moth evolution (and navigation)

[Kenelm Philip]

	The first moths (Zeugloptera) are thought to have arisen a bit over
200 million years ago. The most recent suborder (Sphingoidea) arose just
over 100 million years ago.

	Many insects can fly at a fixed angle to a bright light source,
such as the sun. This behavior is called 'menotaxis'. Some can even allow
for the motion of the sun, and change the angle with time so that they
fly in a straight line as the sun moves. It has been assumed for some time
that nocturnal moths exhibit menotaxis with respect to the moon, or to
bright stars--and this has been an explanation for the way moths spiral
in to bright lights. I believe the phenomenon may be (at least in some
cases) more complex than that--but I am not up on current research in this
area.

							Ken Philip
fnkwp at uaf.edu