There are around 45,000 species of spider in the world, all of them carnivorous, with one exception – Bagheera kiplingi, a jumping spider known for feeding almost exclusively on plants.
Native to the forests of Central America and Mexico, Bagheera kiplingi is only 5-6mm long and spends most of its time on the old leaves of acacia trees, waiting for their opportunity to snatch their favorite meal – the Beltian bodies that grow on the very tips of young acacia leaves. There is only one problem, in order to gorge on their meal of choice, these tiny jumping spiders need to go through a gauntlet of aggressive ants that also feed on Beltian bodies, quickly clip it off with their fangs, and then run away to a safe place to feast on it. Rich in lipids and proteins, Beltian bodies are very nutritious for insects, but extremely unusual for arachnids, the vast majority of which are carnivorous.
Photo: Maximilian Paradiz/Flickr
“Competition in the tropics is pretty fierce so there are always advantages to doing what someone else isn’t already doing,” Professor Robert Curry, from Villanova University, Pennsylvania, told BBC News. “They are jumping spiders, so they don’t build a web to catch food, so they have to catch their prey through pursuit. And the Beltian bodies are not moving – they are stuck – so it is a very predictable food supply.”
The herbivorous diet of Bagheera kiplingi spiders was first discovered in Costa Rica in 2001 by Eric Olsen from Brandeis University, and confirmed in 2007 by Christopher Meehan, an undergraduate student at Villanova University. It was an unusual discovery, as experts knew that some spider species supplemented their carnivorous diet with some pollen or nectar, but this tiny jumping spider went straight for veggies, only occasionally trying some ant larvae.
Just because it doesn’t hunt other living creatures for sustenance doesn’t mean that Bagheera kiplingi spiders have it easy. Every time they go after a Beltian body, they have to get past aggressive ants that have a symbiotic relationship with acacia plants. They provide protection, swarming to attack invaders, and in return, they get all those protein-rich Beltian bodies for themselves.
“The spiders live on the plants – but way out on the tips of the old leaves, where the ants don’t spend a lot of time, because there isn’t any food on those leaves,” Professor Curry explained. “And they wait for an opening – they watch the ants move around, and they watch to see that there are not any ants in the local area that they are going after. And then they zip in and grab one of these Beltian bodies and then clip it off, hold it in their mouths and run away.”
Bagheera kiplingi, the world’s only vegetarian spider, is just one of the many fascinating insects we featured on Oddity Central over the years. For example, did you know that the petroleum fly is the only insect that develops in crude oil? Or that the scorpion beetle is the only insect capable of inoculating toxins through its antennae?
