LETTERS, NOTES AND QUERIES

Containing this month: 
 
Ranatra linearis likes to swim in the briny     Observations of insects feeding on Alexanders     Compliments to Suffolk Nats

 
 

I found and read with interest the article on the SNS website about Ranatra linearis (the water scorpion) walking overland (White Admiral 58). I had a similar strange encounter with Ranatra this weekend in Wells (off your patch I'm afraid in Norfolk). In over 40 years of biology fieldwork (although I now work in university administration) I have never seen Ranatra in a marine habitat. Yet while waiting for the tide to float the boat I was sailing, one swam by, apparently happily, in the incoming salt water. I lifted it out with cupped hands but it seemed perfectly OK and not at all stressed by the salt water. There is no fresh water in Wells other than a bit of seepage into the harbour from the wells at low tide, and I guess garden ponds. I released it and it swam off with the rising tide.

 Any thoughts? All the references I can find - books or web based seem to indicate it's a fresh water species.

Dr Barry Meatyard

Review Editor, Biological Conservation
National Academy for Gifted and Talented Youth
University of Warwick
Coventry

The Story Continues

Since writing to us with this letter Dr Meatyard has continued to pursue the uniquness, or otherwise, of his observation. He has kept us in touch with his findings.

Firstly Dr Meatyard sent us some more details, for the database:

"I'm still perplexed re the marine habitat. Winds had been in the SE for a couple of days - Force 3-ish at sea and since I can't see Ranatra making much progress upwind it's possible it could have been blown up from the Broads I guess, but that wouldn't explain the marine sighting - unless it had just been dumped in the water and 'healthy and active'= get me out of here!"

Had it come from the Broads? From the Internet came the e-mail address for Scott Perkin who is Biodiversity Co-ordinator for the Norfolk Biodiversity Partnership. Dr Meatyard wrote to him:

"I'm wriitng to you in the event that this observation might be of interest. I'm a professional biologist (botanist) although I now work in university administration but retain a number of research and general interests in the living world around me. I was sailing in Wells this last weekend and while waiting for the afternoon tide to lift the boat on Sunday observed a Ranatra linearis swimming actively in the incoming sea water. It was clearly healthy and active although I had no way of knowing how long it had been immersed. There is no fresh water other than seepage from the freshwater wells along the sea front at Wells - although I guess there must be a few garden ponds around. I found an article on the Suffolk Naturalists website relating to Ranatra walking overland, but in over 40 years of field biology I have never seen Ranatra in a marine habitat. Any thoughts? The map ref for the record is TG926438."

Scott Perkin replied:

  "Dear Dr Meatyard Thank you very much for your email and for letting us know about your sighting of Ranatra linearis. I'm afraid that I do not have any experience of this particular species, but I am copying this message to Pat Lorber at the Norfolk Biological Record Centre, as I know that she will be interested in your observation. She may also be able to tell you whether there are any other records of Ranatra linearis occurring in a marine environment. I'm sorry that I can't be of more help with your query, but thank you again for contacting me.. We are always interested in learning of unusual sightings!"

Pat Lorber then replied:

"Dear Dr Meatyard Thank you very much for your record of Ranatra linearis from Wells.  We have 24 records of this stick insect, all from the Broads, and none since 1995, so we are particularly pleased to have yours. I'm copying this note to Dr Tony Irwin, Keeper of Natural History in Norwich, who is an entomologist. I'm sure he will be interested, and perhaps have some comments to add."

It is interesting how quickly and widely observations like this can be tossed around a diverse community such as entomologists these days. That is the real power of the web. Interesting to note no new records in Norfolk since 1995. I am doing slightly better here in Suffolk but this is really only a case of few people sending any records in. (Anybody else got a sighting to report?)
As I did with Andrew Green's original observation about Ranatra walking on land, I have sent Barry Meatyard's observation up to the Heteroptera Newsletter. If they publish it then there may well be more comments. Watch this site!

Finally I couldn't resist including this last e-mailed comment from Barry Meatyard.

"Hi Adrian, You could be converting a lifelong botanist into a heterologist (?).
I've just come out of my greenhouse where I grow insectivorous plants (sorry about that!). I have an 80cm long glass aquarium in which I grow - amongst others - my venus' fly traps. There's about 3 cm of water in the tank which is about 75% by cover occupied by plant pots. It's also occupied by a Corixa this morning. I have a garden pond but to get into the tank it has not only flown into the greenhouse but subsequently has located the tank and its water. I guess they can fly down/up humidity gradients to find new habitat."

And what an interesting idea about humididty gradients, anyone out there got a comment about that possibility ?

Adrian Chalkley
Freshwater Invertebrate Recorder & Web Editor e-mail: aquatic@sns.org.uk

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Observations of insects feeding on Alexanders

I am employed as a gardener at Hopton Holiday Village four miles south of Great Yarmouth. The Park won the David Bellamy Gold Award for Conservation in 2004 and this year I have been tasked with recording the wildlife on the site and producing a report at the end of the year.

Warren Road is situated to the north of Hopton Holiday Village and passes through Gorleston Golf Course on to Links Road in the town. (TG530010). At the point where the cottages are situated it becomes Warren Lane. It is here that many observations have been made during my lunch hour. The lane has a hawthorn Crataegus monogyna hedgerow along its boundaries and there is an over abundance of alexanders Smyrnium olusatrum. This plant has been in flower since the 18^th March; all blooms were out on the 14^th April. On this day there were literally hundreds of drone flies Eristalis tenax nectaring on the blooms. On the sunny day of the 16^th April I observed a Comma Polygonia c-album, a queen wasp Vespa vulgaris, and several yellow dung flies Scathophaga stercoraria feeding on the flowers. There was nothing else in flower along the lane apart from blackthorn Prunus spinosa. Nothing was nectaring on this and I assumed the its scent was masked by the alexanders. I am sure that all the species mentioned take nectar from alexanders. I should be pleased to hear from anyone who has recorded other insects on this pernicious weed.

C.A. Jacobs

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Compliments

I just had to send you a few lines to say what an excellent White Admiral
you and your team produced for Spring 2005. It's a great credit to you and
the society as a whole.

The variety of articles covering diverse species, climate change and more
general topics, all well written, was a pleasure to read. Another clear message
is the more we look the more unusual and /or threatened species we find.

We all worry about where the future naturalists are going to come from and wish
there were more today but we shouldn't be too gloomy. If there were not a
group of gifted amateurs backing up professionals working in our area it
would not be possible to produce such an excellent White Admiral.

I can assure you that other counties (I pass my copy on to naturalists outside
the county) are envious of the talent available in Suffolk that is enabling
so much interesting work and recording to go on.
Well done.

Geoff Woodard

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