More about Moths – Ray Colliers Wildlife in the North

tiger mothMoths are a mystery to most people as they only come across the occasional one inside the house or fluttering against a window at night, attracted by the light.   What adds to the mystery is the fact that the majority of moths are strictly nocturnal and, whilst butterflies visit blossoms by day, moths are mainly the night visitors.   So we never see the very large  numbers of a wide variety of types of moths that flourish in our gardens and the general countryside.   When we think of butterflies we are thinking in terms of around 60 types that includes three that are regular migrants but cannot survive the winters.  When we think of another fairly well studied group, the dragonflies, there are only 56 types and that includes  those that only occasionally  visit the UK.   So it may come  as a surprise to realise  that for moths there are no less than  2,400 types that vary considerably in size and colour  let alone their habits.

There are a few moths that fly by day but most of them are not as bright and colourful as butterflies so still go un-noticed.  One such moth is the silver Y that was mentioned in this column a few weeks ago.   It is called the silver Y because of the tiny marks on the wings that look like the letter Y.    There are plenty of these on the wing now and they are unusual in that they fly not only by day but also by night.   Despite the sheer numbers of silver Y’s they  are solely from migrants each, year they   fly over from the continent and beyond.   The reason for this is that they  cannot survive the winters so have to rely on fresh ones to colonise each year.   The numbers arriving in the Highlands vary considerably each year depending on weather both here and on the continent.    In contrast, one of the smallest of the day flying moths, but a very conspicuous one, is the chimney sweeper moth that can often be seen fluttering over grassland.   It is only one inch (25 mm) across the wings  but the reason it is so conspicuous is that the jet black wings stand out so well.  The very tiny caterpillars of the chimney sweeper feed on pignut hence the reason the adults are flying over grassland.

There are, occasionally, other clues over the presence of moths and one took place last week just along the road.  I had been taking one of our five dachshunds out for a walk and came across a large, black and rather menacing looking  caterpillar scurrying across the road.  As there were a few cars around I picked the caterpillar up in a tissue  and placed it carefully on the roadside  verge.  Then there as another and then another and in the end there were seven in all and each one I carefully moved to safety.   These are one of the very few caterpillars that are easily identified as it could only be that of the garden tiger moth.   The very hairy caterpillars  have the name of  “woolly bears” which seems appropriate.    The reason for the size of the caterpillars is that the adult moth is quite large at  three inches (76mm) across the wings.  They fly by night but being large and conspicuous can often be seen during the day.   They are very unusual in that the cryptic colour on the wings, seen in the photograph from the garden,  varies so much that no two individuals are the same.

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