a researcher at the Agriculture Department's Bee Research Laboratory said Tuesday at a hearing convened by the House Subcommittee on Horticulture, Research, Biotechnology, and Foreign Agriculture.

The mite made its way to the U.S. in the late 1980s and has been a honeybee scourge ever since. It's native to Asia, where honeybees have evolved to repel the mite with counterattacks of their own, but American honeybees have so far been unable to adapt.

As a result, bees are dying off in droves. American beekeepers wave goodbye to roughly one-third of the bee populations they keep watch over each winter. Seasonal honeybee deaths are commonplace, but the rate at which they've risen is steep. A few decades ago, beekeepers saw losses of 10 to 15 percent of the total honeybee population each season. Between roughly 1990 and the present day, deaths have doubled. Scientists have been unable to pinpoint the exact cause of the decline, but they believe the bite of the vampire mite is a leading cause.

Scientists say additional research is needed to determine a lasting solution to the vampire mite menace — and President Obama thinks he can help. The president's budget for fiscal 2015 would invest more than $71 million in USDA-led research efforts to better understand the pollinator decline. But it's unclear whether Congress will greenlight the fund. Lawmakers have already taken steps, however, to boost the flow of dollars into research. The latest iteration of the farm bill — signed into law in February — set aside money to investigate honeybee health and ways to protect it.

Bug-zapping chemicals are the most effective way to eradicate the mite. But the parasite isn't easily kept at bay. Pettis told members of the subcommittee that the pests have adapted to the chemical stock and are now on their way to becoming entirely resistant.

All this is cause for concern. The country's food supply depends on the health of honeybees. Farmers rely on insect pollination for successful harvests, with foods like almonds, macadamia nuts, cherries, blueberries, and plums all leaning heavily on honeybees for their survival. According to a report by the Congressional Research Service, U.S. insect pollination adds $16 billion in agricultural value each year. And honeybees are responsible for the lion's share of this total — making up three-fourths of crop production.

Hopefully scientists act soon. It's unlikely that honeybees will disappear altogether, but sustained population loss could hit Americans where it hurts. "Ultimately if no long-term solutions are developed to slow bee decline, consumers will pay more for the food they buy," Pettis said.