Giannis Giannakopoulos posted this video of the spider web to YouTube.
The genus covers hundreds of species which are found all over the world, although most occur in the tropics and subtropics.
With the growth of the gnat population, the spiders also thrive and multiply.
Thankfully, the webs won't be around to menace the people of Aitoliko forever, according to Maria Chatzaki, a professor of molecular biology and genetics at Democritus University in Thrace, Greece. "It's the ecosystem's natural reactions and once the temperatures begin to drop and the gnat populations die out, the spider populations will decrease as well".More news: Former FBI official Andrew McCabe has book deal
It was likely that abundant food, high temperature and sufficient humidity had provided the ideal conditions for a large number of the spiders to come together to mate.
Neither the gnats nor these spiders are risky to humans.
Wildlife experts say it's not uncommon for spiders to build massive nests for mating, especially when it's hot and humid toward the end of summer.
The tiny spiders don't pose a danger to area humans or plants, Chatzaki told NewsIt, though their rising numbers may be linked to an increase in mosquito populations. "They mate, they reproduce and provide a whole new generation", Chatzaki told the Greek news site, according to a translation from the BBC.