Butterflies offer a colour spectacle (From Lancashire Telegraph)

Butterflies offer a colour spectacle

7:12pm Monday 12th September 2011 in Ron Freethy column By Ron Freethy

September is a wonderful month for watching butterflies. This week I decided to get used to watching butterflies by visiting the wonderful tropical butterfly house at the Ashton Memorial on the outskirts of Lancaster.

It is easily signed from the M6 and the A6. For a modest fee visitors can stroll around the heated butterfly area and buy a colour guide to help identify the species.

I spent some time photograph-ing young people enjoying themselves and also some splendid specimens of the African swallowtail. These are large compared to our butterflies but even the tropical species do not reach the size of other groups of animals. Why should this be?

It is because of the breathing system. This is very efficient for small animals but larger animals such as human beings have large lungs to hold air, and work like pumps.

Each segment of a butterflies abdomen has a hole in it called a spiracle.

This leads into tubes called tracheoles and air leads down into each cell of the body.

This works well for small animals but if they grow too large the breathing system does not work. This has restricted the size of butterflies.