The Australian Orb Weaving Spider – A Master Of Webs

0
823
australian orb weaving spider
I captured this orb weaving spider out in my garden - her colour is the same as where it hides, underneath my gutter. They have the ability to change their colour depending on their daytime hiding spots.

Introduction to the Australian Orb Weaving Spider

The Australian garden orb weaver spider (Eriophora transmarina) is a prevalent spider species with multiple variants in size, shape, and colour throughout Australia’s coastal regions.

They have very broad abdomens when well-fed and display a tremendous colour range from off-white and grey through tan and brown to virtually black. They have an unevenly leaf-shaped pattern on the top of their abdomen with an intricate outline that is darker than the encompassing area.

There may also be some whitish spots or one or more lines. The spiders’ cephalothoraxes leg (heads) and proximal (closer to the body) sections are usually darker, frequently reddish or reddish-brown.

They can switch their colour with each moult to better match the environment upon which they rest during the day. This is called a natural camouflage.

The spiders are well-known for the often large and elaborate webs that they weave at nighttime. They are generally nocturnal feeders, leaning head down in their webs, waiting to capture flying insects.

They develop their sticky, rounded orb webs near lights and amidst trees where insects are likely to pass. During the daytime, the Australian spider will often rest somewhere near the web, under a leaf or twig or in the bark or rock crevice.

They are typically found around human habitation, so they may be spotted resting under leaves and in similar positions. When disturbed or molested, they will retreat towards this rest area.

Australian garden orb weaver
Australian garden orb weaver

Though, under imminent danger, the spider will fall to the ground and “play dead”. Occasionally individual spiders will persist on the web during the day, possibly when the prey has not been taken for a while, but this makes them more exposed to bird predation.

Their spider bite or sting is not dangerous to humans but may produce mild, local pain, redness, and irregular swelling for a duration of 30 minutes up to three to four hours.
The female is bigger than the male, having a 20 – 25 mm body length compared with 15 – 17 mm for the male orb-weaving spiders.

Females may also be recognised by a needle-like epigynum (outside genital structure of female spiders) pointing in the direction of the spinnerets (a silk-spinning organ of a spider).

Classification of the Australian Orb Weaving Spider

  • It belongs to the Araneidae family of spiders
  • It belongs to the Araneae class of arachnids
  • Belongs to the Arachnida order of arthropods
  • It belongs to the Chelicerata subphylum of arthropods
  • It belongs to the Arthropoda phylum
  • It belongs to the Animalia kingdom

Scientific Species Name:

  • Leviana dimidiata
  • Philoponella (genus)
  • There are 12 species of Hackled Orb-weavers in five genera currently recognized in Australia.

Note: The group has not been revised, and there are likely to be many more species and genera.

10 Facts About The Australian Orb Weaving Spider

  1. The spiders most commonly noticed in southeast Australia belong to the genus Philoponella and have a humped appearance.
  2. Golden Orb Weaving Spiders build large and strong orb webs with a golden sheen.
  3. Garden Orb Weaving Spiders lay eggs in a nest made up of webbing.
  4. The spiderlings disperse via ballooning once they mature.
  5. The spiders spin circular webs for prey to fly into at night.
  6. Orb-weaver spiders are not very deadly and only bite when threatened.
  7. The Orb Weaver is a spider commonly found outside homes, in hedges, tall grasses, and trees.
  8. They are helpful predators who feed off pest bugs such as mosquitoes, beetles and other flying insects.
  9. The spiders are most often seen in late summer and early fall.
  10. They are native to Australia and can be found in gardens and open fields, particularly in summer. The males are small and red-brown in colour, while the females are larger, with silvery-grey to plum-coloured bodies and brown-black legs with yellow bands.

What Do Orb Weaving Spiders Look Like?

The regularly seen Garden Orb Weavers are stout, reddish-brown or grey spiders with a leaf-shaped pattern on their fat, roughly triangular abdomens, with two prominent humps towards the front. They sometimes have a dorsal stripe which may be white or brown trimmed with white.

Their Fantastical Orb Webs

Orb-weaving spiders create suspended, sticky, wheel-shaped orb webs. Webs are located in openings between trees and shrubs or structures where insects are expected to fly.

Usually, the spider builds its web in the evenings and takes it down again at dawn. The spider dozes head down in the centre of the web, pausing for prey.

Where Are Australian Orb Weaving Spiders Found

Australian orb-weaving spiders are found throughout Australia, with most records from the more populated eastern seaboard areas. They are commonly found in bushland, coastal sand dune shrubland, mangrove habitats, and around homes and gardens.

Some species, such as Eriophora biapicata and E. transmarina, are often seen as Garden Orb Weavers in eastern and southern Australia. The Garden Orb-Weaving Spider is not aggressive and typically leaves humans alone, rarely biting and carrying such low amounts of venom that they do not pose a threat to humans.

Australian orb weaving spider habitat and distribution
Australian orb-weaving spider habitat and distribution

What Do Australian Orb Weaving Spiders Eat?

They are known to snare flying insects such as flies and mosquitoes by spinning large circular webs.

Garden Orb Weaving Spiders build wheel-shaped webs in breaks between trees and shrubs where insects are expected to fly. When an insect travels into the web, the spider senses the shake or vibration, races out from the web centre and quickly wraps the victim in silk, turning it with its shorter middle legs.

When the prey is bound, the orb-weaver delivers a bite and sits back to let the deadly venom do its job. Once all movement has ended, the spider takes the meal to the centre of the web and consumes it or attaches it up for later.

When food is abundant, these spiders will free large prey rather than risk a fight that may destroy their web. Flying insects, including flies, beetles and bugs (including big prey like cicadas), are popular prey.

Australian orb weaver

Butterflies and day-active moths are sometimes taken but are partially shielded from web capture by the presence of scales on their wings. Those scales can be shed, enabling the insect to fight free of the sticky web.

What Do They Do During The Day?

During the day, the spider sleeps on nearby foliage with its legs pulled under the body.

Australian Orb Weaving Spider Reproduction

Australian orb-weaving spiders reproduce sexually, with the male spider using its palps to transfer sperm to the female during mating. After mating, the female spider will lay eggs in an egg sac, which she will often protect until the spiderlings hatch.

The number of eggs in an egg sac can vary depending on the species, but it can range from a few dozen to several hundred. The spiderlings will typically moult several times before reaching maturity and reproducing themselves.

How long do orb-weaving spiders live?

Orb-weaving spiders have an average lifespan of one to two years. Some orb weavers can live up to two years, but their life span can be reduced due to various dangers. The lifespan can also vary depending on the species.

The lifespan of the Golden Orb Weaving Spider is not specified. The optimal temperature and humidity range for orb weaver spiders to thrive is 20-28°C and 65-85%, respectively.

Predators of The Australian Garden Orb Weaving Spiders

Australian Garden Orb Weaving Spiders have several predators, including birds, lizards, and parasitic wasps. Some birds, such as thrushes and magpies, are known to prey on adult spiders, while lizards, such as skinks and geckos, may feed on spider eggs and spiderlings.

Parasitic wasps, such as the family Pompilidae, are known to lay their eggs on or near orb-weaving spiders, and their larvae will feed on the spider once they hatch. Other Australian Garden Orb Weaving Spider predators may include mammals such as possums and bats, as well as other larger spiders.

Are Australian Garden Orb Weaving Spiders Poisonous?

Australian Garden Orb Weaver Spiders are not considered to be highly venomous to humans, and bites are rare. Their venom is not usually strong enough to cause significant harm to healthy adults, but a bite can still cause mild to moderate pain, swelling, and redness.

People who are allergic to spider bites or who have a weakened immune system may experience more severe symptoms, and it is always best to seek medical attention if a spider bites you. It is a good idea to treat all spiders cautiously and avoid disturbing them.

Banded orb weaving spider
Banded orb-weaving spider

Should I kill an orb-weaver spider?

No, you shouldn’t kill an orb-weaving spider. They are relatively harmless to humans and are reluctant to bite. If you must relocate them, use a cup, gently place it over the spider, put a piece of cardboard over the cup, and set it free in a tree away from where you don’t want it.

Orbweaver spiders spin some grand webs and are not a danger to humans. While their venom is toxic to little insects, it simply isn’t going to do much more than create a red, irritated area that will feel like a bee bite for an hour or two before it passes away.

Are orb weavers native to Australia?

Yes, orb weavers are native to Australia. In fact, Australia has a high diversity of orb-weaving spiders, including many species of the genera Araneus, Eriophora, and Nephila.

The Australian Garden Orb Weaver Spider (Eriophora transmarina) is one of the country’s most commonly encountered orb weavers and is found in various habitats, from urban gardens to bushland. These spiders are well-known for their distinctive large orb webs, which they build to capture flying insects for food.

How do you move an orb-weaver spider?

If you need to move an orb-weaver spider, it is important to handle it with care to avoid getting bitten or causing harm to the spider. Here are some steps to follow:

  • Wear gloves: Wearing gloves will provide a barrier between your skin and the spider, reducing the risk of a bite.
  • Use a cup or jar: Gently place a cup or jar over the spider and carefully slide a piece of paper or cardboard under the cup or jar to trap the spider. Make sure the spider is not trapped against the sides of the cup or jar.
  • Transfer the spider: Carefully pick up the cup or jar with the trapped spider and transfer it to a new location, making sure to keep the cup or jar level.
  • Release the spider: When you reach the new location, slowly tilt the cup or jar to one side and gently release the spider by removing the piece of paper or cardboard.

It is important to remember that orb-weaver spiders play an important role in the ecosystem and should only be moved if necessary. If you do need to move a spider, make sure to release it in a safe location where it will not be disturbed or come to harm.

Further Reading

LEAVE A REPLY

Please enter your comment!
Please enter your name here
Captcha verification failed!
CAPTCHA user score failed. Please contact us!