Sunday, 13 April 2014

Parasitic wasp - Ichneumon stramentor

On Friday night as I was clearing the kitchen getting ready to sit down and watch a film with the family I came across this fantastic ichneumon wasp. It seemed to be drinking water from the kitchen top and wasn't in any hurry to move off, nor was it disturbed at all by the camera and me fussing about around it.

After some detective work on the net, with my books and help from the fantastic experts on iSpot I'm able to confirm it as Ichneumon stramentor.

It's about 1.5cm long if I don't include the antennae, and 2cm including the length of the antennae. It has a long tapered abdomen, the first half of which is yellow and the rear half black, with yellow spot at the tip (both on the top and beneath. Legs have black femora; tibiae are half yellow blending into brown that exceeds to the tarsi. Black thorax (with yellow spot) and black head. This specimen is a female as the males have all black antennae.

It's flight time is from April through to July. Besides our kitchen, it is normally found in meadows, hedgerows and along the woodland edge.

I. stramentor is an endoparasitoid species laying its eggs in the caterpillars of the Large Yellow Underwing and Setaceous Hebrew Character moth caterpillars (possibly others). This is where is get gruesome, with the I. stramentor larvae eating its way through the parasitised caterpillar until the host dies. By which time the I. stramentor larvae is ready to pupate.

In the world of mediaeval myths and legends the ichneumon is the enemy of the dragon. When it sees a dragon, the ichneuman covers itself with mud, and closing its nostrils with its tail, attacks and kills the dragon. Some say it is also the enemy of the crocodile and the asp, and attacks them in the same way. This reflects the parasitoid action of I. stramentor as it lays it eggs in the caterpillar targets.

The Greek word translated as "ichneumon" was the name used for the "pharoh's rat" or mongoose, which attacks snakes; it can also mean "otter".

Saturday, 12 April 2014

Moth trapping

Last weekend I finally got my moth trap out of the garage. This was only it's second outing since I bought it at the end of last year. The first use was almost immediately after unpacking it and assembling it in November. It will come as no surprise to those in the know, that this wasn't a successful trapping initiative. Well the weather was promising a mild and dry night, so I trundled out there with the trap, plugged it in and retreated back to the house - more in hope than expectation.
Saturday morning revealed a damp morning, following some light rain earlier. This didn't inspire any confidence, but after an early breakfast I disappeared into the garage armed with the camera and a new copy of my Field Guide to Moths of UK and Ireland.

Turning over the first two egg trays revealed only a tiny mired bug, Scolopostethus decorates. It is only about 4mm long and I almost missed it in my expectation of finding hundreds of huge moths. It's normally associated with heather and heaths, being found throughout the UK.

The next discovery was an Early grey, Xylocampa areola. this was more like it. A moth in a moth trap! now I had found a moth, the main challenge was to get it off the egg carton. More difficult than I imagined it could be without damaging the little beast.

As it's name suggests this is one of the earliest moths, with a flight season between March and May. According to my guides it can be found in lightly wooded areas and gardens. The larvae feed on honeysuckle, which we have in the garden, so I'll have a hunt later on in the year to see if I can find anything.

Although it is commonest in the south, it can be found throughout the UK

Next discovery was a pair of Common quakers, Orthosia cerasi. Again this is a common and wide spread species. But I don't care, I've got moths in my moth trap.

The Common quaker has a wide range of lowland habitats, including woodland and gardens. The single generation flies in March and April. The larvae feed on Oak, Willow and other deciduous trees.

Then right at the bottom of the trap, and firmly attached to the egg case was a rather bedraggled Oak beauty, Biston strataria. You can see the tips of the wings are slightly damaged. The flight period is from February through to April, so this chap may have been around for a while.

Despite it's name the Oak beauty is not restricted to oak trees, and the larvae have been found feeding on elm, alder and hazel. But it is easy to imagine how effective the coloration might be on the variable bark of the oak.

Close up the "feathering" of the moth becomes more evident. The more I look at this the more fascinated I'm becoming, and I think I'll have to try some more close-ups in the future.

Tuesday, 1 April 2014

Abandoned nest

Over the winter I noticed that a song thrush was visiting the garden on a regular basis. We had always had one visit occasionally, but each week recently I recorded it's presence as part of the BTO Garden Bird census. Then I started seeing two in the back garden at the same time. This also coincided by a song thrush singing it repetitive song early in the morning somewhere in or near the back garden.

Euonymous varigata. The nest is towards the top.

Last week I disturbed a bird from a thick Euonymous bush growing near the fence. It flew away too fast too see what it was. Over the next week or so I kept my eye open and saw a thrush feeding in the garden regularly, and occasionally making a visit the bush.

A close up view of the nest through the leaves

Last week I had was able to confirm that it was nesting towards the top of the bush. However, over the past 4 days I've not seen it making any visits to the nest.

A view of the nest cup

This afternoon, after watching carefully to see if there was any nesting behaviour, or even a presence it seemed that the nest had been deserted. A sneak look showed 4 eggs, with a leaf in the nest form the bush. But the eggs were also wet. It hasn't rained today, so it is almost certain that they've been abandoned. 

Closer up it's possible to see that the cup of the nest also looks wet, further suggesting that the nest has been abandoned.

Closer up it's possible to see the water drops on the eggs, and the cup also looks wet.

This is a shame, as I've not had any birds nesting in there garden for a couple of years now. The last were a pair of blue tits who nested in one of the he boxes. We watched them for weeks going In and out of the he box. In fact they cleared the garden on insects, says this was one of the few years that the Solomon Seal plants weren't decimated by saw flies!

I hope that we may yet have another nest somewhere in the garden this year. So here's to that hope.