Spiders are feared by many and known by few. There are about 650 species of spiders in the UK. The truth about spiders is that they are ferocious predators and fantastically effective at ridding gardens of common insect pests such as aphids. It is estimated that spiders across the UK eat as many as 400 to 800 million tons of insects a year.

Most of us will start to notice spiders in September, this is not because the spiders are cold and looking for warmth, it is the time of year spiders start to mate. Males will start their search for females to mate with.

Mating rituals differ depending on the species. Famously known for its vicious mating rituals, the black widow spider (not found in the UK) will often eat male counterparts once the mating has ceased. For spiders residing in webs, it is common for the male to pluck the strings of the web to alert the potential mate of his presence.

Once the females are impregnated, they carry their eggs from between a few days to a few months (depending on the species) until they are ready to be left in silk cocoons. Some females protect their egg sacs until late autumn, others abandon the sacs immediately. A few species, such as wolf spiders, will carry the egg sacs around and even keep their hatched spiders on their backs for protection.  

A deep dive into some of the UK’s native spider species

Daddy-long-legs (Pholcus phalangoides)

These commonly known spiders build scruffy webs in dark corners. An effective predator of other spiders, this animal drops down on its prey from above. If disturbed or frightened it will spin wildly in its web. As with many species, the eggs are guarded by a female in an egg sac.

The large house spider (Tegenaria gigantea)

Large house spiders often startle passers-by when scurrying to find somewhere safe to hide. In the Autumn males are more active, looking for females. This spider does not catch its prey in a web, but the hairy legs give it exceptional sensitivity to movement of other invertebrates.

Spiders generally love the sun and light, so gardens are great places for them.

Garden orb weaver (Araneaus diadematus)

There are few more beautiful sights than the dew-covered webs of garden orb weaver, whose scientific name even means jewel. These are among our heaviest spiders. As with many species, the female is much larger than the male. The incredible web is eaten and recycled every day, with the web being spun in a careful sequence. Although not all spider species spin webs, all produce silk which serves a variety of purposes from lining burrows to catching flies and other insects.

Crab spider (Misumena vatia)

Watch out for the colour changing crab spider, crouching hidden on flowers in the summer. This species adopts the colouring of its chosen flower, often being bright green or pale white. When insects land on the flower to feed, it strikes, grasping its prey in its strong legs.

Are spiders in trouble?

Spiders are an under-represented part of our ecosystems. They receive a lot of bad press due to their somewhat menacing appearance and vilified characters such as Lord of the Ring’s Shelob and Harry Potter’s Aragog. In reality, spiders are an integral part of good biodiversity and the food chain. Eaten by birds and mammals such as hedgehogs, they provide a food source for some of our more beloved wild species. Not only that but spiders also eat a huge variety of insects such as flies and other garden pests.

Though many insect species are growing in numbers across the UK (such as dragonflies and damselflies), research conducted by the Natural Environment Research Council found in a study of invertebrates that one group studied, terrestrial non-insect invertebrates, which included spiders, had declined by 7% since 1970. So, the next time you come across an eight-legged friend, remember they are great to have around in the garden and home and offer a treat for a passing mammal or garden bird.

Learn more about and how to identify spiders