Words & Photographs by Jim Moffett
Everybody loves beautiful flowers and there are many to see when you visit the Thomas P. Bentley Nature Preserve. We have insects and other pollinators to thank for this beauty and diversity. Many plants flower and offer sweet nectar to attract pollinators such as butterflies, moths, wasps, flower flies, beetles, bees and hummingbirds. While gathering nectar, pollen catches a ride with the pollinator to another flower where it is then fertilized and seed formation begins. Some plants can be pollinated by many different species while others, only a few, and in some cases, only one! Some species of plants are self-pollinated while others, like ragweed, are pollinated by wind.
Our native plant species also play a key role acting as a nursery for the larvae of our butterfly and moth species. Adults lay their eggs on specific plant species. The monarch butterfly is the best example as the adults will only lay their eggs on milkweed species. This is because it’s the only plant that the larvae can feed on until they pupate into adults. Swallowtails lay their eggs on species in the carrot family and spicebush swallowtails only lay their eggs on the leaves on, you guessed it – spicebush!
When choosing plants or trees, consider planting native species that are larval hosts for many species. The birds will thank you! Many species of birds will feast on these larvae and almost all species need these soft bodied insects to feed their young.
For a great book that further explains these important plants, insect, and bird food webs and lists beneficial native host plants, consider reading Doug Tallamy’s Nature’s Best Hope.
Where do invasive plants figure into these mutualistic relationships? Non-native plants are rarely larval hosts and therefore their leaves are seldom eaten by our native caterpillars. This is one reason they can out compete native plants and grow without hinderance. Some butterfly and moth species are fooled by similarities to their native host plants and will lay eggs on a non-native species. The larvae will then starve as they cannot eat the leaves.
Many non-native invasive species of plants produce nectar that native pollinators will consume. Butterfly bush is one example. By offering this plant, our native insect species are pollinating plants that cannot serve any species as larval hosts and not pollinating the plant species that can. This perpetuates the problem by helping non-native plants succeed while beneficial native plants decline.
As non-native plants crowd out our native species, butterfly and moth biodiversity declines due to the lack of host plants and the plant, insect, and bird food web is broken. With fewer caterpillars available for birds to feed their young, bird populations also decline.
At the Thomas P. Bentley Nature Preserve we have been working hard to increase the amount and diversity of native plants and fight back the non-native invasives. Here are some species you may spot at the Preserve:
New England Aster (Symphyotrichum novae-angliae) and Monarch Butterfly
New England Aster is an aster of wet meadows that grows 2 to 3 feet tall. It is pollinated by butterflies, beetles, and many bee species. It is the larval host for the saddleback caterpillar and pearl crescent butterfly, among others. The miner bee Andrena Simplex collects pollen only from this plant to feed its young.
Hollow Joe-Pye Weed (Eutrochium fistulosum) and Great-spangled Fritillary
Hollow Joe-Pye weed is one of three species of Joe-Pye native to the Eastern U.S. It can reach heights of over 8’ tall and prefers damp soil but grows in normal conditions. Tiger swallowtails, monarchs, skippers, and azures are pollinators as well as many bee species.It is the larval host for swallowtails, spotted skippers, painted ladies, eastern tailed blues and many different moths.
There are 10 species of milkweed in Pennsylvania. All which host monarch butterflies and are a nectar source for countless pollinators. They are also a host for the tussock moth larvae. If you are going to plant just one plant, make it a milkweed – monarch butterflies depend on it! Here are three species found at the Thomas P. Bentley Nature Preserve:
Butterfly weed (asclepias tuberosa) and Sweat Bee
Butterfly weed grows 1 to 3 feet tall, needs lots of sun and prefers dryer soils. Sap is translucent, not milky like other milkweed species.
Purple Milkweed (asclepias purpurascens) and Mason Bee
Purple milkweed is one of the tallest milkweed species reaching 6’ tall. This species prefers moist but well drained soil and little shade. A stunning plant!
Common Milkweed (asclepias syriaca) with Mason Bee and Sweat Bee
Common milkweed does well in moist to dry conditions. It can spread by rhizomes creating large patches. Increased herbicide use in agriculture has greatly reduced this species’ availability to monarchs.
Anise Hyssop (Agastache Foeniculum) and Grape Leaffolder Moth
Anise Hyssop blooms throughout the summer and is a magnet for pollinators. It grows 2 to 4 feet tall and prefers well drained soil. There are many varieties for sale at garden stores that may be cultivars of A. Rugosa native to Korea, so be sure to purchase the native A. Foeniculum. Anise Hyssop is the host plant for the buckeye butterfly.
Wild Bergamot (monarda fistulosa) and Hummingbird Clearwing Moth
Wild Bergamot is a tall clumping meadow plant that competes well with our native warm season grasses. Many bee, moth, and butterfly species visit for nectar as well as the ruby-throated hummingbird. The sand wasp also feeds on its nectar and is the main predator of the brown stink bug. Wild bergamot is a larval host plant for the hermit sphinx moth.
American Germander (Teucrium Canadense) and Snowberry Clearwing Moth
American Germander is a 2 to 3 foot tall plant found in moist meadows and edges. It spreads readily by rhizomes to form colonies and is deer resistant. It is pollinated by long tongued bee species such as miner bees and bumble bees. It is also pollinated by butterflies, moths, and hummingbirds.
Canada Goldenrod (Solidago Canadense) and Secondary Screwworm Fly
Canada goldenrod gets a bad rap. It flowers in late summer and wrongly gets the blamed for allergies. The culprit is ragweed which blooms at the same time and is wind pollinated. Goldenrod species have sticky pollen that does not become airborne and is dependent on insects for pollination.
Many species of bee, wasp, beetle, butterfly and moth pollinate goldenrod species. Flower flies are underappreciated pollinators and frequent goldenrod species. Canada goldenrod is the host plant for the brown-hooded owlet moth and 79 other species!
Blue Vervain (Verbena hastata) and Bumble Bee
Blue vervain grows in moist meadows and reaches 5’ tall. Many pollinators visit the flowers in late summer to late fall including long and short tongued bee species, moths, and butterflies. It is the host plant for the buckeye butterfly and the verbena moth.
Evening Primrose (Oenothera biennis) and the Primrose Moth
Evening Primrose is a fascinating plant. Its flowers are closed during the day and open in the evening for pollination. It is primarily pollinated by many moth species such as the primrose moth, white-lined sphinx, and hawk moth. It grows up to 7’ tall and prefers moist well drained soil. Many bird species such as American Goldfinches feed on its seeds.
Keep an eye out for these native beauties and take notice of our great diversity of pollinators and birds on your next summer hike at the Preserve!
