Northern Tree Funnel-web (Hadronyche formidabilis)

The Northern Tree Funnel-web spider is native to Australia and is part of the mygalomorph spider group. Known for its high venom level, it’s considered one of the world’s deadliest spiders. It’s part of the Hadronyche genus, which includes spiders like the southern tree-dwelling funnel-web and the Blue Mountains funnel-web.

Photo Credit: Michael Doe

Physical Description and Identification

Adults

• Size:  Being the largest member of the Atracidae family, they are 1.57 to 1.96 inches (40 to 50 mm) long.
• Color: These spiders have an overall brown body, with a glossy black carapace. Their abdomen, legs, and chelicerae are dark brown. They even possess a purplish or plum tinge on their abdomen’s dorsolateral surface.
• Other Characteristic Features: The males and females have a thinner and longer carapace than the other members of their genus. They have a lot of similarities with the Darling Downs funnel-web, another species of this genus. However, the male Northern tree funnel-web possesses a knobby spur on the shinbone or tibia of their second leg pair.

Eggs

Like most other species belonging to the Australian funnel-web family, they too have round or oval-shaped eggs enclosed in a pillow-shaped sac.

Spiderlings

The spiderlings eventually go on their own once they attain maturation.

The Web

As their name suggests, and like most other spiders of their family, they too build funnel-shaped webs, serving as burrows to trap the prey.

Are Northern Tree Funnel-web Spiders Venomous?

Yes, Northern Tree Funnel-web spiders are venomous and are known for having one of the most potent venoms among spiders. When threatened, both male and female Northern Tree Funnel-web spiders quickly use their venomous fangs to defend themselves. Their venom can be harmful to humans, with symptoms like pain, high blood pressure, and nausea appearing within 15-20 minutes of a bite. The antidote for the Sydney funnel-web spider bite also works for this spider.

Can Northern Tree Funnel-web Spiders Bite?

Yes, Northern Tree Funnel-web spiders can bite. While rare, their bite can be harmful, so caution is advised if encountered.

Ecological Importance and Behavior of Northern Tree Funnel-web

These spiders play a critical role in the ecosystem by managing the populations of their prey, which includes tree frogs, geckos, and various insects. By exerting this predatory pressure, they maintain a balance within the food web of their forest habitats.

Natural Predators: They are hunted by small mammals, reptiles, and birds, which helps control their numbers and supports the biodiversity of their ecosystems.

Prey-Predator Dynamics: As predators, northern tree funnel-web spiders contribute to keeping the insect and small vertebrate populations in check, while as prey, they are a part of the diet for larger animals, showing their integral role in the ecological food chain.

Relationship with Humans: Although their venom is potent, encounters with humans are rare, and bites are infrequent. They prefer to retreat rather than confront, and while their presence can be alarming, they are an essential component of the natural environment.

Quick Facts

Did You Know

• William Joseph Rainbow, an arachnologist and entomologist described this spider first in the year 1914 in the Atrax genus.
• A part of its name, formidabilis, means terrifying in Latin, justifying its ferocity well.

In summary, the Northern Tree Funnel-web spider’s existence highlights the delicate balance of nature, where each species has a role to play, from the silent spinning of webs to the dramatic impact of venom.