Tag Archives: Aeshna mixta

Damsels of Fen Drayton

One of the reasons for my trip to Fen Drayton a few weeks ago was to have a look to see which of our dragonflies were out and about. I went in early June and that time of year is a little early for the true dragons to have emerged, although it’s not impossible. But despite the shortage of the true dragons, the hedgerows and lake sides were abuzz with damselflies.


Male red-eyed damselfly – Erythromma najas

Dragonflies and damselfies are the two members of the taxonomic order ‘Odanata‘ or Odanates. There are two sub-orders within the Odanata: the Anisoptera – the true dragonflies, and Zygoptera – damselflies.

Azure damselfly – Coenagrion puella – the blue form of the immature female

Damselflies in the UK are approximately 4-5cm (1.5-2 inches) long and have thin abdomens and are all smaller and more delicate than the chunkier dragonflies. Having said that, the biggest living Odanate is currently a damselfly who resides in the rainforests of Central America, it has a wingspan of 19cm (7.5 inches) and the abdomen is 10cm (4 inches) long. A real whopper!

Blue tailed damselfly – Ischnura elegans – immature femaleBlue tailed damselfly – immature male – Ischnura elegans

Male and female Odanates, and immature and mature individuals, can often be distinguished by colour. The common blue female below is conspicuously brown so the species gets its name from the electric blue colour of the male. The common blue can easily be confused with the variable damselfly which is the same blue colour, but they are distinguished by the black markings on segment 2 of the abdomen which is shaped like a goblet on the variable and a club on the common blue. Also, the antehumoral stripes (on the side of the thorax) are complete on the common blue and broken on the variable. Although, as the name suggests, the variable is indeed variable and it can make distinguishing the two species a little tricky.


Common blue damselfly female – Enallagma cyathigerum – the only common blue we saw on this trip, perched on my friends finger

The black goblet on segment 2 is visible under the front of the wings on the variable damselfly below. But confusingly, it’s living up to its name because the antehumoral stripes are unbroken.

Male damselflies have two sets of paired claspers at the end of the abdomen which it uses to clasp the female on her pronotum, which is the protrusion in the middle of the back of the head. The claspers have tiny hooks on them which match grooves in the female pronotum and in order to avoid procreational mismatches the hooks and grooves are species specific.

Variable damselfly – Coenagrion pulchellum

In the picture above a variable male has clasped his lady by the pronotum. Male damselflies have primary genitalia at the end of the abdomen on the 8th segment, but in order for fertilisation to take place he needs to transfer a ‘spermatophore’ from the primary genitalia to the secondary genitalia on the second segment at the thoracic end of the abdomen. The female then curls round in to the ‘wheel’ position to transfer the sperm to her genitalia which are underneath her 8th abdominal segment.

A pair of variable damsels in the wheel position

All the Odanates are carnivores, and the larvae which hatch from eggs layed under water are ferocious carnivores, the larger ones will even take small fish! On one occasion last year while I was photographing large red damselflies (Pyrrhosoma  nymphula), a large hawker dragonfly (I think it was a migrant hawker, Aeshna mixta) which had been buzzing around higher up for several minutes suddenly dived down and caught one of my large red damsels. In a few seconds the migrant butchered it and ate it on the wing and the inedible bits of wing and leg were discarded and rained down around me.

Scarce chaser – an immature male

A lone Anisopteran, or ‘true’ dragon was spotted on this trip and it was an immature scarce chaser, Libellula fulva. He was a lovely mustard colour and he can be differentiated from the female by the colour of the thorax which is dark grey in the female, and from the male adult who is electric blue. He undergoes quite a transformation in transitioning from immature to adult.

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Autumnal Anisopterans

Yesterday, 28th October, was one of those glorious sunny autumnal days where the air was fresh but the temperature was raised by bright sunshine, and I’d heard that the winter migrants were arriving on the lakes at Milton Country Park on the northern edge of Cambridge. So I took my camera to work and headed there for a stroll at lunchtime in the hope of snapping a teal or wigeon or perhaps a more unusual visitor. Several waterbirds were on parade including these cormorants:

Several migrant duck species were there too, including wigeon (Anas penelope, Dansk: pibeand), the duck with the chestnut head in the background of the cormorant picture is a male wigeon, tufted duck (Aythya fuligula, Dansk: troldand):


A male tufted duck resplendent in his pied plumage and bright yellow eye

…and gadwall (Anas strepera, Dansk: knarand).

What I didn’t expect to see though, certainly not in the kind of numbers present, were dragonflies. It’s  nearly November and the weather has started to get more autumnal but the warm weather up to now must have suited these airborne predators. In particular common darters (Sympetrium striolatum) were conspicuous, six at one time including two mating pairs. It’s always a treat to watch dragonflies but especially on a sunny day at the end of October, living uo to their name and darting about making a loud low frequency buzzzing noise .

Stunning symmetry of a pair of mating common darters

The darters were sunning themselves on the fence lining a viewing jetty on the edge of a lake and while they were busy warming and copulating a migrant hawker (Aeshna mixta) was patrolling the adjacent reedbeds. All the dragons were pretty much oblivious to my presence unless I ventured too close then they would rise into the air, the copulating couple in tandem, only to return to pretty much the same spot with 30 seconds or so.


Migrant hawker

Every so often one or more of the common darters would chase the hawker away until it lived to its name and plucked one of them out of the air and butchered it whilst flying around our heads, scattering the inedible parts around us. After its aerial snack it headed up into the treetops and disappeared.


The hawker missed a trick. It went to alot of effort catching its darter on the wing when it could have had twice as much protein if it had spotted this pair. But I’m glad it didn’t!