Sunday, 13 July 2008

Red eyes and yellow wings.

Yesterday I decided to go to Walmer Castle to see how the colony of Small Red-eyed Damselflies was faring. What I didn't know was, the Lard Warden of the Cinque Ports was in residence and the Castle was closed until 1.30pm today.

The Castle is an English Heritage site, so once I'd found my membership card I arrived in nice sunshine, just right for the Damselflies.

The colony is on this formal pond in the Queen Elizabeth Garden. The pond has a few water lilies so there's not a lot of searching necessary. Small Red-eyed Damselflies are recent colonists of the UK, being first recorded in 1999. I saw some at a small gravel pit in northern Essex, never expecting them the rapidly colonise and expand their range in the south of England.

There were good numbers of the Small Red-eyed Damselflies (Erythromma viridulum) on the water lily leaves.

There were also a few pairs of Azure Damselflies (Coenagrion puella). This is one of several blue damselflies, best told by the U shape on the second segment of the abdomen.

There was one large Dragonfly hawking up and down the pond. With news of a Lesser Emperor Dragonfly (Anax parthenope) at Sandwich yesterday, and forgetting to bring a field guide with me, I had to phone a friend to check on the characters. This was as I'd first though an Emperor (Anax imperator), but it was worth checking.

I got some close views of the Small Red-eyed Damselflies, and lots of funny looks as a lay on the flagstones dangling my camera over the pond.

This female looks to have just hatched, as it is almost totally lacking in colour.

Moth of the Day.
Another recent addition to British Fauna is Langmaid's Yellow Underwing (Noctua janthina). Only recognised as a separate species in 1991 it was first found in the UK on July 9th 2001 at Southsea. I caught my first on 13th July 2004, on I caught nine in that year, one in 2005, 14 in 2006 but only one in 2007.

At first when seen at rest it looks very similar to Lesser Broad-bordered Yellow Underwing (N. janthe).
The main difference in the hind wing, in the picture above, that has just a small amount of yellow, completely surrounded by a black border.

And, above, on the underside of the forewing, the wing on the right, the border and the dark interior just merge together, whereas in the Lesser Broad-bordered Yellow Underwing the outer edge of the black area is distinctly toothed. The main problem is that these two species are normally very lively and some what reluctant to being handled so looking at the relevant bits is always a struggle.


Candice said...

Ohhh, I love the grounds of Walmer Castle. My husband and I visit from Toronto at least once a year. Your photography is wonderful. What equipment do you use?
Do you know how to determine the gender of dragonflies? I just learned this a couple of weeks ago. If when at rest the wings are held at right angles to the body and fully splayed, it is a male. This is often the way dragonflies are drawn Females at rest hold their wings together and on the top of their backs.

Tony Morris said...

Hi Candice, thanks for the comments. Walmer is very beautiful. I use a Canon 40D and either at 18-50, 35-80 or 100-400 zoom lens. Sexing dragonflies is a little more complicated than that I think. The males and females have rather complicated appendages, that act a bit like a lock and key,you need to look at these sometimes to be certain, although in most species you can tell by colour and pattern.

Candice said...

Hi Tony,
Thanks for the camera info.
Yeah, I know about the 10 segments and all that, but I thought the resting position was a quick, but maybe not infallible way of determining who has landed near you. This maybe something to investigate. So far today in my own garden I've had 2 'males' and 1 'female'. Hope it's not just landing preferences!
Love your site.