#insect decline

How Non-Native Plants Are Contributing to a Global Insect Decline

"Staggering 82% loss in moth numbers at Canterbury sites amid major decline nationwide"

Insects are in trouble. Around the world, scientists are reporting catastrophic declines in their numbers, even in nature reserves that are largely protected from human touch. We are also beginning to see huge drops in the populations of other animals – such as birds – that depend on insects as food. Many of the drivers of those declines are structural, and require strong action by governments to turn around. But there are clear, easy steps that anyone can take to support the insect world. For species under such pressure, any respite is important, and we can create refuges for insects in a world increasingly hostile to their survival. In creating better habitats for insects, you can also reap the benefits: thriving gardens, more songbirds, and a healthier web of life. Here are 25 small, achievable, science-backed actions you can take today – at home, in the garden, or out in the city. Turn out the lights Everyone has seen moths circle a bulb at night. But if that light stays on, researchers estimate one-third of insects trapped in its orbit will die before morning. Light pollution is a huge driver of insect declines: it changes insect behaviour and can even make leaves too tough for them to eat. It is also a relatively easy one to solve, says Brett Seymoure, a behavioural ecologist at Washington University in St Louis. “Once you turn off a light, it is gone. You don’t have to go and clean up, like you do with most pollutants. I am not saying we need to get rid of light at night, I think we just need to use it wisely.” You can help by switching off your outdoor lights or putting them on a sensor, and shading windows so they’re not shining out into the night. You can also ask your local council to consider switching off some street lights for at least part of the night, particularly in parks and nature reserves – a move that studies have shown benefits insects and saves councils money.

Where have all the insects gone?

Of the scant records that do exist, many come from amateur naturalists, whether butterfly collectors or bird watchers. Now, a new set of long-term data is coming to light, this time from a dedicated group of mostly amateur entomologists who have tracked insect abundance at more than 100 nature reserves in western Europe since the 1980s.

Over that time the group, the Krefeld Entomological Society, has seen the yearly insect catches fluctuate, as expected. But in 2013 they spotted something alarming. When they returned to one of their earliest trapping sites from 1989, the total mass of their catch had fallen by nearly 80%. Perhaps it was a particularly bad year, they thought, so they set up the traps again in 2014. The numbers were just as low. Through more direct comparisons, the group—which had preserved thousands of samples over 3 decades—found dramatic declines across more than a dozen other sites.

LEDs may cause more insect declines than other lights

LED lights’ energy saving properties are making them increasingly common, but they may repel some insects at higher rates than older, halogen-style streetlamps.

“We don’t really understand the cause of insect declines,” said Douglas Boyes, a PhD researcher at the UK Centre for Ecology and Hydrology, an independent nonprofit research institute. But he and many other scientists believe light pollution is potentially causing pollinator declines in many parts of the globe.

In a study published recently in Science Advances, Boyes and his colleagues looked at how light is impacting insects. After examining about 500 possible locations with streetlamps in the Thames Valley in the United Kingdom, they found 27 sites with streetlamps that also had a comparable area without streetlamps. They compared the number of caterpillars in the lit and unlit areas...

Domestic beehives linked to spike in viral infections in nearby bumblebee populations 

Many species of wild bumblebees are in decline -- and new research shows that diseases spread by domestic honeybees may be a major culprit.

Several of the viruses associated with bumblebees' trouble are moving from managed bees in apiaries to nearby populations of wild bumblebees -- "and we show this spillover is likely occurring through flowers that both kinds of bees share," says Samantha Alger, a scientist at the University of Vermont who led the new research.

"Many wild pollinators are in trouble and this finding could help us protect bumblebees," she says. "This has implications for how we manage domestic bees and where we locate them."

The first-of-its-kind study was published June 26 in the journal PLOS ONE...