Emerald Dragonflies of Bentley Wood

John Solomon

It was an overwhelmingly dull day on Sunday, the day of the Euros Final, but I had an itch I just had to scratch. Near Salisbury, just to the west of West Tytherley, lies Bentley Wood, which was bought by a charitable trust in the 1980s and is husbanded as a conservation project. It is particularly known for its Purple Emperors, but I was after prey of a different kind. Around a third of the way along from the western side, on the southern edge, lies a meadow, known as the Drainage Field, and in this field is a decent-sized pond. The nearest car park is sited a couple of hundred yards off the West Winterslow to East Grimstead road, at OS 240 296, or, if you prefer What-Three-Words it is found at spouse/smirking/expired – clearly somebody has a sense of humour!

Once you have found the car park, clearly sited up the wide track and on the right, disembark and set off down the track that leads to the right. After a 100 yards or so the track curves fairly sharply to the left and 250 yards later, roughly, there is another large track that comes in from the left in a “T” junction. Take this left hand track. This goes dead straight, down and up, then down and up for around a quarter of a mile, rising to where you can follow it round to the right, on a right-angled bend, or go straight on along a grassy path. Go to the right and follow the track down into the trees and round to the left. Another 150 yards and it will be falling away to the right. At the bottom you cross a wooden bridge and, immediately on the right, is a gate and footpath along the edge of the meadow. Along that path you will find a kissing-gate. Go through and walk diagonally to the left, through another gate and up a short flight of rough steps. The pond now lies in front of you.

The OS ref is 244 282, with What-Three-Words being at approximately lines/diner/educates, and the distance from the car park is the best part of a mile whatever my guesstimates of the various distances above suggests.

I am giving you this detail because if you decide to visit yourself you will discover that Bentley Wood is quite large and, like all woods, notably short of signposts and landmarks. It would be very easy to spend a whole afternoon simply trying to find your way back to the car park!

I was greeted by a gaggle of rather despondent-looking geese on the right hand side of the pond and precious little else. Not auspicious, but the insects I was looking for rarely travel far and tend to roost down in the grass and reeds when the weather is rather less than ideal. The pond is around half clear water, the part nearest to you when you arrive, and half reed bed. I walked slowly round the left bank towards where the reed bed started, watching out over the pond in case anything showed itself. It might have been dull, but it was certainly warm enough, and these insects can’t just hang around and hope that next year is better. They have to do their thing regardless.

Straight away I found my first:

This is an immature male Common Emerald Damselfly. Note that while the upper surfaces of the thorax and abdomen are a vivid green the lower surfaces are more a grey-straw colour. This is the normal adult colouration for the female. To tell the difference look at the very end of the abdomen, to the claspers. The male is much slimmer in this region, with an almost tapering rear end and hooked and pointed claspers:

As is immediately clear the female is rather heavier and stubbier with similarly short and stubby claspers and the small, black ovipositor visible.

We do have this species in Andover, in what is known as the Tench Pond at the town end of Anton Lake, but they are rarely seen as they like to hide away in the reeds. At the Tench Pond these are very difficult to access, so that is why I come here.

I wasn’t finding many at first and became distracted by another species I come here to hunt. A few yards away from the edge of the pond, in the thick but low undergrowth, I was spotting a number of yellow-coloured darters. It wasn’t a case of hunting them but of simply standing there and looking around. If I took a two or three paces forward then I would disturb just as many. It wasn’t long before I managed to get a shot:

This is an immature male Ruddy Darter. When adult they will be brilliantly red, but as young insect they start off their life in the air, as with Emerald Damselflies, they look much the same as a mature female. Speaking of which, I found several of those and here is one that gave me a reasonable shot:

The two sexes can be told apart by the marks on the abdomen. Both are blackish underneath, but the female has a second broken line of black markings running along a third of the way up her sides.

The real problem with identifying Ruddy Darters, of course, is that they are very similar to Common Darters. There are ways of telling them apart. Primarily, Ruddy Darters tend to emerge a little earlier in the year. The presence of so many immature males suggests that the Ruddy Darter is at the beginning of its flight period, I would not really expect to be seeing Commons for another couple of weeks. Just in case, this is a mature male Ruddy Darter:

While this is a mature Male Common Darter:

Note that the Ruddy darter really is a bright red, against which the Common looks dowdy. Also see that the male Ruddy has a club-like form to the lower half of the abdomen while the male Common is much straighter.

The females are tricky and really require a photograph. Here is a female Ruddy:

Here is a mature female Common:

The difference is in the pattern of markings on the side of the thorax, so I’m going to cut in. Female Ruddy:

Female Common:

Now you can see that the female Common has a clearly marked rectangle on her side while in the Ruddy that rectangle is missing its upper line. Like I say, a reasonable photograph is necessary.

I leave you with a female Emerald. This is an immature, and I found a number like this:

As she matures that beautiful rose-pink colouration, so clear along the underside of her abdomen, will fade to a rather duller grey-straw.

I’d been there a couple of hours and a light drizzle had settled in, so it was time to head for home. This year has been rather poor generally, although Black-tailed Skimmers seem to have done well around Andover, but at least at the pond in the Draining Field at Bentley Wood it appears to be business as usual.

As usual, good hunting!

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