Rare spider rediscovered in Essex

Midas tree-weaver had not been seen for eight years

July 2010: A team of conservationists have rediscovered the rare Midas tree-weaver spider in Epping Forest. The spider had not been seen anywhere in the UK for eight years. Buglife, The Invertebrate Conservation Trust and the British Arachnological Society created artificial spider homes in veteran trees in the Essex forest and two female spiders have taken up residence.

HOME-MAKERS: Conservationists created mock nests for the spiders. Picture: Mick Massie

The Midas tree-weaver measures just 2.5mm and has a rather specialised lifestyle, making it very difficult to find, which presents a challenge to the conservationists trying to save them.

The spider has been found in just five locations in Britain and inhabits bird nests, squirrel drays and leaf litter in ancient trees. It feeds on tiny invertebrates such as springtails, which live in rotten organic material.

So how do you go about finding a spider which inhabits such hard to reach spots? Tony Russell-Smith of the British Arachnological Society has come up with a novel, low-tech solution.

Mock nests were made of twigs, leaf litter and chicken manure
By creating mock nests comprising a cluster of twigs, leaf litter and organic chicken manure in a net bag, artificial habitats were offered to the spiders, which were placed in pollarded veteran hornbeam, beech and oak trees in Epping Forest.

In June, the first batch of bags of material were sorted and among the hundreds of other bugs which had made their homes in the nests, including woodlice, millipedes, beetles and other spiders, were two female Midas tree-weavers, both collected from oak pollards.

Tony said: ‘The Midas tree-weaver has not been collected in Britain for the past eight years and it is welcome news that it survives in Epping Forest.

'The fact that this rare species has colonised artificial nests within a month of their being placed in ancient pollards in the forest also provides hope that it will be possible to use this technique to monitor populations of this and other tree inhabiting species in the future.'