|The mystery damsel|
A striking individual with a rusty orange thorax and faint antehumeral stripe
Appears not to have a seg 8 tail light of any description
Not a great photo but I was straining over the fence just to get a shot
. . . . states as we know, the female immature starts in two forms, either rufescens, with a pinkish thorax with faint antehumeral stripe and blue (seg. 8) tail-light, or violacea, with violet thorax and black antehumeral stripes and blue (seg. 8) tail-light. Fair enough, seem plenty of both of these forms :
|immature form violecea|
|immature form rufescens|
Both of those immature forms are little beauties, shame they have to change really. The development of the violacea can go one of two ways, maturing into either the infuscans form (green thorax with black antehumeral stripe and dull brownish tail light) or the typica form which resembles the male (bright blue thorax with black stripe, blue tail light). Here's a few I took earlier :
|The only photo I can find of a mature typical form female|
is this mating pair, where you can see quite clearly the female (left)
is exactly the same shade of bright blue as the male (right)
|This photo shows an individual half-way between the immature violet form|
and the mature bright blue form, she will eventually have a thorax
the same colour as the tail light.
|This individual is again at a stage of development between|
violet and mature but note the dulling of the tail light, I reckon
this individual will morph into the infuscans form
|This dull form may be an early stage of development from the violacea|
|This individual seems to be getting close to the green of the |
mature female infuscans shown in the books
|This green individual photographed in shade is nearer the mark|
Note the combination of the well defined black antehumeral stripe
and brownish tail-light, diagnostic of the infuscans form in whichever
stage of maturity
This form on the other hand, matures into only one type, the infuscans-obsoleta, with yellowish brown thorax, faint antehumeral stripe, and yellow-brown tail-light.
Or does it? because now there is a bit of a twist.
Fast forward to my European field guide (published 2006) :
Which uses the same wonderful Lewington illustrations but the text by Odonata leading expert Klaas Douwe B Dijkstra refers to the different female forms as simply A, B, and C (where A=Typica, B=infuscans and C=infuscans-obsoleta, noting that B and C type females can become very dark when over-mature (a clue to my mystery girl perhaps).
Let's have a look :
|This individual is on the turn from a rufescans, still showing|
the pink thorax but the tail-light browning off nicely
|This (apologies for crap photo) is an ovipositing female of the |
mature infuscans-obsoleta form (type C) according to the books
I think I've nailed it for definite, but the story keeps on throwing more confusion at me. Fast forward again to my latest acquisition (published 2014) :
This guide contains photographs of all the colour forms but the mature form of rufescens is referred to as rufescens-obsoleta rather than infuscans-obsoleta and shows a more orangey form of mature individual, now I'm more confused than ever, what's going on?
I look at the BDS website for clarity. Lo and behold, the home page has an item on the blue-tailed damsel which again refers to a rufescans-obsoleta form, so I look at the species account pages and find no mention of rufescans-obsoleta, but photographs labelled infuscans-obsoleta. (Hope you're keeping up with this :-O)
I then decide to use good old Google and I came across a scientific paper from 1999 which was aiming to standardize the names of the female colour forms and letting it be known that the form infuscans-obsoleta was to be known as rufescans-obsoleta, as simple as that :-)
So it seems that change has come into being and it looks like the BDS is complying with this but has yet to change the names on the species account.
So I conclude that my mystery individual will go down in the records as an over-mature form of rufescens-obsoleta (and certainly not as a boring old type-C female).
And what of infuscans-obsoleta? you may still see it being bandied about but I'm afraid it is now most definitely obsoleter ;-)
PS - By the way, the typica form can also be referred to as the andromorph form, just in case we need a bit more confusion.