Saturday, 16 February 2019

The Emperor's New Clothes

During the past couple of weeks of dipping sessions, I have managed to net a good number of Emperor Dragonfly nymphs from the small 'stripy' Emperors through to fully grown individuals which will emerge in a few months time. To achieve their impressive size, they must undertake up to 15 moults with the nymph getting a little bigger each time as it out grows its previous skin. I have been lucky in the past few years to have seen a few dragonflies moult which leaves them very 'ghost like' in appearance before the skin pigmentation darkens. This can leave them quite vulnerable and they often lay low for a period of time to avoid detection. I would imagine the young Emperor Dragonfly nymphs with their stripy appearance must have this for a reason. Do they spend more of their time nearer the surface in the weeds to blend in while larger Emperor Dragonfly nymphs patrol slightly deeper? I really don't know. Having spent a few hours at Grove Ferry today where I netted a few Emperor Dragonfly nymphs, I decided to see whether I could take a few photos with my phone to show the different sizes in nymphs. As you can imagine, this was not that easy as they were forever trying to walk off my hand. When a couple settled, another one would move but eventually after a bit of patience, I finally had 4 individuals ranging from 7mm to 45mm settled for some photos. I quickly took a few shots before returning them back to the water to carry on their secretive lives.
 
Emperor Dragonfly (Anex imperator) nymphs ranging from 45mm (far left) to 7mm (far right)
 
We can only imagine what it must be like down there to survive but the Emperor Dragonfly nymph is definitely up their as one of the top predators. Their time will soon be upon us. As well as the Emperor Dragonfly nymphs, I managed at Grove to net quite a few damselfly nymphs but despite more scrutiny, I still have not connected with a Small Red eyed Damselfly nymph. However, I did net 1 Southern Hawker nymph, 1 Four spotted Chaser nymph and 1 Common / Ruddy Darter nymph. Earlier at Nethergong, I netted quite a few Broad bodied Chaser nymphs with one brought back for a photo session in the indoor tank.. Also 3 Emperor Dragonfly nymphs and 1 Hairy Dragonfly nymph made for an excellent morning netting in the sunshine.
 
Emperor Dragonfly (Anex imperator) nymphs ranging from 45mm (top) to 7mm (bottom)
 
 

Wednesday, 13 February 2019

Black tailed Skimmer (Orthetrum cancellatum) Nymph - 22mm

It was only a couple of weeks ago that I accidently netted my first Black tailed Skimmer nymph and this gave me the chance to be able to study and photograph the features on this nymph. Last weekend, I decided once again that I would make another visit to Grove Ferry but to an area where I have encountered Black tailed Skimmers in the past few years. My intention was to spend a few hours trying to locate this dragonfly nymph purposefully. The weather was not that kind with near gale force winds but it at least remained dry. Being a bottom dweller in the mud and silt, most of my time was spend with the net in a few areas where I could get amongst the mud in the hope my quarry would be there. After an hour, all I had to show was a number of different sized Emperor Dragonfly nymphs along with a couple of Hairy dragonfly nymphs and Red eyed Damselfly nymphs. I was starting to think that this species was going to elude me when at last as I sifted through some mud in the net, a familiar shape started to appear. I could see straight away that it was likely to be a Black tailed Skimmer nymph and pretty much fully grown as well. A check through the hand lens provided me with a few key features confirming that I had caught my target. I continued on for a while longer where I netted a further smaller Black tailed Skimmer nymph. With the strong wind not letting up, I called it a day and returned my catch but decided to take home the larger Black tailed Skimmer nymph to study and photograph before I later returned it to the area I had caught it. With a tank already prepared, I then spent the afternoon capturing a few images of this nymph which hopefully show of some of the key features, that being the very shallow serrations to the labial palps, the rectangular shaped head and the lack of dorsal spines on S7 and in particular, S8. I'm hoping for some slightly better weather this weekend where I will be hopefully be out in pursuit of trying to improve my images of the Broad bodied Chaser nymph as well as continuing my quest for a Small Red eyed Damselfly nymph.
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph, top view
showing rectangular shaped head (22mm)
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph, top view
showing rectangular shaped head (22mm)

 

 Black tailed Skimmer (Orthetrum cancellatum) nymph, top view
showing rectangular shaped head (22mm)
 

 Black tailed Skimmer (Orthetrum cancellatum) nymph, top view
showing rectangular shaped head (22mm)

  Black tailed Skimmer (Orthetrum cancellatum) nymph showing
very shallow serrations to the Labial Palps (22mm)
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph showing
 lack of dorsal spines on S7 and S8 (22mm)

  Black tailed Skimmer (Orthetrum cancellatum) nymph showing
 lack of dorsal spines on S7 and S8 (22mm)
 
Black tailed Skimmer (Orthetrum cancellatum) Nymph, side view (22mm)
 
 


Saturday, 9 February 2019

Southern Hawker (Aeshna cyanea) Nymph - 35mm

Having netted my first Southern Hawker nymphs last weekend from Grove Ferry, the afternoon was spent photographing both individuals (25mm and 35mm) at home in my indoor tank before returning them back to where I had found them to Grove Ferry. Although thoroughly enjoyable, it can be a painstaking experience to capture the required photos of the species to show the relevant features off, but its often well worth it in the end. I often spend up to a couple of hours photographing the nymphs from various angles but also making the time to study them myself to progress my learning. Quite often, the hawkers when they have found a resting position on some weed will stay there for a while allowing me to fire off shot after shot before checking the photos. Thankfully, the 35mm Southern Hawker nymph performed well and only needed a little coaxing to move into new positions to show off the different features. This morning I made another visit to Grove Ferry where I specifically wanted to target an area for Black tailed Skimmer nymphs. Luck was on my side as I netted 2 individuals, one being almost full grown which was brought back home for a photography session this afternoon before being returned back to its pool at Grove Ferry. I will hopefully post these photos during the week once I have edited them. Although the dragonfly and damselfly season has a while to go yet before the first emergence, I must admit, I'm really enjoying the education of finding and photographing some of the local species.
 
 Southern Hawker (Aeshna cyanea) nymph - top view
 
 Southern Hawker (Aeshna cyanea) nymph - top view
 
 Southern Hawker (Aeshna cyanea) nymph - side view
 
 Southern Hawker (Aeshna cyanea) nymph showing head and thorax
 
 Southern Hawker (Aeshna cyanea) nymph - side view
 
 Southern Hawker (Aeshna cyanea) nymph showing head shape
 
 Southern Hawker (Aeshna cyanea) nymph - head
 
 Southern Hawker (Aeshna cyanea) nymph - top view
 
Southern Hawker (Aeshna cyanea) nymph showing long and slender labial mask
 
Southern Hawker (Aeshna cyanea) nymph showing tip shape to the epiproct


Wednesday, 6 February 2019

Black tailed Skimmer (Orthetrum cancellatum) Nymph

Last weekend whilst dipping at Grove Ferry, as well as catching 2 Southern Hawker nymphs, I also caught what I thought was a Chaser nymph but wasn't quite sure if it may have been a Black tailed Skimmer nymph. I decided to bring the nymph back home with me where the plan was to study the nymph in greater detail to identify it and take some photos before returning the nymph back to the area I found it. One of the first features I looked for was the small yellow fleck which is normally present on both sides of the labial mask which are features on Chaser nymphs. A look through the lens revealed no such mark which then got me thinking that perhaps I had caught a Black tailed Skimmer nymph. This would indeed be a new nymph for me so I then continued looking for features to confirm my suspicions. The shallow serrations on the labial palps ruled out Broad bodied Chaser but not Four spotted Chaser, but the eyes not reaching above the top of the head on the Four spotted Chaser meant this species could also be ruled out. Add to this that both the Broad bodied and Four spotted Chaser also show a quite prominent dorsal spine on S7 and S8 whereas my nymph seemed to show no dorsal spines on S7 and S8. I was now pretty sure I had indeed caught my first Black tailed Skimmer nymph so after finishing photographing the Southern Hawker nymphs, I then spent a while trying to capture some of the features on the nymph which can hopefully be seen in the following photos. I have a few more areas to check out at Grove Ferry in the next few weeks which may yield more Black tailed Skimmer nymphs as well as updating some Broad bodied Chaser nymphs photos, but will also hopefully at some point bump into a Small Red eyed Damselfly nymph... if I'm lucky and keep netting.

  Black tailed Skimmer (Orthetrum cancellatum) nymph showing
 fairly rectangular shaped head
 
  Black tailed Skimmer (Orthetrum cancellatum) nymph showing
 fairly rectangular shaped head
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph - top view
 

  Black tailed Skimmer (Orthetrum cancellatum) nymph - top view
 

 Black tailed Skimmer (Orthetrum cancellatum) nymph showing
shallow serrations to the Labial Palps
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph - top view
 

  Black tailed Skimmer (Orthetrum cancellatum) nymph showing
 lack of dorsal spines on S7 and S8
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph showing shallow
 serrations to the Labial Palps
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph - side view
 
 Black tailed Skimmer (Orthetrum cancellatum) nymph showing
 lack of dorsal spines on S7 and S8

Black tailed Skimmer (Orthetrum cancellatum) nymph showing
lack of dorsal spines on S7 and S8