MOREHOUSE, SARAH and STEVEN B. CARROLL.* Division of Science, Truman State University, Kirksville, MO 63501. - Effect on pollinator behavior of a flower-color polymorphism in Viola pedata.
Viola pedata (birdís-foot violet) is an eastern spring
wildflower common in open woodlands and savannas. Populations
generally include two flower-color morphs, one in which the color of
all five petals is light lavender (LT) and one in which the upper two
petals are dark violet and the lower three petals are lavender (BI).
We followed dusky-wing butterflies (Erynnis), which are the
primary pollinators in northern Missouri, to determine (1) if time
spent on the two flower types differed, and (2) if time spent on an
individual flower was affected by the color of the flower most
recently visited. All four possible transition types were included in
the second analysis. Pollinators spent an average of 12.1 s (se: 1.77)
on LT flowers and 14.7 s (0.61) on BI flowers (t = 1.71, df = 357, p =
0.09). Time spent by pollinators on individual flowers was not
significantly affected by the color of the previously-visited flower
(F3,314 = 0.47, p = 0.70). Previous work has shown that
pollinators visit the two flower-color morphs in proportion to their
numerical representation. These visitation patterns, in combination
with factors such as pollen load size and the compatibility of within-
and between-morph crosses, are likely to have important consequences
for the population genetic structure in this species.
Key words: flower color polymorphism, pollinator behavior, Viola pedata