Overuse of land and warming temperatures are putting insect diversity in danger in some parts of the world, scientists reported Wednesday.

The study, published in the journal Nature, confirmed for the first time a clear and alarming link between warming temperatures and large-scale agriculture and showed that where there are more farmlands, there is a greater decrease in insects.

“These findings lead to huge concerns,” said Charlotte Outhwaite, the lead author of the study and researcher at the University College London, adding that losing insects could threaten human health and food supply.

“Three quarters of our crops depend on insect pollinators(授粉),” Dave Goulson, a professor of biology at the University of Sussex in the UK, previously told CNN. “Without insects, crops will die. We won’t have things like strawberries. We can’t feed 8 billion people.”

Outhwaite said their findings “may only show the tip of the iceberg(冰山一角),"because of the limited amount of evidence in some areas. “But I think there are also a lot of results that we probably don’t really know because there are so many different kinds of insects.” Outhwaite told CNN.

Scientists say, overuse of land has a link with warming temperatures. Destroying natural habitats for agriculture can make the temperature rise sharply. Researchers found great decreases in insect populations in areas of the world that are much warmer. They concluded that in areas with small-scale agriculture, less temperature warming, and more natural habitats, insects only dropped by 7%, compared to the 63% decrease in areas with large-scale agriculture, more temperature warming and less natural habitats. So what can we do to help prevent this?

Summer is coming, and soon beaches will be full of the sounds of people having fun: splashing (泼洒) in waves and playing in the sand. But imagine finding a quieter spot of ocean. If you could stick your ears under the water, you might hear other sounds. And many of those sounds are made by fish.

People have known that fish make sounds since ancient Greece; that is why they gave some fish names like red drum, pig fish or croaker. “They’re based on the sounds these fish make,” said Audrey Looby. She studies fish sounds at the University of Florida.

So far, about 1,000 fish species have been recorded making sounds. Looby’s favorite-sounding fish is the Gulf toadfish. It makes an amazing sound like a boat whistle. Scientists are not sure how many fish make sounds. Some think that it might be as many as 22,000 types, about two-thirds of the 34,000 fish species known. And those are just the sounds fish make on purpose.

Fish sounds are important because they give a lot of information about what is going on to other fish, and to scientists. If scientists hear a fish chewing, then they know there is food available. The warning noises of certain fish species give information, too. They can tell scientists how many fish are living on a reef and where they are located. And fish sounds can tell where the endangered species are located, too, said Looby.

Fish sounds might even help preserve and bring back fish habitats. For example, scientists want to try playing healthy fish sounds in a reef that is dying. The healthy sounds might encourage fish to return and live in the dying reef. “Learning about fish sounds lets us learn about underwater environments and hopefully manage them at the same time,” Looby said.

A butterfly's wings can have many jobs besides keeping the insect in the air. They may be called on to attract mates, to warn potential enemies to stay away, to do other animals or even to provide disguise（伪装）.

All of these roles, though, depend on their colouration—which is unchanging. This plays into the idea that butterfly wings are dead tissue, like a bird's feathers or a mammal's hair. In fact, that is not true. For example, in some species males' wings harbour special cells that release chemicals which attract females.

Nanfang Yu, a physicist at Columbia University, in New York, has been looking into the matter. One of his interests is the optical（光学的）properties of biological materials. That has led him to study butterfly wings in more detail. And, in cooperation with Naomi Pierce, a butterfly specialist at Harvard University, he has now shown, in a paper published this week in Nature Communications, that butterfly wings are, indeed, very much alive.

Initially, Dr Yu and Dr Pierce wanted to know how the insects keep their body temperatures up without their wings overheating.

Unlike birds and mammals, butterflies do not produce enough internal heat to metabolize（新陈代谢）. Instead, they rely on outside heat sources—usually the sun—to bring their bodies up to speed. But their wings, being thin protein membranes（膜）, have a limited thermal capacity. Those wings can therefore overheat quickly if the insects are exposed to the sunlight too long, or, oppositely, can cool down too rapidly if they are flying through cold air.

In their experiments, the two researchers used a laser（激光）to heat up spots on the wings of dozens of butterfly species. When the temperature of the area under the laser reached 40℃ or so, the insects responded within seconds by doing things that stopped their wings heating up further. These actions included a butterfly turning around to minimize its exposure to the laser, beating its wings or simply walking away.