Excessive-speed cameras have revealed the extraordinary searching strategy of the Australian ant-slayer spider, which is extremely profitable and considered distinctive
19 September 2022
The ant-slayer spider of Australia has a unprecedented searching approach that entails leaping over its a lot bigger prey, high-speed images has revealed.
“To our data, it’s distinctive,” says Alfonso Aceves-Aparicio, who’s now on the Max Planck Institute for Chemical Ecology in Germany.
Whereas Aceves-Aparicio was at Macquarie College in Sydney, he seen the weird behaviour of ant-slayer spiders (Euryopis umbilicata) on bushes on the campus at night time.
“I noticed an ant climbing on the tree trunk, and I noticed one thing taking place actually quick,” Aceves-Aparicio says.
He initially tried filming the behaviour together with his cellphone, however capturing all the small print required a high-speed infrared digital camera.
The spiders’ foremost prey is the banded sugar ant (Camponotus consobrinus), which climbs eucalyptus bushes after nightfall to forage. The physique size of the ants is twice that of the spiders.
A searching spider attaches itself to the trunk of the tree with a single silk line after which lies in look forward to the ants, dealing with downwards. When an ant comes shut, the spider jumps and use its hindmost pair of legs to connect the silk line to the ant – a transfer that takes lower than a tenth of a second. The spider doesn’t cease there, however as an alternative somersaults over the ant and downwards.
It finally ends up dangling from the road beneath the ant and properly out of its attain. The spider then grabs maintain of the tree trunk and circles across the ant to completely entangle it within the silk line, solely transferring in for the kill as soon as it’s protected.
So far as Aceves-Aparicio and his colleagues are conscious, this behaviour has by no means been described earlier than in any spider. The approach permits the spider to seize massive and harmful prey with little threat – the staff by no means noticed any spiders being injured.
It’s also extraordinarily profitable, succeeding in 87 per cent of the makes an attempt noticed by the staff. That could be a a lot greater success charge than that of predators akin to lions, wolves and cheetahs, whose assaults succeed lower than half the time.
One other animal that hunts ants on tree trunks, the feather-legged murderer bug, has successful charge of simply 2.5 per cent.
“They succeed quite a bit, past different predators,” says Aceves-Aparicio.
Journal reference: PNAS, DOI: https://doi.org/10.1073/pnas.2205942119
Extra on these matters: