Update on the Green-veined White butterfly

In the previous post I showed a photograph of a Green-veined White butterfly and wondered if it was a gynandromorph. This is the image:

Gynandromorph Green-veined White butterfly

My first thought was that the butterfly was entirely female, but the right wing had been rubbed or damaged in some way, removing some of the scales and hence the pattern. But then I realised that the pattern on the right wing looked exactly like the pattern on some male wings. I then noticed that the abdomen is 'kinked' rather than straight, which is a feature that I have seen in other gynandromorph images, though admittedly of different species. I suppose that if the internal organs are male on one side and female on the other, then the inconsistent internal structure will be reflected in some way in the outer surface.

I showed the image to a number of people and it has now been confirmed as a very rare bilateral gynandromorph.

Bilateral gynandromorphs are female in one half and male in the other, and arise from incorrect cell division at some very early stage in the development. They are very rare and I have been unable to find any other images of this particular gynandromorph anywhere in the literature or on the internet.

Moving on

Over the past few years, I have added fewer and fewer new species to my list each year. The main reason for this is my modus operandi, whereby I search for things that I can photograph and identify specimens mainly from those photographs. This process has limitations: many species need microscopic analysis before they can be identified accurately. Since I don't capture specimens there are many species that I see that I cannot identify. This is a lost opportunity in a number of ways:

• Potential records are not being added to the national database, so the overall picture of what is where is wrong.
• I research the natural history of the species that I identify, and if I don't know what something is, I can't find out what it does.
• All species have loose or tight associations with other species and their habitat(s). I am missing opportunities to find out these associations, and hence my ability to add to our knowledge is reduced.

Basically, I am limiting my knowledge and I am limiting my ability to add to the greater knowledge. So I have decided to start sampling specimens. This will enable me to identify specimens beyond "a tachinid" or "a lesser cranefly". It's a logical progression, and hopefully it will add to your knowledge as well as mine.

On Friday I attended a beginner's course on spider identification. Spiders are an area that I have largely ignored for a number of reasons, and I think it's time to embrace them and begin to record them properly. The literature isn't cheap, but there are hundreds of species out there, and I'm sure I can make some progress in this very under-recorded group.

During the fieldwork we found this harvestman:

The harvestman Platybunus triangularis

Platybunus triangularis is one of the few harvestmen that can be found as an adult at this time of year. The pose with one leg held out as a trigger is typical of harvestmen, since they don't make webs, but pounce on passing insects.

New to my species list.

This Green-veined White butterfly is rather interesting:

Green-veined White butterfly

The obvious oddity is the fact that the patterns on the two wings are different. The left wing is clearly a female wing (it has plenty of dark spots), but the right wing has only a faint, single spot. The wings of male Green-veined White can vary a little, but I have seen identically-marked males. So the question is: is this a gynandromorph (half female, half male)? Another thing to notice is that the abdomen is not straight: it has a distinct kink in it. This is a feature I have seen on images of confirmed gynandromorph specimens. The jury is out, but I'll report back later.

My first collected specimen is a Water-measurer - Hydrometra stagnorum:

Water-measurer - Hydrometra stagnorum

Hydrometra stagnorum is a water-walking bug that can be seen in the company of other water-walking species, but it's a lot smaller (12 mm.) One notable feature is the very long head: this is thought to be used to reach food below the water surface.

New to my species list.

One sunny day

This year seems to be following the pattern of the previous two: once the frost is gone, we enter a period of extended rain and showers that lasts all the way through May and beyond. Any days with sunshine, therefore, are both welcomed by me and utilised fully by insects.

I have seen a couple of white butterflies on verges as I drove along, but this is the first that has settled long enough for a photograph. It's a male Green-veined White: the females have more spots which are also more pronounced.

Male Green-veined White

This is the first of this year's spring butterflies. These Green-veined Whites will have at least one further generation in July, and maybe another one later in September, but I rather suspect this will be a two-brood year given the lateness of the first. Just to keep things amusing, the second generation have more pronounced markings, with second generation males looking quite like first generation females....

The Speckled Wood is also rather late this year:

Speckled Wood butterfly

This is another butterfly that can have three generations per year.

Here's the underside:

Speckled Wood - underside

A couple of years ago, I was photographing fungi in September, and a Speckled Wood landed beside me on some fallen leaves. I turned to reach for the camera and when I turned back I couldn't see it, although I knew exactly where it was. It took me a good 10-15 seconds to see through the camouflage and get the shot.

Most of the 'regular' hoverflies are now present, although still in quite small numbers. This is the extremely common Melanostoma scalare, probably my most frequently-encountered hoverfly:

Female hoverfly - Melanostoma scalare

I still haven't seen a single Orange Tip butterfly this year. Last year I reported that someone had very carefully gathered every single specimen of Cardamine pratensis on the patch and left them in a pretty little 'posy' at the end of the hedgerow. I suspect the entire local population was wiped out at that time. I'm hoping that some mated female finds the couple of flowers that have opened this year and restarts them. The simplest act can have the most devastating effect.

Sun continues

While much of the UK has been under water for the past month, I'd hazard a guess that April was one of the driest on record in Co. Donegal. Although we've had a lot of sun, the wind has been easterly and that keeps things cooler.

Butterflies are out and about, though, and I've had Small Tortoiseshell, Speckled Wood, Green-veined White and now Orange Tip.

The male Orange Tip is unmistakeable, with those bright orange wing-tips:

Orange Tip butterfly - male

The males emerge a few days before the females in order to establish their territory, which they will defend against any moving white object, including pieces of paper. The females will be out next week and then I'll be looking for eggs on their host plant - Cardamine pratensis.

Green-veined White is usually the first of the spring-emerging butterflies on the patch. The males have fewer black markings than the females:

Male Green-veined White butterfly nectaring on Herb Robert

Male Green-veined White butterfly

Here's a shot of the female for comparison:

Female Green-veined White butterfly

Interestingly enough, the Orange Tip and Green-veined White share a common foodplant, but whereas the Orange Tip larvae eat the seedpods, the Green-veined White larvae eat the leaves.


Tachinid flies are parasitic on the caterpillars of larger moths, and are readily identified by their extremely bristly appearance:

The Tachinid fly Gymnocheta viridis

Judging by the number of Tachinids I encounter, it is clear that they are serious population controllers.

The Clouded-bordered Brindle moth is normally found from late May onwards. This is fully a month early, so the heat has brought the overwintering larvae on a bit more quickly than usual.

Clouded-bordered Brindle moth

The moth above is rather unusually marked: the central white 'kidney mark' is missing. Compare with this one from a couple of years ago. http://donegal-wildlife.blogspot.com/2010/06/busy-time.html


Breaking news: the recent mystery eggs that I showed in Juncus rush appear to belong to a leafhopper, rather than a sawfly. Full details in the next post.

High Speed

With the current warm weather, every minute seems to deliver new insects and flowers.

Butterflies are hatching, and as soon as they emerge they seem to be concentrating on the next generation just as quickly as they can. This shot shows a pair of Green-Veined Whites: male at the top of the picture, female at the bottom:

Pair of Green-Veined White butterfly

At the moment, the male Orange Tips are still patrolling, looking for the females:

Male Orange Tip butterfly

I think the underside of the Orange Tip is quite beautiful (as well as being good camouflage):

Male Orange Tip - underside

Small Tortoiseshells are looking very threadbare now: they overwinter as adults and the wings have lost most of their scales.

Small Tortoiseshell butterfly

I was watching another of the cuckoo Bumblebees  - Bombus bohemicus - and managed to get a clear shot of one of the identification features. Since these bees don't collect pollen for themselves, they have no use for pollen baskets:

Cuckoo Bumblebee - Bombus bohemicus

Solitary bees make their own nests, with the female collecting pollen to feed her own brood. Solitary bees are usually either mining bees (make tunnels in soil) or mason bees (make tunnels in soft stone or mortar). It should come as no surprise that there are bees which are parasitic on solitary bees, and there are a few species of Nomada which are kleptoparasitic on solitary bees - they steal the pollen from the tunnels. This appears to be Nomada leucopthalma, a kleptoparasite of Andrena clarkiella, which is just coming to the end of its season (they collect only willow pollen). So Nomada leucopthalma will be coming to the end of its season, too:

Nomada leucopthalma

A few more flowers opened today:

Bush Vetch:

Bush Vetch

 Common Fumitory:

Common Fumitory

 And everyone is talking about the Blackthorn flowers this year. The show is quite stunning:

Blackthorn Flowers

April 28th is St. Mark's day, and the Bibio genus of flies appears on or around that date, so they are commonly known as St. Marks Flies. With this being such an early year, they are a couple of weeks earlier than usual:

Male St. Marks Fly

The large black flies that you will currently see flying with their hind legs dangling down is another, larger, species of Bibio.

 Tomorrow I'm off to a limestone area, so I should find something interesting there.

Little differences

Our native butterflies appear in a rather strict sequence depending on whether they overwinter as adults (e.g. Small Tortoiseshell) or as pupae (e.g.Green-veined White), below:

Green-veined White butterfly

This close-up shows that the 'green' veins are actually made up of  minute yellow and black scales under the wings:

Green-veined White closeup

Male Orange Tip butterflies are also out now, in tight synchronisation with their host plant, Cardamine pratensis.  They are patrolling hedgerows at the moment, establishing their territories, and the females will emerge in the next week or so.

If butterflies and moths are around, then their deadly enemy the Tachinid fly is bound to be around, too:

Tachinid Fly

These are parasitic on the larvae of numerous insects, laying their eggs either near the larvae (so they can be accidentally eaten by them) or directly onto them. They then live internally in the larvae, consuming fat reserves and other non-essential parts before emerging to pupate themselves. In field tests around 80% of butterfly and moth caterpillars are found to be parasitised. Tachinids can be differentiated from other larger flies by the long spines and bristles that cover all parts of their body.

Germander Speedwell is opening up all along the hedgerow:

Germander Speedwell

If you're ever in any doubt about a Germander identification, check the stalks. If they have a pair of rows of hairs, then your identification is secure:

Germander Speedwell stalk, showing the twin rows of hairs

Sawflies are a very under-documented part of the bee and wasp family. They take their name from the female's modified stinger, which takes the form of a saw which is used to cut slots in leaves. She then lays eggs in the slots and they hatch out into larvae that very closely resemble the caterpillars of moths and butterflies. Sawflies can be tricky to identify, but if you see a v-shaped suture on the thorax, then you can be pretty sure it's a sawfly.

Adult Sawfly

I checked the lights last night for moths, but it was raining, so there were no moths around. I did, however, spot this snail crossing the step:

Green-veined White

I've recently seen a few 'whites' flying over hedgerows and fields, but this is the first time I've been able to get close enough for an identification. Green-veined White tends to inhabit slightly rougher areas than the Small White on my patch, with the GVW being seen in rural hedgerows, whilst the Small White is more frequently seen in gardens. The first one I saw was a freshly-emerged female:

Then I almost immediately saw a male on a dandelion 'clock'. I suspect it had also just emerged, since the seedhead isn't a food source.

Whilst the main priority of a fresh specimen is to inflate its wings, this one was also checking out her tongue function:

Although the veins on the underside of the wings appear to be green, a close-up shows that the scales are yellow and black:

Butterflies

We had two glorious days of sunshine and suddenly the butterflies were out in decent numbers.

Orange Tip males emerge before the females and set up territories along hedgerows and sunny banks. I'm always surprised by just how bright those wingtips are.


The underside is a mosaic of black and yellow scales that resemble moss or lichen. Good camouflage:


And here's the underside of a Green-veined White that also emerged on the same day:

Various tinies

The hedgerows are almost up to speed now that all the greenery is available. The availability of greenery brings larvae to feed on it, the presence of larvae brings ichneumonids to parasitise them. This medium-sized ichneumonid is about 15 mm. long, including those wonderful antennae.

Some of the micromoths really are minute, but many are are at least as pretty as the macros, and some are much more beautiful. This is Glyphipterix simpliciella - the Cocksfoot Moth. The larvae live inside stems of Cocksfoot grass. The adult moths are 3-4 mm. long, and can be seen running over the leaves and stems of the host plant at this time of year. The only way to see these is to lie down in a bank of grass and wait for them to land, as when they're flying around they look rather like midges:

I mentioned leaf miners earlier and they have started to appear (indeed some are finished already). This is the mine of Phytomyza chaerophylli - an agromyzid fly. One of the main identification characteristics for the mines of flies is that many of them contain a double row of frass (polite word for dung) in the mine. In these flies, the teeth are oriented in a such a way that the fly must eat right to left and then turn onto its other side and eat left to right. As it turns, its rear end points in opposite directions, resulting in the two rows of frass. The section of leaf shown here is about 15mm. across:


An easily identified hoverfly: Melanostoma scalare. I liken the yellow abdominal patches on these to oven gloves. (Female) fly about 12mm long.

One of my first butterfly images of the year: Green-veined White with the Click beetle Athous haemorroidalis (lower left).