There are lots of insects that farmers hate. But there also are some they like. They protect crops against damage from other insects. A good example is the lady beetle, which is also known as the ladybug(瓢虫)．

    Lady beetles are a natural control for aphids(蚜虫). Lady beetles are red, orange or black. They often have black spots, though some have light colored spots. Different kinds of lady beetles have different numbers of spots. There are lady beetles with four, five, seven and fourteen spots.

    Many of the well-known kinds of lady beetles come from Asia or Europe. They now are common throughout the United States.

    American scientists imported one kind of lady beetle, the multicolored Asian lady beetle, as early as 1916. They released them as an attempt to control some kinds of insects. Over the years, the beetle has become established, possibly helped by some that arrived with imported plants on ships.

    Experts say over 450 kinds of lady beetles are found in North America. Some are native to the area. Others have been brought from other places. Almost all are helpful to farmers.

    The Asian lady beetles now in the United States probably came from Japan. The Asian lady beetle eats aphids that damage crops like soybeans, fruits and berries.

    In the southern United States, Asian lady beetles have reduced the need for farmers to use reskilling poisons on pecan trees. This popular tree nut suffers from aphids and other pests that the lady beetles eat.

    But some people say the Asian lady beetle has itself become a pest. They worry that the lady beetles may eat their late autumn fruit crops.

    Experts say Asian lady beetles may appear in large numbers in some years. But they say the insects are too helpful to be considered as pests.

    I'm a reporter. Last month I was in Stockholm, Sweden. Now I'm in Frankfurt, Germany. Next month, who knows?

    You certainly won't believe that I can call you from my laptop, which is what I'm often doing these days using something called Skype.

    Skype lets me call any phone number anywhere in the world for about 2 cents a minute, a little more to some places, such as the Middle East and Asia. My computer does the dialing, and the processing of incoming and outgoing voices. All you need is a broadband connection (宽带接头). With the basic version of Skype, all anyone needs to make or receive a call is to install the program on his or her computer (and that includes personal digital assistants). All calls from PC to PC are free.

    You don't even need a pair of headphones, though headphones can be a good idea if you wish to be discreet. I use my laptop's built-in microphone.

    The paid service for calling regular telephones is called SkypeOut. The quality is completely clear, provided that there's not too much traffic on the Internet. If there's an echo, hang up and try again, and it usually gets better. There is one warning: on some computers, especially those running older versions of Windows, it doesn't always work, or can sound like a confusing conversation. You can't hear a thing.

    Skype was invented chiefly by a Swede named Niklas Zennstrom along with a group of programmers in Estonia.

    Last week, Vodafone started a test of the UK's first full 5G service, available for use by businesses in Salford. It is part of its plan to trial the technology in seven UK cities. But what can we expect from the next generation of mobile technology?

    One thing we will see in the preparation for the test is lots of tricks with the new tech. Earlier this year, operators paid almost £ 1.4 billion for the 5G wavelengths, and to compensate for that cash, they will need to catch the eye of consumers. In September, Vodafone used its bit of the range to display the UK's first hologram (全息) call. The Manchester City captain Steph Houghton appeared as a hologram in Newbury. It isn't all holograms, however: 5G will offer faster internet access, with Ofcom (英国通讯管理局) suggesting that video that takes a minute to download on 4G will be available in just a second.

    The wider application is to support connected equipment on the "internet of things" -not just the internet-enabled fridge that can reorder your milk for you, but the network that will enable driverless cars and delivery drones (无人机) to communicate with each other.

    Prof William Webb has warned that the technology could be a case of the emperor's new clothes. Much of the speed increase, he claims, could have been achieved by putting more money in the 4G network, rather than a new technology.  Other different voices have suggested that a focus on rolling out wider rural broadband access and addressing current network coverage would be more beneficial to the UK as a whole.

    Obviously, 5G will also bring a cost to consumers. It requires a handset for both 5G and 4G, and the first 5G-enabled smart phones are expected in the coming year. With the slow pace of network rollout so far, it is likely that consumers will end up upgrading to a new 5 G phone well before 5 G becomes widely available in the next couple of years.

    In the 1960s, while studying the volcanic history of Yellowstone National Park, Bob Christiansen became puzzled about something that, oddly, had not troubled anyone before: he couldn't find the park's volcano. It had been known for a long time that Yellowstone was volcanic in nature—that's what accounted for all its hot springs and other steamy features. But Christiansen couldn't find the Yellowstone volcano anywhere.

    Most of us, when we talk about volcanoes, think of the classic cone (圆锥体) shapes of a Fuji or Kilimanjaro, which are created when erupting magma (岩浆) piles up. These can form remarkably quickly. In 1943, a Mexican farmer was surprised to see smoke rising from a small part of his land. In one week he was the confused owner of a cone five hundred feet high. Within two years it had topped out at almost fourteen hundred feet and was more than half a mile across. Altogether there are some ten thousand of these volcanoes on Earth, all but a few hundred of them extinct. There is, however, a second les known type of volcano that doesn't involve mountain building. These are volcanoes so explosive that they burst open in a single big crack, leaving behind a vast hole, the caldera. Yellowstone obviously was of this second type, but Christiansen couldn't find the caldera anywhere.

    Just at this time NASA decided to test some new high-altitude cameras by taking photographs of Yellowstone. A thoughtful official passed on some of the copies to the park authorities on the assumption that they might make a nice blow-up for one of the visitors' centers. As soon as Christiansen saw the photos, he realized why he had failed to spot the caldera; almost the whole park-2.2 million acres—was caldera. The explosion had left a hole more than forty miles across—much too huge to be seen from anywhere at ground level. At some time in the past Yellowstone must have blown up with a violence far beyond the scale of anything known to humans.

    Some years ago, Michel-Andre found himself staring at the body of a dead whale on a beach in the Canary Islands. It was obvious that the animal had been struck violently by a ship——but why? Only later, after surveying the whales which lived in the area and measuring the increase of sound pollution from ships did it become clear that there was a link.

    The whales had become desensitised to the noise of approaching boats and were being struck by them, often seriously. "We never thought that this could be something that could kill," recalls (回忆) Andre, who is the director of the Laboratory of Applied Bioacoustics at the Technical University of Catalonia, Barcelona.

    Andre has spent 20 years developing an advanced system to better understand why incidents like this happen. His underwater microphones have exposed a world of deafening sound and animal communication never observed with such clarity(清晰) before.

    It was not an easy task. Sound waves don't travel through water in the uniform, predictable way they do through the air. Instead, the temperature, salinity (盐度) and, flow of water have great effects on their path.

    What can be done? One solution is to change shipping routes to courses where ships are statistically less likely to meet animals. It's also possible to slow ships down to 18km/h or less, which is less likely to seriously injure a whale.

    As for dealing with the root cause of the problem, the UN's International Maritime Organisation has already published guidelines on how to quieten ships, but it will be a while before the effects of such changes might be observed.

    "The ocean is not our world," comments Andre. But it is ours to look after. And thanks to his work, we can better understand the effects of subsea sound pollution.

The text from my son said it all: "Dad, there's an article you were born to write that the world is finally ready for: Bring Back the Handkerchief!" As my son knows, there's no "bring back" for me. For me, the handkerchief never left. 

My mother raised me with several fixed rules. One was that a gentleman always has a clean handkerchief in his right rear pocket, a piece of simple cotton, roughly 15 inches square and less than four inches when folded. I was a dutiful son, but as a child, I had been wondering what it was there for. After 60 years, my body weight now feels wrong if I'm heading out of the house with an empty back pocket. 

I am sure this habit has sometimes struck friends but in polite company nobody comments on somebody else's business. Children like my kids think of my hankie ridiculously old-fashioned and they have their arguments. If you have to be prepared every day for allergies or a cold, why not choose a little packet of tissues, which saves you from that disgusting business of blowing your nose in the thing and then stuffing it back in your pants?

Point taken. But a handkerchief is more durable and has a far wider variety of uses. Can you grab the handle of a pot that's boiling over with a Kleenex? Or do you recall the cases of skinned knees and drippy noses that hankie wiped? In fact, my wife gave me several new handkerchiefs as gifts. Neither of us can count the number of times her eyes have welled up at a movie, or, as happens, she's needed to blow her nose. 

Yet not even my mother could have anticipated the hankie's new role as an Essential Public Health Appliance. All of us have learnt how hard it is to follow advice from medical experts about not touching your face. Here is an answer. Use your hankie. In case of emergency, your handkerchief can become a makeshift DIY mask that can be pulled over your lower face like a robber entering a bank. 

And it will certainly give me the chance to lift my chin and look at my adult children through one eye, asking in her good-hearted way, "What do you have to say now, smarty-pants?"