Marang Trail - The Magic Of Spiders At Night

3:02 PM  , , , , , , ,  

Marang Trail
South, Singapore
February 2015

Ant Mimicking Spiders (Myrmarachne)


This Myrmarachne Spider avoids being eaten by predators by appearing like an ant rather than a spider. This defense is two-way: Ants are not as palatable as spiders to most general predators, and spider-specialized predators might not recognize these spiders as food.


For mimicry to work optimally, though, spiders must inhabit places with plenty of ants. Not the easiest task, since ants eat spiders. And the poor vision of ants helps. Because these ant-mimicking spiders do not smell like spiders, nor do they smell like ants. In fact, they do no smell like anything at all - They are stealth spiders!

Another one spotted hiding in a curved leaf strung together by its web - See the intricate outlay of threads just to hold the leaf together?
 

Pale Spitting Spider (Scytodes pallida)

The Pale Spitting Spider (Scytodes pallida) has a unique habit of spitting a glue-like and possibly toxic substance at its prey to render them immobile prior to envenomation. Behavioural studies demonstrate that the spider regulates its spit expenditure when offered prey of variable sizes and struggling intensities. 


Moving about on a plant with leaves devoured by grasshoppers into artistic patches, this Sac Spider spreads its long legs over the gaps to balance itself...
 

Though it is produced in venom glands in the chelicerae, the fluid contains both venom and spider silk in liquid form. The venom-impregnated silk not only immobilizes prey such as Silverfish by tying it down, but has a venomous effect as well. In high-speed moving pictures, the spiders can be observed swaying from side to side as they "spit", catching the prey in a crisscrossed "Z" pattern. It is crisscrossed because each of the chelicerae emits half of the pattern. The spider usually strikes from a distance of 10–20 mm and the whole attack sequence is over in a little under 1/700th of a second. After making the capture, the spider will typically bite the prey with venomous effect, and wrap it in the normal spider fashion with silk from the spinnerets.

  

Orb Weavers (Araneidae)

The typical orb-weaver spiders (family Araneidae) are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields and forests. Their common name is taken from the round shape of this typical web, and the taxon was formerly also referred to as the Orbiculariae. However, orb-webs are also produced by members of other families.




Orb-weaving spiders make their webs at night time and usually take them down in the morning. They eat the silk, leaving only the base line to rebuild on. Constructing the web uses a lot of the spider's energy due to the large amount of protein required, in the form of silk and after a time the silk will lose its stickiness and becomes inefficient at capturing prey. Eating their web is a way for the spider to recoup some of the energy used in spinning. The silk proteins are thus "recycled".

An orb-weaver with some web debris and an egg pod on its web...


An  Argiope versicolor (Multi-coloured St Andrew's Cross Spider) flexing itself on its web without its trademark "X"...

A male Argyrodes flavescens (Red Silver Spider) on its own web for once...

Comb-Footed Spiders (Theridiid) are entelegyne (have a genital plate in the female) araneomorph ecribellate (use sticky capture silk instead of woolly silk) spiders that often build tangle space webs and have a comb of serrated bristles (setae) on the tarsus of the fourth leg.

The large golden orb-weavers (Nephilidae) and the long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are indeed closely related to them, being part of superfamily Araneoidea. Their webs are similar to those of the typical orb-weavers, but tend to be less sophisticated and often have an irregular instead of a neat spiral arrangement of the prey-capturing threads.


Members of the species Tetragnatha are stick-like spiders with long legs and well-developed jaws. They build delicate orb-webs with open hubs. The webs are suspended horizontally or in an inclined plane. The male jaws are particularly elongated and are equipped with a spur each. These are instrumental in locking the jaws of the female during mating.


Like many species of the superfamily Araneoidea, Nephila Spiders have striped legs specialized for weaving (where their tips point inward, rather than outward as is the case with many wandering spiders). Their contrast of dark brown/black and green/yellow allows warning and repelling of potential predators to whom their venom might be of little danger.

A Nephila Spider with its freshly-caught dinner...

Golden orb-weavers reach sizes of 4.8–5.1 cm (1.5–2 in) in females, not including legspan, with males being usually 2/3 smaller (less than 2.5 cm, 1 in). They are also the oldest surviving genus of spiders, with a fossilized specimen known from 165 million years ago.

The intricate layout of colours with patches, stripes and spots...

Neoscona punctigera (Ghost Spider)

The last time that Merlion Wayfarer spotted this was in 2012, among the long grass in Punggol. At that time, it was evening, and the spider was dormant. (See "Ghost Spider - Happy Halloween!")

(File Photo)

This time round, it was refreshing to note how active it is at night. Awaken from its daytime slumber, this Ghost Spider was moving about. With its flexible joints, one gets the impression that it is sorting out how not to stumble over its own legs.


Waving its long legs about to increase the perception of its body size - A sign of aggression... 


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