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Habitats. . .Strategic Defenses for Life in the Open
Evidence of the long-standing love-hate relationship in rain forest insects
and plants is sometimes easily seen.
Heliconius Butterflies and Passionflower Vines
Heliconius butterflies
(Heliconius sp.) lay their eggs on the
leaves of the passionflower vine (Passiflora sp.). When the eggs
hatch into hungry, leaf-eating Heliconius caterpillars, the passionflower
vines protect themselves with an array of defenses.
Fake eggs . . .
some passionflower vines grow parts that look
like Heliconius caterpillar eggs. This keeps the female Heliconius
butterfly from laying eggs on leaves that appear to be occupied
by other cannibalistic caterpillars.
Guards . . .
Passionflower vines may enlist ants to pick off
any young Heliconius caterpillars developing on the leaves. In
return the vines supply the ants with nectar.
Weapons . . .
Several passionflower vines have hooked hairs on their leaves
that trap and hold Heliconius caterpillars until
they starve to death.
Dumpers . . .
Some Heliconius butterflies like to lay their
eggs on upward-curling tendrils of passionflower vines. Some
vines produce fake tendrils that are weak and fall off under the
weight of the developing butterfly eggs.
Artful Disguises
Many insects who live in the open use sudden displays of startling
color to confuse an attacker before vanishing. These insects respond
to a poke or a prod with eyespots or a brilliant flash of color
before making their exit.
With its green color and steady movements, this
female katydid
(family Tettigoniidae) generally blends well with its background.
But if disturbed by a hungry lizard or an inquisitive bird, it
quickly opens its forewings to display the bright pattern of its
hind wings.
Mottled markings, knobby antennae, and long front legs make
some
Peruvian walking sticks
(family Phasmidae) look like a dead
twig covered with lichen or mosses.
The eyespots on the tropical
Caligo butterfly
(family Brassolidae)
give it an owl-like appearance--a clever disguise in the face
of predators.
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