Sunday, 26 July 2015

Cucumber spider with egg sac

 While looking for lily beetles, I found this female Araniella sp guarding its egg sac. The sac, made of coarse yellow silk threads, was attached to the underside of a leaf, and the female sat on a loose web underneath, where she was also eating an aphid (below). There are two extremely similar species, Araniella cucurbitina and A. opistographa, which can only be identified by inspection of their epigyne. Both are small and bright green, with a red mark over their spinnerets, which can often be seen from underneath. They live in trees and bushes, and are orb weavers, although their webs are quite small.

Friday, 24 July 2015

Yellow dung fly

This male Yellow dung fly, Scathophaga stercoraria, as the sole occupant of a very wet cowpat after a rain shower. Yellow dung flies are sexually dimorphic, males and females differ in size and colour: males are much larger and brighter yellow than the female. Larger males are better competitors, better to defend a bit of cowpat from other males. Males spend much of their time on the cow pat, while females only come to the cowpat to mate and lay eggs. Dung flies actually feed on other flies and insects attracted to the dung, but also on pollen and nectar and the dung itself, while the larvae will develop on the dung. Although of Yellow Dung flies are associated to large animal dung, especially cow pats, I've had them in the garden before, where they might have been attracted to compost.
A pair of mate guarding dung flies in the garden, 26/08/2006, illustrating their sexual dimorphism.

Tuesday, 21 July 2015

Summer generation Holly Blue

The first Holly Blue of the summer generation. This butterfly has two main larval foodplants: spring generation females lay their eggs on the buds of holly, whereas summer generation ones lay on the buds of Ivy. Unlike the other blues, the Holly blue tends to fly high near trees and bushes.

Monday, 20 July 2015

Marmalade flies everywhere!

Marmalade flies, Episyrphus balteatus, are the most common British hoverfly, and can be seen year round as they are able to overwinter as adults. However, at this time of the year, they are at their most abundant, as I walk around the garden, every flowers seems to have a few males hovering nearby or females feeding on the flowers. These slim, small hoverfly is able to migrate, and this occasionally bumps the numbers of British individuals. They are very distinctive, as the pattern of double black lines in the abdomen is unique to this species. The male above (eyes meet at the top of the head in many male hoverflies), settled briefly on an Agapanthus flower bud, and rubbed its feet together, keeping its wing open for a few seconds.

Sunday, 19 July 2015

Small Skippers

There were many territorial male Small Skippers in a meadow area in the outskirts of town. The males look like little, golden triangles perched on grass tips or flower heads, which dart after passing butterflies hoping for a female skipper. Males and female skippers are easy to tell apart when perched, as males have a dark line parallel to the edge of their forewings, the 'sex brand'. The photo above shows a female, below, a male. Both sexes were enjoying the plentiful creeping thistle flowers.