The trust said the wasps require coastal grazing marsh and fens, where they build a ‘chimney’ of mud above the entrance to their burrow.
Adults are smaller than a common wasp and are mostly black with creamy stripes and orange legs.
Outside the UK, the nearest population is in eastern Europe, in Poland and Estonia.
Witts continued: “Don’t worry, this wasp isn’t going to be interested in your jam sandwiches – it has incredibly specific tastes.
“Mother wasps will only feed their young larvae one species of weevil, which only feeds on two species of wetland plant in the carrot family.”
The wasps were found in an area that had recently been dredged but the trust said they want to tailor the area to support the wasps and other rare insects.
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