Butterflies (a bit off topic)

Joe Shaw jshaw@opuntiads.com
Mon, 13 Nov 2006 16:21:59 PST
Hi Gang,

I enjoyed a news story I read today about the recovery of a population of butterflies in the British Isles.  The British Large Blue butterfly went extinct in Britain in the late 70s.  Now, careful study and land management have allowed to butterfly to prosper again in some locations in England.

The larvae (caterpillars) of the British Large Blue have a specialized life-style and eat thyme plants for a few weeks after they hatch, while still very young they are then taken underground by red ants.  The larvae provide nectar to the ants and in exchange live on ant grubs for some months; after a winter underground the larvae emerge from the ant next and create a chrysalis.  Eventually they emerge as a butterfly.

It turns out that most ants that take the larvae underground are not suitable partners for the butterfly, and only one species of red ant provides the correct conditions for butterfly survival.  Additionally, scientists learned that the special ant species needs a certain habitat to prosper.  The ants need closely cropped grass, better still if the area is untouched by plowing, etc.  

Though the British Large Blue went extinct in Britain, some were introduced from the European mainland into areas that were kept suitable for the red ant host.  It has taken over 20 years but this year produced a banner crop of British Large Blue butterflies.  

The important lesson, of course, is that many species of plants and animals are interdependent; loss of one can cause the loss of others.  

LINK:  News Article, Current Biology, Nov. 2006

LINK:  British Large Blue Info, Wikipedia

LINK:  Large Blue Butterflies, General Info


Conroe TX

More information about the pbs mailing list