Newly discovered spider uses 'ballista' web to capture prey

A newly discovered spider uses an ingenious method to launch its prey into the air, named after an ancient Roman weapon. The ballista spider was discovered in the rainforests of Far North Queensland. The spider is yet to be formally named, but belongs to the genus Propostira. Link copiedShareShare articleA bizarre species of spider from the remote rainforests of Far North Queensland springs a nasty surprise when its prey is lured into its web. The tiny and newly discovered ballista spider — named after an ancient Roman weapon that used a spring to launch a stone — uses an ingenious method to literally launch its prey into the air. A fussy eater, the spider targets a single species, the territorial and aggressive green tree ant, Oecophylla smaragdina, which it lures with a fragrant pheromone. The newly discovered species was first observed by spider taxonomist Greg Anderson. (Supplied: Macquarie University) And its hunting technique is extraordinary. First, the nocturnal spider builds an anchor point on a leaf, a branch, or the forest floor, before spending up to four hours spinning up to 60 vertical tension lines bundled together in a cone near the ground. The spider then wraps the cone with extra silk before retreating upwards. When the ant is attracted, it reacts aggressively, biting the cone — and detaching it from the anchor point. The spider builds an anchor point on a leaf, a branch, or the forest floor, before spinning vertical tension lines. (Supplied: Macquarie University) The ant is then catapulted more than 30 centimetres upwards into the spider's core web, at an acceleration of more than 1,300 metres per second. Once entangled, the spider then wraps the ant in silk to be devoured. The unique arachnid was first observed by spider taxonomist Greg Anderson, who is also an emeritus fellow at the Berghofer Queensland Institute of Medical Research. The species has been found in the remote rainforests of Far North Queensland. (Supplied: Macquarie University) Researcher professor Ajay Narendra of Macquarie University and postgraduate student Pranav Joshi then spent 10 days and nights in rainforest near Cooktown locating specimens. Using high-speed and infrared cameras, they were able to observe the spiders in detail and capture their unique hunting behaviour on film. Mr Narendra said it was extremely unusual for a spider to target such a notoriously aggressive species as the green tree ant as prey — let alone to eat that species alone. "Ants have a range of chemical defences, including the ability to sting in some species, and they use alarm signals to rapidly recruit hundreds and even thousands of other ants as backup," he said. Ajay Narendra and Pranav Joshi spent 10 days and nights near Cooktown locating specimens. (Supplied: Macquarie University) He said the ballista spider's web was the only known example designed to catch a single species, and where the mechanism was triggered by the prey rather than by the predator. It was thought that the mechanism allowed the spider to pick off the potentially hazardous prey one at a time while remaining at a safe distance from ant trails and nests. The spider is yet to be formally named, but belongs to the genus Propostira. Copy linkFacebookX (formerly Twitter)PromotionTop StoriesLabor, Greens cut deal on CGT and negative gearingTopic:Federal Government

Newly discovered spider uses 'ballista' web to capture prey

Key takeaways

More in international