Overview
- The discovery, reported Monday and Tuesday, describes a Propostira sp. in north Queensland that constructs a conical, spring-actuated snare nicknamed the ballista spider.
- Field teams observed the nocturnal spider spend up to four hours building an anchor and 15–60 tightly bunched vertical silk tension lines that form the cone near the ground.
- High-speed video and lab tests show the trap is triggered when a green tree ant bites the cone, detaches the anchor and is flung about 30 centimetres into the main web with measured accelerations up to roughly 1367 m/s² (about 130 g).
- Researchers suspect the spider applies a chemical lure that specifically attracts and provokes green tree ants, but the compound has not yet been chemically identified and the species remains undescribed.
- Biomechanical analysis indicates the snare stores and releases elastic energy with greater instantaneous power density than other known silk catapults, and follow-up work will test how widespread the tactic is and complete the spider's formal description.