Love Spiders - Spiders under threat

Ladybird spider

Male Ladybird spider (Eresus sandaliatus) © Stephen Dalton - from 'Spiders' published by A&C Black

The Ladybird spider (Eresus sandaliatus) is extremely rare and found on just a couple of sites in Dorset. It was thought to be extinct in Britain until it was rediscovered in 1979. The male spider has spectacular colouring and it's not difficult to see why it is called the Ladybird spider! It is between 6 and 9mm long (excluding legs). The female is larger at 10-16mm long (excluding legs) and is black in colour. The female Ladybird spider builds a silk-lined burrow about 10cm deep in sandy soil where she lays her eggs. The young remain sheltered in the burrow for their first winter. The spider needs a specific type of habitat to survive - dry sandy heathland with some bare or lichen-covered patches, and shelter from the wind. This spider is so rare that it is legally protected and spiders cannot be removed from the wild.

Fen raft spider

Fen raft spider ( Dolomedes plantarius ) © Roger Key

The Fen raft spider (Dolomedes plantarius) is one of our largest spiders – adult females can grow to around 7cm in length (including their legs). They are also rather attractive, and have black or brown bodies with white or cream stripes.

The Fen raft spider lives in fens, and other wet areas. They lie in wait amongst the wetland plants for prey to come within striking distance. Their hairy legs allow them to skate across the surface of the water to grab their prey. The spiders also use their leg hairs to sense the vibrations produced by aquatic insects and other small creatures – which they eat. Larger individuals have been known to catch larger animals such as tadpoles and small fish! When they are scared they climb down plant stems and hide underwater.

Female Fen raft spiders are good mothers. After mating the female carries her eggs around in a sac for around three weeks, dipping the egg sac under water every few hours to keep the eggs moist. When the eggs are ready to hatch the female constructs a nursery web, a tent made of silk up to 25cm across, which is attached to plants and suspended up above the water.The young develop in these webs, guarded by the mothers, usually for around a week, after which they disperse into the surrounding vegetation.

The Fen raft spider is very rare in the UK and has been identified as a priority species for conservation action. To find out more about what Buglife is doing to conserve rare water invertebrates, click here

Distinguished jumping spider

Distinguished jumping spider (Sitticus distinguendus) © Peter Harvey

This attractive spider is found on just two sites in the UK and they are both brownfield sites (or previously developed land). The spider is found on West Thurrock Marshes in Essex and Swanscombe Peninsula in Kent.

There are 37 types of jumping spider in the UK, but worldwide it is the largest spider family containing over five thousand species. Jumping spiders have a very large front pair of eyes, and are thought to possess the best vision for an invertebrate after cephalopods (octopus and relatives). This vision, along with an ability to jump, allows them to actively hunt their prey during the day. Their keen eyesight also plays a part in courtship, where males can undertake elaborate dances to woo a female (and avoid being eaten!).

The two sites at which the Distinguished jumping spider has been found are both within the Thames Gateway – Europe’s largest growth area – and both are brownfield sites – land that is prioritised for development by planning policy. Brownfield sites are not merely derelict pieces of land littered with the remains of old buildings. Often nature has reclaimed these abandoned places and they are now hidden oases for wildlife, in the heart of our towns and cities.

To find out more about Buglife's fight to save West Thurrock Marshes from development, click here