A variety of spider species built on one another's work to create a sprawling web that blanketed hundreds of yards of trees and shrubs at a North Texas park, according to entomologists who studied the unusual formation.
Heavy rains early this summer created prime feeding conditions for the spiders, which worked collectively to spin a web that nearly covered a pond ripe with mosquitoes and other insects.
"Normally they are cannibalistic and their webs are separated," said Allen Dean, a Texas A&M University entomologist. "They live in harmony because there's so much food available."
The web covered 180 metres along a trail at Lake Tawakoni State Park, about 72 km east of Dallas. The August discovery of the massive web spurred debate among entomologists about its origin and rarity.
Mike Quinn, a biologist for the Texas Parks and Wildlife Department, collected spiders from the trees and sent them to Texas A&M.
Dean studied 250 specimens and identified 12 families of spiders in the same web. He said the most prevalent type is from the tetragnathidae family, which typically weave individual orb-shaped webs.
Arachnid expert Hank Guarisco, of Fort Hays State University in Hays, Kan., travelled to Texas to take a look for himself. He camped at the park, observing the spiders at night because some of them are nocturnal.
He said he was impressed with the variety of spiders contributing to the web.
"Tetragnathidae are usually solitary spiders who build their own webs and mind their own business," he said. "Here they are sharing a lot of foundation strands that are all over the place. They don't have individual webs anymore."
Heavy rain and wind have weighted or torn down much of the web, park volunteers said.
Researchers said the spiders are still weaving fresh webs between storms. Quinn said there continue to be lots of egg sacks, which can hold dozens or hundreds of eggs.
"The continuing number of egg sacks suggests high productivity, as biologists say," Quinn said.
"The females are fat and happy so to speak. They have done well so far by laying so many eggs that the spiders continue to prosper."