Currently viewing the category: "Net-Casting Spiders"
What's That Bug? does not endorse extermination

Subject:  Four-legged Spider
Geographic location of the bug:  NSW, Australia
Date: 01/12/2018
Time: 07:19 PM EDT
Your letter to the bugman:  Hello Bugman,
Found a four-legged Spider at my fence. When I placed it in a dust pan to put outside it turned out it had 8 legs.
Is this harmful as well?
I keep seeing a lot of spiders lately.
How you want your letter signed:  Carlo

Net Casting Spider

Dear Carlo,
This is a Net Casting Spider in the family Deinopidae.  According to Atlas of Living Australia, they are reported from all over your continent.  According to Australian Museum:  “Net-casting Spiders have a unique way of catching their prey. They make a small web in the form of a net held by the front legs that can be stretched out wide to envelop an unwary insect passing by.”  That site further elaborates:  “Net-casting Spiders have stick-like bodies, with spindly legs. Members of the genus
Deinopis have a large, prominent pair of eyes at the front of the head (hence their other common name of Ogre-faced Spiders) and vary in colouring from fawn to pinkish brown or chocolate brown. Members of the genus Avella have smaller eyes and have subtle greenish brown to grey patterning. The males are smaller and even more slender and stick-like than the females, and can differ from them in their colour and patterning.”  Here is some additional information from Australian Museum:  “When at rest, the spider hangs from vegetation with its head downwards, its long body and long, thin front and back legs held together on each side, giving the spider a stick-like appearance. The spider also assumes a head-down position when it is waiting for prey, except that it now holds its net with the front four legs and suspends itself by the back legs and spinnerets from support lines to surrounding foliage. The net is a blueish-white square of wool-like cribellate silk, whose coiled lines are designed to stretch and entangle prey. In order to have an aiming point, the spider often drops splashes of white faecal droppings onto the leaf or bark substrate over which it is poised. When an insect walks across this ‘target’, the spider plunges its net downward to envelop and entangle it. If successful, the spider silk-wraps the prey item, bites and paralyses it, and then feeds on it. Net strikes will also be made at flying insects that stray too close. An unused net is sometimes stored by hanging it on nearby leaves for the next night’s hunting, or the spider may eat it.”

What's That Bug? does not endorse extermination

Subject: Spider under my pillow
Location: Durban south Africa
December 17, 2016 4:29 am
Hey bugman, I found a spider under my pillow last night and I was wondering if you can identify it for me
Signature: Shane

Ogre Faced Spider

Ogre Faced Spider

Dear Shane,
We are relatively confident we have correctly identified this leggy spider as an Ogre Faced Spider in the genus
Deinopsis from the Net Casting Spider family  thanks to images on iSpot.  According to BioDiversity Explorer:  “They are harmless to man” and “Deinopids are unique in that they actively use and manipulate a web to capture prey. First a scaffold web is constructed and attached to the vegetation over an area where prey will pass. The spider then positions itself with its head up and using a comb-like structure (cribellum) on the tibia of its hind legs, it combs out cribellate silk from a special silk-producing organ called the calamistrum. The calamistrum is a cream coloured band about 1.5 to 2 mm long and about 0.2 to 0.5 mm wide and is situated anterior to the spinnerets, viewed from below. It consists of 20 000 to 40 000 spigots (silk-producing organs), each producing a very fine strand of silk. The silk is combed out onto the normal silk strands of what will be the capture net and has a woolly appearance. In fact, the silk looks like this as it is in a relaxed form, like a relaxed rubber band and has a 400 to 600% stretch capacity. The rectangular capture net made of this crumpled silk has no adhesive capture ability but relies on entangling properties instead – much like Velcro, where the net tangles with projections on the prey’s body.
When the net is ready the spider re-orientates itself on the scaffold web with the head facing down, grasps the net by the four corners with the four front legs, gives it a few stretches, and then relaxes the net and waits for prey. For walking prey, the net is held horizontally or vertically over the substrate and when flying prey is detected, the net is flicked backwards, over the carapace, still in a vertical or horizontal position. Visual senses are used to detect walking prey such as cockroaches, ants and even spiders but vibration senses are used to detect flying insects, moths being the most common prey.
When prey is detected, the spider propels itself forward, stretching the net further and then suddenly releasing the tension, although not letting go of the net. The net contracts and ensnares the prey. Once captured, the prey is then secured further with silk fed from the spider’s spinnerets with the hind legs. While the scaffold net is reused each night, the capture net is used only once. A new capture net is constructed each evening and in the morning it is simply rolled into a ball and eaten.

What's That Bug? does not endorse extermination

Subject: What is this insect?
Location: Perth WA
February 19, 2016 10:01 pm
I found this on my fence outside, there was a spider web around it, but I’m not sure if it came from the insect or anything spider. I tried to search this insect but couldn’t find anything in relation to it, the insect has 6 legs and I’m really curious to know if it is poisonous or not. Thank you hope you can get back to me 🙂
Signature: From Christelle

Netcasting Spider

Netcasting Spider

Dear Christelle,
Though it does not appear to have a net, we believe this is a Netcasting Spider in the family Deinopidae, which is pictured on Brisbane Insects where it states:  ” The species in this family are large and slow moving spiders. They have long body and stick like legs. Their bodies are light brown or grey in colour. They do not build permanent web, instead, they hold the net and throw it towards their prey.”  The Spiders of Australia site has a Deinopidae page where it states:  “The net-casting spider is a common spider and is also often seen in documentaries because of its unique way of catching prey. The spider positions itself, head down, and grasps the rectangular capture net with its four front legs. If a walking insect is detected, the net is pushed over the victim that gets ensnared. Flying insects, like moths, are caught by flicking the web backwards.   The web is made of non-sticky cribellate (woolly) silk. Insects gets entangled in the wooly structure.  The spider relies heavily on its eye-sight. The eyes are arranged in three rows. Two of her eight eyes are extremely large.   The spider is active during the night and during the day she remains camouflaged on a tree bark. Her body length varies between 1.5 and 2.5 cm and they are light rusty brown coloured.” Your individual appears to be missing a leg.

What's That Bug? does not endorse extermination

Subject: netcasting spider
Location: costa rica Tortuguero
March 27, 2013 12:33 am
do you have the exact name for this species?
thank you
Signature: fred from belgium

Netcasting Spider

Netcasting Spider

Hi Fred,
We are unable to do any research on this Netcasting Spider at this time, but it is really a lovely photo.  Perhaps one of our readers will write in with an identification.  We would urge you to provide a comment on each of your unidentified species on our site and then you will be notified in the future if any experts provide information.

What's That Bug? does not endorse extermination

Subject: What’s this strange spider?
Location: Australia, Melbourne
February 16, 2013 12:32 am
Hi
I am from Australia, and as I opened my garage door on a hot summer day I noticed this creature on the door. Initially I thought it was a twig as it remained stationary, but it began crawling upwards once I pulled the door down; completely to my surprise. It appears to me like some kind of spider, but I can not be sure. Could you help me?
Signature: Bo

Netcasting Spider

Hi Bo,
This is a Netcasting Spider,  probably 
Deinopsis subrufa and judging from the size of the pedipalps, it is most likely a male.  The website Where Light Meets Dark has a very nice profile on this species.  More information be found on the Spiders of Australia website.  Jennifer Marohasy’s websitehas some great photos that show how the Netcasting Spider got its common name.

Netcasting Spider

Alright, thanks for the help!

 

What's That Bug? does not endorse extermination

4 legged spider
Location: Sydney, Australia
January 5, 2011 6:25 am
Hello
This has me stumped. Never seen anything like it!
Looks a bit like a spider. Hangs around on the wall like a spider.
Seems to have a thin long body and 4 legs that spread diagonally.
WTB??!
Signature: Sincerely Jonathan

Net-Casting Spider

Hi Jonathan,
We do not recognize your spider and we are posting your letter as Unidentified since we haven’t the time to research this at the moment.  Perhaps one of our readers will have some luck.  You may also try scanning through the Spiders of Brisbane webpages.  There are some spiders that rest with two pairs of legs together, creating the appearance of four legs rather than eight, and this specimen appears to be one of those.

Identification courtesy of Karl
Hi Daniel and Jonathan:
It appears to be a male Net-casting spider (Deinopidae), probably Deinopsis subrufa. You can also check out this site. Regards. Karl

Thanks Karl.  Trevor also supplied us with an identifying comment.

That’s great!  Thank you.
It does look a lot like this one:
http://www.wherelightmeetsdark.com/images/wiki/Netcasting_spider_Deinopsis_subrufa_3.jpg
I reckon that is what I saw or something very close.
Jonathan Young

What's That Bug? does not endorse extermination