JUMPING SPIDERS: the SILER genus


Siler collingwoodi
Siler collingwoodi

In H.K., at least two different species of the Siler genus – Siler cupreus and Siler collingwoodi are known. However, I usually see the S. collingwoodi on my walks. They are very small spiders, with the males being about 4 mm long and the females about 6 mm. They are also amazingly pretty and colourful, with striking orange and blue patterning with reflective metallic iridescent gleam that many spiders also exhibit.


Sub-adult male showing the striking colouration
Sub-adult male showing the striking colouration

The iridescence shows particularly on the juveniles of this species, with their almost black but gleaming colouration.


Juvenile
Juvenile

The females are usually a little less colourful than the males.


Female – less colourful, no setae and thin palps.
Female – less colourful, no setae and thin palps.

It is relatively easy to see the difference between males and females apart from looking at colour, as the males have very hairy, fringed forelegs (the hairs are known as setae). Those fringed arms also help with their courtship displays to the females.


Males also have big fluffy white pedipalps (the little appendages on the front of the spiders, also commonly referred to as palps). Interestingly, when you are looking at sex differences in any jumping spiders, the males store their sperm in their palps, so bulbous palps usually signify the spider is a male.


Male spider with the setae on the forelegs and bulbous palps displayed.
Male spider with the setae on the forelegs and bulbous palps displayed.

The other observable factor that particularly characterizes this spider is that they raise their forelegs up in the air when they are stopped, or when they encounter another spider or insect. So many photos will show them with raised forelegs. They also move very fast and erratically, with lots of stopping and starting, particularly the males.


One of the things that these spiders are known to eat are #ant_larvae. I often see them scurrying after ants on the railings and following the worker ants around. I have observed them predating on adult ants and other small insects as well.


Female spider predating on an ant worker
Female spider predating on an ant worker

One curious thing Siler have been described to do, is biting ants on the end of their abdomen. I actually saw a juvenile Siler doing this to some ants that were resting on the railing. The juvenile is about 3mm long. It approached them, bit one on the abdomen, then scurried a distance away. The ant reacted but did not move, so eventually the Siler moved off.


Approaching for the bite and then moving off – sadly I did not record the actual bite!
Approaching for the bite and then moving off – sadly I did not record the actual bite!

I also have several times watched two males approach each other – they raise up their forelegs, their palps move up and down at speed and they bob their abdomens up and down vigorously. They do much the same to their reflection in the camera. See the photo of the Siler with his camera reflection where he jumped onto my camera, and I watched him displaying into the lens. I had to take that photo with my phone camera!


This photo gives a great idea of size with my fingers there as comparison, as well as showing the spider displaying to himself.
This photo gives a great idea of size with my fingers there as comparison, as well as showing the spider displaying to himself.

They are lovely spiders to look out for, but to see the amazing details you need magnification of some sort – at the least, a phone camera on zoom will help you see these amazing little spiders.


Introduction of Sasha Haldane


I have lived in HK for a long time, but it is only in the last year that I have started to appreciate what amazing creatures we have in our country parks. I started taking photos so that I could spend lots of time outside and now I am learning so much about Hong Kong’s amazing micro world. I particularly concentrate on handrail ecology and my favourite subjects for photographs are jumping spiders. I now go out to photograph Hong Kong’s arthropods a few times every week.


If you would like to see more of my photos I post every day on my Instagram account. I can be found at @haldanesasha.