Monday, December 28, 2009

Waves of Monarchs

Image of a Monarch Butterfly Danaus plexippus.


Several years ago I looked up into my big old walnut tree and noticed the leaves looked particularly odd. It appeared they had turned a rust color.

When I got close, I realized the branches and leaves were covered with hundreds of Monarch butterflies. It was late summer and late in the afternoon. I was witnessing a portion of the southern migration of Monarchs.

Every summer, the last generation of eastern Monarchs migrate south to spend winter in the eastern Micheocan Mountains near Mexico City, Mexico. The first generations die after about 8 weeks (their life cycle.) This last generation will last about 9 months. The life cycle is egg, caterpillar (larvae), chrysalis (pupa) and the adult butterfly.

The scene in the tree was a picture I could not adequately capture with my camera. From a distance it simply looks like dark rust leaves. Up close and the magnitude of the numbers aren't captured.

Today, I found a web site that you might enjoy next fall: http://www.learner.org/jnorth/maps/monarch

This is the Annenberg Media Foundation's Journey North - Fall 2009 Monarch Butterfly Migration: Overnight Roost sightings. They are already setting up for 2010 migration sitings.

Included in this site are other migrations and educational tools for teachers. It features a global study of wildlife migration and seasonal changes.

If you enjoy the Monarch butterfly and would like to encourage them in your garden, plant milkweed. The Monarch (larvae) caterpillar ONLY eats milkweed (their host plant.)

The adult butterfly eats an all liquid diet of flower nectar, water and liquids from mushy fruit (slices of ripe banana, orange, or watermelon.) Think of their mouth parts as a straw sipping liquid.

The particular type of milkweed must be one that is high in a certain toxin that make the emerging butterfly poisonous to predators. The Monarch's coloring is a warning to predators that they are indeed toxic.

The false milkweed, Cynanchum swallow-wart, actually fools the butterfly into thinking it's a host but the larvae will not develop. Do not plant this.

Plant nectar flowers such as butterfly weed and purple coneflowers and plant in masses. Butterflies are near sighted and are more easily attracted if the flowers are very obvious and brightly colored.

Some other tidbits:

  • All butterflies are cold blooded insects and enjoy having flat rocks in the sun to warm themselves.
  • They will also want a moist spot. A saucer filled with wet sand or mud will attract many kinds of butterflies.
  • You can not use insecticides or herbicides - they are deadly to both the larvae and the butterfly.
  • Milkweed is not always liked by some because some varieties can be invasive. Asclepias syriaca is the common one you see on our roadsides and spreads by rhizomes. It is a Monarch favorite but not necessarily an agricultural favorite. Plant where it can be contained.
  • Some milkweed prefer moist conditions - do your research first.
  • The Monarch is one of the longest migrating creatures on earth.
  • 70% of the population in Mexico was killed in 1991 as a result of freezing weather.
  • The Monarch is the Illinois State Butterfly.
  • The Monarch is not a pest and causes no agricultural damage.

As we are sitting inside these snowy days, planning or improving your butterfly garden should include some of the Monarch's needs. And maybe, just maybe, your yard will be an evening hotel for those migrating Monarchs.

No comments:

Post a Comment