Something Monarch Butterflies Just Can’t Live Without

Almost everyone wants to help an underdog. Environmentally, one local underdog has six legs as an adult.

Monarch butterflies, Danaus plexippus, are likely the best-known butterflies on the planet because of their remarkable and much publicized ability to migrate thousands of miles across international borders. They then congregate in the same spots year after year.

Their bright colors and animated appearance make them the ideal image for their popular insect order.

All the flying takes good health and quite a lot of energy. While adult Monarchs can utilize a variety of nectars, the larvae’s diet is limited only to eating milkweed.

Colorful milkweed blooms will soon be gracing gardens and wild locations as the summer approaches. Each one has the potential to support a Monarch butterfly’s larva and contribute to this species’ continuation.

Therein lays the weakest link in this biological chain which stretches into the ancient past.

One historical theory goes that the last Pleistocene glaciations in North America instigated this insect’s migration to Mexico in the east and to the Californian coast and deserts in the west, where there was still plenty of milkweed to support their caterpillars.

Milkweed species are currently sprouting and will soon be producing critical foliage in panhandle Florida. Each plant has the potential to nourish one of these benign and colorful insects.

Monarchs lay their eggs individually on the underside of leaves and sometimes on the flowers of different milkweeds species. There are several native milkweeds which grow wild in the region, along with some introduced species.

These one-at-a-time deposits have several benefits for the larva when hatched. The most notable is these voracious insects have plenty to eat with little chance of competition from siblings or other species.

Milkweed seed heads will appear after the blooms fade in a few months. The seeds can be saved and distributed later in the home landscape and shared with friends.

While milkweeds have an attractive bloom, they quickly go to seed. As such the plant is relegated to wildflower status, sometimes being destroyed as a pest because of its toxicity, and rarely cultivated until recent years.

Additionally, the wide distribution of the eggs improves the chances at least some of the eggs will hatch and reach maturity. Monarchs are exclusively vegetarian and are subject to predation.

Invertebrate pillagers such as ants, spiders, and wasps attack monarch larvae on milkweed plants. Tachinid flies and braconid wasps are known to parasitize larvae.

To add to the odds against survival of the eggs and larvae, there are several microscopic organisms which can infect monarchs during their formative stages. These included a virus, multiple bacteria, and protozoan parasites.

At the hatching of the first instar, or larval phase, the tiny caterpillar is white with a black head. There is a touch of irony when such a colorful butterfly begins life in this monochromatic form.

Development from the white egg to the adult’s brilliant splendor takes less than a month. In North America, the monarchs go through at least four generations a year before they start their migratory trek south in the autumn.

Adult Monarchs are strong fliers which can stay aloft for 11 consecutive hours. In the fall, mature Monarchs have enough fat stored up from plant nectar to permit a continuous flight of over 600 miles without feeding.

There has been a concerted effort to cultivate milkweed and nectar producing wildflowers in the panhandle region by concerned gardeners and others who hope to see Monarchs continue their transcontinental flight.

Each seed which germinates in the local soils offers the possibility of continuing an ageless event which defines nature at its grandest. It is a good time to add this important wildflower to the home landscape.

This seems like a good trade for allowing a weedy wildflower to flourish.

About the author
Les Harrison

Les Harrison is a longtime resident of north Florida, having attended public schools in three counties. He has a Bachelor Degree from the University of Florida in Journalism and a Master’s of Science from Auburn University in Agricultural Economics. He is the author of more than 2000 newspaper and magazine stories and journal articles. During his career, he held positions in private, government and educational (university level) sectors. He holds the title of Extension Agent Emeritus. He can be reached at harrison.gl@gmail.com.

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