Posts Tagged ‘monarch butterfly’

The Milkweed Community

May 13, 2015
Monarch butterfly on common milkweed © Beatriz Moisset

Monarch butterfly on common milkweed
© Beatriz Moisset

The monarch season is coming, and many gardeners throughout the country are getting ready to welcome the arriving butterflies with milkweeds lovingly cultivated in their gardens. They also brace themselves to battle whatever ills may affect the caterpillars. Milkweed bugs and milkweed beetles are seen with hostility. The “dreaded” tachinid flies, and “hated” stink bugs infuriate gardeners even more. Aphids are not welcome. Lady beetles and lacewings generate mixed feelings because they feed on aphids but they are not loath to snack on some monarch eggs or small caterpillars.

Spotted Lady Beetle larva (Coleomegilla maculata) © Beatriz Moisset

Spotted Lady Beetle larva (Coleomegilla maculata)
© Beatriz Moisset

It is important to take a look at entire ecosystems, not just single species as Carole says in “Saving the Monarch Butterfly

“The Monarch Butterfly is in deep trouble, and many passionate organizations have been created to save this single species. But a focus on protecting habitat instead of concentrating on a single species will provide lasting benefits for all species of wildlife and the native plant communities that support them, a far more worthy effort to many environmentalists and wildlife gardeners.”

So, let us take a quick look at some members of the milkweed community. Despite the formidable defenses these plants have, many species have coevolved with them and can use them as food. They incorporate the milkweed toxins and use them to deter their enemies. In turn, many predators have also coevolved and can eat the milkweed eaters. An entire food chain has developed this way.

Large milkweed bug, Oncopeltus fasciatus on common milkweed © Beatriz Moisset

Large milkweed bug, Oncopeltus fasciatus on common milkweed
© Beatriz Moisset

Milkweed longhorn beetles on common milkweed © Beatriz Moisset

Milkweed longhorn beetles on common milkweed
© Beatriz Moisset

Most monarch lovers are familiar with the brightly colored milkweed bugs and milkweed longhorn beetles. Bear in mind that these insects are represented by a fairly large number of species. That is, there are more than just one milkweed bug and one milkweed beetle. A few other beetles also feed on milkweeds, and several moths also do so, among them the tussock moth and the delicate cycnia.

Tussock moth caterpillar © Beatriz Moisset

Tussock moth caterpillar
© Beatriz Moisset

Sooner or later, those who raise monarch caterpillars are bound to meet two insects which will make them unhappy; one is a predator, the spined soldier bug, the other a parasite, the tachinid fly, Lespesia.

The spined soldier bug, Podisus maculiventris, is a good hunter of caterpillars and beetle grubs. It has a sharp beak with which it impales its victims. It injects some saliva which turns the inside of the prey into a smoothie and so it proceeds to drink this nutritious cocktail. The sight of a shriveled monarch caterpillar hanging from the beak of a stink bug causes great distress to the gardener.

Predatory stink bug, Podisus maculiventris on goldenrod. © Beatriz Moisset

Predatory stink bug, Podisus maculiventris on goldenrod.
© Beatriz Moisset

Podisus maculiventris juvenile (nymph) feeding on dogbane caterpillar © Beatriz Moisset

Podisus maculiventris juvenile (nymph) feeding on dogbane caterpillar
© Beatriz Moisset

The tachinid fly mentioned above goes by the name of Lespesia. It lays its eggs on caterpillars of a large number of species. The tiny fly larva digs inside and proceeds to eat its victim until it reaches full size. Then it comes out of the dying caterpillar and dribbles a sticky trail until it drops to the ground. Not a pretty sight.

Tachinid fly, Lespesia © Stephen Luk

Tachinid fly, Lespesia
© Stephen Luk

Tachind fly, Lespesia, Puparium and parasitized tent caterpillar's cocoon © Stephen Luk

Lespesia puparium and parasitized tent caterpillar’s cocoon
© Stephen Luk

Although these two insects on occasion kill some monarchs, we should not hate them. Actually, their diet is so diverse that it includes a number of pests. They are both used as pest controls for this reason and even sold for this purpose. Podisus is known to eat Mexican bean beetles, European corn borers, diamondback moths, corn earworms, beet armyworms, fall armyworms, cabbage loopers, imported cabbage worms, Colorado potato beetles, and velvetbean caterpillars. The tachinid fly is reported to feed on tent caterpillars, armyworms, cutworms and corn earworms.

Nature is far more complicated than it appears at first sight. It may seem paradoxical, but the spined soldier beetle and the Lespesia fly are indirectly the friends of monarchs, because they help cut down on pesticides. Moreover, we must remember that they have coexisted with monarchs for eons without driving them to extinction. The same can be said about the milkweed herbivores –beetles, bugs and moths. They haven’t driven milkweeds to extinction and they are not likely to do so. We are the ones that pose a threat to milkweeds and to monarch butterflies with our pesticides, habitat destruction and introduction of invasive species.

Let saving the pretty butterfly be the portal to saving the entire community, all the creatures that creep and crawl, the ones that jump or fly and even the ones that kill or get killed. Let us embrace the web of life in its totality, with all its beauty and ugliness.

Delicate cycnia © Beatriz Moisset

Delicate cycnia
© Beatriz Moisset

Additional readings
You may find this Flickr album interesting: Milkweed Visitors
More members of the milkweed community
The monarch butterfly as part of the food web: Monarchs and their Enemies

This article first appeared in Native Plants and Wildlife Gardens


Monarch butterfly

April 20, 2011

Monarch on milkweed

The most beloved and best known butterfly in North America is, without doubt, the monarch butterfly. However, people often mistake other orange and black butterflies, such as viceroys and queens, for monarchs.

Queen butterfly. Brown, rather than orange. Author: Russ Ottens, University of Georgia. Creative commons

Viceroy butterfly. Dark line across hindwings. Author: Sander van der Molen Creative Commons

Queens are related to monarchs; their pattern is similar but with fewer lines and a darker color. Viceroys are not related but they look remarkably similar at first sight, probably because they want to fool predators into thinking that they taste just as bad as monarchs. Look for a line that runs across the hind wing of a viceroy, this line is absent in monarchs. Viceroys are a little smaller than monarchs.

Fritillary. No white dots. Black lines don’t go all the way

Fritillaries are also smaller than monarchs and their pattern doesn’t include white dots.
The monarch’s life cycle is remarkable. It migrates in the fall all the way to Mexico, where it spends the winter. It starts migrating back north in early spring, where it reproduces and has several new generations; each keeps migrating farther and farther north through the spring and summer all the way to northern United States and Canada.

Monarch caterpillar on milkweed

The monarchs that live in the western part of the United States only migrate as far south as California where they spend the winter.
The caterpillars are brightly striped black, yellow and white. They feed on milkweeds (several different species) so that is where you also find the adults often; adults take nectar from a variety of flowers, not just milkweeds, and can be seen visiting them.

Habitat. Fields, meadows, sunny spots

Season. In California they are found year round. In southern states such as Texas and Florida they can be seen from February to as late as November. The farther north you go the shorter the season for monarchs. In northern states they are found from June to October.

Flowers. Seen quite often at milkweeds, common, swamp and several other milkweed species. Also found at many other flowers depending on the season: asters, goldenrods, bee balm.

Back to guide

Beginners Guide to Pollinators and Other Flower Visitors