A spider that dines almost exclusively on plants has been described by scientists.
科学家发现了几乎仅以植物为食的蜘蛛。
The spiders have to dodge ants to get to the leaf tips
It is the first-known predominantly（优越地，卓越地） vegetarian spider; all of the other known 40,000 spider species are thought to be mainly carnivorous（食肉的）.
Bagheera kiplingi, which is found in Central America and Mexico, bucks the meat-eating trend by feasting on acacia（洋槐） plants.
The research is published in the journal Current Biology.
The herbivorous spider was filmed on high-definition camera.
Running the gauntlet
The jumping arachnid（蜘蛛，节肢动物）, which is 5-6mm long, has developed a taste for the tips of the acacia plants - known as Beltian bodies - which are packed full of protein.
But to reach this leafy（多叶的，叶状的） fare（食物，费用）, the spider has to evade（逃避，躲避） the attention of ants, which live in the hollow spines（脊柱，脊椎） of the tree.
The ants and acacia trees（刺槐） have co-evolved to form a mutually beneficial relationship: the aggressive ants protect the trees from predators, swarming to attack any invaders; and in return for acting as bodyguards, the ants get to gorge（狼吞虎咽，塞饱） on the acacias' Beltian bodies themselves.
But the crafty Bagheera kiplingi has found a way to exploit this symbiotic relationship.
One of the study's authors, Professor Robert Curry, from Villanova University, Pennsylvania, told BBC News: "The spiders basically dodge（躲开，躲避） the ants.
"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."
But when they get hungry, the spiders head to the newer leaves, and get ready to run the ant gauntlet（铁手套）.
Professor Curry said: "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.
"And then they retreat to one of the undefended parts of the plant to eat it."
Like other species of jumping spider, Bagheera kiplingi has keen eyesight, is especially fast and agile（敏捷的，灵活的） and is thought to have good cognitive skills, which allows it to "hunt" down this plant food.