Butterflies and More at Boyd Big Tree Preserve Conservation Area

If you’re feeling the need to see summertime butterflies and their numbers just don’t seem to be what they used to be in your garden, then plan an afternoon visit to the Boyd Big Tree Preserve along Fishing Creek Valley Road (PA 443) just east of U.S. 22/322 and the Susquehanna River north of Harrisburg.  The Pennsylvania Department of Conservation and Natural Resources manages the park’s 1,025 acres mostly as forested land with more than ten miles of trails.  While located predominately on the north slope of Blue Mountain, a portion of the preserve straddles the crest of the ridge to include the upper reaches of the southern exposure.

American Chestnut at Boyd Big Tree Preserve
A grove of American Chestnuts (Castanea dentata) planted at Boyd Big Tree Preserve is part of a propagation program working to restore blight-resistant trees to Pennsylvania and other areas of their former range which included the Appalachians and the upper Ohio River watershed.

Fortunately, one need not take a strenuous hike up Blue Mountain to observe butterflies.  Open space along the park’s quarter-mile-long entrance road is maintained as a rolling meadow of wildflowers and cool-season grasses that provide nectar for adult butterflies and host plants for their larvae.

Butterfly Meadow at Boyd Big Tree Preserve
A view looking north at the butterfly meadow and entrance road at Boyd Big Tree Preserve Conservation Area.  Second Mountain is in the background.
Walking a Meadow Path
Mowed paths follow the entrance road and a portion of the perimeter of the meadow allowing visitors a chance to wander among the waist-high growth to see butterflies, birds, and blooming plants at close range without trampling the vegetation or risking exposure to ticks.
A Silver-spotted Skipper feeding on nectar from Dogbane (Apocynum cannabinum) flowers.
A Silver-spotted Skipper feeding on nectar from the flowers of Indian Hemp (Apocynum cannabinum).  Like the milkweeds, Indian Hemp is a member of the dogbane family (Apocynaceae).
An Eastern Tiger Swallowtail feeding on Common Milkweed.
An Eastern Tiger Swallowtail feeding on Common Milkweed.
Great Spangled Fritillary on Common Milkweed.
A Great Spangled Fritillary (Speyeria cybele) on Common Milkweed.
A Black Swallowtail feeding on Common Milkweed nectar.
A Black Swallowtail (Papilio polyxenes) feeding on Common Milkweed nectar.
A Pipevine Swallowtail on Common Milkweed.
A Pipevine Swallowtail (Battus philenor) on Common Milkweed.
A Pipevine Swallowtail on Common Milkweed.
Another Pipevine Swallowtail on Common Milkweed.  Note the hook-shaped row of red-orange spots on the underside of the hindwing.
A Pipevine Swallowtail on visiting Butterfly Weed.
A Pipevine Swallowtail visiting the brilliant blooms of Butterfly Weed, a favorite of a wide variety of pollinators.
A Black Swallowtail on Butterfly Weed
A Black Swallowtail with damaged wings alights atop a Butterfly Weed flower cluster.  Note the pair of parallel rows of red-orange spot on the underside of the hindwing.
A Monarch on Butterfly Weed
A Monarch feeding on nectar from the flowers of Butterfly Weed.
A mating pair of Eastern Tailed Blues.
A mating pair of Eastern Tailed Blues on a Timothy (Phleum pratense) spike.
A female (left) and male Great Spangled Fritillary.
A male Great Spangled Fritillary (right) pursuing a female.
Common Green Darner
Butterflies aren’t the only colorful insects patrolling the meadows at Boyd Big Tree Preserve.  Dragonflies including Common Green Darners are busily pursuing prey, particularly small flying insects like mosquitos, gnats, and flies.
Juvenile Broad-winged Hawk
Dragonflies themselves can become prey and are much sought after by Broad-winged Hawks. This very vocal juvenile gave us several good looks as it ventured from the forest into the skies above the upper meadow during midday.  It wasn’t yet a good enough flier to snag a dragonfly, but it will have plenty of opportunities for practice during its upcoming fall migration which, for these Neotropical raptors, will get underway later this month.

Do yourself a favor and take a trip to the Boyd Big Tree Preserve Conservation Area.  Who knows?  It might actually inspire you to convert that lawn or other mowed space into much-needed butterfly/pollinator habitat.

While you’re out, you can identify your sightings using our photographic guide—Butterflies of the Lower Susquehanna River Watershed—by clicking the “Butterflies” tab at the top this page.  And while you’re at it, you can brush up on your hawk identification skills ahead of the upcoming migration by clicking the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab.  Therein you’ll find a listing and descriptions of hawk watch locations in and around the lower Susquehanna region.  Plan to visit one or more this autumn!

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.