Enchanted forest and spiders – amazing phenomena of spider aggregation

Its already few years that we see a special phenomena of aggregation of spiders of the family Tetragnathidae (although you can see few other spider families – but not a s common as the Tetragnathidae) that utilize a population explosion of midges and other insects that emerge from the nutrient enriched treated sewage water in Soreq stream near Jerusalem wastewater treatment facilities in autumn

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Pictures by Igor Armiach

The Tetragnathids have a fast numerical response – mainly demographic response (reproduction) to the prey outbreak but probably also some aggregation response

It seems that the mesh covering the plants is mainly due to drag-line of the juvenile spiders emerge from the egg-sacs, as well as of the adults and possibly some collapse of the orb-webs used for hunting by those spiders

Yet now the spiders do not build any more orb-webs in this site and hunt the midges from the silk covers the plants. Many species in the family Tetragnathidae  have high tolerance to their kin or con-generic individuals and many are known of their aggregations around water, rivers etc.

This year, thanks to a very nice post of Oren Auster (in Hebrew),The Arachnid National Collection was contacted by the press. The Arachnid lab, and especially PhD students Igor Armiach and Shlomi Aharon, were occupied all this week with the press

Reuters (In English) interviewed Igor Armiach, who became a celeb of many news channels all around the globe in few days. See the Video in English

Here are some top links in English

What a tangled web spiders weave in Jerusalem enchanted forest6

What a tangled web spiders weave in Jerusalem enchanted forest7

What a tangled web spiders weave in Jerusalem enchanted forest8

What a tangled web spiders weave in Jerusalem enchanted forest9

What a Tangled Web Spiders Weave in Jerusalem Enchanted Forest10

What a tangled web spiders weave in Jerusalem enchanted forest11

What a tangled web spiders weave in Jerusalem enchanted forest12