Nighttime Pollinators are Under Threat from Artificial Light

For humans, street lamps are associated with safer streets. But for nighttime pollinators, the artificial light poses a concentrated danger that, in the grand scheme of things, poses a real danger to the entire planet. That’s the conclusion of an August 2017 study published in Nature.

During daylight hours, all manner of bees and butterflies can be seen flitting about, spreading pollen from flower to flower. But did you know that when the moon comes up and the sun goes down, that’s when the graveyard-shift pollinators go about their job? Moths, beetles, and other night-owl insects come out at night to take over.

Scientists in Switzerland discovered that artificial lighting led to fewer visits from pollinators and reduced fruit production in patches of cabbage thistle. At the time, the researchers were admittedly in the dark about how artificial light affected nighttime pollinators.

So to learn more, they set up mobile street lamps over plots of the plants that had never before been placed under artificial light at night. They also used night vision goggles to watch and catch the pollinators.

The researchers found that the plots grown under the artificial light experienced 62% fewer visitors from nighttime pollinators, compared to plots grown in the dark. Moreover, the illuminated plots saw 29% fewer pollinator species.

Plants that had been covered in pollinator-proof bags produced about the same amount of fruit, regardless of whether or not they were exposed to artificial light.

Even though there are typically more daytime pollinators than nighttime pollinators, the daytime pollinators failed to make up the difference in lost pollination of plants living under artificial light.

Eva Knop, an ecologist at the University of Bern in Switzerland and first author of the study, said:

“These plants were visited frequently by pollinators during the day, too, so this means that in the daytime, pollinators simply can’t compensate for the lost pollination at night.” [2]

As for why nighttime pollinators struggle to do their job, it could be because many nocturnal creatures have sensitive vision which allows them to navigate the landscape in the dark, and bright light disorients or blinds them. Some may be attracted to the light, which distracts them from their natural habitat. Or it could be the exact opposite – light repels the pollinators, and they fly away.

Scientists need to understand what’s going on, though, because the planet’s daytime pollinators are struggling, and the amount of artificial light grows by about 6% every year.

Franz Hölker, a biologist at Germany’s Leibniz Institute of Freshwater Ecology and Inland Fisheries, who was not involved in the study, said:

“Insects are at the center of many food webs, so if you disturb them, there’s an effect on the entire ecosystem.”

Since artificial light – especially street lamps – are kind of a necessity, there’s really no way to completely solve the problem, but there are ways to ease the burden on nighttime pollinators.

Knop says one suggestion is to avoid using LED lights. They emit a high percentage of a certain type of light that is especially harmful to insects. Instead of leaving porch lights burning all night, people can opt for motion-sensing lights. Also, if you can do without decorative lighting, ditch it.

Knop urged:

“Urgent measures must be taken, to reduce the negative consequences of the annually increasing light emissions on the environment.” [3]


[1] Nature

[2] The Verge

[3] Mother Nature Network

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Could Pollinator Drones Soon Replace Bees?

Scientists in Japan have created tiny drones that pollinate plants; and if bees disappear, the insect-size drones are intended to replace them.

Right now the drones are not autonomous, and they’ve never been tested outside the lab. But they might one day be a necessity. In recent years, bee populations have sharply declined, and bee deaths have been blamed on everything from pesticides to diseases to climate change. The results of a Greenpeace investigation published in the fall of 2016 reveal that unpublished field trials by pesticide manufacturers show that their products cause severe harm to honeybees at high levels. [1]

But why switch to organic farming when you can just build exorbitantly priced robots?

Eijiro Miyako, chemist from the National Institute of Advanced Industrial Science and Technology (AIST) in Japan, found the perfect substance for pollen collection in a decade-old bottle of sticky gel from an earlier experiment he stumbled across while cleaning his lab. The substance, an ionic liquid gel, consists of a collection of complex molecules linked in long chains, and it has the optimal stickiness to pick up pollen grains.

Miyako’s group rubbed the sticky gel on ants and flies – other types of pollinators – and put them on flowers. Each bug was soon covered in pollen.

For use with drones, the gel is a dual-purpose substance: It collects and deposits pollen, and also interacts with light waves to camouflage the drones. The camouflage could come in handy in the future as protection against predators if such drones were deployed in swarms. [1], [2]

Read: First Time Ever – U.S. Adds Bees to Endangered Species List

The team then assembled a 1.6-by-1.6-inch remote-controlled drone equipped with tiny hairs similar to the hairs found on bees. Miyako coated the hairs with the gel and flew the drone into the flowers of Japanese lilies. The tiny robot picked up pollen like a natural pollinator. When it was directed to another flower to release the pollen grains, it successfully pollinated the plant just as the researchers hoped it would. [1]

Source: The Verge

Being able to use drones to assist pollinators is little more than a pipe dream at this point. Researchers know they work, but there are major hurdles that need to be cleared. Trevor Weatherhead, Executive Director of the Australian Honey Bee Industry Council, says:

“This little machine will certainly pollinate, but how many would you need for, say, 1,000 acres? You have your pumpkins and watermelons where the flowers are in under the leaves themselves, and the bees sort of fly in under – I’m not sure how the robots would be able to get in and out.” [2]

If you’re wondering why scientists don’t focus more attention on saving the bees instead of potentially replacing them with robots, you’re not the only person asking that question. Biologist David Goulson from the University of Sussex in the UK, wrote in his blog on February 7, 2017 that we should “look after [bees], not plan for their demise.” [3]

He added:

“I would argue that it is exceedingly unlikely that we could ever produce something as cheap or as effective as bees themselves. Bees have been around and pollinating flowers for more than 120 million years; they have evolved to become very good at it. It is remarkable hubris to think that we can improve on that. Consider just the numbers; there are roughly 80 million honeybee hives in the world, each containing perhaps 40,000 bees through the spring and summer. That adds up to 3.2 trillion bees. They feed themselves for free, breed for free, and even give us honey as a bonus. What would the cost be of replacing them with robots?”

Read: List of Foods We Will Lose if We Don’t Save the Bees

Miyako says he wants to lower the cost of the drones, and he’s going to have to. If conservationists used the same drones that Miyako did, that would equal up to $100 dollars per bee. Honeybee hives contain tens of thousands of bees – a hive of 50,000 bees would cost $5 million to replace.


[1] The Verge

[2] RT

[3] Gizmodo

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