Tuesday 16 August 2011

Small gaps

The rain is still more or less continuous, with very short gaps between showers, and I have had to adopt a new tactic for getting some pictures: I watch the sky to the southwest and wait until I see a gap in the weather some 12-15 km away. I then rush out and hope to reach the fringes of town before the gap in the rain reaches me. That means I'm in place when the temporary stop occurs. This is fine for getting photographs of plants and mines, but not so good for insects because it takes them a little while to realise that the rain has stopped and they have warmed up enough to fly to the nectar sources that I'm watching at the moment.

Tufted Vetch is an odd plant: it grows in only a few places on my patch, but wherever it grows it is rampant. There appears to be no similarity amongst the places it chooses and there are places that appear to be ideally suited, but the plant is absent. It must have some very particular micro-climate requirements.

Tufted Vetch
A few more late summer portraits:
Knapweed or Hardheads


Red Bartsia


Devilsbit Scabious

Taphrina alni is a parasitic fungus on female Alder cones:

Taphrina alni gall on Alder
The tongue-shaped growth reaches 4-5 cm. long and turns red before releasing its spores. Note that the growth is caused by the fungus, but is made by the Alder tree for the benefit of the fungus.


Alder is a good food source for Sawflies: these are multiple mines of Acidia cognata. The broad-shouldered larva can be seen in each of the mines:


Mines of the sawfly Acidia cognata on Alder

This next shot shows just how attractive Angelica is for insects at this time of year. I counted 7 ichneumonids, 2 sawflies and 2 dungflies on this flowerhead:


Angelica with Ichneumonids, Sawflies and Dungflies

One of the few Ichneumons that can be identified by sight: Amblyteles armatorius, which is parasitic on larger moths.

Ichneumon Wasp Amblyteles armatorius

Harvestmen are related to spiders, but they don't make a web. They hide instead in plants, waiting for some unsuspecting insect to come wandering along.
Harvestman Mitopus morio on Angelica
I like how the Angelica echoes the shape of the legs.

The social wasps are divided into two main families: Dolichovespula and Vespula. Dolichovespula species (Dolichovespula sylvestris shown) can be readily identified by the 'malar space', which is indicated by the arrow below:
Dolichovespula sylvestris, a Tree Wasp
The malar space is the distance between the lower edge of the eye and the upper edge of the mobile mandible, or jaw. In Dolichovespula sp., the gap is large, making the face very elongated, whilst in Vespula sp., the gap is virtually non-existent. Most of the wasps that can be seen moving leisurely over Angelica at the moment, including the one above, are males.

The Potato Capsid, Closterotomus norwegicus, is commonly found on Knapweed and other composite flowers. I have never found it on potato:
Potato Capsid on Knapweed

3 comments:

Emma Springfield said...

With all the rain you have had this year, I am surprised that Ireland hasn't floated away. Anyway it seems that you have devised a good plan because you have some exceptional pictures.

The Weaver of Grass said...

The vetches and the knapweed have never been as prolific as they are this year here in North Yorkshire - they are everywhere. The heather is just coming out on the moors too.
As for rain - don't tell e about it - our rivers are full to overflowing and getting second crop silage in is very difficult. In desperatio the farmer is cutting some today as the sun is shining - so we are keeping our fingers crossed.

Gill said...

"With all the rain you have had this year, I am surprised that Ireland hasn't floated away" - Ireland's used to it :-)

Weaver: "our rivers are full to overflowing" interesting - ours are still very low on this side of the county. Although it has rained nearly every day the amounts have not been great, rarely >10mm. Combining is in full swing.