The Vegetarian spider? Well not quite but almost!

According to the Times scientists have determined that there is such a thing as a vegetarian spider. Bagheera kiplingi, a South American species, lives almost exclusively on acacia leaf buds and is thought to be the only spider of about 40,000 species to have largely rejected a carnivorous diet.

“This is the first spider known to ‘hunt’ plants as a primary food source,” said Christopher Meehan of Villanova University, in Pennsylvania, who observed the creatures, about the size of a thumbnail, on a field trip in Mexico. It must be pointed out that he didn’t actually discover the species. It was discovered in 1896 although a female of the species was not found until the 1990s.

B kiplingi is not totally vegetarian: they will sometimes eat the larvae of the ants that have a symbiotic relationship with the acacias where they live (The ants guard the trees from intruders and in return the acacia produces nodules on its leaves called Beltan bodies. These are protein and fat rich. The ants feed on them, as do the spiders). The spider will also resort to cannibalism

Despite this the discovery is a major surprise for zoologists. Before Meehan’s discovery it was that spider physiology made plant-eating impossible. “Spiders aren’t thought to be capable of eating solid food at all,” said Meehan. Normally they secrete enzymes onto their prey to digest them outside the body and then consume what’s left as a kind of soup. B kiplingi, however, eats its vegetables whole.

Ah this is utterly fascinating stuff...