One of Britain’s most endangered insects is set to have a new home in Sussex thanks to work by South East Water and environment organisations Natural England and Buglife.
The Wart-biter cricket – which gets its name from the ancient Swedish medical practice of using them to eat skin warts – was once found across southern England. But their numbers have declined so dramatically, they are now found only in five locations, three in Sussex.
Thanks to a working group led by Natural England this rare species of cricket is set to be reintroduced into a carefully-created habitat around Deep Dean Water Treatment Works, in East Sussex. It has taken more than 20 years to make sure the site is suitable for the crickets. The fussy creatures need a particular kind of habitat which includes bare ground, short turf and taller clumps of grass.
Wart-biter numbers have declined as a result of habitat destruction, loss of suitable grassland and unsuitable grazing regimes. They are considered to be endangered in the UK, and the threat they could die out remains. But thanks to an intensive captive breeding programme by London Zoo and partnerships with environmental groups, landowners and farmers, the cricket now has a brighter future.
South East Water’s Environmental Manager Emma Goddard said: “To be able to release wart biter crickets at Deep Dean is a once in a lifetime opportunity and we are honoured to be able to play host to such a prestigious project. We have worked in partnership with other organisations and individuals over a long period of time to get to this point. We are all very pleased to be playing a part in saving the cricket from the very real prospect of extinction.”
South East Water’s Deep Dean site was identified as a suitable place for the wart-biter to thrive because the land has been carefully managed for more than 100 years to protect water quality in the underground aquifer. This means the land has been kept free from pesticides and chemicals, which also allows rare chalk grassland to flourish in the right conditions. However, in the late 1980s it had become overgrown with brambles and scrub.
The company’s environment team recognised the opportunity to manage Deep Dean with a programme of grazing and scrub control with the intention to restore the chalk grassland and encourage rare insects and plants to flourish. The company worked with local farmers, Natural England and volunteers from the South Downs National Park to create the necessary environment and conditions. Deep Dean was designated in 1953 as a Site of Special Scientific Interest for wart-biters, but they were lost from the site in the 1970s. It is hoped the reintroduced wart-biter crickets will once again thrive at this special site.
Emma continued: “Wart-biters are impressive beasts and some can grow to nearly two inches in length. But they do have very specific habitat requirements which are not easily replicated, and without initiatives such as this one there is still a real chance they could die out.”
Natural England’s Senior Invertebrate Specialist Jon Curson said: “All the hard work of clearing bushes and young trees has paid off and it is now very suitable for our third release of between 50 to 100 Wart-biter crickets as part of Natural England’s Species Recovery Programme.
Numbers depend on how many we can collect from another donor site in Sussex which holds the best population in the country. This warm sheltered spot now provides short grass providing lots of food and the longer grass where they can hide from predators such as crows and from which the males can ‘stridulate’ to advertise for a mate.
“This is a real team effort between Natural England, Buglife and South-East Water. The Deep Dean site is instrumental in securing the future survival of the wart-biter in England.”
Buglife’s Lead Ecologist Dr Sarah Henshall, who is delivering the works on the ground, said: “This is an exciting project to re-establish this iconic species at Deep Dean after nearly 40 years of absence. We aim to capture between 50-100 Wart-biter adults from Castle Hill National Nature Reserve, including females laden with eggs and release them at Deep Dean. We will be carefully monitoring the population and habitat at Deep Dean to ensure the wart-biters thrive.”
- The wart-biter cricket’s Latin name is Decticus verrucivorus
- The cricket ‘sings’ – or stridulates – by rubbing its wings together
- Although they have wings, wart-biters normally move about by walking. They rarely fly as they are too heavy and their wings are not large enough
- Adults lay single eggs in bare soil close to clumps of grass. These remain dormant for at least two years before hatching in mid-spring.
- They reach adulthood in July but most adults survive only until September.