Ants are remarkably well-defended animals,” says Paul Shamble, now at Harvard University, who co-led the work while at Cornell University in Ithaca, New York. “Ants bite, some sting, many have potent chemical defences such as formic acid, and they tend to be quite aggressive, plus they can often recruit similarly well-armed nest mates.”
Myrmaplata plataleoides, also called the Kerengga ant-like jumper, is a jumping spider that mimics the Kerengga or weaver ant in morphology and behaviour. This species is found in India, Sri Lanka, China and many parts of Southeast Asia
It’s an ant. A weaver ant to be precise, found in India and China. It’s a pretty mundane looking ant, so why am I blogging about it? Well, lets look a little bit more closely at the picture. Okay, six legs, big antenna, big eyes, three body sections, large pincers. All very ant-like. But not quite. Let’s look even closer. Those two large antennae aren’t really coming out of the ant’s head, are they? No, they look suspiciously like they emerge from the ant’s body. So maybe they’re… legs? But ants have six legs, don’t they? Well let’s leave that for the moment and look at those big eyes. If you look a bit closer at the front of the ant’s head, there seem to be more eyes that face forward. There are eight of them, in fact. Okay… eight legs, eight eyes… not very ant-like. Because this ‘ant’ isn’t an ant at all. It’s a jumping spider. A Kerengga ant-like jumper to be exact. This is what the actual weaver ant looks like:
When you look at the lengths the spiders have gone to to imitate the weaver ant, these jaws seem very cumbersome and pointless. In fact, they are so large and useless that once they are sexually mature, male Kerengga spiders stop eating altogether. But how can male spiders hide such conspicuous appendages? The solution is quite ingenious.The mimicry isn’t as perfect as that of the female jumping spider, but when their jaws are closed, male spiders look like a weaver ant carrying a small worker ant. Here’s a picture:
And now an action shot:
It's not perfect, but still a pretty good way of hiding ungainly jaws. From a distance, and maybe even at close range, the Kerengga ant-like jumper would be indistinguishable from the weaver ant. The spiders live close to ant colonies, and this offers excellent protection from predators. Though the animal world is full of excellent mimics, I have to say these spiders have got to be right up there in terms of most successful disguise.
This spider Myrmarachne Formicaria another species of jumping spider mimics how an ant looks and moves, this spider avoids being eaten by other spiders and insects waving its front two legs to make them resemble ant antennae.
Shamble’s team recorded high-speed video footage revealing that this jumping spider (Myrmarachne formicaria), also known as the ant-jumper, walks on all eight legs but repeatedly stops – just for about a tenth of a second – and raises its front two legs to make them resemble ant antennae.
Potential predators, whose visual systems are slow, cannot distinguish these stops, but do see the legs go up which, as we suggest, strengthens the mimicry show.
The spiders also walk in zigzags, just as ants do when following a pheromone trail. Most jumping spiders hop or walk forward in bursts, or haltingly. o see if the spiders do the zigzagging and leg-raising to avoid predation, the team made videos of the ant-jumpers, real ants and conventional jumping spiders as they walked along a flat surface. Then, the group showed the videos to other, much larger spiders that normally eat jumping spiders. “We made sure the predatory spider was hungry by luring it with bait,” says Beatus.