Even for a creature as lovely as a
butterfly, bearing the name of an ancient goddess of beauty
is a lot to live up to. No single feature or behavior
connects the Aphrodite fritillary (Speyeria aphrodite)
with the Greek deity Aphrodite, but as one of the showiest
butterflies in Chicago Wilderness, this species is a celestial
beauty in its own right.
The underside and top of an
Aphrodite fritillary. Great spangled fritillaries
have a wider pale band between the last two rows
of silver markings on the underside of the hind
wing. Photos by Randy Emmitt.
About the size of a monarch butterfly,
the Aphrodite is tawny orange with black spotting on the
tops of its wings. The undersides of its wings, ranging
from tan to brown, feature beautiful silvery spots. These
silver markings appear metallic, but they are actually
made of specialized scales. The shiny, reflective color
results from light scattering off these scales
a phenomenon known as structural color rather than
being partially absorbed by pigment.
The Aphrodite fritillary closely resembles
the great spangled fritillary (Speyeria cybele),
a much more common species. A simple trick readily distinguishes
the two butterflies: the area between the silver spots
on the underside of the Aphrodite is a rich reddish brown.
In contrast, a broad pale band runs around the entire
edge of the underside of the hind wing of the great spangled
fritillary. The band (or lack thereof) is readily visible
when the butterflies pause to sip nectar. With practice,
butterfly watchers can even see this feature as the adults
Behavior distinguishes the two species
as well: Although Aphrodites can be strong fliers, they
are less skittish than great spangled fritillaries and
seem to pause more often at flowers. Great spangled fritillaries
typically spend more time flying, making them comparatively
difficult to approach.
A single generation of Aphrodites
emerges each year. Adults begin flying in late June and
early July, males generally appearing before females.
Although Aphrodites mate in midsummer, females do not
lay their fertilized eggs until the end of summer, typically
in the second half of August.
The eggs hatch a week or so after
the female lays them. Newborn larvae consume their eggshells
(a common diet for caterpillars) and immediately crawl
under available cover to hibernate for the winter. They
will not feed again until violets appear the following
spring. As spring progresses, the active caterpillars
develop rapidly, transforming into chrysalides in June.
Aphrodites complete the cycle by emerging as adult butterflies
right around the summer solstice.
The distribution of the Aphrodite's
host plants, the violets, plays a role in where Aphrodites
exist, but the picture is complex in ways researchers
don't fully understand. In the laboratory, Aphrodite caterpillars
can be reared on nearly any species of violet, but in
the field, the butterfly remains much rarer than these
species. In Illinois, Aphrodites inhabit only larger prairies
such as Gensburg-Markham
Lake Prairie, and Illinois
Beach State Park. At those locations, caterpillars
appear to feed mostly on prairie and bird's foot violets.
The populations of Aphrodite fritillaries
and great spangled fritillaries at Illinois Beach State
Park in Zion reveal an important aspect of the ecology
of both of these species. Great spangled fritillaries
can live in more types of habitat than Aphrodites. Therefore,
people often see them fluttering throughout most of the
park, particularly in the black oak savannas. In contrast,
Aphrodites dwell only in the open, wet prairies that occur
in the troughs, or swales, between the park's dune ridges.
As a consequence, visitors wandering the nature trails
are far more likely to encounter great spangled fritillaries
The strong dependence of Aphrodites
on prairie habitats suggests that these butterflies are
one of the species most likely to benefit from prairie
restoration. So far, however, this does not seem to have
happened. Although the species seems to be thriving under
current management on sites where it already flies, Aphrodites
are not colonizing new sites that have been restored to
prairie. One reason for this might be that the prairie
violet species are difficult to restore. The process of
gathering seeds from violets requires much time and effort.
Consequently, many sites that have
otherwise been restored to vibrant communities lack violets.
If land managers can improve techniques for the widespread
planting of prairie and bird's foot violets, we may restore
these spectacular insects to many additional places in