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.

High pressure migrants

Yesterday I showed the first specimen of the hoverfly Eupeodes luniger for this year, and today I saw a lot more. The hoverfly Scaeva pyrastri is known to be migratory and I saw it on the marigolds today:

So I rather think the south-easterly wind that accompanied the current high-pressure weather system has brought in a mass migratory influx from mainland Europe.

I also saw my first 2010 specimen of the parasitic tachinid fly Eriothrix rufomaculata:

I only ever see this on Ragwort. Its host caterpillar is unknown in Ireland, and I'm beginning to wonder if it's migratory, too. I need to sit and think if a migratory parasite makes sense.

Woody Nightshade is a plant that seems threatening in all of its parts:

Maybe it's the purple stalks near the flowers and fruit, but I can certainly see why our ancestors viewed early tomatoes with more than a hint of suspicion.

Occasional names

I saw what appeared to be a minute, strangely-coloured ladybird on the Ragwort and it was only when I blew up the image that I could identify it as a teneral (freshly emerged, and not yet fully-coloured) 10-spot Ladybird - Adalia decempunctata. These are about 3-4 mm. long, so that makes the beetle below it about 1 mm long.


Few Tachinids can be successfully named from pictures, but this is one of them. Eriothrix rufomaculata (named after the distinctive red marks on the abdomen) is a bit of an enigma: it is readily identifiable, but its host and larval stages are unknown. I only ever see it on Ragwort, so Cinnabar moth comes easily into the frame, but the fly has never been reared from them.


Moving on from one nameable beast to another, the ichneumonid on the left is Amblyteles armatorius. Its size can be easily reckoned from the neighbouring Tree Wasp - Dolichovespula norwegica. It's really good to be able to show these close relatives side by side. They aren't particularly dangerous to each other, but the ichneumonid is keeping a very close watch on the wasp - note the antennae.

That wasn't a chance shot, by the way: I noticed the ichneumonid was gradually approaching the Tree Wasp and waited until it was right next to the wasp before I rattled off a few shots.

Angelica is a major nectar source for many insects at this time of year. Female ichneumonids are swarming over the florets, refuelling before they go off in search of hosts.



Evacanthus interruptus is one of the more scarce leaf hoppers in this area. I might see one or two per year.

Phyllonorycter moths are minute - only a couple of millimetres long as adults. This is the mine of Phyllonorycter maestingella, on Beech. The larva tucks the lower surface of the mine a few times, contracting it and pulling the upper surface into a dome, thereby making a tube to live and feed inside.


This glimpse of the emerging Blackening Waxcap - Hygrocybe nigrescens - reminds me that the fungal season is almost upon us. It's time to dust down the fungal part of my brain.