Sunday, November 26, 2006

Hoverflies are still active

This photo was taken on the 18th November and shows a lovely specimen of the Melanostoma scalare hoverfly.

Just like the Tephritis formosa gall fly below, it was found on the flowers of the "Paddy's Pride" species of Ivy. I cannot stress enough the importance of having Ivy in the garden for the benefit of our dwindling insect life.

In the first image, if you look carefully, there appears to be a lime green blob just above one of the legs where it joins the body. This in fact is the haltere, and they are often green or blue/green, which can often be an identification clincher for this particular species.

Hoverflies belong to the group of insects called Diptera, meaning two winged insects. Virtually all other insects have four wings even though the hind pair are often small and at times may be covered by the larger front pair (bees and wasps). The hind pair of wings in the Diptera have become reduced to tiny drumsticks called halteres.

In the second image, there are clearly triangular yellow/orange spots of distinctive orientation, which indicates a female of this particular species.

This species is found between April and November. Widespread and common in grassy situations throughout Britain, but not normally found in mountainous or moorland locations.

Friday, November 17, 2006

Woolly Bears

It's remarkable that this engaging little guy is considered a domestic pest, particularly in southern England. Why a pest? Well this critter requires a protein diet and likes to munch its way through carpets, furs and all kinds of woollen textiles.

This is the larvae of the Varied Carpet Beetle or Anthrenus verbasci and are more commonly known as Woolly Bears.

The adult carpet beetle has attractive black wing casing mottled with patches of white and pale yellow, is up to 4mm long and is found outdoors from spring to early summer feeding on pollen and nectar before moving indoors to lay its eggs. An adult female will produce up to one hundred creamy white eggs and deposit them in cracks and crevices. Within four weeks the eggs hatch and the emergent woolly bears embark on a continuous feeding binge and moult several times before pupating.

I have checked through my records and I noticed one of these guys on 23rd November last year, 17th September this year and finally 9th November this year (this photo). Therefore now is the time to be vigilant and get the magnifying glasses out, stop watching Eastenders, get down on your hands and knees and find a woolly bear.

Monday, November 06, 2006

Fruity little devil

I found this little gem of a fly on the insignificant flowers of my Paddy’s Pride variety of Ivy. I say insignificant, but in reality they provide food for many pollinating insects, such as wasps, green bottles and honey bees during September and October. The flowers are also important to the survival of queen wasps during November and December. [Contrary to popular opinion, large amounts of ivy growing on trees will not cause any harm as ivy is not parasitic].

This photograph was taken on the 5th November on a lovely sunny afternoon when amongst all the wasps, I noticed this fruit fly. The wings are heavily patterned with dark areas and hence they are sometimes called picture-winged flies.

This critter belongs to the Tephritidae (gall flies, greater fruit flies) family and the species name is Tephritis formosa. The larvae live in fruit and other parts of plants and often induce gall-formation. Although the family is called "Gall Flies", only a minority of species have larvae, which actually cause galls. The rest are internal feeders in fruits, stems or leaves.

The larvae of Tephritis formosa are associated with the following plants:
Perennial Milk-thistle, Prickly Sow-thistle, Smooth Sow-thistle and Marsh Sow-thistle.

The female abdomen is pointed and ends in a rigid, telescopic ovipositor while in males it is blunt or round-ended. From my photograph it is difficult to see the tip of the abdomen, but I think it just about shows a slight point.