This morning, the Lower Susquehanna River Watershed experienced remotely the effects of fire and ice.
At daybreak, the cold air mass that brought the first freeze of the season to northernmost New England gave us a taste of the cold with temperatures below 50 degrees throughout.
The air temperature at daybreak in the Gettysburg Basin east of Conewago Falls.
At sunrise, the cloudless sky had a peculiar overcast look with no warm glow on buildings, vegetation, and terrain. Soon, the sun was well above the horizon, yet there was still a sort of darkness across the landscape.
Smoke from massive wildland fires in the Pacific Coast States created a haze that persisted throughout the day in the Susquehanna valley.Away from traffic and the odors of agriculture and urban life, the smell of wood smoke was easily detectable. The haze from fires almost 3,000 miles away made it appear to be an overcast day at Conewago Falls.Due to the sudden cold, there were no insects flying above the Susquehanna during the first hour of daylight this morning, so swallows gathered in the trees to conserve energy until the hunt would be more productive.The diabase boulders at Conewago Falls retain heat and provide an even better refuge from the cold than a dead tree on a chilly morning. Here, a juvenile and an adult Tree Swallow (center) are surrounded by Northern Rough-winged Swallows. Hundreds of each of these migratory species were feeding at the falls today.Two dozen or more Barn Swallows, including this juvenile, were seen among the swarming birds.Several late Bank Swallows, including this one (bottom center), were among the flocks of migrants at Conewago Falls this morning. One Cliff Swallow (Petrochelidon pyrrhonota) was seen as well.A Great Egret (Ardea alba) and a Great Blue Heron.An Osprey searching the clear pools and rapids for a morning meal.A juvenile Bald Eagle with the same goal in mind.The same Bald Eagle keeping a close watch on the Osprey. Bald Eagles frequently ambush Ospreys to steal their catch. For a young eagle, acquiring the skill of fish theft may improve its chances of survival, at least until the Ospreys head south.
All that bright filtered sunlight was ideal for photographing butterflies along the Conewago Falls shoreline. Have a look.
During the late morning, dozens of Monarch butterflies migrated past Conewago Falls. This one paused to feed.The Viceroy (Limenitis archippus) is a Monarch mimic. Its appearance fools would-be predators into thinking it is a Monarch and possesses the same foul flavor as the milkweed-raised model.This Variegated Fritillary (Euptoieta claudia) was among the late-season butterflies at Conewago Falls.The Common Buckeye is presently just that, very common on flowers and moist sandy soil around the falls.The Painted Lady is a regularly-occurring migratory species of butterfly.The Red Admiral is typically a common to abundant migrant. So far in 2020, they are scarce in the lower Susquehanna valley.
It’s sprayed with herbicides. It’s mowed and mangled. It’s ground to shreds with noisy weed-trimmers. It’s scorned and maligned. It’s been targeted for elimination by some governments because it’s undesirable and “noxious”. And it has that four letter word in its name which dooms the fate of any plant that possesses it. It’s the Common Milkweed, and it’s the center of activity in our garden at this time of year. Yep, we said milk-WEED.
Now, you need to understand that our garden is small—less than 2,500 square feet. There is no lawn, and there will be no lawn. We’ll have nothing to do with the lawn nonsense. Those of you who know us, know that the lawn, or anything that looks like lawn, are through.
Anyway, most of the plants in the garden are native species. There are trees, numerous shrubs, some water features with aquatic plants, and filling the sunny margins is a mix of native grassland plants including Common Milkweed. The unusually wet growing season in 2018 has been very kind to these plants. They are still very green and lush. And the animals that rely on them are having a banner year. Have a look…
The flowers of the Common Milkweed were exceptionally fragrant this year. At their peak in early June, their hyacinth-or lilac-like aroma was so prevalent, it drifted into our building and overwhelmed the stink of the neighbor’s filthy dumpster that he had placed 12 feet away from our walls (100 feet from his).Common Milkweed attracts a pollinating Greenbottle Fly (Lucilia species). The dumpster attracts the invasive House Fly (Musca domestica), carrier of dysentery, typhoid, and other wonderful diseases. Are you following this? Remember as we proceed, milkweed is “noxious”.Busy Eastern Carpenter Bees (Xylocopa virginica) load up with pollen from the flowers of the Common Milkweed.A Red Milkweed Beetle (Tetraopes tetrophthalmus) munches on a tender fresh Common Milkweed leaf in mid-June.Following the pollination of the flowers, seed pods will begin to grow. We trim these off the plants. The removal of the extra weight allows most of the stems to remain erect through stormy weather. You’ll still get new plants from underground runners. As you may have guessed, we’re trying to keep these plants upright and strong to host Monarch butterfly larvae.
We’ve planted a variety of native grassland species to help support the milkweed structurally and to provide a more complete habitat for Monarch butterflies and other native insects. This year, these plants are exceptionally colorful for late-August due to the abundance of rain. The warm season grasses shown below are the four primary species found in the American tall-grass prairies and elsewhere.
Big Bluestem, a native warm-season grass in flower.Little Bluestem (Schizachyrium scoparium “Fort Indiantown Gap”) in flower. This variety grows on the tank range at the military base where the armored vehicles and prescribed burns substitute for the herd animals and fires of the prairie to prevent succession and allow it to thrive.Partridge Pea can tolerate sandy soil and is a host plant for vagrant Cloudless Sulphur butterflies.Black-eyed Susan (Rudbeckia hirta) is a popular native grassland wildflower.Indiangrass (Sorghastrum nutans) in flower. This and the other native plants shown here are available as seed from Ernst Seed Company in Meadville (PA). They have an unbelievably large selection of indigenous species. You can plant a small plot or acres and acres using really good mixes blended for purposes ranging from reclaiming pipeline right-of-ways and strip mines to naturalizing backyard gardens.A Red Admiral (Vanessa atalanta) butterfly, a migratory species like the Monarch, on Purple Coneflower (Echinacea purpurea). Yes, it is that Echinacea, the same one used as a supplement and home remedy.
There was Monarch activity in the garden today like we’ve never seen before—and it revolved around milkweed and the companion plants.
A female Monarch laying eggs on a Common Milkweed leaf.A third instar Monarch caterpillar with Oleander Aphids (Aphis nerii) on a Common Milkweed leaf. Both of these insect species absorb toxins from the milkweed which makes them distasteful to predators.Fifth instar (left and center) and fourth instar (right) monarch caterpillars devour a Common Milkweed leaf. There were over thirty of these caterpillars in just a ten by ten feet area this morning. We hope that if you’re keeping a habitat for Monarchs, you’re enjoying the same fortune right now!A slow-moving Monarch stopped for a break after making the circuit to deposit eggs on milkweed throughout the garden.Third instar (top), fourth instar (right), and fifth instar (left) Monarch caterpillars quickly consume the leaf of a Common Milkweed plant. Caterpillars emerging from eggs deposited today may not have sufficient late-season food to complete the larval segment of their life cycle. Need more milkweed!After benefiting from the nourishment of the Common Milkweed plant, a fifth instar Monarch caterpillar begins pupation on Big Bluestem grass.Two hours later, the chrysalis is complete.Another chrysalis, this one on flowering Switchgrass just two feet away from the previous one. An adult Monarch will emerge from this pupa to become part of what we hope will be the most populated southbound exodus for the species in over five years.There it is, soon ready to fly away. And all courtesy of the noxious milkweed.A chrysalis can often be found on man-made objects too. This one is on the rim of a flower pot.Ornamental flowers can attract adult Monarch butterflies seeking nectar. We’re now more careful to select seeds and plants that have not been treated with neonicotinoid insecticides. There’s growing concern over the impact these compounds may be having on pollinating species of animals. Oh…and we don’t mow, whack, cut, mutilate, or spray herbicides on our milkweed, but you probably figured that out already.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York.
