a basic, probably dumb question...

[Doug Yanega]

Mark Walker wrote:

>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.

However, all the examples you give are cases that probably have little or
no visual cues associated (and yes, I should have thought of them myself,
especially the fruit). In fact, I think the examples people have given thus
far fall at one of the two extremes; mostly or exclusively visual, or
mostly or exclusively olfactory. Is anyone actually aware of cases where -
literally - BOTH components are important simultaneously? If not, the most
accurate and generally applicable answer to the original question is
"either/or" and not "both". (ah, semantics ;-)

Peace,

[NOTE THAT I WILL BE LEAVING BRAZIL ON FEB 13]

Doug Yanega    Depto. de Biologia Geral, Instituto de Ciencias Biologicas,
Univ. Fed. de Minas Gerais, Cx.P. 486, 30.161-970 Belo Horizonte, MG   BRAZIL
phone: 31-499-2579, fax: 31-499-2567  (from U.S., prefix 011-55)
                  http://www.icb.ufmg.br/~dyanega/
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82