Every so often nature provides something that is stunning in its simplicity. It can also amaze with an almost perfect replication of reality. There is an exotic fruit fly called “Goniurellia tridens” which has been referred to as a 3-in-1 insect. This fruit fly has relied on some pretty spectacular wing art to protect itself from predators.
This particular fruit fly is not common, it lives and dies in the United Arab Emirate (UAE). This winged creature has been called a piece of “evolutionary art.” The fly’s body is a dull green shade of grey, and it has bright green eyes. So far nothing sounds too much like art, although the color of the fly’s body allows it to blend into the very leaves it lands on.
The art appears on the fruit fly’s wings. These translucent appendages contain what has been called the image of an ant. The perfect image is of what appears to be at first glance “ant-like.” Six legs, a pair of antennae, head, thorax and “tapered” abdomen. According to fly specialist Dr Brigitte Howarth, from the Zayed University, the images are “absolutely perfect.” It was the doctor who first spotted the Goniurellia tridens in the UAE.
The G tridens is part of the tephritidae family that includes 5,000 different species of fruit flies. These insects are also known as peacock flies because of their colorful body markings. These particular fruit flies are called the picture wing species and there are 27 different types who have wing images that range from simple shapes to very complex, like the fly that Dr Howarth discovered.
When the doctor first saw the fly on an oleander shrub in the northern part of Oman, she thought there were several insects all sharing the same proximity. To her, it appeared that the fruit fly was flanked by two ants.
Initially Howarth thought that the fly had an ant infestation on its wings. She explained that the symmetry was so perfect that she decided it was not possible. After taking the fly back to the lab and observing it under a microscope she found out that these “ants” were painted on the wings.
According to Dr Howarth, the fly will “flash” its wings when threatened by a predator. This gives the impression that there are a couple of ants walking around. This presumably confuses the predator and the fly has time to make a speedy get-away. Apparently, it may also be a sort of courtship device.
Unlike the common housefly, the G tridens don’t just “fly up and latch on” to mate. These insects have to dance for their potential procreative partner. These wings are also part of their courtship ceremony. Howarth believes that this another reason for the ornate painting on the fly’s wings.
She thinks that the more precise and colorful the insect reproductions are on the wings, the more desirable it is to a prospective mate. Although it does stand to reason that the fruit fly with its defence mechanism may have nothing to do with mating. Regardless of why the wing art has been developed by the fruit fly, its amazing replication protects it from external predatory threats. This exotic fruit fly has been called a three in one insect because of the extra friends on its wings.
If the painted wings are just a survival mechanism, it has worked very well. The G tridens was first discovered in 1910. Since then, the fly has been spotted in the Near and Middle East, central Asian and India. These “pests” are around us everyday
Females lay their eggs in plant tissue as in fruits and flowers. It is here that the larvae feed. Despite not usually harming the plant many fruit flies are still considered pests.
Whether a pest or a flying piece of art, it is around us every day. Howarth surmises that people sit in their gardens daily surrounded by the incredible art of the fruit fly. There is one thing, though, about the doctor’s hypothesis that doesn’t quite fit.
Why would ants scare off a predator? There is another possible explanation about the insects on the flies wings, spiders. Not just any spider, though, in this case a jumping spider. Apparently, there are other flies, like the Rhagoletis & Zonosemata species who mimic arachnids by holding their wings in a certain way.
The main difference is that these other species of fruit fly do not just use the tips of their wings to fool predators, they use their whole body. But the premise is the same in either case. Fooling a potential threat. In this specific case, jumping spiders. Apparently, one jumping spider will not just approach other jumping spider. There is a certain way that they go about acknowledging one another.
When jumping spiders come across one another, they pose. Essentially showing off markings to identify that they are from the same tribe, so to speak. In the moment that the jumping spider stops to show its markings, the fruit fly escapes. It makes more sense than the ant theory at any rate.
The act of relying on the presence of ants to distract or confuse a possible predator seems rather flimsy when taking into account the realistic rendering of these insect wings. It could well be that the survival painting works in more than one way. Ants for some predators and jumping spiders when these appear.
Either way, it is amazing that nature has given the UAE fruit fly the ability to create this wing art. This type of defense mechanism is not unknown but, so far, it is the one of the most artistic and convincing displays of evolutionary art seen in an insect. Looking at the pictures, it is easy to see why this exotic fruit fly has been labelled the three in one insect.
By Michael Smith