GUIDE TO COMMON SPIDERS IN BORNEO ISLAND
 

Family: Hersiliidae
Genus: Hersilia
(Long-spinnered Bark Spiders)


Species: Hersilia deelemanae

Hersilia deelemanae

♀6.5mm

ESPLANATE 23-11-2014 SUN 12:41PM



They immobilise their prey by spreading silk while jumping over and running around it.

When alarmed, the spider erects its two long spinnerets and darts to the opposite side of the tree with a movement so swift that all one can see is an apparent blurring of a part of the bark. Quick and difficult to capture as they disappear into the narrowest of crevices.

Hersiliids are small to medium (4.5-12.5mm body length) dorso-ventrally flattened spiders, especially the arboreal genera.

The oval abdomen is wider posteriorly with the posterior lateral spinnerets extending out parallel to each other. The inner edge of these spinnerets is lined with silk-producing tubules (spine-like spigots) as opposed to the distally placed spigots of most spiders.

The Hersiliidae mostly live on tree trunks with the long legs stretched out radially on tree bark or lichen-covered crags.

The Hersiliidae, commonly called long-spin or two-tailed spiders, is a smaller family comprising 7genera and 148 species worldwide of which 66species of 4 genera are known from the Oriental Region (Baehr and Baehr 1993, Platnick 2005).


Hersilia deelemanae

The Hersiliidae spiders  can easily be recognized by
1- the flattened body,
2- raised eye region,
3- the extremely long posterior spinnerets.

The above female Hersilia deelemanae has two legs half broken off (see above image)


They are cryptically colored in variegated shades of cream, orange, green, brown, grey and black.


In resting position, the flattened lichen-colored body is pressed against the tree trunk, thus blending perfectly with the surrounding bark, and casting little or no shadow to betray its presence.


Hersilia deelemanae The head region is elevated above the rest of the cephalothorax (a fused head and thorax).

As viewed from above, the carapace of cephalothorax is oval with the 8 eyes situated in two recurved rows, on a raised hump or tubercle.

The anterior median eyes are largest.


"Two-Tailed Spiders". It can be easily identified by its long spinnerets. This  genus of tree trunk spiders known as Two-tailed spiders due to their greatly enlarged spinnerets.

Their elongated posterior lateral spinnerets are disproportionately long and pointed like a pair of tail, hence the name "Two-Tailed Spiders".

This elongated posterior lateral spinnerets which can be as long as the abdomen.

This female's elongated spinnerets is 5mm while its body length is only 6.5mm


Hersilia deelemanae of Sabah ESPLANATE 23-11-2014 SUN 1:03PM

 

Hersilia deelemanae of Sabah living almost exclusively on big tree trunks. Only on large tree of smooth tree surface. 

No account of spotting this spider on oil palm tree yet. Oil palm trees were planted in large scale in Sabah at the cost of deforestation.

The spider color closely matches that of the tree trunks in which it lives. It feeds on moths, ants, and other smaller spiders.


Body length not including tails is 6.5mm.
The two tails itself are 5mm long.

The body is compressed and legs are exceedingly long (except the third pair).
 

This poor creature has two legs half broken, one on each side (see image left)


 

SPIDERS OF BORNEO

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