Saturday, 24 November 2012

Trillion Tropospheric Insects

Tom Stubbs

If you look up at the sky what do you see? Clouds, birds, planes, the sun, what about insects? We are all familiar with butterflies fluttering by during a warm summer’s day. But did you know that updrafts of air can carry them to over 3,000 feet, higher than the world’s tallest building? Up there, the butterflies are joined by flies which travel to heights of around 5,000 feet and even higher than this you find aphids, midges and wasps. Amazingly, beetles are known from heights above 6,000 feet, such as the common ladybird. In the search for mates, Male Gypsy moths can even get to 10,000 feet. If we continue our vertical journey further, to say 13,000 feet, we reach heights exceeding many mountains. Surely nothing can get as high as this? Wrong! Have you ever been sat outside and seen a spider that appears to be floating through the air? These spiders are actually attached to a single silk thread that is carrying like a helium balloon! Using this technique, spiders have been found at 13,000 feet. The highest living insect ever recorded was, believe it or not, an individual termite at 19,000 feet.

So we now know that up above us there are hidden highways of life. Insects use these to search for new habitats, food and mates. Have you ever considered how many individual insects there may be flying above us right now? Scientists believe that if you take a 0.6 square mile column of air going from the surface to the edge of space in a spring or summer month there will be 3 billion individuals within it. So that’s 3 billion insects within a column of just 0.6 by 0.6 miles. Now imagine if you extended this to cover the entire surface of Earth! This makes the scientific estimates of around 10 quintillion (1018) individual insects alive right now seem quite reasonable.

Check out this awesome video for more information.