How Plants Sustain Wildlife

Where is a Mother butterfly to Lay Her Eggs?

Native plants attract an abundance of living things to our homes and parks, but only to the extent that we understand and use “host plants.”

A host plant is simply a place where a pregnant female butterfly (for example) is willing to lay her eggs, because she shows that her larvae can feed upon the host plant.

Pipevine is the “host plant” for the Pipevine Swallowtail butterfly.

Host plants are native plants …

Now, … you may have heard that native plants are very good for ecosystems. But a major reason for this is that native plants serve as host plants. Nonnative plants, typically do not serve as host plants.

Milkweed is the host plant for Monarchs.

Milkweed is the host plant for monarch butterflies because the monarch butterfly caterpillar can only eat milkweed.

The Monarch Caterpillar feeds upon its “host plant” milkweed.

The adult butterfly can feed by sucking nectar from many different plants, but the mother monarch lays her eggs only on milkweed.

Examples of host plants …

So, … here are some examples of insect to host plant relationships …

  • Monarch butterflies need milkweed to reproduce because that’s its host plant.
  • Spicebush swallowtail butterflies need spicebush to reproduce because that’s its host plant.
  • An American Dagger Moth needs a hickory tree to reproduce because that’s its host plant.
  • A blinded sphinx moth needs a hawthorne tree to reproduce because that’s its host plant.
  • A pandora sphinx moth needs Virginia Creeper to reproduce because that’s its host plant.

If you take away these host plants, then you take away the means of survival of these butterflies and moths and all other insects that count these plants as host plants.

Globally, biodiversity is down by an estimated 60%, and continuing to decline. In North America this decline is due in large measure to the decline of insect populations, which is in turn due to the decline in host plants.

This is the very important message that you can convey to decision-makers in our community as you seek their support for the projects that we want to implement.

If you participate with us, then we can all learn dozens of these insect-to-host plant relationships and be able to drive home the significance of native plants and the roles they play in our native ecosystems.

If you develop these and related skills, you will greatly enhance your job opportunities in several fields, including park management, habitat restoration and landscaping.

If you would like to participate in the Environmental Leadership Program, please email Hart at