Thursday, 25 October 2012

Late October 2012

Things are now fairly quiet on the fly front and I expect the forecast cold snap will finish off a few of the flies that are still about. A walk in Sane Copse, Yardley Chase, this morning produced one hoverfly Melanostoma scalare (Fabricius). It had been visiting a flower of Ragwort when I saw it.

Apart from that, I noted the Dryomyzid Neuroctena anilis (Fallen). This is a common woodland species in the Autumn. The mines of Agromyza alnivora Spencer were plentiful on the alder leaves. Whilst examining leaves of beech for mines, I found a very distinctive gall. It consisted of a pustule on both sides of the leaf but on the upper surface a cylindrical growth rose about 4mm from the pustule's centre. Using the excellent "British Plant Galls" by Margaret Redfern and Peter Shirley, I discovered that it was caused by the Cecidomyid fly Hartigiola annulipes (Hartig). So not a bad morning despite the weather.

On 18th October, also in Sane Copse I took three flies. One was the hairy-eyed cranefly Tricyphona immaculata (Meigen). This is a smart, black species, a colour that is not very frequent in craneflies. A small lance-winged fly was Lonchoptera bifurcata (Fallen) and a dung fly was not the usual common yellow dung fly Scathophaga stercoraria (Linnaeus) but another common species S. furcata (Say).

Whilst tidying up the garden earlier in the week I noticed a gallery leaf mine on columbine Aquilegia. It is caused by the Agromyzid fly Phytomyza minuscula Goureau, a new species for my garden.

Friday, 12 October 2012

More about Calliphoridae (blowflies)

Following on from Tony White's piece on Pollenia species on ivy, he sent me another record. This time of the very colourful Calliphorid Cynomyia mortuorum (Linnaeus). This too was feeding on ivy flowers in Byfield. I have not seen this species in Northants and nor have I received any previous records. However, it is a widespread species so should be recorded more frequently. I did see one whilst on the Dipterists Forum field trip to Speyside and the Cairngorms in July. We were investigating a promising looking area of bog and old pines close to the Cairngorm Lodge Mountain Centre near Aviemore. A dead shrew was lying on a stump and several calliphorids were visiting it. These included the C. mortuorum. I took the photos below.

Cynomyia mortuorum (bottom right) and other calliphorid flies on a dead shrew, near Aviemore.

Closer view of Cynomyia mortuorum.
All photos on this blog are copyright John Showers 2012.