Saturday, 8 October 2016

A Wealden Wood in Autumn

The Small Copper (Lycaena phlaeas) is a delightful little butterfly that manages to fit in three broods in most years. I have often found that it can be rather scarce in the spring but by the third brood in September and October it can be quite abundant along sheltered woodland and field edges.
Small Copper (Lycaena phlaeas
The following photographs are of two different males seen this week. The first image is of form caeruleopunctata which has a row of sub-marginal blue spots on the hind wings.

As insect numbers fall away at this time of year, my attention turns to seeking out other stages in the butterfly life cycle. Insects don't just die off at the season's end without having ensured the continuation of the cycle for the next season. Butterflies pass the winter in any one of their life cycle stages depending on the species. With the exception of the Green Hairstreak (Callophrys rubi), which passes the winter as a chrysalis, all other British Hairstreak species see out the winter in the egg stage. 
The Purple Hairstreak (Quercusia quercus)
The eggs are laid at the base of terminal buds of oak, its only foodplant. No more than a millimetre in diameter, they look like tiny sea urchins. The indentation at the top of the egg is the micropyle through which fertilisation occurs.

The hole on the side of another egg in the next two photographs indicates that it has been predated upon, possibly by a small bug or spider but probably by the tiny Trichogramma parasitic wasp.

A potential culprit for such egg predation is this tiny Crab Spider hunting amongst the foliage of the oak tree. When at rest, it bears a close resemblance to an oak bud and it can be difficult to spot amongst a terminal cluster. I think that this species is Xysticus lanio.

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