Friday, 2 December 2016

Another new Cranefly for Northants

In mid-September I was sweeping under some willows next to a dried up pond in a former sand pit near Yardley Hastings when I took a small insignificant-looking cranefly. Back at home I keyed it out as a male Ormosia bicornis. On checking its distribution and status, I discovered that this is a Vulnerable (RDB2) species mainly recorded from calcareous woodland in Herefordshire. Its known distribution is shown on the NBN gateway:

As neither the location nor the habitat matched the literature, and with the scarce status of the species, I asked for a second opinion from John Kramer, who helps run the national cranefly recording scheme. John took the specimen and extracted and cleared the genitalia. He mounted the genitalia  on a slide and photographed them at the Natural History Museum in London. I have attached his photograph. It shows the characteristic twin spines on the styles that give it its "bicornis" name. These spines are at the top left and top right of the photo? The specimen now resides in the NHM's collection.

Photo by John Kramer, 2016

Saturday, 12 November 2016

Flies and Dead Wood

Many flies from a several families breed in various forms of dead wood. These microhabitats can range from the rotting sap under the bark of a felled tree, through rot holes in the trunk and larger branches or rot holes in the roots accessible at the base of a tree, to dead wood lying in streams or wet places. Added to this are the fungi that grow in these situations that provide habitat for other species. When a mature wood is clear-felled there can be a break in the continuity of these habitats. In natural woodland there is a range of tree ages from saplings to over-mature and dead trees. Many of our rarest flies are dependent on dead wood and, as most only have a short life-cycle, a population can be lost when woodland is cleared. Re-planting does not help as it will take maybe 50 plus years to start to develop the next population of dead wood, long after the dependent species have died out. Where new woods are established near ancient woodland, some people are trying to artificially create dead wood habitats through a variety of means. Some techniques are illustrated on the website of the Vetree project:
See the link to training materials and look for the video on creating decaying wood habitats. It might be possible to emulate some of these techniques in the garden.

On the subject of dead wood, this year has thrown up some interesting records from felled poplar. During a Northants Diptera Group meeting at Pitsford Nature Reserve,  Kev Rowley swept Solva marginata (the Drab Wood-soldierfly) from near a felled poplar. This wood-soldierfly has been rarely reported in Northants, except in the far North-east of the county. Its larvae develop in the rotting sap of poplars that have been felled for about 1-2 years. This record shows that it is more widely spread in Northants than appears to be the case from the NBN Gateway

Encouraged by Kev's find I investigated a poplar log pile in Sulby. I could not find any wood-soldierflies but did sweep a number of flies from the surrounding vegetation. When I  got round to examining my catch I found the lance fly Lonchaea hackmanni and the short-palped cranefly Gnophomyia viridipennis. Both of these species are associated with poplar and may be new to  the current Northants county.  (Vice-county 32 includes the former Northants area of the Soke of Peterborough).

Tuesday, 11 October 2016

New cranefly for Northants

On 5th October I was visiting Sulby Gardens, mainly to look for hoverflies. However, as I was walking alongside the shady stream I swept the vegetation. I took several common species of cranefly but one stood out as different because of its peculiar appendages on the last sternite. I keyed it out to be a male Tipula staegeri, subgenus Savtshenkia. The NBN gateway shows it as being widespread except in the Midlands. I sent a photo to John Kramer from the national Cranefly Recording Scheme and he confirmed its identity and that they had no records of it from Northants. It is an easy species to identify in the male because of the appendages on the last sternite, slightly mottled wings and a yellowish stigma. It is found alongside shady streams from late September to mid November.

Shropshire Craneflies

At first sight the title seems to be irrelevant to this blog. However, it is the title of a new book by Pete Boardman. Although it specifically covers Shropshire and only the craneflies found there, there is much of interest to anyone who wants to know our craneflies better. One of the features of the book is the use of a synoptic key rather than the usual dichotomous key. This involves looking at a list of features, each of which is assigned a letter. By noting the letters that apply to your specimen you look up a table of species with those features. The detailed species descriptions and close up photos should then be able to confirm your determination. As yet I have not yet tried the keys so cannot comment on their effectiveness. However I have successfully used the species descriptions and photographs to confirm identifications where the Cranefly Recording Scheme's keys left me with some doubt. The photos, which are annoted, definitely clarify interpretation of the drawings in the CRS key. 

The book contains a checklist of British genera, showing how many species there are in the UK and Shropshire and giving the latest names. There is also a checklist of species. I checked this against the Northants data and found one species from Northants that is not covered in the book. I intend to check that species is correct if I can find the voucher. Although there may be other species that occur in Northants but not in Shropshire, there is no doubt that the book will be very useful to cranefly enthusiasts in Northants.

I did notice a few minor errors but none that affected the usefulness of the book so I highly recommend it. An excellent piece of work.

Thursday, 6 October 2016

Dipterists Forum produce video to promote study of flies

Dipterists Forum, the society for the study of flies have produced this video to encourage more people to get involved

Sunday, 10 April 2016

Early April 2016

The cool, showery weather has not been great for searching for flies. Yesterday, we had a meeting at the Wildlife Trust's Ring  Haw field station as a follow-up to Roger Morris and Stuart Ball's workshop on fly families, held in January at Cambourne. Seven of us attended plus Roger and Stuart. Although the weather was cool and breezy we did manage to do some field work. The plan was to practice some collecting techniques and then identify the finds down to family level or lower if possible. In all we found representatives of 22 families, with representatives of Nematocera, lower Brachycera, Acalypterates and Calypterates present. One special find was a hovering male Cheilosia nebulosa over the old railway track. This was almost the exact place that Graham Warnes found one a couple of years ago. The session went very well and I think everyone felt they had gained from the experience.

Monday, 28 March 2016

March 2016

With the cold weather of late, there have been very few flies other than midges about. I have used the time to identify all my Northants specimens for last year.  There were just over 2400 records of flies in Northants from all sources. This brings the Northants database to just over 20,000 records. I shall be doing some more analysis of data when weather conditions prevent active recording.

The good weather on Good Friday brought out the first hoverfly in my garden. A single drone fly Eristalis tenax was holding territory in a sunny patch over my lawn. It also brought out the first dark-edged beefly Bombylius major. Both these species should soon become frequent as the weather warms up. 

At Yardley Hastings Sand Pit on 17th March a single, large, very active fly was spotted on low vegetation. It turned out to be a parasitic fly (family Tachinidae) Gonia picea. This fly is a parasioid of the larvae of the antler moth.

With poor weather for searching for adult flies, I have been looking at leaf mines. The fly mines I have noted during the month were:
Chromatomyia aprilina on honeysuckle
Chromatomyia primulae on primrose
Phytomyza ranunculi on lesser celandine.

Most intriguing was a mine on a shrub in the Orangery at Castle Ashby Gardens. The plant was labelled Jasminium wallinderium but I have been unable to trace the causer. Both David Manning and I took sample leaves to try to rear out an adult but mine is looking decidedly dead. The following is a photo of the mystery mine.

Friday, 12 February 2016

Flies on fungus

A number of species of fly are associated with fungi. The larvae of many species from several families live in the fruiting bodies. However some species of fungi use flies to spread their spores. This is the case with the stinkhorns. When the fruiting body bursts through its sac, it sends up a stem which is tipped with a foul-smelling "gleba". Flies that are attracted to carrion or dung are attracted to the gleba and then carry off the spores to spread the fungus. David Arden found a stinkhorn at Pitsford Reserve near the Walgrave bird hide and photographed it. The photograph shows how effective the gleba is at attracting flies. In the photo, the chestnut coloured flies with black spots on the wings are Members of the Dryomyzid family, Neuroctena analis. The flies with grey thoraxes and yellow abdomens are members of the Muscid family, probably Phaonia species.

(C) David Arden, 2015

Sunday, 31 January 2016

Another Cistogaster globosa

Today I was going through some specimens I caught last summer when I found a female Cistogaster globosa. I took it in the Whitestones area of Twywell nature reserve on 26th July 2015. This is the third county record, and each is from a different site. However they all have the following in common:
- previously quarried area
- rich flora
- dry conditions allowing the soil to heat up quickly.
This specimen was a female. It is similar in shape and size to the male illustrated in the previous blog but the abdomen is plain black.