For one tiny Australian spider, somersaulting is the key to taking over ants twice its dimension.
Ants — armed with highly effective jaws and typically chemical weapons — are so harmful to spiders that fewer than 1 p.c of arachnids try and hunt the bugs (SN: 9/8/21). Excessive-speed footage now reveals that the Australian ant-slayer spider (Euryopis umbilicata) can deal with this dangerous prey by leaping over and lassoing its victims with silk.
The looking maneuver hasn’t been present in some other spider species, researchers report September 19 within the Proceedings of the Nationwide Academy of Sciences.
“This acrobatic conduct is simply fascinating. I’ve personally by no means seen this sort of looking,” says Paula Cushing, an evolutionary biologist and curator of invertebrate zoology on the Denver Museum of Nature & Science, who was not concerned within the research.
Alfonso Aceves-Aparicio, a behavioral ecologist on the Max Plank Institute for Chemical Ecology in Jena, Germany, stumbled throughout the somersaulting spiders whereas strolling residence one evening. A graduate scholar at Macquarie College in Sydney on the time, Aceves-Aparicio was intrigued when he observed darkish dots darting throughout the pale bark of a eucalyptus tree.
The dots have been tiny spiders transferring amongst ants. Instantly, one of many spiders jumped. “I believed it was making an attempt to flee an ant,” Aceves-Aparicio recollects. “However then I noticed the ant floating and I believed, woah, there’s one thing occurring right here.”
Aceves-Aparicio borrowed a high-speed digital camera to see what the spiders have been doing in better element. By slowing the motion down, he and his colleagues might see that the spiders have been in actual fact looking ants in a totally unknown method.
Most ant-hunting spiders use webs or sneak up on their prey from behind to reduce danger. However regardless of being smaller than their prey, Aceves-Aparicio’s spiders have been dealing with banded sugar ants (Camponotus consobrinus) head on. Every spider positioned itself in order that it might watch ants as they moved up the tree. As one approached, the spider flipped above its prey. As soon as within the air, the spider latched a thread of silk onto the ant.
This single tethering motion — carried out within the house of milliseconds — decided whether or not the hunt would succeed. If the tether caught, the spider then darted across the ant, deftly encircling them with extra silk and yanking them off their toes to be dragged off and consumed.
What stands out to Aceves-Aparicio and his colleagues was the approach’s effectiveness. Predators like lions and wolves are inclined to miss round 50 p.c of their meant targets. The success price of the 60 spider hunts that the researchers filmed was a staggering 85 p.c.
To Aceves-Aparicio, the invention exhibits that extraordinary behaviors can conceal in plain sight. “The message right here is to have just a little curiosity and to concentrate,” he says. “There are issues occurring in all places. We simply need to be there to search out them.”
