Cribellate Orb Weaver

Description:

Uloboridae; Zosis; Zosis geniculata (Olivier, 1789). This spotting deals with an aspect of the behaviour of Z. geniculata that I could not squeeze into https://www.projectnoah.org/spottings/20.... Of course, there is adequate space for description, habitat and Notes, but the space for pictures is limited and what I want to mention here really needs the pictures above. What I want to describe here is the style of movement which I have observed in Z. geniculata. My first impression of this species was how elegant and poised it looked when sitting at rest with its long front legs straight out in front and close together. It makes me think of is a classical pianist who will adjust his seat to be just right and then carefully sit in an upright position and reach out both hands to make sure the finger tips are just right on the keyboard, no under or over-reach, either of which would impair his ability to perform. This spider seems to display the epitome of elegance. Then when it decides to move, all the formality and grace fall away in an instant. This ancient species staggers around, stumbling and tripping at every step giving a wonderful impersonation of an inebriated man. My thoughts went from the utmost admiration to utter disappointment in a heartbeat. But, amazingly, this "drunken dance" produces an orb web which obviously works very well. If not, this species would not have survived for hundreds of millions of years. So, what's the big deal? Why did I think this worthy of a long description. Well its because suddenly, in the middle of this crazy performance, the spider returned to elegance and grace in the blink of an eye. When it decided to tidy up one of the longer "anchor lines" of the web, it suddenly stretched out to its full length and calmly glided along, doing whatever it was doing to the strand. After a moment of elegance, the wild, craziness returned. The photos above represent, obviously, the calm graceful period. I wonder if the style of movement which looks so uncontrolled (but obviously works very well) had any part in Olivier's choice of the species name "geniculata". "geniculatus" is the Latin adjective which means jointed and I think "geniculata" is part of the declension of the noun meaning "joint". Obviously, this spider has the same number of leg joints as other species, but the combination of the markings on the legs and the strange perambulation rather makes it look as though it has too many joints.

Habitat:

This Zosis geniculata was spotted, in our front garden, building a web on some plants growing up against the garden wall.

Notes:

Pictures and info: https://www.inaturalist.org/taxa/172199-...... https://www.thailandnatureproject.com/zo......