Trekking Through the Jungle
As you are tramping through the jungle, you see all sorts of amazing creatures. Every now and then, though, you see something that really takes you by surprise. This little ‘insect’ was definitely the surprise on this occasion.
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The Ant on the Leaf
As I was brushing past a bush, I noticed an ant on one of its leaves. It was about the right size, shape and colour of the other ants we had seen around, but something looked slightly off about it. I turned back for a closer look.
A Very Convincing Mimic
The number of legs were the first thing that gave the ‘ant’ away. Ants are insects, and all insects have six legs. I counted again, and this particular critter had eight! Arachinds have eight legs… And, with one look at its face and its cute, forward-facing eyes, I realised I was staring at a jumping spider.
Why would a spider mimic an ant?
Ant-mimicking spiders may be mimicking an ant because either:
1. Ants can be quite aggressive and unpleasant, and some spiders lack strong defences of their own. The spiders make use of their resemblance to well-defended ants to avoid being attacked by their predators, some of which may also be ants. This is called Batesian mimicry. A great example of this is a study which showed that praying mantises (a predator of jumping spiders) avoided both ants and the ant-mimicking jumping spiders, but would quite happily predate the ordinary jumping spiders which didn’t resemble ants. Check out our references below for the full paper.
2. The spiders might be predators of ants, so they disguise themselves as ants in order to successfully approach their prey. This is called aggressive mimicry.
As for which type of mimic ours is, we’re not entirely sure. We have read that ant-hunters often do not visually resemble ants very closely. Our spider’s chelicerae (the mouth-parts it uses to ‘bite’) are large compared to some of the other ant-mimicking spiders we’ve seen online. Does this mean it doesn’t resemble an ant as much? Are big chelicerae for hunting aggressive ants?
If you can shed any light on this for us, please let us know in the comments!
Want to Read More?
Check out another of our invertebrate posts, this time from New Zealand:
References and Further Reading
Nelson, X.J., Jackson, R.R., Edwards, G.B. & Barrion, A.T. (2006) “Living with the enemy: jumping spiders that mimic weaver ants”. The Journal of Arachnology 33: 813–819. PDF here.
Nelson, Ximena; et al. (April 2006). “Innate aversion to ants (Hymenoptera: Formicidae) and ant mimics: experimental findings from mantises (Mantodea)”. Biological Journal of the Linnean Society. 88 (1): 23–32. Read the paper here.
Wikipedia Website – Ant Mimicry – https://en.wikipedia.org/wiki/Ant_mimicry
(Retrieved 5 December, 2017)