Thursday, 28 April 2011

New lough

A visit to a new location - an interesting blend of heath, bog and lake - yielded a decent set of images for today.

We're right in the peak of the Orange Tip butterfly season, and there were hundreds of them chasing, nectaring and egg-laying on their host plant: Cardamine pratensis. This is a male, and if you look closely, you can see a single orange egg just to the right of centre:

Male Orange Tip and egg
This is the first female I saw this year, although there were plenty at the location:

Female Orange Tip butterfly
Every plant had one or two specimens of either sex jostling for position:

Orange Tip males

Bog Violet is easily distinguished by its pale, rounded flowers and very round leaves. It's always found in boggier areas:
Bog Violet

This Flame Carpet moth was flying around in broad daylight, although I usually only see it late at night:
Flame Carpet moth
Staying with moths, this Drinker Moth caterpillar was basking on a large rock. I associate these with dry grasses and reeds.
Drinker Moth larva

The leaves on the Willow bushes are only just opening and already the Willow Leaf Beetle - Lochmaea caprea - has made an appearance. The black larvae will eat the upper surface of many leaves over the next few weeks.
Willow Leaf beetle - Lochmaea caprea
The black fly at the top of the picture is a male of one of the Bibio St. Marks Flies.

Wednesday, 27 April 2011

Good Weather

We're currently in the best spell of weather that I can remember since moving to Ireland 12 years ago. It's already an early year in many places and it's difficult to keep up with the backlog of images that I'm taking. Nice complaint to have...

I'll start off with a picture of what has to be my favourite bee - Andrena cineraria. Andrenas are all solitary bees, digging their own little tunnels, laying the eggs and collecting pollen to feed the growing larvae. Andrenas are generally quite difficult to identify, but Andrena cineraria is very distinctive with its grey shoulder stripe. She looks rather like a thin bumblebee worker:

The mining bee Andrena cineraria

I haven't seen any female Orange Tip butterflies yet, but they're obviously around. This single egg was laid today behind the flower where the seedpod will form:

Egg of Orange Tip butterfly

The egg is clearly very fresh (it's green), but it will be orange by tomorrow.

I got a nice side-shot of the very common Melanostoma scalare hoverfly:

Male Melanostoma scalare hoverfly 
These are by far the most numerous hoverfly at this time of year. Later on in the year, the females fall prey to the parasitic fungus Entomophthora muscae in very large numbers.

Moths are continuously coming to light at night, and I spotted this little (1 cm.) moth:

Moths of that size are usually micromoths, but this is one of the macromoths that confuses all newcomers to moth identification. It's the Least Black Arches - Nola confusalis, which feeds on a number of woody shrubs. Judging by the specific name, I rather suspect the people who originally named it were a bit confused, too.

Something to look out for:

Entry holes of Cocksfoot moth larvae in Cocksfoot grass
The Cocksfoot moth is very numerous around verges with Cocksfoot grass, and will shortly be seen flitting around like glittering dust. If you look at stems of last year's grass and peel back the top leafblade you might well find these holes indicating where the pupa has overwintered. These minute moths are well worth looking for: their metallic slate-grey background with white feathering is very beautiful.

Thursday, 21 April 2011


I live in an area of highly acid soil, so I'm always keen to visit limestone areas. Soil type largely governs which plants can be found in a particular area, and different plants support different insects, so I always expect to find something new or different on these trips. Lough Erne is also much closer to sea level, so it's probably 7-10 days earlier than my local area.

My local violet is the Common Dog Violet - Viola riviniana, but this area has both riviniana and Viola reichenbachiana. The most obvious differences are the narrower flower and more pointed leaves: 

Viola reichenbachiana

And the dark, straight spur behind the flower:
Viola reichenbachiana spur
Both violets were growing on a verge accompanied by Ground Ivy:
Ground Ivy

Bluebells were just starting to open:

And this Dock Leaf Beetle - Gastrophysa viridula - was either touring or lost: they are rarely seen far from Dock leaves.

I spotted my first Ichneumonid of the year. The size suggests that these will be looking for either large flies or small moths:

This flower is Cardamine pratensis, which is the main foodplant of the Orange Tip butterfly, but is also used by the Green-veined White:

The minute moth is Micropteryx calthella, which is associated almost exclusively with Buttercups in my area, but it clearly uses other nectar sources when they are available. I don't expect to see Micropteryx calthella for perhaps another 3 weeks on my patch (the buttercups aren't even in bud yet).

I was delighted to find a new hoverfly species on the same verge. This is Epistrophe eligans, one of the earlier species to emerge:

 Male Epistrophe eligans

Another plant that I only ever see on limestone is the Cuckoo Pint, a most wonderful member of the Arum family:
Cuckoo Pint

No matter where I find Holly, I always find its leaf miner, Phytomyza ilicis. I was always curious that only one species of miner lives in Holly leaves because it seems such a safe place for an insect to live. It turns out that Holly heals very quickly when damaged, and the plant considers the mine to be a wound. Phytomyza ilicis is the only miner that moves quickly enough to keep ahead of the healing process:

Phytomyza ilicis on Holly

Moth flies are a mysterious group of flies that run around on plant leaves like little planes trying to take off. The larvae live in cesspits, drains and compost heaps:
Moth Fly
Lough Erne is a large expanse of water, so I usually expect to find some water-based species.

Alder Fly larvae are aquatic, and I only ever find the adults near rivers, ponds or lakes. The Alder Fly Sialis lutaria has to be one of the least aptly named of all species. It isn't a fly (it has 4 wings and is related to lacewings) and it has no association with Alder:
Alder Fly Sialis lutaria

Talking of aquatic species, I spotted this Coot sitting on her nest:


A couple of fungi to finish.

Last year I found a rather rare fungal infection - Taphrina crataegi - on Hawthorn. The leaves are only just open, and this bush was already infected:

Taphrina crataegi on Hawthorn
This appears to be the first record for Northern Ireland.

April 23rd is St. George's day, and St. George's mushroom - Tricholoma gambosum - is traditionally found around this date:

St. George's mushroom - Tricholoma gambosum

The spores are minute, around 5 x 3 microns:

Tuesday, 19 April 2011

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.

Sunday, 17 April 2011

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:

Wednesday, 13 April 2011

Early year?

I'm hearing many reports of species being 'early' this year. Species have been appearing at earlier and earlier dates over the past few years; so much so that it has almost become the accepted norm and people don't even mention it any more. But this year I'm again noticing that more people are making special mention of early specimens of moths, butterflies and other insects, so perhaps things are particularly early this year.

The following shot certainly illustrates that trend as far as I'm concerned, but before I discuss it, what type of insect do you think the following picture shows? (bumblebee, wasp, fly, other?):

Male Eristalis intricarius
Well, to put you out of your misery, it's a hoverfly: a male Eristalis intricarius. These are good bumblebee mimics, and at first glance, when they're stationary, they are easily mistaken for Bombus lucorum.

A few identification pointers might help. Firstly, it has only two wings; flies have two wings, bees have four. Secondly, the head is almost completely made up of eyes. In a bee, the eyes are long and narrow, with visible parts of the 'face' on both sides of the eyes. (Incidentally, the fact that the eyes meet in the middle is what makes it so clearly a male). Thirdly, what appears to be an orange stripe between the wings is actually the shiny scutellum, and isn't really a stripe at all. Finally, if you look carefully at the wing veins, you can clearly see the famous 'Eristalis bulge', which is unique to the Eristalis group of hoverflies:

Eristalis 'bulge'
The shot also illustrates another of the wing features which identify hoverflies: the 'False margin':

The trailing edge of the wing is not constrained by a vein: it is free to flex as the wing moves. I rather suspect this is one of the main reasons why a hoverfly can hover so accurately.

In terms of earliness, I have only once seen Eristalis intricarius before June: I have come to regard it as a summer species. The references say from March, but that would probably be a date from much further south.

The next shot shows a couple of tiny flies (on Dandelion for scale). On the left is a Sepsid fly: these run around on leaves and flowers with their wings flapping up and down in a semaphore fashion. On the right is one of our smallest hoverflies, Neoascia podagrica:

Sepsid (L) and Neoascia podagrica (R)

Here's a close-up of the (8mm. long, female) hoverfly:

This is again much earlier than I would normally expect to see it.

In terms of grasses, the first to flower around here is usually Sweet Vernal Grass, but that hasn't appeared yet.  Instead, I found Meadow Foxtail:

Meadow Foxtail
I have included a little insert (top left) showing the very short 'ligule' which can be used to assist with identification.