Why Leave the Leaves?  Ask a Red-banded Hairstreak!

Thinking about doing a fall clean-up in your garden?  Maybe you are planning to remove the layer of naturally fallen leaves that are beginning to blanket your planting beds?

I hope my encounter with a Red-banded Hairstreak will prompt you to change your plans.

On a recent walk on a woodland trail near my home in central New Jersey, I had just turned around to head back to my car when I noticed a flutter of brownish wings at ground level at the edge of the trail. My first thought was that it was probably a moth, but when I saw the insect in profile, I could tell it was a butterfly. As I looked more closely, I saw the tell-tale markings of a Red-banded Hairstreak.  I decided to watch for a while.

A Red-banded Hairstreak walking on the forest floor
A Red-banded Hairstreak walking on the forest floor

She stayed on the ground, walking over obstacles that seemed like they would be a challenge for someone her size, especially when she could choose to fly. While I observed her, she climbed over leaves, rocks, leaf stems and small branches, never once taking to the air.  Several times she paused in place for a few seconds.  Was she just resting, or maybe getting her bearings? No! She had a purpose in mind.

The Red-banded Hairstreak pauses.  Wait! Is she laying an egg?
The Red-banded Hairstreak pauses. Wait! Is she laying an egg?
No question this time! This Red-banded Hairstreak is laying an egg. Her curved abdomen is the tell-tale sign.
No question this time! This Red-banded Hairstreak is ovipositing (laying an egg). Her curved abdomen is the tell-tale sign.

Red-banded Hairstreak caterpillars eat fallen leaves and other decaying plant matter.  This little female was laying eggs on or near the kinds of material that her caterpillars would need to eat when they hatched. She alternated walking for a bit with brief pauses to lay an egg.

She walks on, over leaves and twigs.
She continues walking, over leaves and twigs.
Our Red-banded Hairstreak pauses at another promising spot to lay an egg.
Our Red-banded Hairstreak pauses at another promising spot to lay an egg.
She walks on over rocks . . .
She walks on over rocks . . .
She walks over twigs until she pauses one more time to lay an egg on detritus
She walks over twigs until she pauses one more time to lay an egg on detritus

After nearly five minutes, she flew off, presumably scouting for another promising location to lay more eggs.

The caterpillars that hatched from her eggs will spend the winter snug in the fallen leaves, waiting for warm spring days to arrive before completing their metamorphosis to become the next generation of Red-banded Hairstreaks.

Since my encounter with the Red-banded Hairstreak in the woods, I’ve seen other individuals in my own shade garden several times.  Fortunately for them and for me, I leave the fallen leaves undisturbed in the garden. I recommend you do the same!

Red-banded Hairstreak on White Wood Aster (Eurybia divaricata) in our shade garden
Red-banded Hairstreak on White Wood Aster (Eurybia divaricata) in our shade garden

American Cranberrybush

American Cranberrybush  (Viburnum opulus var. americanum synonym V. trilobum), also called Highbush Cranberry, Cranberrybush Viburnum, and several other common names, is not the source of the cranberries often served for Thanksgiving dinner.  Those cranberries come from an unrelated species, Cranberry (Vaccinium macrocarpon), a member of the heath family, and a plant that is more closely related to blueberries than it is to American Cranberrybush.

American Cranberrybush (Viburnum opulus var. americanum) fruit

American Cranberrybush gets its common name from the color of its bright red fruit, which does resemble the cranberries so often used to make holiday side dishes or to garnish a salad.  The common name Highbush Cranberry refers to this shrub’s height, which can be in the range of 8 to 12 feet (2.5 – 3.6 meters), much taller than the species that yield fruit for those traditional dishes.

This lovely shrub blooms in spring, usually some time in May.  Its floral display consists of two types of flowers arranged in a large rounded cluster, creating a lace-cap effect.  Large white sterile flowers form the perimeter of the flower cluster, surrounding a dense group of much smaller fertile flowers that make up most of the inflorescence.  The job of the sterile flowers is to be showy enough to attract potential pollinators to the fertile flowers, where the work of reproduction is carried out.  This floral strategy is shared by Hobblebush Viburnum (Viburnum lantanoides, synonym V. alnifolia) and some of the hydrangeas.

The sterile perimeter flowers bloom first.

American Cranberrybush (Viburnum opulus var. americanum) flower cluster. The large sterile flowers around the perimeter are in bloom, while the fertile flowers are still in bud.

Then gradually, the fertile flowers open for business, enticing pollinators to visit, including many flies, bees and beetles, all important pollinators.

American Cranberrybush (Viburnum opulus var. americanum) flower clusters. Many of the small fertile flowers in the center of the inflorescences are in bloom, in addition to the sterile flowers around the perimeter. If you look closely at the top cluster, you can see a fly (a potential pollinator) foraging for nectar and pollen.
Foraging Mining Bee (Andrena sp.) on blooming American Cranberrybush (Viburnum opulus var. americanum) flowers.
Mining Bee (Andrena sp.) and another tiny pollinator a bit above and to her right, on blooming American Cranberrybush (Viburnum opulus var. americanum) flowers.

Spring Azure butterflies use the flowers and buds of this and other spring-blooming viburnums, and a few other woody species as food for their caterpillars. 

Spring Azure butterfly

Hummingbird Clearwing and several other moth species also use this and other viburnums as food for their caterpillars.

Hummingbird Clearwing (Hemaris thysbe) moth

American Cranberrybush leaves have three lobes, resembling the leaves of Red Maple (Acer rubrum). To protect itself from hungry marauding caterpillars, American Cranberrybush has glands on its leaf stems just below where the stem meets the leaf blade. These glands are extra-floral nectaries, designed to lure insects that can be enticed by both a sweet nectar treat and the protein available from a caterpillar. Ants, wasps, even some flies are potential security guards that are paid for their presence with nectar from these glands, with the potential for a bonus: as many caterpillars as they can find.  Ants drink nectar and eat caterpillars and other insects. Wasps and flies drink nectar, and some also hunt caterpillars or other insects to feed their young.  The presence of these predatory insects helps protect American Cranberrybush from foraging caterpillars.

Note the bumps on the leaf stem, just below the 3-lobed leaf blade. They are the extra-floral nectaries.

American Cranberrybush is a variety of a look-alike shrub, European Cranberrybush (Viburnum opulus) which is of European origin and can become invasive in North America.  The two can interbreed, which has the undesirable potential to lead to the loss or alteration of the native variety. The best way to tell the two apart is by their extra-floral nectaries.  On American Cranberrybush, these nectaries are somewhat convex or slightly rounded at the top, while those on European Cranberrybush leaf petioles (stems) are concave.

By late June, developing fruit replaces successfully pollinated flowers, ripening as the summer goes on.  The fruit is a drupe, a fleshy fruit with a single seed encased in a stony pit. Peaches and cherries are examples of fruits that are drupes.

American Cranberrybush (Viburnum opulus var. americanum) developing fruit, late June in Pennsylvania.
American Cranberrybush (Viburnum opulus var. americanum) ripening fruit, mid-July in Pennsylvania.

American Cranberrybush fruit has a relatively low fat content, so it is less desirable for migrating birds than some other options like Spicebush (Lindera benzoin).  It often lasts well into the winter, but this year, where I live and play in central New Jersey and eastern Pennsylvania, the fruit was already gone by mid-November. Of course, we have already had a few hard freezes, followed by warm-ups.

American Cranberrybush (Viburnum opulus var. americanum) fruit, November, in Pennsylvania.

Robins, Bluebirds, Hermit Thrush, Cedar Waxwings, grouse and many more birds eat American Cranberrybush fruit. 

Cedar Waxing – they are among the birds who eat American Cranberrybush fruit.

All kinds of animals, from moose to fox to squirrels and mice also eat the fruit.

Gray squirrels and many other animals eat American Cranberrybush fruit.

What about humans?  If we get to it before our animal neighbors do, can we use this fruit as an actual cranberry substitute?  If it is cooked with sugar or other sweetener added, people find the fruit of American Cranberrybush edible, too. Some sources say that fruit from European Cranberrybush tends to be more bitter.

Look for American Cranberrybush in wet woods or along streams in its native range, from Nova Scotia to British Columbia in Canada, and in the United States from Maine to Washington state, south to New Jersey, West Virginia and Illinois, although it is more common in the eastern US. The USDA also shows it in one county in New Mexico.

Happy Thanksgiving!  Enjoy those cranberries!

American Cranberrybush (Viburnum opulus var. americanum) fruit

Related Posts

Time for Cranberries!

Praying for Spring? So is Hobblebush Viburnum

‘Will Work for Food’ – Extra-floral Nectaries

Partridge Pea Puzzles

Resources

Beadle, David; Leckie, Seabrooke. Peterson Field Guide to Moths of Northeastern North America. 2012.

Cech, Rick; Tudor, Guy.  Butterflies of the East Coast.  2005.

Eastman, John.  The Book of Forest and Thicket.  1992.

Levine, Carol. A Guide to Wildflowers in Winter. 1995.

Peterson, Lee Allen.  A Field Guide to Edible Wild Plants of Eastern and Central North America. 1977.

Illinois Wildflowers

USDA NRCS Plant Database

USDA NRCS Plant Guide

Missouri Botanical Garden Plant Finder

Downy Skullcap and the Amorous Skippers

Apparently I planted some Downy Skullcap (Scutellaria incana) in our garden last year and then promptly forgot, so it was a delightful surprise when the vivid blue flowers began to bloom in long stalks above gray-green foliage.

Downy Skullcap (Scutellaria incana) with Flower (Syrphid) Fly

Downy Skullcap (Scutellaria incana) with Flower (Syrphid) Fly

Each long tubular flower has an entrance with a hood- or cap-like overhang at the top, and a floor with a white pathway beckoning to visitors who might help pollinate the flowers.

Downy Skullcap (Scutellaria incana) Flower

Downy Skullcap (Scutellaria incana) Flower

The almost sapphire blue flowers are especially attractive to bees, and are thought to be most often pollinated by Bumble Bees (Bombus species) but they entice other pollinators as well, including flower flies, bee flies, and small butterflies.

I watched for visitors to the flowers in our garden and at another near-by site, Bowman’s Hill Wildflower Preserve. At both locations, bees were the most frequent visitors on days when I checked, and of the bees, Small Carpenter Bees (Ceratina species) were the most common.

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species)

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species)

Don’t be put off by the fact that they are called carpenter bees.  These tiny bees won’t be drilling holes in the deck, siding or wood trim of your home.  They nest in the stems of dead or broken twigs, excavating nesting cells by chewing through the pith, the softer tissue inside the stem.  Small Carpenter Bees are pollinators of many plants, especially those with small flowers.

Each bee crawled inside the flower, disappearing down the throat until they reached the nectar reward at the bottom.

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species) crawling down the throat of the flower to reach the nectar reward

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species) crawling down the throat of the flower to reach the nectar reward

But it wasn’t just nectar they were after.  Bees need a balanced diet.  They wanted pollen, too, for the protein and lipids it provides.  The flowers’ reproductive parts, the stamens and pistils, are hidden under the hood at their entrance.  After emerging from drinking nectar at the depths of a flower, each bee then checked under the hood for pollen, which is dispersed from the anthers at the stamens’ tips.  Some bees even went straight for the pollen without bothering with the nectar.  Hopefully some of that pollen was later deposited on the stigma of another flower, the female flower part where pollen must be placed in order for pollination to occur.

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species) emerging from the flower

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species) emerging from the flower

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species) harvesting pollen

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species) harvesting pollen

Much larger relatives of these tiny bees, Eastern Carpenter Bees (Xylocopa virginica), also visited the flowers.  Although these bees can be excellent pollinators, it pains me to tell you that in the case of Downy Skullcap, Eastern Carpenter Bees are thieves. They can’t access the flowers’ nectar by going through the inviting entrance, thus interacting with the flowers’ reproductive parts and helping with pollination.  So instead, they bite through the floral tube near its base, directly accessing the nectar, doing nothing in return to assist the plant in its reproductive goals.  Interestingly, a Honey Bee tried to discourage the Eastern Carpenter Bees from this dishonest activity by trying to chase them away, with some success. And yes, regrettably, Eastern Carpenter Bees might choose to nest in the wood of your home.

Downy Skullcap (Scutellaria incana) with Eastern Carpenter Bees (Xylocopa virginica) robbing the flower of nectar by biting through the floral tube to drink it.

Downy Skullcap (Scutellaria incana) with Eastern Carpenter Bees (Xylocopa virginica) robbing the flower of nectar by biting through the floral tube to drink it.

While looking for Downy Skullcap flower visitors in our garden, I spotted a male Zabulon Skipper drinking nectar.

Male Zabulon Skipper drinking nectar from a Downy Skullcap (Scutellaria incana) flower

Male Zabulon Skipper drinking nectar from a Downy Skullcap (Scutellaria incana) flower

A moment later, I noticed a female Zabulon Skipper, doing the same.

Female Zabulon Skipper drinking nectar from a Downy Skullcap (Scutellaria incana) flower. Notice the bee disappearing into the flower above hers.

Female Zabulon Skipper drinking nectar from a Downy Skullcap (Scutellaria incana) flower. Notice the bee disappearing into the flower above hers.

Then the male flew over to the female and suggested a ‘hook up’.

Female (top) and male (bottom) Zabulon Skippers, negotiating a hook up. Their wings are a little out of focus because both were vibrating them energetically as a lead up to an agreement.

Female (top) and male (bottom) Zabulon Skippers, negotiating a hook up. Their wings are a little out of focus because both were vibrating them energetically as a lead-up to an agreement.

She was apparently persuaded by his pitch.  They went off to a more secluded spot, and stayed there beyond the limits of my attention span.

Zabulon Skippers, mating

Zabulon Skippers, mating

Zabulon Skippers, mating

Zabulon Skippers, mating

These small butterflies are common in gardens and natural areas, specializing on many grass species as food for their caterpillars, including Purpletop (Tridens flavus), Purple Love Grass (Eragrostis spectabilis), and other related species.

Purpletop (Tridens flavus), a caterpillar food for Zabulon Skippers

Purpletop (Tridens flavus), a caterpillar food for Zabulon Skippers

When the flowers have finished blooming and drop away, a cap-shaped calyx, the set of sepals that act as bud scales remains, providing the inspiration for the common name ‘skullcap’.

Cap or dish like calyxes of Downy Skullcap (Scutellaria incana)

Cap- or dish-like calyxes of Downy Skullcap (Scutellaria incana)

‘Downy’ in the common name and ‘incana’ in the scientific name, which means hoary or quite gray, refer to the short soft hairs present on the flowers and stems of this plant. Hoary Skullcap is another common name for the species.

Downy Skullcap is native in the United States from New York west to Wisconsin, south as far as Texas and the Florida panhandle.  It can tolerate full sun to full shade, dry to moist soil. Blooming in mid-summer, it makes a dramatic addition to a garden.  Add it to yours and wait for the real drama (food foraging, bee face-offs, theft, flirtation, sex!) to begin.

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species)

Downy Skullcap (Scutellaria incana) with Small Carpenter Bee (Ceratina species)

Resources

Cech, Rick; Tudor, Guy.  Butterflies of the East Coast.  2005.

Eaton, Eric R.; Kauffman, Ken.  Kaufman Field Guide to Insects of North America.  2007.

Rhoads, Ann Fowler; Block, Timothy A.  The Plants of Pennsylvania.  2007

Stearn, William T. Stearn’s Dictionary of Plant Names.  1996

Willmer, Pat.  Pollination and Floral Ecology. 2011

Wilson, Joseph S.; Carril, Olivia Messinger.  The Bees in Your Backyard. 2016.

Illinois Wildflowers

Lady Bird Johnson Wildflower Center Plant Database

Missouri Botanical Garden Plant Finder

USDA NRCS Plants Database

 

A Spring Ephemeral Ecosystem That Hosts Butterflies

There is a time during early spring when woodland understory plants carpet the forest floor.  These plants emerge from the ground through a covering of fallen leaves, and before the tree canopy above them finishes leafing out, they bloom, develop fruit, disperse their seeds, and their visible parts die back.  They spend the rest of the year storing energy in their underground root systems, waiting for their window for photosynthesis the following spring.  These plants are the spring ephemerals, a term that reflects the brevity of their appearance above ground.

Trout Lily (Erythronium americanum), Virginia Bluebells (Mertensia virginiana), and Mayapple (Podophyllum peltatum)

Spring ephemerals support an entire ecosystem of animals that depend on them for their continued existence.  Some of those animals are also ephemeral in nature, active and visible to us humans for the same time period during which the plants on which they depend are active.

Spring Beauty (Claytonia virginica), Trout Lily or Dogtooth Violet (Erythronium americanum), and Dutchman’s Breeches (Dicentra cucullaria) are just a few of the spring ephemerals. They all provide food for a variety of pollinators, primarily native bees and flies who are active during the brief time these flowers are blooming.  Bees and flies visit flowers for both nectar and pollen, essential food for themselves, and in the case of bees, also for their larvae.

Spring Beauty (Claytonia virginica)

Trout Lily or Dogtooth Violet (Erythronium americanum)

Spring Beauty and Trout Lily host mining bee species that specialize on their pollen.  Just as Monarch butterfly caterpillars can only eat the leaves of Milkweeds (Asclepias species) to survive, these bees can’t digest the pollen of any other plants. Without these plants, we wouldn’t have the bees.  In turn the bees are very efficient pollinators for the plant species on which they specialize.  About twenty-five percent of our native bees are specialists on a small group of related plants.

Spring Beauty (Claytonia virginica) with mining bee

Trout Lily or Dogtooth Violet (Erythronium americanum) with mining bee, probably the specialist Andrena erythronii

In addition to bees and flies, Spring Beauty’s shallow bowl-like flower shape also accommodates dining for spring flying butterflies.

Juvenal’s Duskywing drinking nectar from Spring Beauty (Claytonia virginica)

Dutchman’s Breeches’ primary pollinators are queen Bumble Bees, newly emerged from their winter shelters.

Queen Bumble Bee pollinating Dutchman’s Breeches (Dicentra cucullaria)

Some native Mustard (Brassicaceae) family members are spring ephemerals, including Cut-leaved Toothwort (Cardamine concatenata), Toothwort or Crinkleroot (Cardamine diphylla), and Smooth Rockcress (Arabis laevigata).  The flowers of Mustard family members have four petals arranged in a cross shape, often forming a tube at the base of the flower.

Cut-leaved Toothwort (Cardamine concatenata)

Toothwort or Crinkleroot (Cardamine diphylla)

Smooth Rockcress (Arabis laevigata)

Not only do these plants provide nectar and pollen for early flying bees and flies,

Cut-leaved Toothwort (Cardamine concatenata) with bee

but they are also food plants for the caterpillars of some butterflies in a group called the Whites.  Where I live in New Jersey, Cut-leaved Toothwort and Smooth Rockcress host a member of this group called the Falcate Orangetip.  At rest they are unmistakable, with a gray and white marbled pattern on their ventral (under) side, the males with the distinctive orange wing tips above. They are very flitty, though, so it’s hard to get a good look, or a photo!

Falcate Orangetip drinking nectar from Spring Beauty (Claytonia virginica)

It was only a year ago that I first spotted this butterfly, on a woodland trail where Cut-leaved Toothwort and Smooth Rockcress are both present.

In the northern tier of the eastern United States and in parts of Canada, the Mustard White butterfly uses some of these same Mustard family members as its required caterpillar food.  The West Virginia White, a fairly uncommon butterfly’, uses both Toothwort species.

Mustard White drinking nectar from Bluets (Houstonia caerulea)

In flight both the Falcate Orangetip and Mustard White can easily be mistaken for the very common, non-native Cabbage White, so in spring it’s worth taking a careful look at any small white butterfly you see in a woodland area where these native mustard family members are present.  The butterflies’ active period mirrors that of their caterpillar food plants, so you can only see them for about 4-6 weeks during the spring.

Cabbage White

Without our native Mustard family members, the Falcate Orangetip and Mustard White and West Virginia White butterflies would cease to exist.

There is a whole ecosystem of species interdependent with native spring ephemerals that can only be observed during the fleeting weeks of early spring.  This is just a tiny window into that world.  For more on the spring ephemeral ecosystem, see the posts listed below. Even better, go outside and experience it for yourself!

Cut-leaved Toothwort (Cardamine concatenata) with bee

Related Posts

Cut-leaved Toothwort

A Carpet of Spring Beauty, Woven By Ants

Dutchman’s Breeches and Squirrel-corn

A Tale of two Spring Beauties

Signs of Spring – Mining Bees

Bloodroot

Spring Comes to the Sourlands

Rue Anemone and a Bee-fly

Trillium, Flies and Ants

Milkweed – It’s Not Just for Monarchs

Resources

Butterflies and Moths of North America

https://www.butterfliesandmoths.org/species/Anthocharis-midea

https://www.butterfliesandmoths.org/species/Pieris-oleracea

Pollen Specialist Bees of the Eastern United States

Brock, Jim P.; Kauffman, Ken.  Kaufman Field Guide to Butterflies of North America.  2003.

Cech, Rick; Tudor, Guy.  Butterflies of the East Coast.  2005.

Glassberg, Jeffrey.  A Swift Guide to Butterflies of North America.  2012.

Rhoads, Ann Fowler; Block, Timothy A.  The Plants of Pennsylvania.  2007

 

Holiday Gift Ideas for Your Wild Neighbors

American Robin with Winterberry Holly (Ilex verticillata) at Bowman’s Hill Wildflower Preserve, New Hope, PA

Looking for the perfect holiday gifts for the birds, butterflies, bees and other wildlife neighbors outside your windows?

The answer is simple.  Give them plants that are native to where you live.  Plants and animals have evolved together over many centuries in such a way that they depend on each other for their survival.  Animals depend on native plants for food, shelter, nesting sites and materials.  Plants in turn depend on animals to help disperse their seeds, and in many cases for essential assistance in reproduction, as their pollination intermediaries.

You’ll be doing yourself a favor, too, since native plants, once established, typically don’t require fertilizer, watering or other special care.

The American Robin shown here with Winterberry Holly (Ilex verticillata) was one member of a flock of Robins that swooped down to devour the bright winter-time fruit.  Winterberry Holly has fruit high in carbohydrates and low in fats, a recipe for being ignored during migration season in fall, but devoured during the cold days of winter when birds need those carbohydrates. In exchange for this winter feast, birds ‘disperse’ the seeds complete with fertilizer after the seeds move through a bird’s digestive system.

If you live in North America, here are a few resources to help you learn which plants are native where you live:

Lady Bird Johnson Wildflower Center

Audubon

North American Native Plant Society

Also check with your local state or province native plant society.

For the birds, another great gift idea is a heated bird bath.  Birds need to drink and bathe even in winter.

What else can you do? Less:

  • Leave the fallen leaves in your planting beds.  They provide habitat for overwintering insects, and the insects are food for birds.
  • Don’t use pesticides or herbicides
  • Reduce your lawn size if possible
  • Chop up leaves on your lawn with a mulching mower to create a natural chemical-free fertilizer

Happy holidays!

Related Posts

A Wildlife, Family and Pet-friendly Lawn

Red-banded Hairstreaks Need Sumacs and Leaf Mulch

For Great Spangled Fritillaries, Leave the Leaf Litter

American Robin with Winterberry Holly (Ilex verticillata) at Bowman’s Hill Wildflower Preserve, New Hope, PA