jackz432r

[Paul Harfield]

Thanks Pauline

Sunday 27.5.2018 & Friday 1.6.2018 White Letter Hairstreak

My searches for White Letter Hairstreak larvae are restricted to a couple of sites where there are low branches. After having some success at finding larvae recently I thought finding pupae would be similarly straightforward (not so!). As detailed in an earlier post, over 2 weekends I was able to locate a total of 15 larvae at my primary White Letter Hairstreak site and 2 at a completely new location. These larvae were all reaching maturity and 1 had changed colour ready for pupation. I marked all of these larvae for ease of relocation.

My larval search area. The branches shown here are between waist and head height and semi-shaded by higher branches and surrounding vegetation.

27.5.2018 Typical feeding damage and the culprit. This was the only larva I could find that was still green and feeding

Brimming with confidence, I returned to my prime site 27.5.2018 expecting to find pupae. After a lengthy search I was surprised to find that of the 15 larvae found previously I was only able to locate 2. One of these was still green and actively feeding. The other was suspended for pupation but had yet to shed its larval skin. This was located right at the tip of a branch at approximately chest height. I was also able to find 1 previously unseen larva which had changed colour. So where have all those larvae gone? Predation is ,I suppose the most, likely reason they were not present or maybe pupae are just much more difficult to find than I was expecting.

27.5.2018 More typical feeding damage together with the larva which had now changed colour

I returned to the location again 1.6.2018 to check on progress. The previously seen suspended larva was now completely pupated but no further larvae/pupae could be found

27.5.2018 This larva was the only one I could find which was close to pupation together with the wider context of its location, right at the tip of a branch.

1.6.2018 The same individual now fully pupated.

[Wurzel]

Interesting shots Paul, how much foliage do they get through? I guess it won't be long until the adults will be flying

Have a goodun

Wurzel

[Pauline]

Incredibly interesting observations Paul. You will remember (well, who could forget! ) that I have reared them and I am currently interested in comparing behaviour in captivity with that of the wild. Despite providing plenty of foliage, with the exception of one who pupated on a branch, the others determinedly made their way down and buried in the earth to pupate. Do you think it is possible that this may be the case with some of your missing larva? Is it possible that their chosen location to pupate varies? I'm putting up a few shots but please feel free to delete as I don't want to clutter your diary:

Any chance of scrabbling about in the earth??? Given their colouration it may also provide better camouflage than a leaf?

[ernie f]

Paul, great series of WLH pre-butterfly shots. It will help me in my searches this year.

[millerd]

Terrific shots of the WLH on the elm - very useful in spotting the feeding damage! They seem quite low down and accessible as well, so I shall have another look local to me and see what I can find.

Dave

[Paul Harfield]

Thanks Ernie, Dave and Wurzel for your comments

Incredibly interesting observations Paul. You will remember (well, who could forget! ) that I have reared them and I am currently interested in comparing behaviour in captivity with that of the wild. Despite providing plenty of foliage, with the exception of one who pupated on a branch, the others determinedly made their way down and buried in the earth to pupate. Do you think it is possible that this may be the case with some of your missing larva? Is it possible that their chosen location to pupate varies? I'm putting up a few shots but please feel free to delete as I don't want to clutter your diary:
Any chance of scrabbling about in the earth??? Given their colouration it may also provide better camouflage than a leaf?

Thanks for the suggestion Pauline, it had occurred to me. I was hoping somebody else might suggest it. I can not find any references to this species pupating in the soil, but it would be a logical explanation. I was very surprised that I could not find more given the number of larvae found. It would also make sense given the Purple Hairstreaks pupating habits.

All I need to do is find some proof . Luckily this location is quite secluded so some 'scrabbling around in the earth' might be in order. I have reared just 2 larvae this year and both have pupated on the side of the container containing cut foodplant! I will provide soil next time and see what happens.

[bugboy]

Well done with those WLH larvae, I've been looking on every Elm this year but I've yet to get lucky. The Elm at the main colony I visit is all protected by banks of Bramble otherwise I'm sure I'd found some by now. Still, can't really complain, it's that very Bramble that brings the adults down every year

[Pauline]

If it helps in your search Paul, none of the larva strayed very far from the base of the plant and all pupated within 2" depth. I have a feeling you will find proof as I have been convinced since rearing them that this must happen in the wild too. I believe at the time I recorded it and posted it there were suggestions that I hadn't provided enough foliage (not true) or that perhaps it was the stress of being captive bred which I wasn't convinced about. I can't remember if I asked for experiences from others who had reared them (that was certainly my intention) but if I did, I didn't get any replies. Good Luck.

[David M]

Great larval images, Paul, and thanks too for the photos of feeding damage, which will prove to be a useful pointer when I'm out surveying local elms myself.

[Pete Eeles]

Brilliant reports, Paul! I particularly appreciate the "context" shots, such as the larval feeding damage. Superb!

Cheers,

- Pete

[Paul Harfield]

Thanks Pete, David, Pauline & Bugboy for your comments

Recent Doings

In The Garden - I have a potted Wych Elm kindly donated by Pauline a couple of years ago. I was not totally happy with the outcome in 2017 for White Letter Hairstreak larvae I reared sleeved on this growing food. They seemed to do better on cut food in water. So this year I did not use the potted Wych Elm, but it has not gone to waste. My local Commas seem to find it very attractive. This year I have had up to 8 larvae munching away on it. They seem to have come on at a tremendous rate. I also watched as a bird took one the other morning. As of today I appear to be down to 3 which are nearing fully grown. Not far away another larvae is munching on my Buddleia Globosa.

2.6.2018 Several Comma larvae on Wych Elm in the garden

9.6.2018 A week on and Comma larvae in the garden are almost fully grown

2.6.2018 Another larvae eating my Buddleia Globosa

Silchester Common - I did not make it to Bramshott Common again this year. However, I happened to be working in Silchester on Friday afternoon so to avoid the rush hour, I popped in for a look around. I managed to locate just one Silver Studded Blue very late in the afternoon.

8.6.2018 - Silver Studded Blue - Silchester Common

White Letter Hairstreak - I have reared just two larvae this year. Both emerged this week the first on Wednesday 6th and the second on Friday 8th whilst I was having my breakfast! I released them back at their original site this morning. Although I could not locate any more there or at another site close by, I popped in to the IBM/Lakeside complex at Cosham and found at least four individuals very active in the sun.

9.6.2018 Two reared White Letter Hairstreak newly emerged just before release.

9.6.2018 Distant record shot from IBM/Lakeside at Cosham today

I also took Paulines advice and spent some time 'scrabbling around in the earth' Needle in a haystack comes to mind. Needless to say I did not find any White Letter Hairstreak Pupae buried in the ground or in leaf litter.

[Wurzel]

Cracking stuff Paul, the circle is complete for another year Good to see you're already looking for next years set

Have a goodun

Wurzel

[Maximus]

Nice stuff, Paul, and lovely reared WL Hairstreak. We have Mullion moth larvae on our Buddleia Globosa too

Mike

[David M]

Beautiful WLH images, Paul. The season is exploding and it's hard to know which species to concentrate on right now. Well done with your successful rearing exploits. That's two more individuals to assist with future generations!

[Paul Harfield]

White-Letter Hairstreak - 2018 - Part 1

It will be of no surprise to some that for the last 6 weeks or so I have devoted almost all of my butterfly time to the White-Letter Hairstreak. The flight season is the culmination of all the work I have put in during the rest of the year identifying suitable sites etc. Some might consider this quite obsessive, true but I think this hobby requires a certain degree of obsession. My self imposed task is to correct the 'under-recorded' tag which always accompanies any mention of this butterfly particularly in Hampshire. To do this my aim this year is to identify as many new Hampshire sites for this butterfly as possible and to try and keep tabs on those discoveries I have already made. I have also set myself the challenge to observe and record egglaying behaviour in this butterfly.

Soberton. My newest Elm find, this one is probably for next year.

West End Football Fields. This was the only site I visited this year where there was nothing at all to report, but I was successful not very far away.

The fantastic weather together with being well organised has enabled me to visit 27 different sites throughout June and July. Nearly all of these sites are 'new' or revisits to last years 'new' sites. Of those 27 sites there were only 6 where I did not record any adult White-Letter Hairstreak activity, but on only 1 of those sites was there nothing at all to report. At 2 of those sites I had sightings which I was unable to confirm as White-Letter Hairstreak, 1 site I found eggs but saw no adults, bad timing of my visit within in the flight season accounted for another and Dutch Elm disease seems to have wiped out one of the sites I found last year. I still have a long and ever growing list of promising sites to visit. Next year I will either have to make some selective choices, enrol some help or give up work .

These are a few of the sites that I did not make it to during the flight period this year. This is next to Bay House School in Gosport.

this along the B3349 New Odiham Road at Shalden

and this one in the middle of the 'Merityres' roundabout in Andover

My earliest record this year (as previously posted) was on 9th June at the well known IBM/Lakeside site near Portsmouth. This is my indicator site as it is always an early one. However, I have not seen a confirmed adult since 8th July (in Winchester). I am sure there are still some about but they require a lot more effort/luck to find at this stage in the season. The extremely hot/dry weather throughout the flight period, which helps early in the season, must have shortened the flight period significantly. My count at each site is typically between 3 and 6 individuals with a few sites into double figures. However, when surveying a new site a singleton is a satisfactory result.

These are the typical type of record shots I like to get at a new site as a minimum requirement. This one on Ash from West End, Southampton 22.6.2018

This is from Silkstead 1.7.2018

and this one on Hazel from Curdridge 24.6.2018

I have published a list of the majority of these sites on my BC Hants & IOW branch website news page giving a grid reference and a very brief location information. I do not think it necessary to publish the complete list here as it will only be of limited interest unless you live in Hampshire. If anybody does want specific information about a particular site then please PM me.

In the next post I will focus on a couple of the sites/areas which might be of more general interest or stand out for one reason or another.

[Wurzel]

Sterling work Paul It was good to have your 'Hairstreak spotting eyes' at Shipton the other day I might have to tap you up for some info on any sites near to the Wiltshire border next season

Have a goodun

Wurzel

[Pauline]

You do realise don't you Paul that you'll not be able to stop now until you have covered every Elm in Hampshire ....and then every couple of years you'll have to update that info Seriously, you're doing the work of a whole team of observers and I'm sure I'm not the only one who appreciates the info you are providing

[bugboy]

Great work Paul. It's amazing that in the 21st century there's still so much we don't know about some of our widespread species!

[Pete Eeles]

Great stuff, Paul! And thanks for being so generous with the site listing on the Hants/IOW branch page ... I hope it generates some interest among the locals!

Cheers,

- Pete

[NickMorgan]

You do realise don't you Paul that you'll not be able to stop now until you have covered every Elm in Hampshire ....and then every couple of years you'll have to update that info Seriously, you're doing the work of a whole team of observers and I'm sure I'm not the only one who appreciates the info you are providing

Hear hear! The information yo9u give about White Letter Hairstreaks is really interesting and I have learned a lot. I am particularly interested since Iain Cowe has discovered them in South East Scotland, not far from our new house. I have been looking for the wrong sort of feeding damage on the leaves, so will have to start again!
I have noted for some time that the Elms only grow to a certain size and they then die off, presumably from DED. I had always imagined it was the width of the stem that was critical and that the Elm Beetles would only lay eggs on trunks of a certain width. However, I recently learned that it is the height of the tree that is critical, presumably because the Elm Beetles fly above a particular height. I may start trying to cut the taller branches on my Elm trees to ensure they survive a bit longer.