Heterometrus silenus, also known as New Zealand arboreal tiger spider, is a species of arboreal (tree-dwelling) tiger spiders that can be found in New Zealand. It is also called ‘The Stealthy Predator’ because of its unique ability to conceal itself by blending into the background to ambush its prey. Heterometrus Silenus are small to medium-sized arboreal (tree dwelling) tiger spiders that have a brown or yellowish-brown carapace with whitish areas and markings. They have six eyes instead of eight like other Araneidae, which makes them look different from others. These beautiful little creepy crawlers are endemic to New Zealand and they are present only in the islands of North, South, and Stewart. They live mostly in old-growth forests with abundant native plants and trees like kahika, rimu, harakeke, maiota, hekanaka taw

What does Heterometrus silenus look like?

Heterometrus silenus is a species of small to medium-sized arboreal tiger spiders that can be found in New Zealand. It is also called New Zealand arboreal tiger spider because it can be found only in New Zealand and nowhere else. A female New Zealand arboreal tiger spider measures approximately 14–21 mm in length, with a male measuring 10–16 mm. The carapace of these arboreal tiger spiders is brown or yellowish-brown with whitish areas and markings. They have six eyes instead of eight like other Araneidae, which makes them look different from others. The first pair of legs are shorter than the rest and are used for grabbing prey and holding onto branches. The second pair of legs is thicker and longer than the rest and are used for climbing. The third pair of legs are thinner than the rest and are used for walking.

Heterometrus Silenus Scientific Classification

Kingdom – Animalia Phylum – Arthropoda Class – Arachnida Order – Araneae Family – Theraphosidae Genus – Heterometrus Species – H. silenus

Lifespan

The lifespan of Heterometrus silenus depends on the conditions in which they live. In captivity, Heterometrus silenus can live for 4-7 years; in the wild, they can live for only 2-3 years.

Heterometrus Silenus Habitat

These arboreal tiger spiders prefer old-growth forests with abundant native plants and trees like kahika, rimu, harakeke, maiota, hekanaka and taw. They can also be found in other types of forests or shrubs and can sometimes be seen on grasses. They build their webs in the upper parts of trees and shrubs, where they are in a favorable position to sneak up on prey or to catch insects flying by. They usually build their webs at the end of branches, or on the underside of leaves like the silver tree fern or the nikau palm.

Diet

Most of their food is obtained by ambush. They are mostly nocturnal predators that hunt in the dark and wait for their prey to pass by. They are also known to hunt in the day, when their prey is less active. They prefer to hunt for spiders and insects, but sometimes also feed on nectar, pollen, and fruits. There have also been some reports of Heterometrus silenus eating small lizards.

Interesting Facts About The Heterometrus silenus

• Heterometrus Silenus are small to medium-sized arboreal tiger spiders that have a brown or yellowish-brown carapace with whitish areas and markings. • They have six eyes instead of eight like other Araneidae, which makes them look different from others. • The first pair of legs are shorter than the rest and are used for grabbing prey and holding onto branches. • The second pair of legs is thicker and longer than the rest and are used for climbing. • The third pair of legs are thinner than the rest and are used for walking.

Why are they called ‘arboreal tiger spider’?​

Heterometrus silenus is called ‘arboreal tiger spider’ because it can be found only near trees in the New Zealand forests. The New Zealand arboreal tiger spider has eight legs like a tiger, and it can climb trees like a spider. Other arboreal tiger spiders found in New Zealand include Grammostola porteri and Cytaea rasta. The Grammostola porteri is known as the ‘forest tropical species’ and Cytaea rasta is known as ‘forest temperate species’.

How do they camouflage?​

Heterometrus silenus is a very good camoufleur. It can even trick the eyes of birds looking for food. The camouflage of Heterometrus silenus is not just limited to its colour. It also has special patterns on its body that help it to blend in with the tree bark. It has whitish areas on its carapace, which look like spots of lichen growing on a tree bark. The underside of its abdomen has a pattern that looks like a broken line of bark that is not continuous. It also has white spots on its legs, which look like seeds falling from the tree.

Conclusion

These arboreal tiger spiders are endemic to New Zealand. They can also be found in other types of forests or shrubs and can sometimes be seen on grasses. Heterometrus silenus are very good camoufleurs and can even trick the eyes of birds looking for food. They build their webs in the upper parts of trees and shrubs, where they are in an advantageous position to sneak up on prey or to catch insects flying by. They usually build their webs at the end of branches, or on the underside of leaves like the silver tree fern or the nikau palm. These arboreal tiger spiders have six eyes instead of eight like other Araneidae, which makes them look different from others. The first pair of legs are shorter than the rest and are used for grabbing prey and holding onto branches. The second pair of legs is thicker and longer than the rest and are used for climbing.