Dragonflies

Damsels, Dragons and lakeside chivalry!

It is quiet in the woods — the leaves of the canopy obscuring the birds hopping silently, keeping a low profile as they raise their young and avoid predators. But there is a hum of insects today in the swingeing heat — bumble bees, honey bees, wasps, flies and beetles dance in the sunbeams that penetrate the woodland. Clambering over the late summer blooms, they feed and pollinate as they go, pausing to clean the stick blackberry juice from their feet.

Near the ditches and the ponds the Dragonflies patrol — a great big hawker zooms over the pond then starts to patrol its margins hovering a meter or so above the water, whisking himself away in a flash of yellow and blue just as I find him in the view finder. Fortunately Bill has had more luck (or expertise) and these are mainly his photos.

Dragonflies and damselflies spend most of their lives in water as fierce, carnivorous larvae or nymphs. Damselfly larvae have fanned tails which are gills but dragonfly nymphs take in water through their rectums where they have internal gills (when in difficulties they can fire out water and jet propel themselves from danger). They gradually grow, moulting their skins as they get too small, until just before their final moult, when they heave themselves out of the water up some twig or reed and start to breath air — then something amazing happens.

A Hawker Nymph from our pond.

They do not pupate like butterflies –withdrawing into a casket to re-organise their bodies for an aerial life. The skin of the living nymph simply splits and its adult self hauls itself out!

Southern Hawker, one of the larger dragonflies, having an “out of character” rest.
Here is a female Southern Hawker — generally females and immature males are harder to identify

Adult dragonflies like the Southern Hawker are very territorial so you will usually only see one on a particular stretch of pond bank except when an interloper enters his territory when there will be an aerial skirmish — a dog fight — the resident male seems usually to prevail and the interloper withdraws to find another territory. When a female appears the male will try to mate with her, grabbing her by the scruff of the neck with claspers on the end of his abdomen. If she is willing she curls her abdomen round to the accessory genitalia on the ventral side of his abdomen just below his waist where he keeps his sperm — thus they form a conjugal wheel or copula. You will see them flying, conjoined like this in tandem. They lay their eggs in water or on submerged vegetation depending on the species. Sometimes the male guards the female while she lays but in some species you will see them, still in tandem — the male holding the female by her neck and dipping her tail into the water to lay, then pulling her out — escaping the powerful surface tension of the water — to dip her in at another location, spreading their bets and increasing the chances that their offspring will survive.

Large Red Damselflies — The chivalrous male holding onto his mate as she lays her eggs
Another larger dragonfly is the Brown Hawker with its orange wings seen here at Woodwalton Fen.
The Common darter is smaller but widespread in lowland habitats often seen basking in the sun on brambles or bare ground.

Different species of dragonflies fill different niches in the water-side world. Hawkers, skimmers and darters prefer standing water whereas the large red damselflies like bogs and ditches. The beautiful demoiselle (that’s its name) and the banded demoiselle like running water like the stream in our valley. Damselflies perch with their wings folded, are smaller and daintier, flutter more weakly and have eyes that are more widely spaced — the eyes of dragonflies meet in the middle.

Beautiful demoiselle
Banded demoiselle

You will see lots of blue damselflies around the edge of our pond — they are not so territorial and don’t spend their time fighting.

I think this is a male Common Blue Damselfly — note the “hammerhead” eyes
Libellulia depressa — Broad Bodied Chaser –the first dragonfly to populate our pond. Territorial but earlier in the year than the Southern Chaser.
Four spotted chaser — territorial and widespread seen here in July at Brigstock.
Standard
Ecology

Nymphs and Shepherds

Just two years ago we put the bung into the plug hole of our newly dug pond and let Nature do the rest.

Common Hawker Dragonfly defending his new territory.

Common Hawker Dragonfly defending his new territory.

Last summer this Common Hawker Dragonfly patrolled its banks and skirmished with intruders for the territory, occasionally looping the loop with a yellow spotted female of his species who must have gone on to lay her eggs in the water, because look what we just found!

Aeshna juncea -- Common Hawker Dragonfly Nymph

Aeshna juncea — Common Hawker Dragonfly Nymph

And that wasn’t all — the water is alive with biological activity, a million tadpoles whizz around our pond-dipping bucket, getting in the way and obscuring our view of the newts and myriad nymphs — not so easy to identify in life because most of the pictures are of exuvia (the dried up skins of the nymphs, abandoned by the adults after they emerge).   The harder you look the more nymphs appear and all are interacting — some snapping at passers by, others knocked over by a clumsy water beetle — a microcosm.

Here are a few that my grand-daughter helped sort out and photograph–

Damselfly nymph -- probably Enallagma cyathigerum being buzzed by a Common Water Boatman

Damselfly nymph — probably Enallagma cyathigerum being buzzed by a Common Water Boatman

The identification is more to do with common things being common and having seen a lot of the adults flitting about last summer — here’s one of them —

Common Blue Damselfly (probably).

Common Blue Damselfly (probably).

Blue and Azure damselflies are tricky to distinguish — especially when they are alive!

And what about our friend Libellulia depressa, the Broad Bodied Chaser, the first Dragonfly we spotted by the new pond (often the first to colonise a new pond, said the book, and they were) —

I think this could be one of his offspring

Fat bottomed nymph -- maybe an early Chaser (Libelullia depressa) or a Darter (Sympetrum spp.)

Fat bottomed nymph — maybe an early Chaser (Libelullia depressa) or a Darter (Sympetrum spp.)

Please comment if you think I am wrong in any of my identification — I may well be, but you have to start somewhere!

Standard