Subject: Beautiful Spider
Location: Manglayang Mountain, West Cibiru, West Java, Indonesia
January 26, 2013 7:43 am
Hello again Daniel,
Last Thursday I go to the abandoned cabin in the woods again where I found the wolf spider.
This guy have this interesting long stretched legs, 2 tails like on the end of it’s abdomen, and beautiful colored abdomen.
I wonder what spider is it, hope that you could help.
ps. I sent the high res images…male and female.
Signature: Mohamad Idham Iskandar
Dear Mohamad,
We are positively thrilled to receive this intriguing posting. As your email notes, there are two tails on the abdomen that are very distinctive. They are actually spinnerets, organs used by the spider for spinning silk. A spinneret is identified on BugGuide as a: “Structure at or near the tip of a spider’s abdomen which produces silk (there are normally a group of them).” BugGuide also notes: “Most spiders have spinnerets visible from only from the side or below. Prominent spinnerets visible from above help to identify the Family Gnaphosidae and the genus Agelenopsis in the family Agelenidae.” We have never seen such prominent spinnerets, and it is also very unusual that your spiders have very short lets in the third pair. We did an internet search for spiders with long spinnerets in Indonesia and found several images including this image on FlickR identified as a Two-Tailed Spider or Long Spinneret Bark Spider in the family Hersiliidae. FlickR also has another image from Panama. BioDiversity Explorer has this to say about South African Hersiliids: They “Have distinctive elongate lateral spinnerets, which are used in prey capture by swaying them over the victim thus wrapping the victim in silk. Two genera in southern Africa: Hersilia is usually found in trees and Tyrotama is usually found under rocks.
The Hersiliidae is a family of spiders noted for their elongated posterior lateral spinnerets which can be as long as the abdomen in long-spinnered bark spiders and less in rock living species. Hersiliids are small to medium (4.5-12.5mm body length) dorso-ventrally flattened spiders, especially the arboreal genera. They are cryptically coloured in variegated shades of cream, orange, green, brown, grey and black, features they share with the family Selenopidae. Both families are quick and difficult to capture as they disappear into the narrowest of crevices.” The Spiders of South India website has this information on the family: “Popularly called two tailed spider, this is common spider in southern India. It lives on tree trunks of large tress and also common on the trunk of coconut palm. Its colour closely matches that of tree trunks in which it lives. It feeds on moths, ants, and other smaller spiders. Cocoon is generally laid in the holes crevices of tress. It can be easily identified by its long spinnerets.” In trying to determine which species you have in Indonesia, we found Hersilia baliensis listed on Wikipedia, and searching that name led us to the Le Monde des Insectessite with images from Bali.
Wow thanks a lot Daniel for the ID,
they are really hard to see even though the size is relatively big about 6 to 8 cm from toe to toe,
but when I try to see closely I mean really really closely 🙂 there they are just sitting there waiting for me take photos of them and there are a lot of them it’s about 5 or 6 with different sizes.
I sent you another photo of them with different background for whatsthatbug image database and another spider with long spinnerets that I couldn’t identify because I only could take one photo of them from right side before he run away, maybe next time I’ll hunt them down for a photo session :).
