Max Anderson

[Padfield]

I'm delighted you're finding the cats, Max! It's remarkable, isn't it? So much easier than looking for them by day (if not so easy to photograph them)!

Just one word of caution for others copying this method. While UVA from a torch is fairly harmless, you should remember that your pupils are fully dilated at night and you can't, of course, see the actual UV. I've no idea how much is reflected off the leaves. I bought a pair of UV goggles, as used by moth trappers, to protect my eyes. I believe over-exposure to any UV, A or B, can accelerate cataracts, for example.

Serious stuff over. Brilliant shots, Max, and of the black and brown hairstreaks too. I wish I'd thought of this when I had them on my doorstep in Switzerland.

Guy

[Max Anderson]

Just one word of caution for others copying this method. While UVA from a torch is fairly harmless, you should remember that your pupils are fully dilated at night and you can't, of course, see the actual UV. I've no idea how much is reflected off the leaves. I bought a pair of UV goggles, as used by moth trappers, to protect my eyes. I believe over-exposure to any UV, A or B, can accelerate cataracts, for example.

^^^Thanks for this Guy, definitely something worth emphasising to those that are interested^^^

Brilliant shots, Max, and of the black and brown hairstreaks too. I wish I'd thought of this when I had them on my doorstep in Switzerland.

I was mesmerised by the whole experience to be honest. It's quite surreal to start with, and I didn't expect it to work as well as it did. Thanks again for your guidance on this!

Hello Max - I've just jumped in to this amazing conversation - can I ask a silly question? Does UV light hunting have to be done in the dark or does it work in twilight?
Best wishes, Janet

Ideally it should be very dark, any light will reduce the effectiveness of the UV torch. It can be done, but it makes things more difficult to see.

Unfortunately I’m told that PE larvae do not fluoresce under UV, but I will certainly double check. I’m mainly looking forward to WLH surveys around my elm lined local streets, and as I have accidentally collected several recently, I can only imagine they are everywhere.

I'm sure your sources are very reliable, but would be good to get confirmation of this from you. Yes, I'm in a similar situation where I'm surrounded by roadside elms, and I'm really interested to see how prevalent they are.

[David M]

Your commentary on your exploits regarding locating Hairstreak larvae via UV is highly illuminating, Max (if you'll pardon the pun).

They really DO stand out very clearly using this method and your stargazing analogy is quite appropriate.

Superb stuff.

[Max Anderson]

Black hairstreak

The black hairstreaks that I'm monitoring in Sussex have been pupating this week. I returned late last week to undertake further UV torchlight searches and in addition to the four larvae that I had found previously, I located another two. At the beginning of the week I headed back over during the night to check on progress and was only able to locate two of the six larvae, one of which was pre-pupa. I expected that the reason I was unable to find any others may be because the chrysalises do not flouresce under UV - which I'm still to confirm for definite.

pre-pupa

This morning, I was able to locate a total of three pupae, all of which were on twigs. I will return at some stage to check whether they flouresce under UV, however I'm pretty confident that they don't. The mimicry from the pupae is magnificent, and there is clearly some considerable variation in the extent of the colouration between individuals. I wish I had more time to dedicate to further study, but my spare time is frustratingly sparse at the moment.

[trevor]

Great work Max. What else can I say!.

Bound to see you in the next few weeks.

Stay well,
Trevor.

[Benjamin]

Great stuff Max - if you had more time you could really learn a lot about the site with this method. A couple of years ago I managed to find some eggs and was lucky enough to follow one all the way, but it took a massive amount of time and although interesting, didn’t really teach me anything I didn’t already know. If I’d have spent a similar amount of time with the UV torch method I’m sure I’d have learned a lot more - especially as BH cats are very easy to track.

I’ve explored my local elms at night now, but soon realised that the street lighting is too strong for good results. I have found some WLH cats low down, but need total darkness to search higher up. Not a problem you encounter in the middle of Ditchling Common I’m sure!

Shame the pupae don’t fluoresce, but they don’t tend to travel far to pupate, so you’ll have a good chance of locating them near to where the cats were last seen.

[Max Anderson]

Brown hairstreak

At my local playing field, the brown hairstreak cats are getting on nicely and should be pupating soon. The main margin has been heavily cut back, with 75m of highly suitable habitat lost. Only one intact blackthorn plant remains along the main margin, where there had been around 70 eggs counted during the winter. After speaking with the groundskeeper, I learned that this happens every year in late spring, as a requirement for cricket and football pitch maintenance. Nonetheless after searching for only 10 minutes, I managed to find 6 larvae.

A very interesting site that I'm excited to see during August. Exceptional numbers of eggs maybe an edge effect. I suspect that the reason for the high density of eggs is because the site is one of the southernmost sites that they could occupy within the area. The urban area, which surrounds the site, may serve as a barrier, within and beyond which there is little or no suitable habitat. I would be interested to hear from any others who have experienced exceptional abundance of species along an edge of their range, with potential barriers to dispersal in play.

[Pauline]

Very interesting reports Max. Just wish I had the nerve to wander round my local woods in the pitch black. Perhaps BC might consider some night field trips?

[Max Anderson]

Thanks Pauline - I think there would be some value in running some field trips during the night. Partly beccause some species are only active at night as larvae, and also because its super interesting! It's easy to forget that butterflies only spend a short duration of their lives as adults..

[Neil Freeman]

Fascinating posts Max. I was aware that some inverts fluoresce under UV light but would never have thought of using it for butterfly early stages.
Great stuff.

... I think there would be some value in running some field trips during the night...

Could be a combined event with a Moth Night with some running moth traps whilst other wander around with UV torches away from the lights of the traps.

Cheers,

Neil.

[David M]

Very revealing, Max. If I had a colony near me I'd be trying this method myself.

[Max Anderson]

Black hairstreak

I managed to make a few visits to Ditchling common to catch up with black hairstreak adults, which began to emerge from 12th/13th June. Lots of activity spread across the site and an estimated 25-30 individuals seen at peak around 10 or so days later. Some enjoyable moments observing egg laying and nectaring, with success finding a freshly laid egg.

Some ideas and plans for work next year are being pieced together.

[Pauline]

That's a great egg Max. What a fabulous colour. I thought I saw a couple egg-laying in Epsom and had a quick look for eggs but I was looking for something white-ish. I would never have seen that. I reared a few of these many years ago having been given the larva as a 'gift' by a well-meaning friend but I have never seen the egg. Might have to go back to Epsom.

[Wurzel]

Some fantastic images there Max of a species I've only encountered once before Really like the in flight shot showing the topside - it's odd isn't it that despite the glorious undersides we butterfliers covet the topside images for this species?

Have a goodun and stay safe

Wurzel

[Max Anderson]

Thanks both.

Yes, Wurzel - I think the difficulties associated with photographing the dorsal sides of this and many other species makes it more of an attractive prospect! We do like a challenge.. I've actually been working on some more in-flight photography that I hope to share at some point in the near future too..

[Max Anderson]

White-letter hairstreak

Time spent making observations and reporting has been very limited of late. For the best part of the last month or so, I’ve been undertaking the first part of my summer fieldwork; visiting my field sites at sunrise and sunset as part of some research to understand how nocturnal insects contribute towards pollination compared with diurnal insects. As a consequence, I’ve had what feels like jet lag for a month, but I’m finally finished with the first half of my fieldwork, which means the sub-early starts are coming to an end.

On my way home each morning, I pass through Hollingbury, which is home to a healthy population of WLH. I spent a few mornings catching glimpses of males fighting above the ash and elm trees, and a short transect around the treelines alongside the road and woods yeilded 35-40 individuals between 08:45 and 09:45 on 14th July. The vast majority of sightings were of silhouettes or spiraling males in groups of 2-5. In the evenings, before heading back out to the field sites, I stopped off once or twice to look for any that had come down to nectar. A group of 3 or 4 individuals had come to rest on a walnut tree, and descended to nectar on creeping thistle and bramble between 17:30 and 18:30.

When walking around Brighton and Hove, I've observed WLHs in abundance on roadside trees and parks. Given the elusiveness of WLHs and other Satyrium spp., they are certainly under-recorded and I think under appreciated.

[Benjamin]

Spot on Max - I see them down in local front gardens throughout the flight period - often before they are officially thought to be on the wing. For me, having them as such an ever-present throughout June/July has been one of the highlights of moving down to Brighton.

Looking forward to hearing more about your plans with the hairstreaks for next year….

[trevor]

Great work with the Black Hairstreak Max.
One observation, there weren't as many coming down to the bracken this year,
but the smallish Oak at the start of ' Hairstreak alley ' was often host to BH
flying around the tree top. I imagine honeydew on the Oak leaves was the attraction,
and basking was taking place up there too.

Keep up the great work,
Trevor.

[David M]

...When walking around Brighton and Hove, I've observed WLHs in abundance on roadside trees and parks. Given the elusiveness of WLHs and other Satyrium spp., they are certainly under-recorded and I think under appreciated.

Very true, Max, although they are certainly not under-appreciated by me. This is a fascinating species, and I wish I were able to see 35-40 in a year rather than in a single visit!

Good luck with the rest of your fieldwork!

[Wurzel]

Lovely set of shots Max I rate Hairstreaks quite highly as their elusiveness adds to their cache

Have a goodun and stay safe

Wurzel