A hoverfly species so rare it was named the ‘Phantom’ was spotted last week near Ivinghoe Beacon.
It is believed to be the first recorded sighting of the red-listed species in the Chilterns, on the National Trust’s Ashridge Estate.
It was discovered by National Trust entomologist Peter Brash and satisfied a lifelong ambition for the insect expert.
He said: “I first saw a picture of the Phantom 23 years ago and immediately wanted to see it.
“Nobody knows much about this enigmatic hoverfly.
“Some say it only survives for around ten days as an adult, whilst others say that it stays in the tree canopy and only descends to the ground to breed.”
The Ashridge estate is managed for conservation and to create a diverse range of habitats.
The estate rangers have created the perfect conditions for the Phantom Hoverfly, which lives on chalk grassland and favours shaded areas near scrub.
Much of the chalk downland habitat at Ashridge is managed with the Duke of Burgundy butterfly in mind, which relies on plants like the cowslip for its food.
The Duke of Burgundy is one of the most rapidly declining butterflies in the UK.
Lawrence Trowbridge, lead ranger at the National Trust’s Ashridge Estate, said: “The great scale of the estate enables us to create the right kinds of habitats for a range of species across a whole landscape.
“Chalk grassland is like our very own tropical rain forest, it’s a grassland jungle and literally teaming with life.
“Knowing what species we have is key and surveys carried out by experts like Pete enable us to consider how our conservation work can benefit these rare creatures.
“The Phantom Hoverfly is a new one for me. I’ve been a ranger here for 25 years and I’ve never seen it.”
Facts about the Phantom Hoverfly (Doros profuges)
> It is 1.5 cm long with an elegant narrow waist and black and yellow bands across its body
> This is thought to be the first ever recorded sighting of the Phantom Hoverfly in the Chiltern Hills. Across England, there are approximately 1-2 sightings of the rare insect every year.
> The Phantom Hoverfly is listed as a priority species on the UK Government’s Biodiversity Action Plan.
> It is believed that the management of chalk downland on the estate for rare Duke of Burgundy butterflies has also benefited the Phantom Hoverfly.