Horse Chestnut Scale InsectFriday 19th May 2000
IT'S LAUNCH DAY at last for my booklet on Coxley Valley which I've been working over a period of months. It gets off to a good start with a signing session at Ossett Books. I've known the valley since visiting as a child, but I've been amazed how much history there is in the landscape; Domesday villages, medieval iron-working, the world's oldest railway tunnel, a Victorian pleasure gardens. I've also included a little about the wildlife, the wild flowers and the landscape.
The upper trunk and undersides of some of the branches of a Maple are dotted with Horse Chestnut Scale Insects, Pulvinaria regalis. They look like tiny trilobites and are no bigger than a baby's fingernail, 5-7 mm long. These are actually the carapaces (the shell-like armour) of the females, who die after laying 3,000 eggs. The newly hatched young appear as cotton wool around these nursery shelters. The yellowish crawlers head off towards the branches and can sometimes be seen as a 'moving carpet of dust'. They feed on sap on the leaves and smaller branches before the next generation of females return to lay their eggs.
Like aphids, the honeydew they excrete can lead to sooty moulds growing on leaves, leading to a reduction in tree growth. There is no practical cure. This species appeared in England in 1964 and was known in Europe before that date, but it isn't known in what part of the world it originated. My thanks to Sarah Bell for pointing out the insects and to Roger Gaynor for the identification. The information on the life cycle comes from an H.M.S.O. publication.
Under the eaves of an old school building, two or more pairs of Swallows have built their open cup nests, constructed of mud.