On 6th June Steve Murray had some brief sightings of one, perhaps two, emerald dragonflies at the scrape at Tyttenhanger gravel pits but was unable to confirm the species. Today (7th June 2016) he was able to obtain better views and confirm that at least two male Downy Emeralds were present.
Downy Emeralds were occasionally seen in the county during the first half of the twentieth century, mainly in the Aldenham/Radlett/Bricket Wood area, with the last of these records being on 28th July 1956 when two were caught, and released, at a field meeting of the London Natural History Society at Aldenham. Away from this area one was recorded near Knebworth on 11th June 1922. The only other recent record is of one seen at West Hyde on 27th June 2010.
The nearest known established populations are in Epping Forest, to the west of London, and north of Leighton Buzzard.
In other news, Barry Reed has confirmed that Scarce Emerald Damselflies are again present at Hertford Heath.