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Non-Pest Insects Are Declining: Scientists

Governments are trying to improve the situation.

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A ladybug rests on the petals of a flower in the Capitol Hill garden in Washington. VOA
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A staple of summer — swarms of bugs — seems to be a thing of the past. And that’s got scientists worried.

Pesky mosquitoes, disease-carrying ticks, crop-munching aphids and cockroaches are doing just fine. But the more beneficial flying insects of summer — native bees, moths, butterflies, ladybugs, lovebugs, mayflies and fireflies — appear to be less abundant.

Scientists think something is amiss, but they can’t be certain: In the past, they didn’t systematically count the population of flying insects, so they can’t make a proper comparison to today. Nevertheless, they’re pretty sure across the globe there are fewer insects that are crucial to as much as 80 percent of what we eat.

Yes, some insects are pests. But they also pollinate plants, are a key link in the food chain and help decompose life.

“You have total ecosystem collapse if you lose your insects. How much worse can it get than that?” said University of Delaware entomologist Doug Tallamy. If they disappeared, “the world would start to rot.”

He noted Harvard biologist E.O. Wilson once called bugs: “The little things that run the world.”

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A bug stands on the petals of a flower in a house garden in Virginia. (Photo: Diaa Bekheet). A study estimates a 14 percent decline in ladybugs in the United States and Canada from 1987 to 2006. VOA

The 89-year-old Wilson recalled that he once frolicked in a “Washington alive with insects, especially butterflies.” Now, “the flying insects are virtually gone.”

It hit home last year when he drove from suburban Boston to Vermont and decided to count how many bugs hit his windshield. The result: A single moth.

Windshield test

The un-scientific experiment is called the windshield test. Wilson recommends everyday people do it themselves to see. Baby Boomers will probably notice the difference, Tallamy said.

Several scientists have conducted their own tests with windshields, car grilles and headlights, and most notice few squashed bugs. Researchers are quick to point out that such exercises aren’t good scientific experiments, since they don’t include control groups or make comparisons with past results. (Today’s cars also are more aerodynamic, so bugs are more likely to slip past them and live to buzz about it.)

Still, there are signs of decline. Research has shown dwindling individual species in specific places, including lightning bugs, moths and bumblebees. One study estimated a 14 percent decline in ladybugs in the United States and Canada from 1987 to 2006. University of Florida urban entomologist Philip Koehler said he’s seen a recent decrease in lovebugs — insects that fly connected and coated Florida’s windshields in the 1970s and 1980s. This year, he said, “was kind of disappointing, I thought.”

Insects
A multicolored Coccinellidae septempunctata, commonly known as seven spotted ladybug or ladybird walks on a leaf in a house garden in Virginia. VOA

University of Nevada, Reno, researcher Lee Dyer and his colleagues have been looking at insects at the La Selva Biological Station in Costa Rica since 1991. There’s a big insect trap sheet under black light that decades ago would be covered with bugs. Now, “there’s no insects on that sheet,” he said.

But there’s not much research looking at all flying insects in big areas.

The evidence

Last year, a study that found an 82 percent mid-summer decline in the number and weight of bugs captured in traps in 63 nature preserves in Germany compared with 27 years earlier. It was one of the few, if only, broad studies. Scientists say similar comparisons can’t be done elsewhere because similar bug counts weren’t done decades ago.

“We don’t know how much we’re losing if we don’t know how much we have,” said University of Hawaii entomologist Helen Spafford.

The lack of older data makes it “unclear to what degree we’re experiencing an arthropocalypse,” said University of Illinois entomologist May Berenbaum. Individual studies aren’t convincing in themselves, “but the sheer accumulated weight of evidence seems to be shifting” to show a problem, she said.

insects
Several scientists have conducted their own tests with windshields, car grilles and headlights, and most notice few squashed bugs. Flcikr

After the German study, countries started asking if they have similar problems, said ecologist Toke Thomas Hoye of Aarhus University in Denmark. He studied flies in a few spots in remote Greenland and noticed an 80 percent drop in numbers since 1996.

“It’s clearly not a German thing,” said University of Connecticut entomologist David Wagner, who has chronicled declines in moth populations in the northeastern United States. “We just need to find out how widespread the phenomenon is.”

The suspects

Most scientists say lots of factors, not just one, caused the apparent decline in flying insects.

Suspects include habitat loss, insecticide use, the killing of native weeds, single-crop agriculture, invasive species, light pollution, highway traffic and climate change.

“It’s death by a thousand cuts, and that’s really bad news,” Wagner said.

To Tallamy, two causes stand out: Humans’ war on weeds and vast farmland planted with the same few crops.

Insects
Light pollution is another big problem for species such as moths and fireflies, bug experts said. Pixabay

Weeds and native plants are what bugs eat and where they live, Tallamy said. Milkweeds, crucial to the beautiful monarch butterfly, are dwindling fast. Manicured lawns in the United States are so prevalent that, added together, they are as big as New England, he said.

Those landscapes are “essentially dead zones,” he said.

Light pollution is another big problem for species such as moths and fireflies, bug experts said. Insects are attracted to brightness, where they become easy prey and expend energy they should be using to get food, Tallamy said.

Jesse Barber of Boise State is in the middle of a study of fireflies and other insects at Grand Teton National Park. He said he notices a distinct connection between light pollution and dwindling populations.

“We’re hitting insects during the day, we’re hitting them at night,” Tallamy said. “We’re hitting them just about everywhere.”

Lawns, light pollution and bug-massacring highway traffic are associated where people congregate. But Danish scientist Hoye found a noticeable drop in muscid flies in Greenland 300 miles (500 kilometers) from civilization. His studies linked declines to warmer temperatures.

insects
Some insects are pests. But they also pollinate plants, are a key link in the food chain and help decompose life. VOA

Other scientists say human-caused climate change may play a role, albeit small.

Restoring habitat

Governments are trying to improve the situation. Maryland is in a three-year experiment to see if planting bee-friendly native wildflowers helps.

University of Maryland entomology researcher Lisa Kuder says the usual close-crop “turf is basically like a desert” that doesn’t attract flying insects. She found an improvement — 70 different species and records for bees — in the areas where flowers are allowed to grow wild and natural alongside roads.

The trouble is that it is so close to roadways that Tallamy fears that the plants become “ecological traps where you’re drawing insects in and they’re all squashed by cars.”

Still, Tallamy remains hopeful. In 2000, he moved into this rural area between Philadelphia and Baltimore and made his 10-acre patch all native plants, creating a playground for bugs. Now he has 861 species of moths and 54 species of breeding birds that feed on insects.

Also Read: Kun- Faya & Fun Art Exhibition at India Habitat Centre in Delhi

Wagner, of the University of Connecticut, spends his summers teaching middle schoolers in a camp to look for insects, like he did decades ago. They have a hard time finding the cocoons he used to see regularly.

“The kids I’m teaching right now are going to think that scarce insects are the rule,” Wagner said. “They’re not realizing that there could be an ecological disaster on the horizon.” (VOA)

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Climate Change Left Its Fingerprint On The Most Extreme Disasters in 2017

The science is progressing to the point where ignoring it could cause legal problems

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Climate change
A Feb. 11, 2017, aerial photo released by the California Department of Water Resources shows a damaged spillway with an eroded hillside in Oroville, California. VOA

Drought in the United States and East Africa. Floods in Peru and Bangladesh. Heatwaves in Europe and China. Even unusual cloudiness in Japan. Climate change left its fingerprints on some of the biggest climate extremes of 2017, according to a new assessment.

The report highlights how a changing climate has real-life implications for the professionals who have to deal with the consequences. Case in point: water managers faced with record-breaking rainfall that overwhelmed a faltering dam in California.

“This is not a problem for the future. It’s a problem for today,” said Penn State University climate scientist David Titley, who was not involved with the research.

Seventeen studies from 10 countries make up the report, which the American Meteorological Society has been publishing annually since 2011.

They tease apart the factors that led to each extreme event and estimate the extent to which climate change contributed.

Drought, Climate Change
In this July 26, 2017, photo, soybeans grow in a farm field near Indianola, Iowa. Drought conditions are getting worse in several states, and extreme heat and weeks with little rain have begun to stress corn, soybeans, wheat and livestock. VOA

For example, drought parched the U.S. Northern Great Plains in the summer of 2017, drying up farms and ranches, sparking wildfires and racking up more than $2 billion in damage.

The study found that climate change did not affect the amount of rain that fell over the region.

However, higher temperatures brought on by global warming meant that soil dried out quicker. That means a drought of this severity is 1.5 times more likely than it would have been without climate change, the report said.

The report was released at the fall meeting of the American Geophysical Union in Washington, D.C. It comes as U.N. climate negotiators are meeting in Poland.

At that meeting, U.S., Russian and Saudi negotiators aimed to downplay a dire report from the Intergovernmental Panel on Climate Change on the impacts of global warming.

The new study’s findings confirm what the IPCC first predicted nearly 30 years ago, said study editor Martin Hoerling, a climate scientist at the National Oceanic and Atmospheric Administration.

Climate Change, hurricane michael, Storms
In this photograph released by the Sri Lankan Air Force media division on May 29, 2017, flooding is seen in the country’s Matara district. VOA

According to the group’s first report, the impacts seen today are “the type of change in weather and climate that we would experience if we continued on a trajectory of increasing carbon dioxide,” Hoerling said. “We have certainly done so, and the consequences are unfolding.”

In Oroville, California, last February, the consequences of climate change provided a case study in the challenges of managing critical infrastructure in the face of a changing climate.

A series of torrential rains overfilled the lake behind the Oroville Dam. Because of a damaged spillway, overflowing water threatened to destroy the dam. Nearly 200,000 people downstream were evacuated.

The reservoir was already full when the storm that nearly broke the dam hit. One major reason, the report notes, was the unusual warmth at the end of the previous year. Storms that would normally have fallen as snow instead fell as rain.

Other California dams handled the deluge without incident, however, noted study co-author and hydrologist Julie Vano at the National Center for Atmospheric Research. It was the combination of climate change-driven extreme weather and the damaged spillway that made Oroville a near-disaster.

Fire, CLimate Change, California
Firefighters battle a wildfire as it threatens to jump a street near Oroville, California. VOA

“With aging infrastructure and more development happening in places where there’s risk exposure, we really need to think about how we manage our systems,” she said.

The science is progressing to the point where ignoring it could cause legal problems, according to attorney Lindene Patton with the Earth & Water Law Group.

Drought in the United States and East Africa. Floods in Peru and Bangladesh. Heatwaves in Europe and China. Even unusual cloudiness in Japan.

For example, she said, take the owner of a hypothetical chemical plant located near a river.

Engineers typically design safety features based on historical rainfall patterns. “If your calculations are done assuming 1970s rainfall events,” Patton said, “then your design would not be prepared for today’s climate.”

Also Read: As Climate Talks Come to a Halt, Africa Suffers From Global Warming

When climate science can show that rainfall patterns have changed, she added, “if you don’t use that different set of rainfall tables and a chemical release occurs, then you may find a claim is made against you.” (VOA)