BDeed's picture

Burnet

Observed: 10th July 2011 By: BDeed
Merseyside BioBankThe Wildlife Trust for Lancashire, Manchester and
BDeed’s reputation in InvertebratesBDeed’s reputation in InvertebratesBDeed’s reputation in InvertebratesBDeed’s reputation in Invertebrates
Burnet3
Burnet6
Description:
Identifications
Species interactions

No interactions present.

Species with which Five-spot Burnet (Zygaena trifolii) interacts

Comments

ophrys's picture

lonicerae/trifolii

I agree that the merged spots and rounded forewing suggest trifolii. Can the commoner lonicerae be ruled out, though, from the picture? The date suits both. I am not sure...

Ian
_________________

My Flickr photos...

http://www.flickr.com/photos/52163027@N02/

Michael Skelton's picture

Five-spot Burnet

The distribution maps on NBN suggest trifolii is much the more likely in this area of Cornwall.

BDeed's picture

location

I have only included the two pictures but they were quite abundant in the 'marshes' just outside Marazion which are a RSPB reserve, i know it's not exactly best practice but if lonicerae was present in this area of Cornwall and in such abundance would it not have been recorded previously?

DavidHowdon's picture

Probably

Geographical location is how I identified the 5SB aggregate on my local site as well. Although I do also try to look for larvae each year as well to get some records that would be reliable even to the more pernickety recorder.

But nothing in the description or notes indicated how the identification had been carried out so for iSpot purposes (and to avoid leading less experienced lepidopterists to thinking these species can be identified on the wing) it is worth having the alternative - and this discussion thread here.

ophrys's picture

Burnets

I agree with what David has said here. My earlier comment was not suggesting that the ID was wrong, just wondering how we can be sure from the photo (which is what we are presented with on iSpot). Nine people have agreed with the ID, which is pretty conclusive agreement; that is great, as long as everyone is aware that the two cannot 100% reliably be told apart from a photo...and that in many parts of the UK both can be found.

Ian
_________________

My Flickr photos...

http://www.flickr.com/photos/52163027@N02/

BDeed's picture

Burnets

I agree with both of you, and i am not sure why lonicerae isn't recorded that far south and west as everything else seems to suggest the species could be there and i am all too aware of species being under recorded, in fact checking the NBN Gateway again for the aggregate it does cover the tip of Cornwall and had i been more aware of that particular aggregate i may have suggested that instead of the 'strict' trifolii.

--- edit ---

I should also mention however as Ian has pointed out the photo alone is not proof of an identification, that the location is always included with an iSpot ID to assist in identification.

For anyone that isn't already aware clicking on the location just below the photo(s) will bring up a map display of where the species was recorded.

ophrys's picture

Location

I totally agree. Location is one of the quickest ways to narrow down the likely identification of so much that appears on iSpot; and that is just as true for UK observations, as for those from abroad.

It's possibly worth a reminder, too, that while the NBN maps are probably very full for moths, that is far from true for some other orders (diptera, say), so they have to be used with care.

Ian
_________________

My Flickr photos...

http://www.flickr.com/photos/52163027@N02/

DavidHowdon's picture

An even for moths

They (and the data, which I think is the same, pubished in the recent atlas) are regarded as provisional.

Martin Harvey's picture

provisional

Any map of wildlife is provisional, or at least becomes provisional the moment it is published! Good job too, otherwise there would be nothing left to discover and be surprised about!

----
Entomologist and biological recorder

DavidHowdon's picture

The difference

I think the difference with those maps was that they were not convinced that they had fully finalised data validation so not only was it provisional in the usual sense (that as soon as published things move about) but also provisional in that it may well contain some errors which in a 'final' version would have been corrected.

Martin Harvey's picture

Five-spot

An interesting set of comments above, and lots of sensible advice. It's not easy to come to a definitive conclusion about the two species of five-spot burnets. Butterfly Conservation recently produced an excellent "guide to difficult moth species" that focuses mostly on those few species that can only be identified following dissection, but it has this to say about these burnets:
"In spite of much research no clear and consistent differences in the genitalia, or other internal or external structural morphological characters have been found which consistently differentiate individual adult specimens" (http://www.mothscount.org/article/56/22/daggers_darts_and_difficult_spec... - but seems to be out of print already)

The true Five-spot Burnet has until recently been very scarce in the county for which I am moth recorder (Berkshire), but it is becoming a bit more frequent again, and thus it is getting harder to be sure of the situation in relation to Narrow-bordered Five-spot. My understanding is that where Narrow-bordered Five-spots have merged spots, it is an unusual occurrence and would be expected only as an occasional aberration among typical examples with separate spots, so if BDeed's population has a predominance of merged spots then I would regard that as a clear indication that it is going to be true Five-spot.

There are differences in habitat preferences and flight period as well, but these are complicated by differing preferences aong different subspecies, and I'm aware of at least one population which doesn't follow the rules! Both the "Marsh and bog" habitat and the date given for this observation are in line with expectations for true Five-spot Burnet, sub-species decreta.

So the balance of evidence seems to me to be very strongly in favour of true Five-spot, but as others have said it is not possible to be absolutely certain. Finding eggs or larvae would be the thing to do for further confirmation.

----
Entomologist and biological recorder

DavidHowdon's picture

Which one

At the risk of prolonging this long beyond the point where everyone gets bored. I would slightly (only very slightly) disagree with "so if BDeed's population has a predominance of merged spots then I would regard that as a clear indication that it is going to be true Five-spot."

I think if BDeed's population has a predominance of merged spots it is a clear indication that there is a population of 5SB there, but I'm not sure it makes it a clear indication that any specific example taken is 5SB as there could also be a population of NB5SB.

But with the additional evidence about distributions etc. I think this one is looking good for 5SB.

Now who wants to do Bayesian statistics.