Researching decline in the small tortoiseshell - help needed

[Owen Lewis]

VOLUNTEERS NEEDED FOR A STUDY INTO RECENT DECLINES IN THE SMALL TORTOISEHELL: Many people have noticed dramatically reduced numbers of the small tortoiseshell butterfly during the last two summers. One possibility is that Sturmia bella, a parasitoid fly that has arrived recently in the UK, may be to blame. A new project to investigate this is underway, based at the University of Oxford. We are now looking for volunteers to help with this research by collecting and rearing small tortoiseshell and peacock caterpillars to assess levels of parasitism. We are asking volunteers to collect batches of up to 30 wild larvae of Small Tortoiseshell and/or Peacock butterflies this summer, and to rear them to determine how many die from parasitism. Emerging butterflies can be released into the wild, and any emerging parasitoid pupae should be sent to us for identification. We are hoping to collect data from as many localities as possible across the UK, and we will be linking information on the frequency of parasitism from Sturmia bella and other parasitoids to information from the UK Butterfly Monitoring Scheme on trends in butterfly population sizes. If you are interested in taking part, please check out the instructions and details on the web at http://users.ox.ac.uk/~scat3369/ or contact me, Owen Lewis(owen.lewis@zoo.ox.ac.uk) at the Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.

[Perseus]

Hello,

The BBC rang me up. Do we have the name of the researcher please?

His name wasn't in the Times report, some maybe he is shy of publicity?

Adur Butterfly & Large Moth List
http://www.glaucus.org.uk/Butterfly-list2008.html

Cheers

Andy Horton
glaucus@hotmail.com
Adur Valley Nature Notes
http://www.glaucus.org.uk/Adur2007.html
http://www.glaucus.org.uk/Adur2008.html
Adur Valley Nature Notes: June 2008
http://www.glaucus.org.uk/June2008.html

Adur Valley & Downs Gallery
http://www.flickr.com/groups/adur/pool/

[Pete Eeles]

Er ... isn't it Owen Lewis?

Cheers,

- Pete

[George]

I would love to help but sadly have not seen a single Small Tortoiseshell this year - plenty of Peacock larval webs however but not found any ST yet.

George

[Perseus]

Er ... isn't it Owen Lewis?

Cheers,

- Pete

I found:

Article details
Article title The recent occurrence of Sturmia bella (Meigen) (Diptera: Tachinidae) in south-west England, including rearings from two host species of Nymphalidae
Author Allen, A. A.
Journal title BRITISH JOURNAL OF ENTOMOLOGY AND NATURAL HISTORY
Bibliographic details 2005, VOL 18; PART 4, pages 269-270
Publisher THE BRITISH, ENTOMOLOGICAL AND NATURAL HISTORY Country of publication Great Britain
ISBN ISSN 0952-7583
Language English
Pricing To buy the full text of this article you pay:
£5.00 copyright fee + service charge (from £7.65) + VAT, if applicable
http://direct.bl.uk/bld/PlaceOrder.do?U ... archengine

[Gruditch]

I saw another Small Tortoiseshell today, that brings my year total up to a massive five. And what the hell has happened to the Small Copper, only seen two all year.

Gruditch

[Dave McCormick]

my totals been about 6 for whole year - 3-4 peacocks too, whats up? Last year I counted 30+ small tortoiseshells around this time on a farm wall full of valerian.

[MikeW]

None so far this year, and very few last year.

[PaulJBN]

Saw an absolute cracker of a small T today in Abingdon - brilliant orange - very strongly coloured.

Wasn't able to get a pic though - couldn't get into a good enough position.

Also saw Small T in April just east of Exeter.

Have seen Small T on and off, in small numbers thoughout this summer in South Oxfordshire.

This is my first complete year of lepping so I wouldnt know which butterfly was 'not around as much as before' as I only have the last 12 months to go on

[Dave McCormick]

The other day in my area I noticed that small tortoiseshells were on the increase again. I must have saw at least 20 in a small area here. 7 or so more in a field about 400 yards or so away, so before we had next to no tortiseshells, now we have much more. Hope the numbers stay up in my area next year.

[Rogerdodge]

I have just returned from a week on the Norfolk Broads, and the most frequently observed butterfly there was - the Small Tortoiseshell.
I am wondering if the later broods are less affected by the fly parasite?
Does the fly only lay eggs early in the year perhaps?
If so, this could be the route for a survival strategy for the butterfly?
Just some idle thoughts.

Roger

[Shirley Roulston]

I don't mind collecting larvae for someone else but I don't like touching catapillars and if they got out of their box or nest and start crawling round the house ugh. Has any one got a photo of larvae and I'll have a look, surely in 8 acres I can find something. Small Tortoiseshell's are in short supply here but the Small Copper's have increased. Shirley

[Susie]

Here you go, Shirley, all you could possibly want to know about them including pics of the larvae. http://www.ukbutterflies.co.uk/species. ... toiseshell

If I come across any caterpillars I would be pleased to take part in the trial, but as I have only seen one all year I think it is pretty unlikely.

[Shirley Roulston]

Don't tell me the larvae is the baby caterpillar?

[JKT]

Not quite. Larva is the latin word for caterpillar. Larvae is the plural.

[Eris]

I'm of the opinion that the rise in Hornet numbers is having a bad effect on butterfly populations. A few years back we never saw one, now they turn up each year. I keep hearing other people talking about seeing them now as well.

And to watch a hornet hunt other insects makes you realise what efficient predators they are.

I now hear that hornets are moving into more towns and urban areas ( and where do lots of small torts hang out? town gardens)

Yes it might well be the parasite, but I'm betting a bigger beastie that makes a noise like a B52 bomber when it dives past your ear, might also be playing a part.

So just for interest sake... do many of you who are seeing plenty of small torts also have fairly large numbers of hornets in your area or are they still pretty scarce?

[Gruditch]

Hornets are undoubtedly a formidable predator, well capable of taking dawn a Hawker Dragonfly, ( see You Tube if you don't believe me ). However from my observations they rarely take butterflies, that's not to say they are not on the menu. When on the hunt, Hornets usually check out flower heads looking for an unsuspecting Hover fly or Bee, on most occasions ignoring any butterflies present. Their other method of hunting, is to just take another insect out of the air, usually bees and flies and occasionally butterflies. By far there favourite pray is a sap run on a tree, have even seen them sharing with a Purple Emperor. Many of the more successful woodland butterfly sites in my area, have good numbers of Hornets, and I think you are being a bit unfair on them.

Gruditch

[eccles]

As mentioned elsewhere in these forums, I saw hundreds of small torts at Puxton Moor on Saturday 13th September. But I didn't have time to check nettles for larvae. I didn't see any hornets either.