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Tales from the Balsa

10/5/2017

I have just finished preparing this lecture for the BDS. It has taken ages and it's convinced me that Lestids are my quest in 2018. The photo that follows this brief narrative is of the Balsa del Pinar. This is the object of much of my research since 2010 when I first came across it. The top picture shows it in 2010 whilst the bottom one is as I found it in 2012 - bone dry. If you want top know what happened next then come along to the BDS Annual meeting in Bristol on Nov 18th. I don't think you will be dissappointed.

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ICO 2017

7/22/2017

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Had a great day at Clare College in Cambridge paying tribute to the great Philip Corbet; I think we did him proud. He wrote a number of books but I think his best was his first A Biology of Dragonflies". I read it back in the 1970s and was so engaged by it that I missed my train stop on at least one occasion and was late for work.

In his presentation, Frank Suhling referred to one of my unpublished papers "The Dragonflies of Cameroon - A key to the identification of Larvae" It was written back in the late 1990s and revied in 2000. Its obviously out of date and is its revision is one of my projects but if you want a copy just send me an email

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Researchgate

5/6/2017

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I have been meaning to do this for ages. I have spent this morning uploading all my papers going right back to 1983 onto Researchgate. Even going back to what I did on Oxygastra and Macromia when both species were much less known than they are now.

Look on Researchgate.net. Any problems let me know

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Feigning Death to avoid Sex

4/30/2017

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Can you believe that this hit the national news. Dragonfly females make out that they are dead to avoid sex. So what’s new? Why is this news. Let’s get back to basics. When mammals want to make babies they have to go through all that tiresome business of sex; indeed some mammals (Lions) have to do every 15 minutes or it won’t work. Many insects on the other hand (dragonflies included) only need to have sex once as the females can store the male’s sperm. In addition, sex can be a very time consuming process; If you live for only 4 weeks and sex takes up to 24 hours as it does in some damselflies, it’s a huge portion of your life that you should be spending laying eggs. It is easy to see how females, once mated, try to avoid sex. As for feigning death, I have witnessed this in the Pseudostigmatidae, which are huge helicopter damselflies found in South America. They are far too slow and cumbersome to fly away from predators so at the sign of danger they simply shut their wings and fall to the ground. I remember my friend Pete spending the whole of an afternoon in Brazil looking for a fallen insect. It was so well camouflaged he never found it. Avoiding predators certainly but avoiding sex? Hawker dragonflies (Aeshnidae) provide the best examples. Some species lay in tandem (see picture of Anax ephippiger in earlier blog) but where the females lay alone they need to adopt avoiding techniques. Boyeria irene, one of Europe’s commonest hawkers, breeds along shady banks of streams and rivers. The females usually appear late in the day when most males have left.They work their way amongst the tree roots to lay but if a male comes by they freeze. They stop rustling their wings and are completely motionless until the danger passes. Aeshna juncea adopts a similar technique freezing and flattening its body against the ground until the male moves away. Of course it doesn’t always work. I remember seeing a male spot a female ovipositing. She tried to fly off but the male literally knocked her to the ground, coupled with the stunned female, who copulated as she recovered.
Moving on to the darters and clubtails (Libellulidae and Gomphidae) they do not have ovipositors so simply distribute their eggs over the surface of the water. The females cannot hide but I think the boot is on the other foot. Copulation is fairly rapid and the females appear to relish the attention. I remember observing Orthetrum cancellatum on a lake in Dorset and Crocothemis erythraea on a river in Spain. The females were having a.ball. A few seconds of oviposition followed by some quickie sex then back to the egglaying. What a life.
A cannot leave this subject without mention of the genus Ischnura. These are small damselflies which, almost uniquely amongst Zygoptera, oviposit alone. More importantly the females are dominant and whilst ovipositing woebetide any male that comes near, they are abruptly chased off. Indeed there is one species Ischura hastata which is a common American species. It has a colony in the Azores where no male insects have ever been found; the females lay viable unfertilised eggs. Perhaps Ischnura has provided the ultimate solution to male harassment; no need to feign death, eliminate sex altogether.

We know about the colony in the Azores. Do other species of Ischnura operate with out males?

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Dragonfly hunting – Anax ephippiger in Almeria

3/24/2017

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My friend Isidrio (Facebook) says that I must have had “mucha suerte y mucha paciencia” when photographing the oviposition of this species. Suerte (luck) is much the most important. Let me tell you the story.
Anax ephippiger is a wanderer and an opportunist; it can turn up almost anywhere but it is most common in southern Europe and Africa. Henri Dumont (pers comm) reported seeing literally millions around lakes in the Sahara.
I first saw it in the Gambia in the 1990s and although I have recorded it in many parts of Spain these have only been isolated records. On Saturday (11-March) we arrived in Aguadulce; the weather was good and, most importantly here, there was very little wind. The forecast looked bad so we decided to walk to my favourite pond on the coast. We arrived and the only dragonfly around was A. ephippiger and mostly copulas (I managed one photo – see Facebook). What luck!! Unfortunately, the pond was as full as I have ever seen it; I peered through the reeds and there were at least 6 pairs looking to oviposit. To see them properly I would have to get in the water; but I had no equipment, close observation would have to wait. I tried next day but the wind was a gale and the temperature had dropped, no sign of any dragonflies. On the following days, The weather got even worse with winds gusting to 80 km/hr and torrential rain causing torrents in the Rambla in Aguadulce.
On Wednesday 15-March we went north to Cazorla and then to the Subbeticas returning on the following Wednesday. On Tuesday 21-March we looked at the weather forecast for Aguadulce. It had been fine with high temperatures and the wind had dropped but it was due to increase again on Wednesday afternoon. Next morning we drove straight back to the coast. The weather had clearly been good as all the snow on the Sierra de Gador had disappeared; but The palms were blowing ominously and when we arrived at the pond there was indeed a strong breeze. Had I blown it? Was I too late? On went the dry suit and I ventured to the edge of the pond fearing. There they were, at least three pairs, which, because of the wind, were searching out broken reed stems floating in the sheltered side of the pond. Up to my waist in the pond I just had to wait and let the beasts get used to me. Two pairs obliged and I was able to observe them oviposit closely. Just half an hour later the wind had become so strong that the insects disappeared. We had timed it just right. Luck is usually the key but as Gary Player the great golfer once said. “The more I practice, the luckier I get”.

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The Rain in Spain

3/14/2017

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It all started so well. Anax ephippiger copulas on the beach pond at Aguadulce. No wind and temps in the 20s.
Yesterday it all went pear shaped and rain and wind dominate the scene. There is even water flooding down the rambla next to Laura's flat, which I have not seen before. First day we had dragonflies, second day we had orchids. Today has been about lunch. Off to Cazorla tomorrow hoping for better weather.

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The Exuvia of Urothemis thomasi

3/10/2017

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I have been working on the description of this exuvia ever since I found it in Wadi Wurayah way back in 2013. I have had a great deal of help from J-P Boudot, Christophe Brochard and Richard Seidenbusch, many thanks to them. At last the paper is published. If you want a copy just let me know.

You have to admit its a really pretty exuvia

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Spain 2016 - a hard year

11/29/2016

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I have updated the database with all this year's records and I am now sorting out the exuviae. As for the records it has been a difficult year. The main fieldwork has been the Balsa de Pinar in Teruel. This is a paper for next year so I won't bore with the details here.

The two milestones have been :

Zygonyx torridus new to Almeria
Gomphus pulchellus new to Teruel

Both discoveries were made from exuviae. The Zygonyx find will appear in Boletin ROLA to be published soon.

As for the Gompid look at SB6 sub-page newly added to the Exuviae Collection page.

So why has the year been so hard; the weather of course. May was disaster but it wasn't until October and then the November trip that things really improved. The problem, as always, has been wind. Fine bright warm weather is vital for studying dragonflies but when it's windy you might as well stay in bed.

I remember the last trip to Aguadulce. I visited the pond by the beach. For the first time this year the wind had dropped and the pond was alive with odes and most especially many pairs of Anax parthenope ovipositing. They are pictured here. The day before I had visited the pond. It was windy and there was nothing about. This day without wind it was alive.

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Changes to the website

11/4/2016

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To be honest not a lot. I have added another section to car hire in Spain (Dragonflies of Iberia). I have great plans for the winter but you will just have to watch this space.

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Dorset 2016

11/4/2016

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For my sins way back in 2014 I got involved with surveying Coenagrion mercuriale in the Isle of Purbeck. Its having a bit of a hard time because many of the streams on which it used to occur and becoming overgrown and neglected mainly due to lack of grazing. The site that I became involved with was on MoD land and the problem here is that the Mires on which it used to breed are drying out; simply starved of water. I have been out with my bucket measuring flow rates and am hoping to meet with the site managers to see if we can't improve matters. One plus is that the drying conditions seem to suit Ischura pumilio (pictured) which is also becoming rare in the region. I'll keep you posted on progress.

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Tales from the Balsa

ICO 2017

Researchgate

Feigning Death to avoid Sex

Dragonfly hunting – Anax ephippiger in Almeria

The Rain in Spain

The Exuvia of Urothemis thomasi

Spain 2016 - a hard year

Changes to the website

Dorset 2016

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