Sunday, 26 July 2009

Tiger Tiger burning bright

Many mothers running light traps have noticed the decline in the numbers of Garden Tigers over the last few years. The is particularly so in the south of England. Just as noticeable is the disappearance of it caterpillars, the hairy Woolly Bears. Last night was memorable therefore when I found two Garden Tigers in one trap. They are readily attracted to light, but normally arrive late. The adults do not feed so they are not attracted to flowers.

Garden Tiger (Arctia caja)

Like many highly coloured insects the pattern acts as a warning to potential predators. not only is the moth unpalatable it is poisonous. One of the things I like is that if you compare the patten on any two individuals they are very similar but also so individually different.

The Rothamsted Insect Survey has been monitoring Macro moth numbers since 1933 and the full national network came into being in 1968. The survey uses a number of very large, fixed traps that take daily samples through out the year. The massive amount of data accumulated by amateur mothers also adds a huge amount to the knowledge about moth populations. Rothamsted has a particular project of Garden Tigers and an Open University Ph.D. student, Sarah Anderson is studying 'Conservation Genetics' of garden tigers. Her goal is to see how the changes in the distribution of A. caja has affected the genetics of local populations. This information will improve understanding of the genetics of rapidly changing populations such as threatened or invading species.

Dog's Tooth (Lacanobia suasa)

There weren't very many other moths last night but I did get one that was new for the garden, a Dog's Tooth. This is named after the back mark on the forewing that is said to resemble a Dog's Tooth. I never cease to be in awe of the people who dreamt up the names of our moths, what imaginations they had!

2 comments:

Dean said...

Garden Tiger. Now that`s a species i`d love to see. And your pics have done them real justice. Nice ones, Tony.

marga said...

Garden Tiger is a great name for a moth!