The green tree ant, *Oycophylla smaragdina*, is not easy to catch, known for its ferocity and aggressive behavior. These arthropods possess a powerful bite and can spray defensive acids. Therefore, it's no surprise that few predators dare to hunt them, but scientists have recently discovered a spider brave enough to do just that.
This newly discovered species, found in the tropical rainforests of northern Queensland, Australia, specializes exclusively in trapping this type of ant. It achieves this by weaving a clever and powerful trap that uses a spring-loaded mechanism to store energy and then release it, propelling the ants directly into its web at tremendous speeds.
This trapping system is unprecedented in spiders. The discovery of this previously undescribed species, which is likely a new and exciting species, was announced in a recent study published in the journal Current Biology, which provided a detailed description of the trapping strategy and its mechanical characteristics.
Exceptional trap engineering
This tiny night spider was first spotted by biomedical scientist Professor Greg Anderson of the QIMR Berghofer Institute for Medical Research in Brisbane, Australia, who is also a wildlife photographer. In 2022, while working in the rainforests of Australia's Cape York Peninsula, the spider taxonomist came across a sight that made him double-check what he was seeing: it appeared to be a spider trapping a green tree ant.
During the day, the tiny, earthy-colored spider, no larger than a small coin, shelters on the undersides of leaves above an area where green tree ants are active in search of food. As darkness falls, it slowly descends from its web by means of a silk thread, a distance of about 50 centimeters, until it finds a suitable structure—a leaf, a twig, or even the forest floor—to which it attaches its base.
It then returns to the main web, leaving behind what could be described as a "tension thread," and repeats the process—which can take up to four hours from start to finish—with astonishing precision to build a fan-shaped web of silk tension threads. This gradually creates a long, tightly coiled, cone-shaped structure, which the spider then wraps in thinner silk threads before rapidly pulling itself upwards.
"The pivotal moment that convinced us that we were dealing with a truly unusual hunting strategy among spiders was when we first saw its web," says lead researcher Dr. Jonas Wolf, a researcher at the School of Natural Sciences at Macquarie University in Sydney, Australia. "It contained a tiny silk cone, a structure we had never seen in any other spider. From that moment, we knew we were dealing with something extraordinary."
Once the thin silken sheath is fully in place, a worker green tree ant is attracted to the trap within seconds. Upon closer inspection of the thread, the ant displays aggressive behavior, attacking it with its bites without realizing it is about to meet its fate.
In a flash, as the ant tries to free itself, the thread breaks free from the anchor point to which it was attached, and the ant is launched directly upwards for a distance of more than 30 centimeters until it reaches the main spider web in only about 42 milliseconds.
Jonas explains to Al Jazeera Net that "this process takes fractions of a thousandth of a second, which is too short a time for the human eye to distinguish its details in time. When watching the event live, you see the ant on the ground one moment, and then you see it in the next moment hanging inside the net, without being able to see what happened between these two moments."
As the ant struggles to break free, it becomes increasingly entangled in the web threads, allowing the spider to approach and envelop it in silk threads, ultimately turning it into a delicious meal for this specialized predator.
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