The Aeshnid Dragonflies

 

I love Aeshnid Dragonflies. It was a love affair that probably began at Dungeness in 2010, when the big Aeshna mixta, Migrant Hawker dragonflies, provided me with excellent photography subjects and generally kept me entertained between counting passerines when I was doing my Undergraduate dissertation. I wondered at the speed at which they could climb and dive and turn, more than matching a Helicopter or a Swallow for aerial agility. I watched their hunting flights, the speed at which they could bring down insect prey small and large (ish), and how relaxed and complacent they would become when they perched up to eat and digest. I love the jewel markings like inset sapphires in their long, knitting-needle abdomens. I love their huge, wrap around compound eyes, affording a wide field of vision to spot prey and predator alike.

Aeshna juncea nomming a Speckled wood Butterfly. Isle of Mull, June 2014

These big insects are predators and no mistake. During their few short weeks on the wing they grab prey up to the size of large butterflies off the wing, and I have seen a Common Hawker (Aeshna juncea) eating a Speckled Wood Butterfly on a sunny June day on the Isle of Mull, completely unbothered by me and my camera lens, fixated on dismantling and hungrily devouring the smaller insect. They are hunters in their youth, too. A. juncea can spend a couple of years as a larva, in the small ponds in which it lives, hunting even small vertebrates like tadpoles and froglets, a veritable tiger among the pondweed. They can live at considerable latitudes, their growth limited by the low temperatures, while cogeners in Southern Europe can have several broods a year.  A. juncea is sometimes called the Moorland Hawker, for the Northern and Upland habitats in which it can thrive.

Migrant Hawker, Otmoor, Oxfordshire, August 2022

Aeshnids in the British Isles come in two genera, Aeshna, a name which Wikipedia claims might originate from a misprint, Aechma being ancient Greek for Spear, presumably in reference to their elongated shape and predatory nature, and Anax, from the ancient Greek for a king or leader, the emperor dragonflies. Both these genera are widely distributed around the globe. They are members of the order Odonata, infraorder Anisoptera, and now thought only distantly related to the similar, huge insects of Carboniferous palaeontology, though in the air they do appear true heirs to these prehistoric monsters. In adulthood all are predatory, and most are territorial, individuals patrolling stretches of hedgerow or pond side and tolerating no insect intruders.  Their larvae, called Nymphs, are, like other odonata, ambush predators, lurking in the pondweed and snatching passing water life. As large insects, they can take multiple years to mature.

Female Migrant Hawker, Essex, August 2022

In the Autumn, our most numerous Aeshnid here in Southern England is the Migrant Hawker (Aeshna mixta) which can be found, sometimes forming large groups of individuals, terrorising the little midges and such which gather in glades and on open rides, sometimes far from the water in which they started their lives. These groups can reach some numbers, and, unusually for dragonflies, they can be surprisingly tolerant of each other, seldom engaging in the high pursuit, rolling, dangerous territorial fights which seem to occupy a lot of time for other species. The Migrant Hawker only spends one year as a larva, emerging in late summer and early Autumn and remaining on the wing until mid-November where we are now.  It’s first segment is identified by a ‘golf-tee’ shaped marking. Sometimes a larger Southern Hawker (Aeshna cyanea) appears, and menaces them. This beast, which once bred in our Essex garden pond, is substantially larger than the migrant hawker, and tolerates few rivals. Its abdomen is jewelled in Blue and Green.

Elderly Migrant Hawker being 'mobbed' by a Willow Emerald Damselfly. RSPB Rainham Marshes, Essex, October 2021

More recently, Southern England, and my home county of Essex in particular, has become a hotspot for a new Aeshnid. The Southern Migrant Hawker (Aeshna affinis) is increasingly common on the ditches and grazing marshes which line the Essex coast from the Thames to the Stour. This beauty has a thorax washed with blue over a base of green, and a vivid blue abdomen. Its segment one is marked with a ‘Deadpool mask’ marking, recalling the face of Marvel’s sweary superhero.  First identified in the county in 2007, my summer was full of these stunners, fighting and breeding over clubrush and reed lined ponds and ditches in July and August. By my understanding, how long the Essex population spends as a larva remains unclear, though it is probably one year, and this incredibly handsome invertebrate is one of climate change’s winners, locally at least, benefitting from the hotter summers.

Southern Migrant Hawker, Bower's Marsh, Essex, July 2022

In contrast, Brown and Norfolk Hawkers are relatively dull in colour, large and robust, the Brown Hawker (Aeshna grandis) having brown flushed wings, and the Norfolk Hawker (Aeshna isosceles), now found much more widely in the UK than confined to Norfolk, though still considered rare and localised. The Norfolk Hawker has big, green eyes, and is relatively widespread in Continental Europe and North Africa. The Brown, which is large, has two pale diagonal stripes on its thorax and subtle blue eyes. It too is doing well, expanding its British range.

Emperor Dragonfly, male, Bowers' Marsh, Essex, July 2022

Though recently the Lesser Emperor (Anax parthenope) has been confirmed breeding in Southern England, for a long time the only Anax dragonfly in these islands has been the spectacular Emperor Dragonfly (A. imperator). This big, green and blue Dragon, by some measures the largest species in Britain, is common and familiar. I have witnessed them ovipositing in borrowdykes on the Essex marshes, and in city centre park ponds. The male has a solid, muted green thorax and a bright blue abdomen, distinctive by their size. They fly in high summer, into August, and range across much of the country.  

Southern Migrant Hawker, Essex, August 2022

Aeshnids form a most impressive family of insects.  Predators, aerobats extraordinaire, survivors and thrivers, wonders and jewelled terrors of freshwater bodies and their environs, nymph and adult. And even in November, it is not too late to see the distinctive shape of a Migrant Hawker, patrolling the hedgelines near you.