Butterflies Need Trees Too

Autumn is the perfect time to celebrate Tree Week. We encourage you to not only take a stroll and enjoy the fall colors, but also take a moment to think about all the life these trees support. Among those branches are thousands of different invertebrates, including centipedes and beetles, cocoons and chrysalises. Some trees are capable of supporting hundreds of species of animals.

According to research by Professor Doug Tallamy, an entomologist at the University of Delaware, oak trees support the largest diversity of moths and butterflies at 534 species. Compare this to milkweed, the host plant for the Monarch, which supports only 12 species of moths and butterflies. In his book “Bringing Nature Home” Professor Tallamy promotes the use of native plants to support native wildlife in our own backyards; and he tells us why it is so vitally important to support this ecosystem.

Zebra Swallowtail
A Zebra Swallowtail (Eurytides marcellus)

In the life span of a tree, it will support thousands, most likely millions, of lives. As the tree grows from a young sapling, it starts to provide shelter and food for these animals. Aphids and other plant sucking insects will start feeding on the young saplings. Near the roots, isopods (roly-polies) move in and find refuge, while worms crawl through the soil bringing oxygen and water to the tree.

When leaves expand, butterflies and moths lay their eggs so their young can grow. Flowers start to emerge and the bees and flies arrive to pollinate, which then bear fruit for birds and mammals to eat. All the while, the animals are helping fertilize the tree with their droppings, opening up the canopy for light by eating the leaves and branches, and helping make the tree strong.

Then as the tree matures and eventually dies, the dead wood is once again a home, this time for decomposers like worms. Wood boring beetles lay their eggs and feast on the final bits of sap. Termites and ants move in to form their homes and break down the wood even more. Finally a seed from a neighboring tree falls into the decomposing wood full of nutrients and a new tree life begins again.

Toxomerus marginatus on zizia
A flower fly (Toxomerus marginatus)

Our lives are no less effected by trees than other animals. Trees provide us shelter, oxygen, and food which is directly affected by pollinators. It is estimated that 80% of all crops require animal pollination. This means that approximately every third bite of food is brought to you by a pollinator. We all know that honey bees play a vital role in this cycle, but so do all the pollinators that aren’t in the news. The flies, beetles, solitary bees, and butterflies are all pollinators of our flower gardens and crops. They are also pollinators of a great number of our trees.

Apples, almonds, and cherries are just a few examples of crops that are dependent on bee and fly pollination. The majestic Tulip Poplar trees are pollinated and act as a host plant for the Giant Swallowtail. Pawpaw trees, besides being fun to say, are host plants of the Zebra Swallowtail and are pollinated by beetles and flies.

Papilio cresphontes
A giant swallowtail caterpillar (Papilio cresphontes) feeds on a leaf.

Some trees are solely dependent on a single pollinator, such as the Joshua Tree, which is pollinated by the small, gray Pranuba Moth. This relationship is unique in that the moth doesn’t actually feed from the tree’s flowers. The moth lays its eggs in the flower’s ovaries, and when they hatch the caterpillars feed on the seeds. Without each other, neither would survive.

So as you go out and enjoy the trees in the region, stop and look closer. You may find a Jumping Crab spider well camouflaged or a caterpillar hiding under some bark for the winter. You will definitely find a home for many animals that are dependent on this ecosystem to survive. As you stroll the grocery store aisles, pick strawberries in the spring, or simply enjoy a chocolate bar, thank our pollinators. Then take the next step and plant your own pollinator garden. And don’t forget to add a few trees.

Some native trees that support pollinators:

Tulip Poplar Liriodendron tulipifera | Black gum Nyssa sylvatica | American Holly Ilex opaca | Serviceberry Amelanchier arborea | Honey Locust Glenditsia triacanthos | Maples Acer | Dogwood Cornus florida | Staghorn Sumac Rhus typhina | Hawthorn Crataegus | Sourwood Oxydendrum arboreum | Linden Tilia


Laura Chisholm – Senior Manager of Collections, Education, and Facilities at the Sophia M. Sachs Butterfly House

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