Famiglia: ARANEIDAE

Nome comune:

Nome scientifico: Zilla diodia (Walckenaer, 1802)

Global distribution (WSC 2021): North Africa, Europe, Turkey, Caucasus, Russia (Europe, West Siberia), Iran

GPS (Neapolis):

37.077391, 15.279792

37.078101, 15.281047

37.074942, 15.276348

Caratteristiche anatomiche: Araneide fra i più piccoli osservabili in Sicilia, raggiunge lunghezza del corpo di soli 3 mm nei maschi e 4,5 mm nelle femmine. Peculiare di questo ragno è il disegno sull’opistosoma (parte posteriore del corpo) costituito da una macchia bianca in alto, delimitata da un contorno nero, due macchie laterali al centro scure ed un disegno scuro a foglia terminale.

Comportamento: Ragno diurno, costruisce una ragnatela orbicolare molto fitta, con 50 raggi, al cui centro sosta attendendo le prede.

Anatomical features: one of the smallest Araneidae to be seen in Sicily, its body length is only 3 mm in males and 4.5 mm in females. A peculiarity of this spider is the pattern on the opisthosoma (rear part of the body) consisting of a white spot at the top, bordered by a black outline, two dark lateral spots in the centre and a dark terminal leaf pattern.

Behaviour: A diurnal spider, it builds a very dense orbicular web with 50 spokes, at the centre of which it stops to wait for prey.

I would be very astonished if a tailor made a suit that fit me without taking my measurements or first fitting me with it. I would assume that he had obtained my correct measurements from his own body, because all human bodies look alike on the whole. Because of this fact, ready-to-wear suits can fit one; they reproduce the normal proportions of the human body in various sizes. Every tailor's shop, therefore, is a gallery of hollow shapes of the human body.
In the case of the spider, however, these prerequisites do not occur — and yet, it is possible for the spider successfully to fit the web to the hollow shape of a fly. It uses this hollow shape not in the fly's interest, but to destroy it. In the spider's Umwelt the web represents a meaning-utilizer of the meaning-carrier 'prey'.
The meaning-utilizer is attuned exactly to the meaning-carrier, so that one can designate the spider's web as an image of the fly.
The spider as tailor reproduces the fly's image without the human tailor's tools. The spider cannot take measurements of its own body to build the web, because its shape differs completely from the fly's shape. Nevertheless, it spins the size of the mesh to accord with the size of the fly's body. It measures the strength of the web's threads to resist the force of the insect in flight. The radial threads of the web are spun tighter than its circular threads, which yield slightly, enclosing the fly and entangling it in their sticky droplets. The radial threads are not sticky; they serve the spider as the shortest route to the captured prey. The fly is then rendered powerless by a web the spider spins around it.
Spiders' webs are mostly to be found in 'runways' of flies.
A special miracle is that the threads of the web are so finely spun that the construction of the fly's eye is too crude to perceive them, and the fly plunges without warning to its own destruction. In an analogous manner and completely without warning, we drink water that contains invisible cholera germs.
The web is truly a refined work of art that the spider has painted of the fly.
But stop! That is not what the spider does at all. It weaves its web before it is ever confronted with an actual fly. The web, therefore, cannot represent the physical image of a fly, but rather it is a representation of the archetype of a fly, which does not exist in the physical world.
…
An original program exists both for the fly and the spider. And I would maintain that the fly's original program (or 'archetype') influences the original program of the spider in such a way that the spider's web can be called 'fly-like' (fliegenhaff).
Behind a curtain of natural events, the various programs or archetypes are linked by a comprehensive meaning-plan.
In individual instances, it is enough to trace out the articulation between specific meaning-utilizers and specific meaning-carriers so as to gain an insight into the web of the Umwelts (Umweltgewebe).

Jakob von Uexküll, “The Theory of Meaning,” 1982

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