The scaly wings

Moths are not as popular or admired for their beauty as their cousins the butterflies. However, they have an essential ecological role as pollinators and are essential to life on earth, writes Abré J Steyn

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It’s not only reptiles and fish whose bodies are covered in scales. There’s a huge group of insects comprising 100 000 species, found on all continents except Antarctica, whose bodies are covered by thousands of tiny scales like tiles on a roof. Their scientific name, Lepidoptera, is derived from Greek and literally means “scaly wing”. We know them as moths and butterflies.

Butterflies are just about the most beautiful creatures alive and surely the most popular insects in the world. Nothing enhances the serenity of a beautiful garden more than a number of colourful butterflies flitting about and many people have spent a lifetime collecting them. Moths, however, aren’t so popular. To the casual observer they seem more drab than butterflies and while some moths can be a downright nuisance, a few others are serious agricultural pests. Because of these two quite different reasons, Lepidoptera is the most studied of all insect groups.

Some people are more sensitive to the irritation of moths than others. I once witnessed an example of this when we were working on an Italian documentary about the yellow mongoose of the Kalahari. Two friends of mine involved drove all the way from Pretoria to the Kalahari to see how we were progressing on location. Water is a scarce commodity in the Kalahari and at the time, there was a tremendous outbreak of diurnal (active during the day) white owl moths in the area.

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There were millions of them and they congregated wherever there was the least bit of moisture. A solid mass of hundreds of them would jostle with each other under a dripping tap, trying to get a sip. The moths would also investigate any other possible source of moisture, whether it was your eyes, nose or lips, and shared anything you drank. When you went behind a bush to answer the call of nature, you were engulfed in a swirling cloud of thirsty moths. They made life so unpleasant that within a few days my friends couldn’t endure it anymore. They packed up and left for home, without ever having seen any action on set.

Moths versus butterflies
The scientific distinction between moths and butterflies is vague, but some of the more obvious differences are that butterflies are diurnal and when at rest, most of them close their wings up against each other. They also have long, club-like antennae. Moths are mostly nocturnal, although many find lights irresistible. Most species fold their wings flat or roof-like over their bodies. Their antennae can be a variety of shapes, from short to extremely long. They can be simple whip-like structures or combed, while many males have delicate feather-like antennae.

The larvae of some moth species appear simultaneously in vast numbers, and if they happen to utilise agricultural crops or produce as food, the stage is set for a serious pest invasion. Examples of these are army worms, codling moths, American bollworm, maize stalk borer, cut worm and a few others.

Some species are also troublesome in houses, such as the cosmopolitan Indian meal moth and various species of clothes moths – one of the few creatures able to digest the protein keratin, which occurs in hair and wool. They can destroy clothes, linen and expensive carpets. There’s also one kind whose larvae eat dry horn. They’re of concern to hunters as they can cause serious damage to trophies.

Essential to life on earth
Most moths are not only harmless, but highly advantageous to humans and more importantly, essential to life on earth. We’ve all kept domesticated Chinese silk moth caterpillars as kids – the world would have been a duller place without the exotic silk garments which have adorned beautiful women throughout the ages.

But what’s more important is that without moths, the world would starve. Malnutrition in many parts of Africa would have been much worse, were it not for the rich protein in the larvae of mopani moths. Some moths don’t feed as adults, but most do. Like bees, moths feed mostly on nectar and are therefore the chief pollinators of the night. The flowers of many plants are adapted to be pollinated only by moths.

Moths are also the chief source of food for millions of birds, bats and other small animals, which other larger animals and even humans depend on. Their role in the global food pyramid is vital, as is their irreplaceable role as pollinators. This is why I consider the use of illuminated insect electrocution devices highly irresponsible and a sign of ecological ignorance. They’re non-selective and some of their intended targets, like codling moths and mosquitoes, aren’t attracted to light at all.

Masters of disguise and beauty
Although some moths may not appear colourful, when observed close up, they display very interesting patterns which disguise them during daytime when they need to hide from their enemies. Many, like the peacock (or emperor) moths and some of the owl moths, have large “eye spots” on their wings, which in many cases closely mimic the eyes of owls, hence their name. While this scares off diurnal birds, it doesn’t ward off bats and nightjars, which are great moth predators.

Some moths are extremely colourful and can rival any butterfly. These colours are usually highly contrasting and function as warning colours – red, yellow, orange, black and white. These moths are either daytime flyers, unpalatable or even poisonous because of the plants they eat, like some of the tiger moths. The same holds true for their brightly coloured caterpillars. I find moths most intriguing and beautiful photographic subjects and they’re much easier to photograph than their hyperactive butterfly cousins!

Contact Abré J Steyn on 083 235 4822 or e-mail [email protected]