A population of one of Britain’s most endangered insects will receive a boost when more of the bugs are released for the second year running at a new habitat on the South Downs in Sussex.
The wart-biter cricket, which gets its name from the ancient Swedish medical practice of using them to bite off human skin warts, was once found across southern England. But their numbers have declined so dramatically that they are now found only in five locations, three of which are in Sussex.
Now, thanks to work by South East Water and environment organisations Natural England and Buglife, this rare species is being reintroduced into a carefully-created habitat around Deep Dean Water Treatment Works at Lullington.
It has taken more than 20 years to make sure the site is suitable for the crickets. The fussy creatures can only survive on exceptionally high quality chalk grassland which must include areas of short turf, taller clumps of grass and small patches of bare ground.
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 partnerships with environmental groups, landowners and farmers, the cricket now has a brighter future.
South East Water’s Deep Dean site, now a designated Site of Special Scientific Interest, 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.
South East Water’s Head of Environment Emma Goddard said: “We are honoured to be able to play host to such a prestigious project. Without such initiatives there is a real chance these magnificent insects could die out.”
Natural England’s Senior Invertebrate Specialist Jon Curson said: “We hope to release more than 40 adult crickets this year 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.
“Once eggs have been laid it takes two years for them to hatch so we won’t really know the outcome of last year’s efforts, when we introduced the first batch of 74 adults, until next summer.”
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 will be carefully monitoring the population and habitat 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 to attract a mate
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 usually in mid-spring
They reach adulthood in July but most adults survive only until September