Sunday, 4 August 2013

Angelica time!

Angelica is one of the most important late summer nectar sources: their flowerheads are often covered in insects. Flies, hoverflies, bees, wasps, sawflies, ichneumonids, beetles and moths are often seen nectaring next to each other - mostly in harmony - but they all tend to keep a watchful eye just in case one of the sawflies gets a bit ambitious. A few spiders also lurk under the umbels and the remains of previous meals can often be seen hanging on gossamer threads.

I got a nice comparison between two identifiable ichneumonids - Amblyteles armatorius and Ichneumon extensorius - on Angelica today. Amblyteles armatorius is one of the larger parasitic wasps, at around 25 mm. long:

Amblyteles armatorius
These are parasitic on larger moths.

Ichneumon extensorius is very similarly patterned, but is much smaller, at around 15 mm. long:

Ichneumon extensorius
Sadly, the remaining 2998 or so species of our parasitic wasps need a specimen, a microscope, a reference collection and several volumes of conflicting books in order to get an identification. If I had another life, I would 'do' these.

Almost every head of Angelica has a male wasp crawling slowly over it. The males are ejected from the nest as 'excess baggage' as soon as they are ready.

Male wasp

Another frequent visitor to Angelica is the fly Sciara hemerobioides: in fact, it's the only place I've ever seen it.

Sciara hemerobioides
It took me perhaps 3-4 years to get that id: for ages I was sure it was a sawfly.

This area is on the edge of an old bog that was planted with Spruce in the 1950's. The trees were harvested about eight years ago, and some of the original vegetation is beginning to return. This is Marsh Woundwort:

Marsh Woundwort

Almost surprisingly, about 2 metres away, I found Hedge Woundwort:

Hedge Woundwort
That might explain why I have found the hybrid Woundwort - Stachys x ambigua - near here from time to time. I don't see the hybrid every year, but I suppose since the hybrid is sterile, it would need to be recreated each year.

I spotted this hoverfly and thought it was my usual Xylota segnis, but the yellow end to the abdomen intrigued me. Turns out it's Xylota sylvarum, and is new to my species list.

Xylota sylvarum
The larvae can be found in rot holes and sap runs in older trees.

The Large White butterfly was not recorded for around 12 years in my local area, but as soon as I planted some cabbage, they came flooding back. I found this batch of eggs this morning:

Eggs of Large White butterfly
Here's a close-up:

Large White eggs - close-up


Gill said...

Why have some of those large white eggs got hairs? Are you going to let them hatch or save the cabbages?

stuart dunlop said...

The female makes a glue to stick the eggs on the leaves and sometimes it makes strings. I'll let them hatch: the cabbages have plenty of leaf and I might get to photograph some parasites on the caterpillars.