Butterfly Defense Mechanisms (PowerPoint)

							Butterfly
Defense
Mechanisms
3 Main Types of Defenses
 Camouflage
    “Cryptic coloration” allows moths and butterflies to
    blend into their surroundings. Females especially
    have earth tone colors that blend in with bark, leaves,
    or lichen.
  Warning Coloration (aposomatic coloration)
    Bold patterns and bright contrasting colors (especially
    yellow and black, orange, or red) warn predators that
    insect may bite, sting, or taste bad

 Mimicry
  Some insects deter predators by mimicking the color
   patterns of other less edible insects or animals
Warning Coloration

                     As caterpillars, they feed on milkweed,
                      from which they gain toxins like cyanide.
                     Caterpillars sequester the toxins into
                      parts of their body where they cause no
                      harm
Viceroy butterfly



 –As adults, the bright colors warn
 predators that the butterflies taste
 bad and are toxic. If eaten,
 predators (like birds, lizards,
 monkeys) spit them out and learn
 to avoid them in the future                Monarch butterfly
Coral snake (Costa Rica)
– Have relatively small fangs and are rather timid,
  prefer to escape than stay and fight
– Bright and memorable color pattern, (called
  aposomatic coloration) warns predators to
  stay away
Experiment by Brodie et al 1993
 Hypothesis 1: If aposomatic coloration is effective, then
  more predation attempts should be seen on brown
  models than on coral models, because predators should
  be warned away by the bright color of the coral models,
  but not by the brown models.
Camouflage




– 3 moths: each use
                         This eacles moth is
  a different
  coloration strategy    camouflaged to
  to blend into leaves   look like a leaf
                     Green katydid of Costa Rica.
                     – Some even have what
                       appear to be fungus and
                       disease spots or chewed
                       holes on their wings, but
                       those are just additional
                       parts of the camouflage.




– Brown katydid of
  Costa Rica
  More camouflage




Schizura ipomaea: larva   Clemensia albata (little
                          white lichen moth)
Limenitis arthemis   Colias philodice
                     (clouded sulphur)
(viceroy)
    Mimicry
Poisonous pipevine mimicked by eastern tiger, eastern
black, red-spotted purple, and spice bush swallowtail




        Pipevine swallowtail             Eastern tiger
 Batesian Mimicry: One species is
  harmful/distasteful, and the other is not
 Mullerian: both are harmful/distasteful
          Viceroy                    Monarch

Viceroy butterflies have long been thought to be
palatable mimics of Monarchs, which are distasteful
and toxic. More recently, ecologists have determined
that both Viceroys and Monarchs are distasteful,
making this a classic example of Mullerian mimicry in
which both species benefit.
Other forms of mimicry
             Eye spots mimic birds or
         snakes, that when flashed can
         startle a predator giving it a few
         extra seconds to escape.
             Eye-spots also give predators a
         false target. A butterfly has a better
         chance of surviving an attack to
         the outer part of its wing than an
         attack to the head.

         Hover flies do not sting or bite,
         but they gain protection by
         looking like stinging bees, an
         example of Batesian mimicry.
 Swallowtail caterpillar: mimics a foul tasting blob of bird
  excrement. If a predator sees through the disguise and
  attempts to attack, the caterpillar has a second line of
  defense. It rears back, extrudes a forked scent gland called
  the osmeterium and lets off a foul odor.
How does the plant protect
itself from the caterpillar?
1) disguises - Some passion flower vines produce leaves that look
like the leaves of other kinds of plants. If the butterflies think they
aren't passion flower vines, they won't try to lay their eggs here.

2) fake eggs - A passion flower may grow imitation eggs. When the
butterfly comes to lay her eggs, she thinks that the leaf is already
occupied...and goes off to look for an empty vine.
3) weapons - Some passion flower species grow
hooked hairs on the surface of their leaves. These
hairs kill the caterpillars.

4) guards - On occasion, passion flower vines get
ants to guard them. The vines supply a special nectar
that the ants like to eat. In exchange, the ants pick off
any young cateripllars that develop on the vines'
leaves.

                                    5) dumpers - Since butterflies like to lay
                                    their eggs on the tendrils of the vine,
                                    some vines grow special extra weak
                                    tendrils. When an egg laid on one
                                    begins to develop and becomes heavier,
                                    the dumper tendril can't hold its weight
                                    anymore, and the egg falls off.

                                     –   http://uts.cc.utexas.edu/~gilbert/teaching/zoo369/lect6.html
Natural Selection
     Individuals with more favorable traits in a particular
      environment are more likely to survive and
      reproduce than those with unfavorable traits.
     Because these traits are heritable, favorable traits
      become more common in the population over time.



  Adaptation: a trait (structure or behavior) that has
   changed over time to make an organism better suited
   to survive and reproduce in its environment
Peppered Moth
 http://www.echalk.co.uk/tasters/taster1/taster.htm

 In England, the majority of peppered moths originally
  had light coloration, which camouflaged them well
  against the light colored trees.
 After industrial revolution of 19th century, all the soot on
  the trees made them easier to spot by predators, and
  light colored moths died off, while dark colored moths
  had the advantage, and rose to higher frequency.
 When environmental standards improved, light colored
  moths increased in frequency again
What is the biggest threat
to butterflies?
  Habitat destruction
    Development of land for farms and houses,
     roads, walmart…
  Other threats:
      Use of pesticides
      Invasive species
      over-collecting of larva and eggs
      Extreme climate conditions (hurricanes,
       freezes, and droughts)
What can you do to help?

  Provide diverse habitat of host and
   nectar plants (especially for endangered
   or rare species)
  Don’t use pesticides in your garden
  Learn more about how destruction of
   habitat leads to loss of endangered and
   threatened species, and tell others
   about it