Natives vs. Aliens:
It’s a War out There
Story and photographs by Susan Corcoran
N
ative plants like old friends are
comfortable in their surroundings.
Over long periods of time they
have adjusted to their location,
allowing them to survive extremes of climate and
needing no coddling to thrive. They find adequate
nutrients in the local soil and are not bothered by
local pests. They are useful as well; on Kiawah natives
hold the sand in our dunes and filter ground water.
In the maritime forest they provide food, shelter, and
protection from predators to resident and migrating
wildlife.
Scientists are now finding the link between native
plants and wildlife is more complex and critical
than even they thought. Recent studies reveal that
the leaves from native plants are vital to the diet of
a number of vegetarian insects, insects that convert
plant energy to protein. It turns out these insect
herbivores are the primary protein for some of our
favorite wildlife. Birds and butterflies depend on
their tiny protein packed bodies for sustenance and
to fuel the reproductive process. Later virtually all
land birds feed this plentiful and reliable food to their
hatchlings. Most insect herbivores can only survive
on the leaves of host plants “with whom they share
an evolutionary history,”* i.e. native plants. Although
we tend to think of insects as pests, the reality is
without insect herbivores there would be serious
consequences up and down the food chain.
Additionally some native plants serve as nursery
host plants. Like a birthing center for butterflies,
these are very specific plants where butterflies lay
their eggs. The same plants are the only food source
for newly hatched young as they progress through
their larval stage. Much has been written about the
monarch’s (Danaus plexippus) affinity for milkweed
as a food source and a nursery for their young. The
zebra longwing (Heliconius charitonia), state butterfly
of Florida and an occasional visitor here, is another
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