Wildflower Meadow Update

Do you recall our “Photo of the Day” from seven months ago…

Riverfront Park Wildflower Meadow
Here’s something to look forward to in the new year.  The good citizens of East Donegal Township in Lancaster County have partnered with Alliance for the Chesapeake Bay to establish an extensive wildflower meadow on what had been a mowed field of turf grass at Riverside Park in the Susquehanna floodplain near Marietta.  As the photo shows, the lawn plants have been eliminated in preparation for seeding with a diverse assortment of native grasses and wildflowers to provide habitat for birds and pollinators including butterflies, bees, and other insects.  Once established, the meadow’s extensive vegetative growth will help reduce stormwater runoff by better infiltrating rainfall to recharge the aquifer.  During flood events, the plantings will provide soil stabilization and increase the ability of the acreage to uptake nutrients, thus reducing the negative impact of major storms on the quality of water in the river and in Chesapeake Bay.  Check the project’s progress by stopping by from time to time in 2024!

Well, here’s what that site looks like today…

Riverfront Park Wildflower Meadow
The wildflowers, thousands of them, are now in bloom!
Riverfront Park Wildflower Meadow
Black-eyed Susan and Blue Vervain (Verbena hastata) dominate the assortment currently in flower.

And there are pollinating insects galore, most notably butterflies…

Cabbage White
A Cabbage White collecting nectar on Blue Vervain.
A Sulphur
A Clouded or Orange Sulphur among the grasses in the meadow.
Silver-spotted Skipper
A Silver-spotted Skipper.
Least Skipper
The Least Skipper is our tiniest butterfly.
Little Glassywing
The Little Glassywing (Vernia verna), this one feeding on vervain nectar, deposits its eggs on Purpletop grass, which then functions as the host plant for this butterfly’s larvae.
Summer Azure
A Summer Azure (Celastrina neglecta) feeding on the nectar of a Black-eyed Susan.
Common Buckeye
A Common Buckeye on a “Gloriosa Daisy”, a showy, large-flowered cultivar of Black-eyed Susan.
Red-winged Blackbird
A Red-winged Blackbird with a caterpillar found among the meadow’s lush growth.
Tiger Swallowtail
An Eastern Tiger Swallowtail on Blue Vervain.  Nearby Yellow (Tulip) Poplars and other trees serve as host plants for this butterfly’s larvae.
Black Morph Eastern Tiger Swallowtail
The black morph of the Eastern Tiger Swallowtail shows subdued shading in the wings that closely resembles the brilliant color patterns of the more familiar yellow form.
Sachem
The Sachem, this one visiting a Black-eyed Susan, is a variable species with a range that normally lies south of the 40th parallel, the line of latitude that intersects the Susquehanna in the area of the Conejohela Flats at Washington Boro.
A Sachem visiting the blooms of Oxeye sunflower.   During recent weeks, scorching winds from the south and southwest have transported an abundance of these vagrant skippers into the lower Susquehanna valley and beyond.
Sachem
A male Sachem approaching the bloom of a “Gloriosa Daisy”.  Miles north of the 40th parallel, wandering Sachems are currently the most numerous of the butterflies at the Riverfront Park wildflower meadow.
Partridge Pea
Here and there among the meadow’s plantings we noticed one of our favorites starting to flower, the Partridge Pea.
Cloudless Sulphur
Partridge Pea happens to be a host plant for another vagrant from the south, the big, lime-yellow Cloudless Sulphur.  We saw at least half a dozen patrolling the meadow.
Zebra Swallowtail
The stars of the show are the Zebra Swallowtails, gorgeous butterflies that rely on stands of native Common Paw-paw trees in the river floodplain to host their eggs and larvae.
Zebra Swallowtail
The red-white-and-blue underside of a Zebra Swallowtail.
Zebra Swallowtail
WOW!

Why on earth would anyone waste their time, energy, and money mowing grass when they could have this?  Won’t you please consider committing graminicide this fall?  That’s right, kill that lawn—at least the majority of it.  Then visit the Ernst Seed website, buy some “Native Northeast Wildlflower Mix” and/or other blends, and get your meadow planted in time for the 2025 growing season.  Just think of all the new kinds of native plants and animals you’ll be seeing.  It could change your life as well as theirs.

Snowberry Clearwing
A Snowberry Clearwing (Hemaris diffinis), more commonly known as a hummingbird moth, visits the flowers of Blue Vervain in the Riverfront Park wildflower meadow.

Fussy Eaters

She ate only toaster pastries…that’s it…nothing else.  Every now and then, on special occasions, when a big dinner was served, she’d have a small helping of mashed potatoes, no gravy, just plain, thank you.  She received all her nutrition from several meals a week of macaroni and cheese assembled from processed ingredients found in a cardboard box.  It contains eight essential vitamins and minerals, don’t you know?  You remember her, don’t you?

Adult female butterflies must lay their eggs where the hatched larvae will promptly find the precise food needed to fuel their growth.  These caterpillars are fussy eaters, with some able to feed upon only one particular species or genus of plant to grow through the five stages, the instars, of larval life.  The energy for their fifth molt into a pupa, known as a chrysalis, and metamorphosis into an adult butterfly requires mass consumption of the required plant matter.  Their life cycle causes most butterflies to be very habitat specific.  These splendid insects may visit the urban or suburban garden as adults to feed on nectar plants, however, successful reproduction relies upon environs which include suitable, thriving, pesticide-free host plants for the caterpillars.  Their survival depends upon more than the vegetation surrounding the typical lawn will provide.

The Monarch (Danaus plexippus), a butterfly familiar in North America for its conspicuous autumn migrations to forests in Mexico, uses the milkweeds (Asclepias) almost exclusively as a host plant.  Here at  Conewago Falls, wetlands with Swamp Milkweed (Asclepias incarnata) and unsprayed clearings with Common Milkweed (A. syriaca) are essential to the successful reproduction of the species.  Human disturbance, including liberal use of herbicides, and invasive plant species can diminish the biomass of the Monarch’s favored nourishment, thus reducing significantly the abundance of the migratory late-season generation.

Monarch caterpillar after a fourth molt.  The fifth instar feeding on Swamp Milkweed.
A fifth molt begets the Monarch pupa, the chrysalis, from which the showy adult butterfly will emerge.
Adult Monarch feeding on Goldenrod (Solidago) nectar.

Butterflies are good indicators of the ecological health of a given environment.  A diversity of butterfly species in a given area requires a wide array of mostly indigenous plants to provide food for reproduction.  Let’s have a look at some of the species seen around Conewago Falls this week…

An adult Silvery Checkerspot (Chlosyne nycteis) visiting a nectar plant, Partridge Pea (Chamaecrista fasciculata).  Wingstem (Verbesina alternifolia), a plant of the Riparian Woodlands, is among the probable hosts for the caterpillars.
A Gray Hairstreak (Strymon melinus) visits Crown Vetch, a possible host plant.  Other potential larval food in the area includes Partridge Pea, Halberd-leaved Rose Mallow (Hibiscus laevis) of the river shoreline, and Swamp Rose Mallow (Hibiscus moscheutos), a plant of wetlands.
The Eastern Tailed Blue (Cupido comyntas) may use Partridge Pea , a native wildflower species, and the introduced Crown Vetch (Securigera/Coronilla varia) as host and nectar plants at Conewago Falls.
The Least Skipper (Ancyloxypha numitor) is at home among tall grasses in woodland openings, at riverside, and in the scoured grassland habitat of the Pothole Rocks in the falls.  Host plants available include Switchgrass (Panicum vigatum), Freshwater Cordgrass (Spartina pectinata), and Foxtails (Setaria).
The Zabulon Skipper (Poanes zabulon) is an inhabitant of moist clearings where the caterpillars may feed upon Lovegrasses (Eragrostis) and Purpletop (Tridens flavus).
The Eastern Tiger Swallowtail (Papilio glaucus), a female seen here gathering nectar from Joe-Pye Weed (Eutrochium), relies upon several forest trees as hosts. Black Cherry (Prunus serotina), Willow (Salix), Yellow Poplar (Liriodendron tulipifera), also known as Tuliptree, and Green Ash (Fraxinus pennsylvanica) are among the local species known to be used.  The future of the latter food species at Conewago Falls is doubtful.  Fortunately for the Eastern Tiger Swallowtail, the “generalist” feeding requirements of this butterfly’s larvae enable the species to survive the loss of a host plant.
A female Eastern Tiger Swallowtail, black morph, gathering nectar from Joe-Pye Weed.
The Zebra Swallowtail (Protographium marcellus), an adult seen here on Joe-Pye Weed, feeds exclusively upon Pawpaw (Asimina) trees as a caterpillar.  This butterfly species may wander, but its breeding range is limited to the moist Riparian Woodlands where colonial groves of Pawpaw may be found.  The Common Pawpaw (Asimina triloba), our native species in Pennsylvania, and the Zebra Swallowtail occur at the northern edge of their geographic ranges in the Lower Susquehanna River Watershed.  Planting Pawpaw trees as an element of streamside reforestation projects certainly benefits this marvelous butterfly.

The spectacularly colorful butterflies are a real treat on a hot summer day.  Their affinity for showy plants doubles the pleasure.

By the way, I’m certain by now you’ve recalled that fussy eater…and how beautiful she grew up to be.

SOURCES

Brock, Jim P., and Kaufman, Kenn.  2003.  Butterflies of North America.  Houghton Mifflin Company.  New York, NY.