The Italian Almanac


Italian Science - November 3

An extensive study by Turin University's Animal Biology Department has shown that spiders could be a strong marketing point for Italian vintners, faced with an increasingly 'green-minded' public. First and foremost, spiders act as natural 'insecticides' devouring insects that feed off grapes and destroy the crop.

The study showed that a healthy colony of spiders living in a hectare of vineyard were able to eliminate some 20 million insects - weighing in at around seven kilos - over the course of a growing season. Secondly, a flourishing spider population indicates a healthy, pollution-free environment, as arachnids are sensitive to their surroundings and steer well clear of areas that have been doused in chemicals.

The study - which ran from spring through to autumn, as spiders don't spin webs in winter - kept track of almost 2,000 webs. A complex method of identifying how different webs were created revealed that Italy's vineyards were popular homes with nine of the country's 14 species of web-spinner. The study showed that the denser the inter-vine foliage, the more webs there were. Grass, leaves and small plants provided the perfect microhabitat for spiders. These, in turn, helped keep the vineyard healthy and insect free.

There are around 1,400 species of spiders living in Italy. All but one - a distant relation of the Black Widow, whose bites cause fever, nausea and dizziness - are entirely harmless to humans.