It mysteriously vanished from England after the long hot summer of 1976, but the chequered skipper butterfly is taking to the skies again as part of a bid to revive 20 endangered species.

Several dozen mostly female butterflies have been collected in Belgium and released in a secret location in Rockingham forest, Northamptonshire.

What sounds like a simple operation has taken months of meticulous preparation by Butterfly Conservation scientists, who have surveyed suitable habitat, advised on how forest rides are mown, and identified the ideal region of Europe that best matches the climate and vegetation in Northamptonshire.

“It is a privilege to help return this charismatic little butterfly to its former stronghold of Rockingham forest,” said Dr Nigel Bourn, Butterfly Conservation’s director of science. “It has taken many years and a lot of hard work from many people to get to this point and I am very proud to be part of the team collecting these beautiful butterflies and returning them to England at last.”

Four Butterfly Conservation scientists were joined by the Belgian conservation authorities and volunteers, using nets to catch these fast-flying butterflies. The catchers were soaked by thunderstorms and chased by wild boar but collected 42 of the butterflies, 31 female and 11 male, transporting them in individual containers inside a cool-bag in a van via the Channel Tunnel.

More females were caught than males because these are already mated, and carrying eggs they will hopefully lay on their principal food plant, false-brome (Brachypodium sylvaticum), which is now widespread in the woods of Rockingham forest.

While there is a growing number of successful reintroduction schemes with birds such as red kites and white-tailed eagles, it has proved more complicated to put back smaller insects. This is only the second official reintroduction scheme for an extinct butterfly in England, following the success of the large blue, which was revived via caterpillars brought from Sweden after becoming extinct in 1979.

The chequered skipper reintroduction is part of the £4.6m Heritage Lottery Fund Back from the Brink project, which aims to save 20 species from extinction and benefit 200 more in 19 locations around England. In Rockingham, forest rides (access tracks or paths) are being widened to enable wild flowers to flourish and woodlands are being restored to benefit other species including adders, willow tits, lesser-spotted woodpeckers and barbastelle bats.

In Rockingham, a select group of volunteers will help follow the newly released butterflies to see which flowers they nectar upon and where they lay their eggs. Andy Wyldes last saw the butterfly more than 40 years ago in Northamptonshire, when he was 11 years old. “It’s fantastic, it’s exciting and it means not having to travel all the way to Scotland to see it,” he said.

It took butterfly scientists more than a decade to bring back the large blue butterfly. Photograph: Martin Fowler/Alamy

Wyldes and other volunteers must guard this secret location because scientists are worried that trampling of grass by enthusiastic butterfly-spotters could endanger the caterpillars, which feed high on the grass stems.

It took butterfly scientists more than a decade to bring back the large blue. While Bourn said he was confident this four-year reintroduction programme would be a success, he said it was important they put more individuals into a second site next year in case the secret site is discovered.

The chequered skipper was once found in woodlands from Oxfordshire to Lincolnshire but its sudden disappearance in the 1970s took conservationists by surprise. Changing forest management with a decline in coppicing and the planting of conifer plantations made woodlands too shady for the butterfly, and it is thought that the drought during the summer of 1976 was the final death knell.

The butterfly continues to thrive in the highlands of Scotland and scientists believe it can only survive in moist woodlands where the grasses on which the caterpillars feed stay green and grow for most of the year. But the chequered skipper feeds on a plant in Scotland which is not found in England and so scientists brought specimens from an area of Belgium where the food plants and, crucially, rainfall, matches that of Northamptonshire. The British scientists were helped by experts from Belgium’s government and the Research Institute for Nature.