a basic, probably dumb question I haven't found the answer to yet.

[Mark Walker]

I'm going to go out on a limb and suggest that both color and "scent" are
used, depending on species of both plant and butterfly.  The delicate
symbiotic relationship between plant and animal here would suggest that both
species would exploit all available cues.

On a related note, many butterfly species do not nectar at flower blossoms
at all.  Some go to rotted fruit, others to running tree sap.  Still others
are more fond of licking salt at moist sand or urine deposits.  I have had
several hitchhiking butterflies that have been attracted to my sweat while
walking through the bush.  In one case, a rapid flying Zebra Swallowtail
(Eurytides marcellus) made a U-turn as it passed me, and then remained on my
person for 20 minutes while I continued to walk.

IMO, there would appear to be strong evidence of something more than just
optical attraction.

Mark Walker.

> At 08:39 PM 1/18/1999 -0300, Doug Yanega wrote:
> 
> >I suppose I'm not the only person who has seen butterflies attracted to
> >orange or yellow objects that have no scent at all. Secondly, of the
> >butterfly-pollinated flowers I know personally (quite a few here in
> >Brazil), I cannot think of one with a noticeable scent, in *strong*
> >contrast with moth-pollinated flowers. Given these observations, it seems
> >that scent is unlikely to be critical for most butterflies (but I always
> >will allow for possible exceptions). Others here may know better.