It’s May which means as well as singing birds and woodland flowers, it’s time for Dragonflies, and in particular, the emergence of Four-spotted Chasers at the Dragonfly Ponds. But with the cold weather in April, things in the Dragonfly world are a bit late. So I was delighted on Tuesday, to find the nymph of a 4 spot crawling up a post near the ponds. 4 spot nymphs will crawl up to 5m away from the pond in an effort to find a good support on which to climb up and emerge. After a while the back of the thorax split and the emerging Dragonfly pumped itself free, pulling out the white linings of the nymphal breathing tubes as it came out. Once most of the adult is out, it has to rest for a while so the soft legs can harden before it flips up to pull the abdomen out. Then, haemolymph, or insect blood, is pumped into the wing veins to expand them. And it was at this stage that I realised something was wrong. Two of the wing buds didn’t expand and haemolymph oozed out from a damaged vein in another wing.
This 4 spot wasn’t going to make it.
Sadly, only 50% of Dragonfly emergences are successful, mainly due to incomplete expansion of wings, but also predation from birds and wasps. This morning, at least 50 of them have emerged from the Central Dragonfly Pond here at Saltholme. Some of them have damaged wings, but most have made it. Now they’re just sitting in the grass and sedges waiting for some sun.