Exploring Milkweed Ecology Which Creatures are Connected to Milkweed? Milkweed plays a central role in the lives of monarch butterflies. They can't live without it! (And to think that we call it a "weed.") Ecology is the study of the interactions between living things and their environment. Here are 8 different animals that interact with a milkweed plant, in one way or another. Read the behaviors described below, then see if you can name the correct organism: Animal Behavior Tachinid flies   Bees   Ants   Milkweed Tussock Moth   Milkweed Beetle (or Milkweed Bug)   Monarch Butterfly   Oriole (and other birds)   Aphids   Behavior A: Like monarchs, this species lays its eggs on milkweed leaves. Unlike monarchs, who usually lay only a single egg per plant, this species lays a cluster of a dozen or more eggs on a single leaf. The larvae are found in late summer feeding on milkweed. Larvae are not found alone, but are feeding in groups or "colonies." This species does not migrate the way monarchs do. Instead, it over-winters in the cocoon stage. Behavior B: These insects feed by sucking plant juices. They feed in colonies and excrete a sugary waste produce called honeydew. They have "plump, pear-shaped bodies and two tubes, or cornicles, which project like exhaust pipes from their abdomens," according to the Virginia Cooperative Extension Service (VCES) website, where you can see a slide show about these insects: Behavior C: This creature eats the seeds and tissue of the milkweed plant. Again from VCES, "These insects have few predators because they concentrate in their bodies the bad tasting compounds found in the sap of milkweed plants. The bugs use the bright coloration to advertise their bad taste. They are one of a small group of insects that have the ability to tolerate the toxic compounds in the milkweed plant. They are therefore important in regulating populations of the [milkweed] plant." Behavior D: This species is known to use the stringy fibers found on dead milkweed stalks to build its nest. It uses the stalks of the plants from the previous summer that died back during the winter. This is a good reason not to cut back old milkweed plants, even if they look like "dead weeds." Behavior E: These animals feed on a variety of materials, including live and dead insects, honeydew from aphids, grease, etc. They sometimes use milkweed plants as a place to "farm" aphids. (Just as a farmer guards cows for their milk, this species guards aphids for their honeydew.) Behavior F: This animal is one of the many insects that pollinate milkweed flowers. If you observe a milkweed flower very closely, you can watch this species arrive at the flowers to drink the sweet nectar. At the same time, the animal's legs will be caught on the unique milkweed looks like a pair of "saddle-bags" carried off on the feet of this species. When this insect visits the next milkweed flower, it delivers the pollination sacs that will pollinate it. Behavior G: This animal is a parasite of the monarch butterfly. It lays its eggs on the monarch caterpillar. When the maggots hatch, they burrow through the monarch caterpillar's skin and feed on its internal organs. The monarch caterpillar will die just as the larva of this insect emerges. Behavior H: This species uses milkweed as its only host plant (meaning it ONLY lays its eggs on milkweed). Typically only one egg is laid on each milkweed plant, so that the larvae won't compete with one another for food. As an adult, this species again uses milkweed, this time to drink its nectar. Summer Milkweed Patrol Visit a milkweed plant regularly this summer, and sketch the different animals you see. Watch how the milkweed plant changes as creatures chew on, suck from, and crawl all over the plant's leaves. How many different animals can you find that: Lay eggs on the milkweed plant? (Use milkweed as a host plant.) Forage on milkweed leaves, eating the plant material? Forage on the insects that forage on the milkweed leaves? Suck juices from milkweed leaves and seeds? Drink nectar from milkweed flowers? Pollinate milkweed flowers (so milkweed can make viable seeds for reproduction)? Eat milkweed seeds? Use the "downy" milkweed seeds for lining their nests? Carry milkweed seeds to other places (thereby planting milkweed)? Use the milkweed plant for cover or shade? National Science Education Standards Organisms have basic needs. They can survive only in environments in which their needs can be met. (K-4) Each plant or animal has different structures that serve different functions in growth, survival, reproduction. (K-4) All animals depend on plants. Some animals eat plants for food. Others eat animals that eat plants. (K-4) Living systems at all levels of organization demonstrate the complementary nature of structure and function. (5-8) An organism's behavior evolves through adaptation to its environment. How a species moves, obtains food, reproduces, and responds to danger are based in the species' evolutionary history. (5-8) Copyright 2001-2007 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form