Return to HRS home page Dipterists Forum
A Dipterists Forum recording scheme

Navigation
Home
Forum
Photo gallery
Maps
Checklist
Hoverfly Newsletter
Memberlist
User-groups
FAQ
Search

User
Username:

Password:

 Remember me



I forgot my password

Don't have an account yet?
You can register for FREE


Search

Advanced Search

Who is Online

In total there are 9 users online :: 0 Registered, 0 Hidden and 9 Guests

Registered Users: None

[ View complete list ]


Most users ever online was 248 on Wed Dec 12, 2007 11:53 pm


Rhingia rostrata in Northamptonshire

 
Post new topic   Reply to topic    Hoverfly Recording Scheme Forum Index -> General discussion
View previous topic :: View next topic  
Author Message
Roger K.A. Morris



Joined: 06 Nov 2005
Posts: 1583

PostPosted: Sat Sep 01, 2007 7:31 pm    Post subject: Rhingia rostrata in Northamptonshire Reply with quote

I've taken R. rostrata at both Greate Wakerley Wood and Bedford Purlieus today - massive range change so for goodness sake keep your eyes peeled folks - this one is on the move big time!

Roger
Back to top
View user's profile Send private message
conopid



Joined: 03 Sep 2005
Posts: 342
Location: Shrewsbury, Shropshire

PostPosted: Sat Sep 01, 2007 8:23 pm    Post subject: Reply with quote

Hi Roger,
The second brood of R rostrata is certainly making a good showing here in the Welsh borders. I have noticed that it is flying with Rhingia campestris, which is always far more numerous at sites where they fly at the same time. However, I do find that rostrata is noticeably lighter and brighter in colour and many specimens are quite a bit smaller than campestris. If recorders keep these hints in mind, they should spot the species fairly easily. If it's now turning up in the East Midlands it would certainly seem to be on the increase in a big way and I should think it will be in many places if recorders make the effort to find it in amongst all the R campestris.

_________________
Nigel Jones
Shrewsbury
Shropshire
Back to top
View user's profile Send private message
Tony White



Joined: 12 Mar 2006
Posts: 61
Location: Byfield, Northants

PostPosted: Sat Sep 01, 2007 8:57 pm    Post subject: Rhingia rostrata in Northamptonshire Reply with quote

Well done Roger,

It certainly is a big extension of range. I've been keeping an eye open for it here in the west of Northamptonshire (where it should more logically occur) but have only found - in abundance - R. campestris. However, you've inspired me to search more diligently.

Tony White[/i]
Back to top
View user's profile Send private message Send e-mail
John O'Sullivan



Joined: 05 Oct 2005
Posts: 128
Location: Sandy, Bedfordshire, UK

PostPosted: Sun Sep 02, 2007 9:08 pm    Post subject: Reply with quote

Well, today I visited Potton Wood in Bedfordshire, just on spec and before reading this strand, and lo and behold there were at least a dozen rostrata in a place where I have never seen them before, despite many visits; all or most were feeding on knapweed. I could hardly believe my eyes! Having read your post, Roger, I am now slightly less amazed than I was, but still delighted. There were no campestris present at all.

However, a little later, at the nearby RSPB reserve of The Lodge, I found a female campestris to compare; much darker bodied, the black edges of the tergites very obvious in any side view, and from beneath, and the closed wings, viewed from above, narrower, more pointed and darker. The scutellum of rostrata does seem a bit more orange than campestris, at least in females, but nothing like as bright as the abdomen, which really stands out in the field, even showing through the closed wings from above. All the male rostrata I saw (about 6), had an obvious, isolated, black tip to the abdomen, contrasting strongly with the bright orange, and very distinct, especially in views from behind. The black rings on the hind tibiae of the female campestris seemed fairly clear in a good view, but in rostrata only a really good view in captivity showed that they were all a rather dull orange; in other words, I don't think that this is a good field mark. Nor would I say that the length of the "snout" is a very useful distinguishing mark, unless you have both species together in front of you.

I will keep a sharp eye out for rostrata elsewhere locally.

Here's to some more surprises for us all this autumn!

John
Back to top
View user's profile Send private message
conopid



Joined: 03 Sep 2005
Posts: 342
Location: Shrewsbury, Shropshire

PostPosted: Mon Sep 03, 2007 3:21 pm    Post subject: Reply with quote

By Jove! Just what is going on with Rhingia rostrata? It appears to be increasing very dramatically after years of great rarity. Surprised
_________________
Nigel Jones
Shrewsbury
Shropshire
Back to top
View user's profile Send private message
Tony White



Joined: 12 Mar 2006
Posts: 61
Location: Byfield, Northants

PostPosted: Mon Sep 03, 2007 6:46 pm    Post subject: Reply with quote

It seems that not a lot is known about the larval requirements of R. rostrata. If the larvae are aphidophagous, and the favoured aphid species has shown a rapid increase in its range, then rostrata could follow. This is pure speculation of course but if this expansion in range is genuine rather than apparent, then it needs to be explained. Alternatively (again positing an aphid pabulum) rostrata may have transferred to another aphid with a wider range. It could be a parallel with the Juniper Shieldbug, once confined to a very small area in Surrey where juniper occurred, then finding Lawson's Cypress to its taste and vastly increasing its range to become one of our commonest shieldbugs.

Any thoughts out there?
Back to top
View user's profile Send private message Send e-mail
John O'Sullivan



Joined: 05 Oct 2005
Posts: 128
Location: Sandy, Bedfordshire, UK

PostPosted: Mon Sep 03, 2007 9:25 pm    Post subject: Reply with quote

Well, Tony, as you invited thoughts, what about this? Stubbs and Falk says that badger latrines have been suggested as possible larval habitat. I reckon from the high number of road casualties round Beds and Cambs these days that badgers are doing pretty well; could the fly be following?

Not exactly scientific, but there might be something in it.

John
Back to top
View user's profile Send private message
Roger K.A. Morris



Joined: 06 Nov 2005
Posts: 1583

PostPosted: Mon Sep 03, 2007 10:41 pm    Post subject: Reply with quote

This is definitely not an aphidophagous species. Martin Speight thinks it is associated with dry dung. Alan and I are still inclined to believe in some wetter form of dung - and badger seems most likely.

Does anyone fancy running breeding experiments on badger latrines? Worth a try at your site John.

Regards

Roger
Back to top
View user's profile Send private message
chris webster



Joined: 19 Jan 2006
Posts: 12
Location: Reading Berks

PostPosted: Wed Sep 05, 2007 9:38 pm    Post subject: Reply with quote

Does it occur in the Irish Republic? The badger population there has been greatly reduced, with eradication claimed in some areas, so there might be a consequent decline in rostrata.
I saw none from the first peak here in Berks, and just one recently down in south Hants. I'll check the local cemetery tomorrow, as they have been seen within yards of the badgers' sett there in previous years.
Back to top
View user's profile Send private message Visit poster's website
Ian Wynne



Joined: 16 Oct 2007
Posts: 4

PostPosted: Tue Oct 16, 2007 12:52 am    Post subject: Reply with quote

Hello Roger,

Apologies for the late reply but have only just manged to successfully join this group.

Very interested to hear that you have taken R. rostrata in Northants. I'm familiar with the species in Sussex, Hants and Kent, but have never recorded it in Herts until this year when I took a voucher at oregano in my garden (in St Albans). There are a couple of old records for the extreme SW of the county (from the 1950's if I remember correctly) but none since, despite reasonable recording effort (though I've not been 'active' in Herts for the last five years or so). Last year, while living Sussex (where rostrata is reasonably frequent), I confined a gravid female with a dead rabbit (Cats: who would have them!) but she showed no interest at all. Proves nothing of course, but then I guess Alan's suggestion of an association with carrion was a stab in the dark.

Hope all is well with you.

Ian Wynne
Back to top
View user's profile Send private message
Roger K.A. Morris



Joined: 06 Nov 2005
Posts: 1583

PostPosted: Sun Oct 28, 2007 11:22 pm    Post subject: Reply with quote

Hi Ian

Thanks - would be good to have updated records

regards

Roger
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Hoverfly Recording Scheme Forum Index -> General discussion All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group