Wednesday, 24 August 2016

Life in a ditch

I was working near Downham Market in Norfolk today, doing a water vole survey. It was hot work with the sun blazing down and temperatures in the mid-twenties, wading through a heavily vegetated ditch containing brooklime, water-cress, reedmace, water-starwort, sweet-flag and various other species.

There were plenty of dragonflies on the wing and one of the first I found was one of the spreadwing species, or emerald damselflies as they're pehaps more frequently called. My suspisions were immediately aroused because I'd never seen common spreadwing (i.e. emerald damselfly) in that kind of habitat before, I usually see them in very acidic areas of bog, or around shallow pools. I knew that there are now three species of spreadwing in the UK but I wasn't sure of the status of the rarer species in these rapidly changing days of climate change. Though I couldn't remember exactly what the differences are, I did at least know that they include the markings on the side of the thorax and the colour of the appendages, so I tried to get photographs which showed both. Fortunately these confirmed that the species in question was willow spreadwing, a fairly recent colonist to the UK and a first for me in this country, though I have previously seen them in Spain. From rare vagrant to the UK just 10 years ago, willow spreadwing can now be found in many places in Norfolk, Suffolk and Essex. Other dragonflies seen today included ruddy and common darter and brown and migrant hawker.





Also today we found a long-wingeed conehead bush cricket, a first for me and a nice comparison with their short-winged cousins I saw at Marshside and Arnside a week or two ago.


While we were in Norfolk it seemed a good opportunity to have a look for some hoverflies, and there was quite a nice selection, including a new one for me in the form of Cheilosia impressa.


Perhaps most spectacular though was this impressive fly, Nowickia ferox (thanks to Ray for the ID).






Ruddy darter.



Common darter.





Water-cress


Water-starwort sp.

Sunday, 21 August 2016

Pennington Flash

I went out today not really birding but looking for hoverflies at the flash. However down at the western end I looked up from photographing a hoverfly and found myself face to face with a juvenile black tern! While I was watching it a greenshank flew up calling from the bay and appeared to fly away, but 30 minutes later I heard it again from the same area. 





 There was a fantastic variety of hoverflies at the flash, here a few of my favourites.


What a beauty! The bumblebee mimic Eristalis intricarius. This is a female.



Baccha elongata (right) with Melanostoma scalare.


Dasysyrphus tricinctus.



Helophilus pendulus


Myathropa florea. Note the batman logo on it's thorax!


Syrphus sp. unfortunately not identifiable to species from photos.



Ling Calluna vulgaris in full flower. There were a lot of hoverflies in this area.

Saturday, 20 August 2016

Strumble Head

I was at Strumble Head in Pembrokeshire for 6.30am and stuck it out until 12.30pm. The predicted storm 'Hildebund' arrived as promised over night with gale force south westerlies pushing thousands of sea birds into Cardigan Bay. Unfortunately it then failed to veer west leaving many of the birds miles offshore. Still, it was decent seawatching with many thousands of Manxies passing close by which always offered the hope of something rarer, plus bonxie and a possible long-tailed skua and the usual hundreds of gannets etc.

Highlight though was three storm petrels battling against the wind at close range. It was great to see them pattering across the water!

Year: 242 (Storm petrel)

Friday, 19 August 2016

Xylota segnis at Appleton Reservoir


Following my discovery of the stunning Xylota sylvarum at the reservoir a week or so ago, today I found a second species of Xylota on the same sand stone wall. This is the smaller Xylota segnis. One of the ways you can identify this species from the other small Xylota is by the row of spines along the base of the hind femur, which fortunately are clearly visible in this photo.

The Xylota species are really interesting, they rarely come to flowers, and behave in a similar way to predatory Ectemnius wasps, running around and flying short distances with a darting kind of flight, sometimes apearing to chase other, smaller insects. Of course they also look a bit like Ectemnius wasps, and I wondered if their behaviour was part of the mimic or just coincidental, perhaps because the hoverfly itself is predatory. In fact the hoverfly is not predatory, it feeds on pollen which has fallen from flowers onto the leaves of plants, or in this case onto the wall (which was overhung by several tall species of plant).

Just to make them even more fascinating, apparently the further north you go the more likely they are to come to flowers, until by the time you get to Scotland they come to flowers with the same regularity as any other hoverfly species.

So it would appear perhaps that the wasp like behaviour is part of the mimic, though this is just speculation on my part.




Tuesday, 16 August 2016

Hoverfly behaviour - Eristalis nemorum



I came across this "pair" of Eristalis sp. hoverflies in Preston today. Eristalis species can be very difficult to identify, but these were behaving in a way I have not noticed before. I'm assuming that they are male and female and that the male is the flying insect which was buzzing around the female.

Apparently (according to the experts on FB UK Hoverflies) this is typical behaviour of E. nemorum. Interesting that in this case the behaviour is more of a clincher than the markings, which are very variable in all Eristalis species.

Sunday, 14 August 2016

A few hoverflies from the weekend

On Saturday I visited Burton Mere Wetlands and then Martin Mere with Ray, and on Sunday Malham Cove and Tarn with Elaine. Here is a selection of the hoverflies we saw.

Burton Mere Wetlands


Dasysyrphus albostriatus


Episyrphus balteatus "Marmalade hoverfly"



Syritta pipiens


Syrphus ribesii


Melanostoma sp - possibly scalare


Myathropa florea


Riponnensia splendens


Eupeodes corollea


Helophilus pendulus

Martin Mere


Syritta pipiens


Volucella pellucens "Great Pied Hoverfly"



Eristallis intricarius

Malham


Leucozona glaucia


Eristalis horticola


Eristalis pertinax



Sericomyia silentis



Helophilus trivittatus


Platycheirus albimanus

 
Eristalis horticola


Melanostoma scalare


Eristalis rupium