My lake

My lake

Tuesday, 22 July 2014

Glow-worms

This is a short-ish post showing one of the reasons I went out at dusk armed with torches last week. As well as finding those Forest Bugs that I showed in my previous post I sort of found what I'd been looking for! I was also interested to see if moths were attracted to torch light - well it seems they aren't really, only one landed on my torch but I could see there were plenty around. I didn't see a lot else other than a roosting Magpie who woke up and then woke the rest of his family and they all started cackling up in the tree tops. And the Tawny Owls were hooting away but we can hear them indoors anyway and are used to their sound at various times of the year.

Having found a Common Glow-worm nymph in the veg patch back in the spring, I'd been dying to get out and see if I could find any adults. I'd seen some females glowing after dark at my previous house many moons ago and that was pretty cool, but of course I don't have photos from back then. I didn't see any females glowing but when I went to check on the large torch that I'd laid in the grass for a while, blow me down if I didn't find a male Glow-worm on it! I have checked the different species and I think this is the Common Glow-worm Lampyris noctiluca, although there is another species very similar called Lamprohiza splendidula which is smaller, and has two clear patches in the head shield over the eyes, but I can't see that in any of my photos. 

Male Glow-worms are attracted to light.

I had to get it onto my hand to take photos, otherwise I found they just went down into the grass thatch, not trying to hide but were too hard to photograph like that. It seemed perfectly happy to wander about on my hands and fingers. I seem to be forever showing bugs on my hands these days, I guess it's just a convenient place to put them. :-)

Common Glow-worm (Lampyris noctiluca).

Then after I'd had my walk around (accompanied by 3 cats, which I was pleased about as I am scared of the dark and it was less spooky with them about, even if they did scare off any interesting critters that may have been in the vicinity!) I found another one! I know this isn't the same one... unless he got a white marking on him somehow in less than half an hour. I think it's a bit of bird poo or something as I don't see any images of Glow-worms that show markings like this.

Common Glow-worm (Lampyris noctiluca).

So this week I'll attempt to stay up late and go out again and see if there are any females still glowing. Apparently the females glow for up to 2 hours after dusk during June and July, so here's hoping.

I've shared these before but here are the pictures of the nymph I found, which by the way eat snails, so are a perfect critter to have in the garden!

Common Glow-worm nymph (Lampyris noctiluca).

Common Glow-worm nymph (Lampyris noctiluca), showing its amazing mouth parts.

Saturday, 19 July 2014

A freshly moulted shield bug

Whilst picking blackcurrants one day I suddenly noticed a pale coloured bug and then realised it was in the final moment of moulting. My camera was nearby but I was deep within the currant bushes so had to get buggy onto my hand whilst grabbing the exuvia with the other, then extricate myself and get to my camera. The bug was happy to wander around on my hand whilst I took photos and then I put it back onto a currant leaf. At the time I didn't know what kind of bug it was, but after looking at the exuvia (the moulted skin), I think I have managed to ID it as a Forest Bug (aka Red-legged Shield Bug), Pentatoma rufipes.

From the British Bugs website:

A large brown shieldbug which has orange legs and slightly hooked projections at the front of the pronotum. The pale spot at the tip of the scutellum varies from orange to cream.

This species overwinters as young nymphs, which feed mainly on oak. Alder, hazel and other decidous trees are also used, including apple and cherry. Adults are partly predatory, feeding on caterpillars and other insects as well as fruits.

New adults may be found from July onwards, surviving until the late autumn, and eggs are laid in August. Adults can sometimes be found in the early spring, suggesting that a secondary breeding cycle may be possible. Widespread and common across Britain in wooded areas, orchards and gardens.

Adult: July-November
Length 11-14 mm

Link to this site further down in the post.

Such a cool critter freshly emerged from a moult.

Checking my watch strap out.
My arms are not that hairy, by the way. The camera lies!

I wonder how long they take to change to the final adult colouration....
I couldn't exactly keep it to find out!

The exuvia upside down and head end towards us.
I find these things so fascinating, look at those eyes and what looks like a proboscis!

Right way up and back end towards us.

There are few photos on the web of this bug after a moult; in fact I could only find two. One is on the British Bugs website with a picture of a teneral adult, and the other on fellow bug lover JJ's blog - he has a great picture on this post of one actually in the process of moulting! In fact it was thanks to photos by JJ and also Amanda (The Quiet Walker) that I was able to ID the bug below, that I hadn't realised was the final instar nymph of the Forest Bug. 

Final instar nymph of Forest Bug (Pentatoma rufipes) on a scabby looking pear in my orchard.

Another Forest Bug nymph that I saw the same day,
funnily enough beside another orchard.

They are not easy to photograph as I've only seen them in shady places (not surprising given their name and habitat!) and the adults are shiny and reflect light. 

Adult Forest Bug (Pentatoma rufipes).

Forest Bug adult on a gooseberry bush.

Last night I finally managed to stay awake and get outside after dark armed with some torches to see what I could find out there. I found quite a number of the adult bugs on the trunks of trees - now as far as I know, they are not nocturnal, so I'm wondering if they were there during the day and I never noticed? I need to find out!

Forest Bug at night on tree trunk, taken using the little-used pop up flash of my SX50 and torch light.

Sunday, 13 July 2014

Raising Swallowtails - Part 11 - Video of a Pupation

I thought Part 10 would be the end of this series but then I thought I'd see if I could get a video of one of my caterpillars pupating. I've missed nearly all of them doing it but one day I noticed one of them twitching and wriggling a bit, so decided to set up my makeshift studio (lots of kitchen paper and blue tack) and set my camera video running, just in case. 

Well the twitching went on for a long time so my Cybershot batteries were running low and I switched to my Powershot SX50, which just about fitted OK on the mini tripod although it sagged a bit. But it annoyingly kept turning itself off every 16 minutes, so I had an egg timer in my pocket set to 15 mins so I could keep running to check and reset it filming!

At this point a friend on facebook who has the same camera told me how to switch the auto power down setting to off, but as I went downstairs to reset the camera, guess what started happening? Luckily there was enough time before the camera turned itself off to capture the whole pupation, and then I reset it to film some more over a period of time. So with the help of my OH and his Mac software, 'we' have edited this little film to show the pupation and how the newly formed chrysalis goes about changing afterwards into the shape that it stays like until a butterfly emerges from it, about 11 to 16 days later.

So with thanks to (another) friend who mentioned that I could make the video appear bigger here rather than the automatic small size it comes in at when linking to Youtube here it is .... and if you are reading this via an email subscription, you will not see this video so you will have to come direct to the blog to view it.


I'm onto the second batch of caterpillars/chrysalises now and am glad I'm not coming across more tiny caterpillars outside, as food is getting a bit low! There are already quite a few large caterpillars outside on the dill and fennel, and we've now found three of them settled down in pre-pupation outside. Two were in completely inappropriate places so had to be brought inside and the third I am keeping an eye on outside to see what happens so more about that in a later post..... I can already see that life is tough for the outdoor ones compared to my pampered indoor pets. 

Of the two we found outside and brought in, one had decided that a nice yellow string lying flat on the ground was a good place to pupate! In an effort to try to tidy up in the aftermath of the septic tank installation, we had strung a line to try to redefine lawn and gravel drive and started edging after the ground was softened by recent rain. Thankfully that caterpillar hadn't yet made its cradle so was brought indoors where it quickly settled down and pupated! One thing I noticed by bringing it indoors is how much more green it was than my indoor raised caterpillars - and in fact of the indoor ones, the dill fed caterpillars are more green than the fennel fed ones. 

Outdoor caterpillar comes in and shows its Ringo face (butt end!) one last time before pupating.

The other one was on a woody weed stem which had to be taken out; this was at the edge of my gravel drive but the ground levels had changed since the pipework had been laid and I was waiting until after my houseleeks had flowered before having to remove them (and the weeds!). That one is now indoors too, on its weed stem.

Something that I have only recently learned is how to sex the Swallowtail butterfly. As male and female are pretty much identical in markings I hadn't realised until after some research that there is a difference.... males have claspers at the end of their abdomen which they use to grab the female whilst mating. It's not very apparent or easy to see as the claspers are usually held together, but it seems to me that the female has a more flat end to her abdomen, which seems to be fatter as well, whilst the male is slimmer and has a pointy end. So I think in the last batch there were far more males than females, which is a good thing given there are only limited food resources round here, and I don't want them laying eggs on the neighbours' carrot leaves and being considered as pests!

I shared this before but now realise this is a male, as you can clearly see the claspers
(pointy bits) at the end of the abdomen.

Lastly, and I know this is a disjointed post, but this is what comes of having shared stuff on facebook then realising I hadn't done so here, here are some pics of one of the caterpillars making its cradle. Before taking the photos I had never really thought about how they did this, but having watched for a while on a rainy afternoon they actually spend a fair amount of time repetitively making silk threads and weaving them from side to side, so the cradle is made up of many threads. It is very tough stuff as after they've eclosed I have to pull off the chrysalis shell and some of this silk from the mesh lid that they are so fond of and the threads get left behind. I still can't see exactly what is going on so I might have to make a video, although it would have to be speeded up somewhat! :-)

By the way, these shots were all taken one handed as I was having to hold up the mesh lid to get at the caterpillar. You can see what I'm talking about better in the final photo. 

It was a bit of a slow process.

Quite a lot of silk strands are made to form this cradle.

Photobombed!

The new cradle showing multiple strands - it is visible just behind the third true leg
(front pointy legs) and what you see to the right is old silk from a previous cradle.

Oh and one more just showing how this lot decided it would be fun to group up, and what
a nuisance it is for me with them on the mesh as I can't easily photograph anything
going on here, let alone video it! So few of them use the sticks I provide.