Thursday, 31 October 2013

Longitarsus -Flea beetle

Got confirmation yesterday via iSpot of a tiny beetle I found crawling up the back door post earlier in the month. It could be of the genus Longitarsus, one of the many species of flea beetles. In fact there are about 700 species of Longitarsus. Many are very similar and experts are needed to identify them down to species level, and that is one thing I am not!

The chap I found was less than 5mm in body length, orange metallic colouring, and the hind legs were enlarged. They are called flea beetles because of their escape mechanism of jumping vertically when disturbed. 

Adult flea beetles overwinter in leaf litter, garden debris, or other sheltered places. As temperatures begin rising in spring, the adults emerge and locate suitable host plants on which they feed. Some flea beetles will feed on weeds until garden crops are available. In late spring, female flea beetles lay eggs in the soil around the base of host plants. Tiny larvae feed on roots and root hairs for about a month, and then pupate in the soil. Multiple generations of flea beetles may occur in many areas.

Wednesday, 30 October 2013

The First Fieldfare of the Year - Turdus pilaris

Saw the first fieldfare of this autumn in the garden this morning. the photos are not too good as it was early morning and the sky overcast. But it's definitely a fieldfare. It was feeding on the Rowan or Mountain Ash. Unusually it was on it's own, and I couldn't see any others around. Although we tend to get a little excited about seeing fieldfares in the UK, they are common in Europe. I was in Poznan, Poland earlier in the year, and the local park across the road was chock full of fieldfares feeding, squabbling and protecting their territories.

The Welsh name for the Fieldfare is Socan Eira, meaning 'snow lover' or 'little snow gaiters'. Possibly a reference to the fact that they are winter visitors (1). In Polish it's Kwiczol (2), which is something similar to the call they make to my mind which is a harsh 'chack-chack'.

It is a winter migrate from northern Europe, but there are records of breeding in the UK. They start to arrive in the UK from October through to November. If the weather is mild their arrival is delayed as food remains available in northern Europe. However, if the winter arrives early in Scandinavia the number arriving here can be huge.

The Fieldfare is a member of the Thrush family, and the similarity with other members is clear. They are more often seen in flocks in the countryside, but when food becomes scarce later in winter, or if the weather is harsh they readily visit gardens. So I was surprised to see one so soon this year outside.   It is commonly thought that they are berry eaters, but in fact prefer worms, grubs and other invertebrates. Switching to fruit and berries when their preferred food is less available.

The graph below shows the reporting rate on the BTO Bird Track website of the appearance of the Fieldfare for 2012 and 2013 to-date (3). The cold winter of early 2013 reflects the frequency of reported sightings.

One thing I noticed as I was watching it feeling on the berries, this particular Rowan is the only one of three nearby that still has it's berries. The other two have dropped all their berries, one of which has made a right mess of the vegetable garden.

1: Cocker, M. & Maybe,.R. (2005) Birds Britannica. Chatto & Windus.
2: BTO
3: BTO Bird Track

Thursday, 10 October 2013

Red Admiral - Vanessa atalanta

A little bit of sunshine after a few wet days here in South Wales brought some beauty into the vegetable patch the other day. This is the first time I can remember seeing a Red Admiral so late in the year, and I photographed this one feeding on one of the last plums left on the tree. The day before I also saw a speckled wood.  2013 has been a good year for butterflies, certainly better than the washout last year. I have certainly seen more butterflies this year, though that may be because Ive been looking! 

The results from the Big Butterfly Count (1) this year showed a general increase in almost all the species. The red Admiral came in number 11 in the list with a 69% increase compared to the count in 2012.

Grand total
% change from 2012
Small White
Large White
Meadow Brown
Small Tortoiseshell
Green-veined White
Six-spot Burnet
Red Admiral

The Red Admiral is primarily a migrant to the UK, spreading up from Southern Europe by migrating generations as the year progresses. Though in the south of England there is some evidence that it over winters (2). The frequency of sightings of Red Admiral increases as the year progresses. the graph below shows the average number of butterflies seen on transects between April and October across the UK (3). The blue line gives average counts over the full BMS series (1976 to date) and the red line gives the average for the last year.

The caterpillars feed on Common Nettle (Urtica dioica). However Small Nettle (U. urens) and the related species, Pellitory-of-the-wall (Parietaria judaica) and Hop (Humulus lupulus) may also be used. There are some nettles near by, but I have to admit they are not allowed in the garden.

3: The United Kingdom Butterfly Monitoring Scheme.

Tuesday, 8 October 2013

Owl Midge

Discovered a fantastic and small midge in the vegetable garden the other day. At first I thought it was a micromoth, but after a great sea of bemussed serarching through my books I found out is is in fact a midge.

There are 99 British species at least, with probably many more undiscovered yet. All very small with hairy, pointed wings. Although this is not a very good photograph, you can easily see how hairy it is.

There is not a great deal of information available on the internet or anywhere I have looked so far. One thing I did find out is that all the sources agree that they are a very difficult group to identify without microscopes. So for now I'll have to be content with just an identification down to genus level.

They have tiny eyes with few facets, and seem to rely more on their antennae than their eyes. The antennae are covered in sensitive hairs that pick up scents and vibrations. Often the adults can be found in huge swarms around sewage filter beds, and in such habitats are an important food source for bats. The adults fly both during the day and night in spring and summer. In many species the adults do not feed and lack mouthparts. In warmer countries some species are known as Sand flies and can be vectors of disease.

The larvae (see below) feed on decaying matter and are aquatic or semi-aquatic. Occasionally they can breed in sink traps.

I think I'll keep a look out for them and see if I can get some better photographs in the future.