Saturday, 22 October 2016

More Willow Emerald Ovipositing

Species still flying in Northants are Common Darter, Migrant Hawker, Southern Hawker and Willow Emerald Damselfly. Adult Willow Emeralds are being elusive though, probably because there are few around, however my searches have found more new ovipositing scars. I hope soon to actually catch a female in the act rather than finding the aftermath. I have included a 100% crop of one of the Willow branches that clearly shows where two eggs are located inside the scar. I have counted over 140 eggs now which is really exciting for next year.

100% crop of the first image showing the two eggs in each scar.

Sunday, 16 October 2016

Willow Emeralds oviposit in Northants

Finedon Pocket Park and the Boardwalks Nature Reserve remain the only two sites where Willow Emeralds have been recorded in our County, although I am sure there are many more out there. Ovipositing has been recorded in North Bucks, so it seems logical that it has happening in Northants too. I have kept regular surveys of Finedon PP in the hope of finding more adults, but on Friday (14th), I was scanning the Willows and noticed some scarring on the branch. Willow Emeralds oviposit into the young stems of Willows and other soft stemmed trees, that overhang the water. My photos were confirmed as Willow Emerald tracts or ovipositing scars, by Adrian Parr of the BDS. Once you know what to look for, they are quite easy to recognise. The beauty of this is that you can record ovipositing when there are no adults around and it gives all winter to hunt for more.

I counted 39 scars on this branch, and each scar contains two eggs, so there is the possibility of 78 larvae and adults emerging next year. Obviously some will fail and some larvae will perish. But I am hoping good numbers will survive. Whether this is enough to start a new self-sustaining colony remains to be seen.

Please use what time you have available to hunt for these scars on trees overhanging ponds, small lakes and slow flowing rivers. Next year may very well be an exciting one for Willow Emeralds in Northants!

Tuesday, 4 October 2016

Ovipositing Common Darters

Migrant Hawker numbers are on the decline now, as are Southern Hawkers, but Common Darters are still numerous and busy ovipositing. At Summer Leys, Migrants and Darters were numerous on Sunday and many pairs of Darters were ovipositing at Finedon, where I met up with Doug and Jim looking for the Willow Emeralds (unsuccessfully). I have heard that Willow Emeralds hve been recorded in North Buck, Beds, Cambs and Lincs so we are surrounded and there must be more out there in Northants too.

I captured a sequence of several shots of a pair of ovipositing Darters and merged them in PhotoShop to show how the male flips the female down into contact with the substrate for egg release. I think I've just about mastered the AF servo settings on my camera to give me the best chance of capturing these events, even so success rate is still low, and at 14 frames per second, 1 second in real time can still lead to 14 out of focus shots!