Editorial: A lot is riding on finding culprit in honeybee deaths | The Sacramento Bee

For more than a decade, scientists have been trying to solve the mystery of honeybees disappearing by the millions.

There are many suspects, but one has become the focus of scientists and regulators worldwide. Over the past two months, several scientific studies have pointed to a family of pesticides – an insecticide widely used in agriculture but also found in backyard products.

While there is debate over the culprits, the threat to a critical component of our food supply should be removed.

The neurotoxic insecticide, chemically similar to nicotine, impairs honeybees’ ability to forage for pollen and lessens their ability to rebuild their colonies over winter. One scientific study pointed to more disturbing widespread ecological problems.

A four-year analysis by 29 scientists reviewing more than 800 peer-reviewed reports concluded for the first time that insecticides called neonicotinoids, or neonics for short, are “causing significant damage” to beneficial insects and are a “key factor in the decline of bees.”

Just as startling, the insecticide was linked to drops in bird and reptile populations, according to the Worldwide Integrated Assessment. Not only does the pesticide kill insects, it changes the tunneling behavior of earthworms, and creates health problems for snails and aquatic life – all part of the diet of birds and reptiles.

“We are witnessing a threat to the productivity of our natural and farmed environment equivalent to that posed by organophosphates or DDT,” Jean-Marc Bonmatin of the National Center for Scientific Research in France and one of the lead authors of the assessment, said in a news release. “Far from protecting food production, the use of neonics is threatening the very infrastructure which enables it.”

In 2006, when the loss of honeybees in the United States was reported between 30 percent and 90 percent, the phenomenon picked up the name “colony collapse disorder.”

Various reasons have been given, including parasitic mites, pesticides, malnutrition and loss of natural foraging habitat, or a combination of those and other factors. But the threat posed by neonics was not among the top reasons beekeepers themselves reported for loss of their colonies last year, said Eric Mussen, an apiculturist of the University of California, Davis. Parasitic mites and starvation were cited as the top two causes.

“Colony collapse disorder is a consequence of overwhelming stresses,” Mussen said in an interview. “Among other stresses, the bees are living in a pool of pollution. It’s a combination of everything beekeepers are putting in their hives and we are putting into the environment.”

While honeybee populations have slightly rebounded, their disappearance remains a mystery that confounds scientists and should worry the rest of us. About one-third of the food we eat – apples, melons, broccoli, squash and many other fruits, vegetables and nuts – grows with the help of bees.

California farmers depend on bees pollinating 870,000 acres of almond trees in February and March for a $3 billion harvest. After pollinating plum and cherry trees, then citrus blooms in April, honeybees are trucked throughout the United States where they provide an essential service that produces $30 billion in crops each year.

The loss of such an integral factor to worldwide agriculture triggered the scientific studies and a re-evaluation of neonics by regulators.

Last year, the European Union restricted the use of neonics for two years. The U.S. Environmental Protection Agency is reevaluating their use. Last week, the U.S. Fish and Wildlife Service said it will phase out the use of neonics in federal wildlife refuges in the Pacific Northwest and Hawaii.

In California, the state Department of Pesticide Regulation began reevaluating neonics in 2009 but doesn’t expect results until 2016. Seven years is a long wait. Farmers depend on honeybees to pollinate more than 100 different crops in California each season.

Scientific research may take time to determine the cause, but there is a prime suspect that could be taken out or our backyards, and our fields and orchards.

We should have learned a few lessons by now in tinkering with the environment: Too often, we have introduced a solution to one problem only to create a ripple effect of harmful consequences.