Bee populations decline in California for first time in 40 years

Several species of bees have gone missing in California, according to new research.

A study into bee populations in the state found that several once-common species of the insect have declined in population since the 1980s.

Other smaller-scale studies have shown that bee populations around the world have significantly reduced due to climate change, the decline of habitats and the use of bee-killing pesticides.

The study was led by UC Riverside and aimed to document changes in bee populations across California since the last study was conducted in the 1980s.

Entomologist Hollis Woodard and supporting researchers collected bees from 17 sites, representing six different ecosystems previously known to be home to a large variety of bees.

But, they could not locate more than 10 bees in those sites at the time of their visits.

In total, the team collected 17 types of bees, accounting for only 68 per cent of the species historically known to be in the state.

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Bees are key to food production and help to pollinate crops worth $3 billion annually in the US alone. Foods they help pollinate include tomatoes, peppers and berries.

On the research, Ms Woodard said: “Although we found that relative to other sites the mountains are home to the most diverse bumble bee populations, even at those sites we also failed to find some species that used to be there.”

One of the missing species included the Western bumble bee which is an important pollinator of wild plants and crops and used to be one of the most common bumble bees found in California.

“We didn’t find it even once,” she said. “If it was okay, we should have seen it.”

The most commonly found species found was Bombus vosnesenskii which represented more than half of all bees the team collected. It is the most dominant species in California.

“Even the most dominant species has lost a lot of suitable habitat since the last large-scale survey,” Ms Woodard said. “The winner is not doing great.”

While the team said they may have found more species of bees if they collected larger sample sizes, they did not want to disturb the already struggling populations of the insect.

Woodard hopes that the U.S. Endangered Species Act – which prohibits listed wildlife from being trapped, taken or collected, except for conservation or scientific purposes – and recently introduced state laws would help in protecting struggling bee populations.

“Generally, the state list directs more action toward more local measures. It’s good for them to be covered under both,” Ms Woodard said.

“I hope the state listing also encourages Californians to feel like they have a stake in helping the bees survive, because bees certainly help humans survive.”