Britain's Heaviest Spider

by Glenn Norris

Ecologist

The Four-spotted Orbweaver Araneus quadratus is Britain’s heaviest spider, coming in at a whopping 2.5 grams. As you would expect, being such a robust spider, she needs a substantial web to hold her bulk and is most commonly found in vegetation of at least knee-height, often in grasslands and heathlands in Sussex. As a large colourful spider she can be vulnerable to predation so for periods of the day she will retreat to a small tent of vegetation and silk at the corner of her web which will also keep her dry in wet weather. 

The spider is distinguished from other orbweavers by having four white spots forming a square on its abdomen, which can range from pale yellow-green to rusty red. One of the most influential and eccentric spider naturalists of the 20th Century, W.S. Bristowe, describes in his book ‘The World of Spiders’ how they can even change from yellow-green to red when moved to darker surroundings over a few days.  The Four-spotted Orbweaver was subject to another of Bristowe’s odd experiments on spiders where he was dared to taste some of our native fauna by a fellow naturalist; of the five he tried that day, this species was by far the tastiest offering what he describes as a ‘slightly nutty flavour’.   

Both of these colour forms can be found at our Stedham and Iping Common nature reserve amongst the tall heather in late summer along with the Strawberry Orbweaver, Cucumber Spider, Angled Orbweaver and Garden Cross Spider.