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NEWSLETTER No. 44 -  Autumn 1999

WEST MIDLANDS BRANCH, BUTTERFLY CONSERVATION

 

Autumn Glory

September certainly did us proud, the warm sunshine allowed the Large Whites, Small Tortoiseshells and the Red Admirals to search for the last vestiges of nectar in the Buddleia blossoms. September is the last month of the "official" butterfly season, but a warm spell in October will often encourage one last fling before the frosts of November bring the season finally to a close, and even then the odd hibernating butterfly is sometimes tempted out to bask in the feeble rays of the winter sun. This is probably not a good idea as it tends to use up part of the fat reserve that they have built up to get them through the winter and which they cannot replace because of the absence of flowers on which to nectar. The same problem arises when a butterfly (usually a Small Tortoiseshell or Peacock) appears in the house in mid-winter, aroused from its sleep by the house heating. The best one can do is to transfer it to the coolest room available or maybe a shed or garage where it will have to take its chance with the predatory spiders.

Another of our winter hibernators is the Comma (remember the orange ones with the deeply indented wing margins and the tiny silver "," on the underside?). They were once a pest in Worcestershire. The caterpillars feed on nettles and hops and in the last century became a serious menace to the Worcestershire hopyards causing great damage to the growing hop vines. The hop pickers used to call them "hop cats". However the discovery of nicotine sprays rapidly wiped out the Comma colonies (and probably some hop pickers too!). Since the last war it has staged something of a comeback and is slowly extending its range, but now the caterpillars feed mainly on nettles. I've had a golden-leafed form of the hop growing on a pillar in the garden for several years and late in July I noticed some small holes in the leaves and on the underside were some tiny caterpillars. Two weeks later on returning from holiday, one had already turned into a chrysalis and a second was fully grown and hanging by its tail below a leaf, its body forming the shape of a letter "J". Half an hour later it had turned into a perfect chrysalis, fawn in colour with two small but brilliant silver spots. The butterflies emerged about two weeks later and after allowing their wings to dry and harden for about an hour, flew off into the sunshine. Unfortunately I missed the actual, wonderful moment of emergence from the chrysalis, but maybe I'll be lucky next year.

Looking back over the summer, it's been a pretty poor butterfly season, partly as the result of 3 consecutive years of unsettled spring weather and partly because of a steady decline in butterfly numbers that has been taking place over the last 50 years and particularly over the last 20 years. Next month we'll take a look at the overall picture. How we go about measuring the health of the butterfly populations and what is being done to help not only the butterflies but all wildlife.

Digby Wood.