There was much excitement in the summer when Darren Bast discovered Willow Emerald Damselflies (Lestes viridis) at Herts & Middlesex Wildlife Trust's Amwell nature reserve on 3 September this year. This was the first time they had been recorded in Hertfordshire.

Now after a great bit of detective work by Barry Reed and HMWT staff, we have proof that they are breeding.

Tim Hill, Conservation Manager, at HMWT explains:

"On Thursday 27 November Charlie Bell, Jenny Sherwen, and I went with Barry Reed to the sallow trees by Hollycross Lake at Amwell NR where he had seen the Willow Emerald Damselflies 'ovipositing' - laying eggs - on the branches on 13 September (as shown in his photograph above). We all searched for and found small scars on the trees which show where damselflies laid their eggs into the bark and are proof positive of their breeding for the first time in the county."

We found three separate locations in an hour's search. All the ovipositing was on branches which were about 10mm in diameter hanging over water. The branches were 300mm-1500mm above the water."

?It is thought that after the eggs hatch, the 1st instar nymphs emerge in the spring and fall into the water where they complete their development, emerging as adults in late summer to start the cycle again.

Thanks to Steve Brooks from the Natural History Museum for advice on the search and information on the ecology of the damselflies.

For more information see British Dragonfly Society website