Vanessa at night - no 3

[Stan Gorodenski]

Eduardo Marabuto wrote:
> 
> But is the way you mentioned to find out if they fly at night, running
> night traps
> (I suppose, based on light?) considered artificial light? If they are,
> this won't
> really come to an end!
> Why not use infra-red glasses to see at night?

This has started me thinking.
One way to determine if they fly at night is the following.
Get about 100 paper cups.  Cut the bottom off and cover each opening
with netting held in place by rubberbands.  Put one Vanessa in each and
then place the cups at various places in an locality away from man made
lights according to Paul's distance criteria of one quarter mile.  One
hour after sunset (Paul's criteria), open the end of the cup the
butterfly is not resting on, if it is resting on one of the netting ends
at all.  Throughout the night monitor the cups to see if any are
missing.  One might also put a florescent mark on both upper and lower
wings.  The butterfly may have simply crawled out of the cup without
flying.  One could then see if this happened by the use of a florescent
light.  If a butterfly is not in its cup and has not merely crawled out,
it could be concluded (one would also have to find some way to rule out
predation) that it indeed is flying at night.

Instead of paper cups, florescent marked butterflies could maybe be
placed individually in the open in various marked locations one hour
after sunset with the use of carbon dioxide in the same way geneticists
temporarily gas Drosophila.

Stan

 
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