Out for an early walk on a sultry June day, I gazed across my father's hayfield -- a monarch butterfly lilts past.

It puffs upward, then comes back to me, navigating the radiating currents of air rising from a baking landscape. Summer has come early, as a sudden heat wave brings August-like weather our way.

I wonder about the monarch that passes -- is she a newly emerged adult heading north or perhaps has she been traveling, flitting our way from points south? This may even be her final destination -- the field I stand in has patches of milkweed along the edge -- she may even lay her eggs here, and it will be up to her offspring to continue the journey north.

Milkweed -- I can hear the disgust in my father's voice when he utters the word. However, my opinion is quite a bit different. Understandably, a farmer does not want milkweed in a hayfield. However, in a natural setting or in a patch of your garden, milkweed is not only beautiful to look at -- but it also provides a micro-habitat in which many critters thrive.

The monarch butterfly is one of the insects that uses milkweed exclusively as the host plant for its young. Once they transform into butterflies, they often sip the nectar of milkweed flowers, and females will lay their eggs among the foliage.

A keystone to the monarch's survival, milkweed is sought by fertile females when they are ready to lay eggs. They lay the eggs singly on the underside of a leaf. The plant is toxic to most animals with a backbone.

Once hatched, the caterpillar lives on the plant, growing through its different larvae stages and all the while eating milkweed leaves exclusively.

The monarch's ability to thrive on this plant protects it -- in both caterpillar and butterfly stages of development -- from many would-be predators. It takes only one experience of biting into a monarch for an animal to learn to avoid this distasteful black and orange insect forevermore.

Hazards of the Nectar

The flower of the milkweed is beautiful, and the blossoms are very unusual.

Instead of developing stamens -- which produce powdery pollen like standard flowers -- milkweed has five small, dark openings in the flower column called pollinarium glands. Nestled inside these glands are upside down V-shaped structures called pollinaria. The tips of the V look like minute saddlebags. The bags are yellow with many grains of pollen stuck together.

When an insect is attracted to the milkweed flower and crawls all around investigating how to get to the nectar, one of its legs will slip into the tiny opening of a pollinarium gland.

As this insect pulls its leg free, it will pluck out the set of saddlebags with their globs of pollen, carrying it to the next flower, where it will dislodge, bringing enough pollen to fertilize a whole milkweed pod. Each flower that accomplishes fertilization will produce a pod with many seeds.

There are hazards for those that seek the nectar of milkweed. Some bees and other insects will leave a leg behind when trying to dislodge it from a pollinarium gland. Others are too weak to escape and die entrapped on the flower. For additional information see: http://www.backyardnature.net/fl_milkw.htm

Good Micro-Habitat

Milkweed is hearty, and many varieties grow one to two feet in height. The Web site http://www.duke.edu/~jspippen/plants/asclepiadaceae.htm describes many North Carolina varieties.

Milkweed provides a micro-habitat for a long list of wildlife, and there is really quite a bit of melodrama among the critters living there.

Monarch caterpillars crawl about munching leaves. The female is careful to lay a single egg per plant, so monarch caterpillars are solitary foragers. Sometimes Tachinid flies, when reproducing, will find a monarch caterpillar, lay eggs on the caterpillar's skin and when the eggs hatch the maggots eat the caterpillar.

Bees, moths, butterflies and hummingbirds consume the nectar of the blossoms. Crab spiders live among the flowers preying on the insects attracted by nectar. The harvestman (which looks like a daddy longlegs) cleans up the spider's leftovers and also feeds on any insects that die entrapped in milkweed blossoms. The harvestman also enjoys a sip of nectar for dessert.

Orioles use dried fibers from old milkweed stalks to build their nests. Milkweed Tussock Moths live on milkweed vegetation, but unlike the monarch, many eggs are clustered together and the Tussock caterpillars live in colonies as they munch away on the milkweed.

There is also a milkweed beetle, which spends its larval stage in the soil eating milkweed roots. After emerging, it eats the leaves and buds of the plant. Fall is this beetle's favorite time of year because milkweed seeds are a preferred food.

Then there are milkweed aphids that find milkweed irresistible. These aphids are golden yellow with black legs, and interestingly all the individuals of this species are thought to be female, managing to reproduce from eggs without fertilization.

Predators of aphids, such as the ladybug, are often found munching on these plant-sucking insects, unless there are protective ants around.

Ants will farm aphids for their honeydew. As aphids suck juices from plants, they exude a sweet substance called honeydew. Ants love honeydew and will tend the aphids, protecting them from predators -- all the while collecting the honeydew excreted by the aphids. It is a bit like farming milk cows.

The list continues, but perhaps I have sufficiently illustrated that a patch of milkweed tucked in a sunny spot of your garden can provide a great deal of entertainment.

Migration Picking Up

An unusually cool and wet spring slowed monarch migration, but with the steamy days of early June their progress leapt forward.

These butterflies are an interesting lot. The ones we see migrate from among only 12 mountaintops dotted through Mexico, but these butterflies travel up to 3,000 miles on their southern journey.

Their migration is similar to birds except that each individual butterfly will make only one trip. It will be the great-great grandchildren of these fall migrants that will find their way south the following fall.

The life cycle of spring and summer monarchs is much like most butterflies and moths. The eggs hatch into caterpillars that munch on milkweed plants, then go into dormant cocoons, and emerge as adults. The stages are completed in about a month and adult monarchs of spring and summer will mate, lay eggs and die within three to five weeks. Each generation spreads farther up the globe into parts of Canada and Nova Scotia.

In late summer, when monarchs emerge from their cocoons, the shorter, cooler days trigger changes that make them physically and behaviorally different. This generation will not mate until the following spring.

Instead, the adult monarchs of fall change from solitary foragers to social butterflies that travel south in clusters, sipping large amounts of nectar and storing fat in their abdomens until they return to one of those 12 mountaintops in Mexico -- their annual cycle complete.

Meanwhile, milkweed seeds are maturing, and pods split to release seeds. Each seed will have a white puff of filament, the fairy-like adventurers spilling out to scatter on fall breezes, dispersing to a new patch of soil. The seeds then wait for the warmth of spring rains, germination: the beginning of a new cycle.

Judy Jessop and be reached by e-mail at jgjessop@gmail.com.