Saturday, September 13, 2008

Monarchs Are Definitely Back

fter a drop in population last year, monarchs are definitely back and to get a great look at the monarch in different stages of life be sure to stop by The Great Frederick Fair Butterfly House!! Hosted by Master Gardeners and Wildlife Gardening Adventures. There will be caterpillars, chrysalides and live butterflies by the dozens that will be tagged and released all week. Also, lots of educational material will be available for butterfly gardening. The Master Gardeners will also have a booth in the same building (14A) that will have information for the home gardener. Now, back to your question. The monarchs have recovered form their losses of 2002 and are in great numbers this year! The travels of this delicate flyer have fascinated both gardeners and scientists for years.

Monarchs float in to our garden in the Mid-Atlantic around the fourth of July. Butterflies will find the nectar in masses of tall, bright flowers planted in a sunny location an irresistible meal. Adults seek the nectar of the blooms, and in return play a role in pollinating flowering plants. But these butterflies only live a few weeks. Soon they mate and search for a place to deposit their eggs, and it must be the right place. True butterfly gardens are planted with not only the attractive nectar but also the larval host plants, which caterpillars feed on.

Different butterflies utilize different host plants to nurture their young. Watch closely and you'll see Black swallowtail larvae on parsley or dill, and Fritillaries on violets.

As caterpillars, monarchs (Danaus plexippus) will only be found on members of the milkweed family. Yes, those roadside weeds with the silky "parachute" seeds and the latex loaded sap. In your garden you may want to plant another species of Asclepias that you might find more attractive. To see all the stages of a monarch's life, you'll need milkweed. We've grown a lot of monarch caterpillars and the sight of a female finding a milkweed plant is so satisfying! They seem to enjoy butterfly weed (Asclepias tuberosa) for the nectar, but will leave eggs all over common and tropical varieties (A.syriaca, A.curassavica).

When the eggs hatch the tiny caterpillar begins eating the tender milkweed leaves. Eating is a caterpillar's main job and milkweed is the only food the yellow, white and black striped caterpillars eat. By ingesting toxins from milkweed, monarchs give themselves some protection from predators. Birds won't feed on larvae or adults because they taste terrible. A caterpillar will eat and grow for about two weeks, shedding its skin four times as it grows. Then it will find a secure place to hang down and slip out of its skin one last time changing into a beautiful jade green chrysalis trimmed with gold. Inside the chrysalis the transformation takes place. A butterfly emerges in about 10 to 14 days. The monarch has a large abdomen and its wings are crumpled. As it hangs upside down its wings expand and harden.

Somehow, the late summer monarchs know the time is right to migrate. Not wasting any energy on reproduction until spring, the state of diapause will allow them to build up fat reserves for hard times ahead.

They seem to follow the late afternoon September sun from our yard as they orient toward the southwest. Butterflies start collecting together and head south starting in late August in Canada and the northern states. In some places a steady stream of orange and black floats by, at times in large numbers. The flying rivers of monarchs have been studied for years. Researchers have been placing identification tags on orange wings since the 1930's trying to figure out the whys, wheres and hows of the annual trek. It wasn't until the mid 70's that the masses of overwintering butterflies were "discovered" in Mexico. In 2001 we joined in the tagging project with Monarch Watch and sent off dozens of monarchs we had watched grow from eggs deposited in our garden.

Tagging monarchs has led to the mapping of migration routes. We now know that monarchs west of the Rocky Mountains will generally overwinter in awe-inspiring clusters along the California coast, some east coast monarchs sit out the winter months in Florida, but masses more fly to central Mexico. This is the location ours head to each fall.

High in the Transvolcanic Mountains west of Mexico City at and altitude of 10,000 feet grows a straight, tall fir tree known as the oyamel. At about a dozen known sites oyamel trees are covered with monarch butterflies from November through March. The population varies, but 100-200 million have been recorded. Here they collect after traveling as far as 2500 miles. Winter is the dry season and the air is cool at this altitude, but under the canopy of oyamel forest monarchs conserve their strength and roost on the trees as tight as shingles on a roof. Back-lit in the forest, they give the appearance of bunches of grapes hanging in clumps on the trees. They can be so thick on a branch that the limb breaks with their weight. As the sunlight warms the butterflies, movement starts. Some times gently, sometimes in a burst like fireworks, they leave the trees. They look for nectar in flowers and water in mountain springs. They catch the sunlight and sparkle, dancing like fairies. So many in flight at once makes for an otherwise unknown experience: the sound of butterflies on the wing.

As spring approaches the beating of wings begins to leave the mountain retreat. The butterflies mate on their way back to the north and start looking for milkweed. Females must mate and return to the milkweed in the north. This is the breeding ground they depend on and we can all help the plight of this endangered phenomenon by planting milkweed. Again, be sure to stop by the butterfly house during The Great Frederick Fair this year

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