Tuesday, 19 August 2014

Different eyes

Last week I returned to my old stamping grounds in Berkshire, England, as part of a 1750 mile round trip through Scotland, England, Wales and Ireland. It's 15 years since I lived there and I was astonished at how much had changed. Then I suddenly realised that it was me that had changed most of all: I instinctively knew that I was on alkaline soil (something I never knew before) and there was even evidence of chalk. This kind of information just wasn't apparent to me before I began to study wildlife seriously.

The plants, of course, are different to those that I find on my home acidic soil, and that leads to a completely different set of leaf-miners, since most miners are specific to a single plant or family of plants. Different plants, different insects, a 15 year gap. Everything seemed new and different.

One of the first 'new' species I saw was the leaf-mining micromoth Cameraria ohridella on Horse Chestnut:

Mines of the micromoth Cameraria ohridella on Horse Chestnut
This species has spread rapidly northwards and westwards since it arrived in the UK around 2001, and it has now been found in Belfast and Dublin. Described as new to science in 1986, it affects mainly Horse Chestnut, but can also be found in Acer species. Although the leaf damage is extensive, affected trees are not under threat, since the mines are started after the leaves have established.

The Harlequin Ladybird, however, is a serious problem: 
The Harlequin Ladybird, Harmonia axyridis 
This is larger than our native species and out-competes them when they have a common food, such as aphids. When Harmonia arrives, the local species are all but eradicated. I saw plenty of these, but no native 7-spots, 10-spots or 14-spots.

Another interesting observation: at home I have Red Campion and Red dead-nettle. Here I found White Campion:

White Campion

And White dead-nettle:

White Dead-nettle

There was also evidence of garden escapes, with some Geranium species in large swathes. I found this gall on many of the leaves:

Uromyces geranii on Geranium sp.
It seems to be the fungal rust Uromyces geranii.

All of the above species are new to my species list.

I managed to sneak up on a resting Painted Lady. These are always rather tricky to photograph:

Painted Lady butterfly

Quite pleased with that picture.

I also managed to get a shot of a male Common Blue Damsel:

Common Blue Damsel
These were particularly frisky on the day.

I still have some species that I need to identify, so I'll post more as information arrives.

Thursday, 24 July 2014

Little finds

Some of the best finds can be unexpected and completely accidental.

En-route to pick up a car earlier in the week there was a detour, so I stopped at a lay-by to confer with Mr. Google. I spotted this wonderful little moth out of the car window and jumped out with the camera. It's the Latticed Heath:

Latticed Heath Moth
This is a Clover feeder and is found in grassy areas. One generation in this area.

New to my species list.

Yesterday I was called out to examine what appears to be a fungal rust on Himalayan Balsam:

Fungal attack on Himalayan Balsam
This is an extremely invasive plant, and it has now reached most parts of Britain and Ireland. To date the local populations have been free from predators or parasites, since it is an introduced alien. But last year I found a leaf-miner and now we have this fungal rust, so perhaps we can expect populations to begin to weaken. That might just open up opportunities for other parasites to take hold, so perhaps we're seeing the start of some kind of weakening/control. I can certainly confirm that the miner has spread very rapidly and has now been found in perhaps half a dozen new sites around the country, some hundreds of kilometres apart.

After I had examined the rust, I went back to the car-park to find a stand of Comfrey on a stream-bank. Some of the leaves had a fungal attack and I have now identified this as Melampsorella symphyti:

The fungal rust Melampsorella symphyti on Comfrey
There are very few records of this on the FRDBI and seems it's new to Ireland.

A few more recent images are instructive:

This is the excellent Nettle associate Calocoris stysi: 

The Mirid Bug Calocoris stysi
The leaf-mining fly Pegomyia solennis is one of the few that are communal. Always found on Rumex sp., especially Broad-leaved Dock:

Larvae of the communal Dock miner Pegomyia solennis
Some leafhoppers are absolutely minute. This is the Meadowsweet specialist Eupteryx signatipennis, about 3 mm. long:
Meadowsweet specialist leafhopper Eupteryx signatipennis
New to my species list.

Finally, another oddity. I have a huge Lavatera bush in my garden and it is usually covered in bees, wasps and hoverflies all nectaring. I had assumed that the bees were gathering pollen, too, but it seems that the pollen is no use to Honeybees and Bumblebees: they actively remove it after they have taken the nectar:

Honeybee removing pollen from Lavatera.
Note the empty pollen baskets.

Wednesday, 16 July 2014

Background research

Weather hasn't been too good recently, so I have been working away researching all manner of creatures from spiders to beetles, to parasitoids.

A colleague in Galway found a parasitised larva of the 4-spotted Footman moth a couple of weeks ago. Here is her original image:

The larvae of the parasitoid have consumed non-essential parts of the moth larva and have emerged and pupated en-masse. The original larva is still alive, and will move away from the batch of parasitoid cocoons. There are a number of strategies that parasitoids use to avoid being parasitised themselves, and allowing the original host to temporarily survive and walk away will lessen the chances of the parasitoid cocoons being detected by the hyperparasitoid, since the hyperparasitoid will use the original larva as a vector and be distracted by it.

I received the cocoons last week and yesterday two adult Braconid wasps emerged. The remaining 22 cocoons are still intact.

I used the key to Braconidae to get the specimens to genus (Apanteles), and then used a 1973 paper from the Bulletin of Entomology to refine the search (there are over 250 species of Apanteles on the UK list). The most striking photographic evidence for identification are the wing-veins. 

This is my photograph of the diagnostic part of the wing veins of the Galway specimen:

And this is the reference image of the wing veins (rotated to be in a similar position to the sample above):

The similarity is striking, and leads us to Apanteles octonarius, which is known to be a parasitoid of the 4-spotted Footman moth. The adult parasitoid wasp is 2.5 mm long.

There is one previous record of Apanteles octonarius on the Irish list, and that was from Mayo in 1911. I am now seeking validation of this identification, since this group is new to me (apart from Apanteles glomeratus, which parasitises the Large White butterfly, and which I showed last year.)

Another bit of research centred around the Tachinid Eriothrix rufomaculata. This Tachinid can be readily identified by the two red marks on the top of the abdomen, (and which give it its specific name):

I predicted last week that this fly would shortly appear, since I had noticed a large number of other migrant species, including the Red Admiral butterfly, the hoverfly Scaeva pyrastri and a number of migrant moths. I am certain that this fly is migrant to this country, since I can predict its arrival by monitoring the arrival of other species.

That photograph was taken using the new 70D, which continues to amaze me daily.

Tuesday, 24 June 2014

New camera and other stuffs

So I bought myself a Canon 70D. The EOS 350 had served me well for nearly 10 years, so it was certainly time for an upgrade.

The 70D has far too many features to discuss here, but it has a few that I am already finding indispensable. Firstly, it has a revolutionary new focussing system, which enables it to more or less instantly decide which direction (nearer or further) to go when focussing. The 350 was fast, but the 70D is near-instant, which is crucial when photographing insects. A fully-articulated rear screen enables me to take shots above my head or down at ground level. 20 megapixels means I don't have to get so close, so depth of field can be better. It can operate over wi-fi, so uploading images means less wear and tear on memory card transfers from camera to computer and back again. Video mode means I can tag images with a piece of voice annotation.

Here are a few shots:

This is the 10mm. micromoth Celypha lacunana, which is out in very large numbers on my local hedgerow:

The micromoth Celypha lacunana

 And this is the strange-looking hoverfly Xylota segnis:

The hoverfly Xylota segnis
The first time I saw it running quickly over leaves, I thought it was a wasp of some kind with those long, grasshopper-like rear legs.

Formica fusca is the ant which is most numerous in my heathy area, and they can often be seen climbing Willow bushes to 'milk' their aphids. This one was behaving very strangely, cropping the fine hairs from a Bramble leaf. I have absolutely no idea why it was doing that.
Formica fusca, an ant
Orchids started flowering last week, so now is the time to see them at their best.
Common Spotted Orchid, with a touch of Heath Spotted

'Cleaner' Common Spotted Orchid

I also took a record shot of the white version of Bush Vetch, which is still slowly expanding its range along a ditch:

White variant of Bush Vetch

 It's still early days for the camera, but I think the results are shaping up well for the future.

Sunday, 15 June 2014

Donegal butterfly day

It rained.

But we were in a far north coastal area on limestone, so I still hoped that I might find something new.

When it rains there are compensations. I got this shot of water droplets on the moss Tortula muralis.

Water droplets on Tortula muralis
I also found Common Scurvy Grass, a new plant for me:

Common Scurvy Grass
The leaves are very thick and succulent.

New to my Species List.

Being on coastal grassland, I expected to find Burnet moth larvae and this one posed nicely on the Clover leaf:  

6-spot Burnet Moth larva

Very close nearby I found Pyramidal Orchid:

Pyramidal Orchid
There were many other orchids in this grassland area, the majority being Early Marsh Orchid, but most had already gone over.

One of the boggy areas had plenty of Sundew:

Sundew with captured insects

We also found a leafminer on a young leaf of Smooth Sow-Thistle:

Chromatomyia 'atricornis' on Smooth Sow-thistle
Chromatomyia 'atricornis' is the name for a complex of species where the actual determination can only be secured by dissection of emerging males.

Finally, another confirmation of the limestone: Field Scabious, which I haven't seen within 150 miles of this location:

Field Scabious

Saturday, 7 June 2014

Cottage Farm pre-survey survey

We are about to take part in a trial of a botanical survey methodology, so we had a pre-survey scan to select particular survey plots for the trial.

My camera is always with me, so I got some shots on the fly.

The first new species for me was a leaf gall on Wych Elm made by the aphid Tetraneura ulmi:

Gall of the aphid Tetraneura ulmi on Wych Elm
Here's a shot of the leaf (I rarely see this species of tree):

Leaf of Wych Elm
Both new to my Species List.

I also spotted feeding signs of what I think is another Aphid on the same tree:

Feeding signs on Wych Elm.

Then I was delighted to spot a single specimen of a male Banded Demoiselle - Calopteryx splendens:

Banded Demoiselle
It was very wary and rarely stopped as I followed it around. That's the only usable shot that I got.

New to my Species List.

This male Azure Damselfly was much more photogenic, allowing me a decent number of shots before it levitated away.

Azure Damselfly

Friday, 6 June 2014

A couple of surveys

I was invited to help with a couple of surveys this week and found some interesting specimens. The first location was a disused mill with associated ponds, dams, millraces and reservoirs. This is a wonderful site covering tens of acres, with old deciduous woodland and various meadows in addition to the water features mentioned above. It was also on limestone, which I always find interesting. Sedge and grass specialists would have a field day here. We were actually hoping for butterflies, but it was dull and wet, so I concentrated on leafmines, which are always there despite the weather.

First interesting specimen was this one on Ground Elder:

Blotch mine on Ground Elder
Most mines are specific to family, perhaps even species of plant, but this is the mine of Phytomyza angelicastri, which is more usually found on Angelica. So this isn't a new mine for me, but it is a new host for that species. I can now add that insect to plant association in my Donegal Wildlife database.

There were a couple of specimens of Early Marsh Orchid in the middle of a path next to one of the ponds:

Early Marsh Orchid
Sawflies are one of the least-studied groups of insects. They are difficult to identify to species, often requiring dissection for a certain identification. The larvae are also poorly documented, and since they can change their appearance dramatically when they shed their skin, identifications are very tricky. One or two species can be identified from photographs, but first you have to eliminate similar-looking Ichneumonids. This is the sawfly Tenthredo livida (male):

The sawfly Tenthredo livida (male)

One of the main characters that can be used to separate Ichneumonids and Sawflies is the microsculpture on the thorax. In this case, it looks like the letter 'M':

Close-up showing microsculpture on the thorax
Ichneumonids tend to have a smoother thorax, although that's not a hard and fast rule.

This Eristalis hoverfly caused me a few id problems.

Eristalis nemorum  (male)
One of the main keying features for these is the facial stripe, which is more or less absent on this specimen. So that immediately keys to Eristalis arbustorum. But this didn't look right for that species. The key caters for specimens of E. arbustorum with a slight facial stripe caused by wear and tear, but this still didn't key out properly until I took into account the very narrow stigma (dark thin line) on the outside edge of the wing. This is a feature of Eristalis nemorum, which I am now told can sometimes be found with no facial stripe. I suspect that some of this variation is caused by the fact that my local specimens are found on acid soil, but this specimen was on lime.

Caddis flies are always found near water, since the larvae live at the bottom of ponds, ditches, etc.
Caddis Fly

Shield Bugs, in common with all other Heteroptera, go through a series of nymph stages before becoming adult. In each stage they become slightly more like the adult in size and pattern. This appears to be a final-instar (full-size, with larger wing-cases) nymph of Pentatoma rufipes:
Final instar nymph of the shieldbug Pentatoma rufipes
 There was a family of Mute Swans on one of the mill ponds:
Mute Swan and cygnets
I wouldn't normally go near swans with cygnets, but I was advised that this pair were calm enough. The male quickly got between me and the family and hissed a bit, but stayed to the side, watching me until he saw that I was just taking photographs. Interestingly enough, this is new to my species list.

All in all a lovely location that I will revisit in the future.