My favourite of the blue/black damsels, interesting because of their many colour variations during development and their short adult lives are quite different from the majority of damsels.
It is widespread on all kinds of habitats, though usually found in small numbers. The best sites in Gateshead are Kibblesworth, and my favourite, Clockburn Lake outlet stream, where they DO appear in good numbers and ease of access makes it a great place to study and photograph them.
They shouldn't really be confused with any other damsel in the northeast, though the blue tail-light is similar to that of the mature male Emerald damselfly, but anything more than a glimpse should rule that out.
In Southern England the larva has a one year life cycle, but further north it can be one or two years, so though they start to emerge late May there are two peaks of emergence, with the 2nd year larvae emerging first through to mid-June, then a second peak in mid-July when the one year larvae emerge.
Another strange feature is that they often emerge upside-down, (on emergent plant stems just a short distance above the water surface), though the reason for this is unknown.
And unlike most other Odonata, the newly emerged blue-tails (of both sexes) tend to stay close to the breeding site as they mature (though there is obviously a percentage which disperse as they can be found good distances from water and are often the first to colonise new ponds), and both sexes and all the colour variations of the development stages can be found among the bankside vegetation, where they will fly even in dull, cool and windy weather, unlike other dragons not relying on sunshine to perform their daily tasks. This is probably just as well, as, though adults can live up to 8 weeks their average lifespan is reckoned to be just 10 days.
|Blue-tailed Damselfly (immature and almost mature male)|
Males can be aged by the colour of the thorax. they begin life green, then
change to blue/green after 5-6 days . . . .
|. . . before becoming a rich blue fully mature|
male after 2 weeks (if they live that long)
|Immature females can be either this very colourful|
rufescens form, which after about 8 days . . . .
|. . . matures into a much duller|
yellow/brown known as infuscans-obsoleta,
|Or they can start life as the pretty violacea form . . .|
|. . . and mature into a largely green damsel|
known as infuscans . . .
|. . . or the typica form which resembles the male.|
Sexual maturation is much quicker than in most other species, copulation can take place after just 3 or 4 days, so couples can be seen in the mating wheel while still in immature colouring. Copulation can take up to 6 hours (believed to be so the male can ensure it is his sperm that will fertilize the eggs) but the females oviposit alone usually late in the day to avoid being pestered by males.
|infuscans-obsolete female ovipositing alone, laying eggs|
into submerged plant stems.
They feed by both the usual aerial capture method, and also by plucking prey from plant stems or even spider-webs. Great dragons!