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

Time for Cranberries!

Image

Cranberries, especially in the form of relishes and baked goods, are a Thanksgiving tradition made possible by Cranberry (Vaccinium macrocarpon), a low-growing, creeping, evergreen shrub native to North American bogs and fens. Cranberry lends itself well to cultivation for commercial use, making cranberry based dishes possible throughout the year.

Cranberry (Vaccinium macrocarpon)

The flowers of this native shrub bloom in early to mid-summer, a prerequisite for the fruit that will come later in the season.

Cranberry (Vaccinium macrocarpon) in flower

In order to produce the tart but luscious and festive fall fruit, Cranberry’s flowers must be pollinated with assistance from insects, primarily bees.

Cranberry (Vaccinium macrocarpon) flowers

The flowers are most efficiently pollinated by bees who are capable of sonication, or buzz pollination.  In the case of Cranberries, this process is performed by bees that are able to hang upside down from the bottom edge of the flower’s corolla (collection of petals) and vibrate their wing muscles without moving their wings.  This sets up just the right motion to release pollen from the flower like salt from a shaker dusting the bee’s underside.  When the bee moves on to the next flower, its pollen-dusted abdomen brushes the flower’s stigma (female reproductive part), depositing pollen from the previous flower.

It’s not every bee that has this special talent.  Honey Bees don’t have the skills necessary to buzz pollinate.  The best Cranberry pollinators are the native bees with which it has evolved, and who can sonicate (buzz pollinate), including several species of Bumble Bees, Sweat Bees (Halictidae) and Mining Bees (Andrenidae).  The presence of these native bees significantly increases the yield of commercial cranberry operations.

Bumble Bee getting in position to buzz pollinate a Shooting Star (Dodecatheon Meadia) flower. The structure of this flower is very similar to those of Cranberry (Vaccinium macrocarpon).

Other food we eat, including blueberries, tomatoes, eggplant, and peppers are produced by plants whose flowers are also most effectively pollinated through buzz pollination.

With the help of the bees, this tough little shrub produces abundant fruit that ripens in the fall and resists spoiling, perfect timing for inclusion in a late fall or winter feast.

Cranberry (Vaccinium macrocarpon)

In addition to being tasty and nutritious, Cranberry has medicinal value. Consumption of cranberries or unsweetened cranberry juice can help prevent urinary tract infections.

Humans are not the only consumers of cranberries.  Birds including Sharp-tailed and Ruffed Grouse, Bobwhites, Mourning Doves and American Tree Sparrows are known to eat cranberries,

Ruffed Grouse

American Tree Sparrow

as are Chipmunks.

Eastern Chipmunk

Cranberry hosts the caterpillars of several moths who can only eat the leaves of this and a few related species.  The Bog Copper butterfly is also a specialist on Cranberry and the closely related Small Cranberry (Vaccinium oxycoccus).

Cranberry is indigenous in the United States from Maine to Minnesota, south from northeastern Illinois to Delaware, and from there reaching as far south as Tennessee and North Carolina primarily through the Appalachians; it can also be found in coastal Washington state and Oregon, and Nevada county in California.  In Canada it is native from Newfoundland to Ontario, in British Columbia and the Northwest Territories.  The top five states in commercial cranberry production are Wisconsin, Massachusetts, New Jersey, Oregon and Washington.  British Columbia and Quebec are the top cranberry producing provinces in Canada.

Why is the range of this plant primarily in northern latitudes and higher elevations?  The answer lies in the fact that Cranberry is much less successful in producing flowers and fruit unless it goes through a sufficient period of dormancy induced by day length change and cold temperatures.  To successfully break dormancy, the plants must experience a cumulative number of ‘chill hours’, usually defined as temperatures between 32 and 45 °F (0 – 7.2 °C), during the winter months.  A study done by University of Wisconsin researchers found that 1500 chill hours seemed to be in the optimal range for successful bloom of cranberry flowers.  As the climate changes and night time temperatures warm, the geographic range where these optimal conditions can be met may shrink.

Enjoy those cranberry dishes while you can!

Manoff’s Apple Cranberry Chutney!

Related Posts

The Buzz about Shooting Star

Love Blueberries?  Thank a Native bee

Resources

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

Eastman, John.  The Book of Swamp and Bog.  1995.

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

Foster, Steven; Duke, James A.  A Field Guide to Medicinal Plants and Herbs of Eastern and Central North America.  2000.

Hoffmann, David.  Medical Herbalism.  2003.

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

Biobest Sustainable crop Management

Illinois Wildflowers

https://illinoiswildflowers.info/plant_insects/plants/vaccinium_macrocarpum.html

http://www.illinoiswildflowers.info/flower_insects/plants/lg_cranberry.htm

Lady Bird Johnson Wildflower Center Plant Database

The Canadian Encyclopedia

University of Wisconsin Extension; Cranberry Crop Management Journal

University of Massachusetts, Natural History of the American Cranberry (Vaccinium macrocarpon)

USDA NRCS Plants Database

USDA REEIS Cranberry Cold Hardiness in Relation to Dormancy and Bud Development; Source: University of Wisconsin

United States Department of Agriculture National Agricultural Statistics Service New Jersey Field Office – Cranberry Highlights

US Forest Service – What is a Fen?

 

 

WisCONTEXT: Pollinators Provide Extra Buzz To Wisconsin’s Cranberry Crop

https://www.wiscontext.org/pollinators-provide-extra-buzz-wisconsins-cranberry-crop

 

Another Migrating Butterfly, and the Plants that Sustain It

Common Buckeyes have been, well, really common this year.

Common Buckeye drinking nectar from Short-toothed Mountain Mint (Pycnanthemum muticum)

That isn’t the case every year in the areas I frequent near the Delaware River in central New Jersey and eastern Pennsylvania.  Common Buckeyes are not year-round residents this far north. They migrate south in late fall to spend the winter in warmer territories, often as far south as Florida.  In migration they can sometimes be seen in large numbers, often moving along the coast in the eastern United States, or sometimes following river valleys.  They migrate north in spring and early summer, sometimes reaching as far north as southern Canada.  Their numbers vary from year to year in these northern locations, becoming increasingly rare the further north they go.

On warm sunny days even in late October, I am still seeing Common Buckeyes often drinking nectar, mostly from flowers that are members of the Aster family.  This family of plants, which includes asters, goldenrods, sunflowers, bonesets, beggar-ticks, and more are typically the most abundant plants blooming in late summer through the end of the growing season.

Common Buckeye nectaring on Aromatic Aster (Symphyotrichum oblongifolium)

Common Buckeyes can also be found basking at ground level, catching the low rays from the late season sun.

Common Buckeye basking

Common Buckeyes frequent open fields, roadsides, gardens, and even beaches, especially where nectar plants are available.

Common Buckeye drinking nectar from goldenrod flowers along the sandy beach at Cape May, New Jersey

Common Buckeyes have a fairly broad geographic range, and have evolved to use a variety of plants as food for their caterpillars, including plantains, figworts,

Lanceleaf Figwort (Scrophularia lanceolata), a caterpillar food plant for Common Buckeye butterflies

gerardia,

Purple Gerardia or Purple False Foxglove (Agalinis purpurea), a caterpillar food plant for Common Buckeye butterflies

Monkey Flower,

Allegheny Monkey Flower (Mimulus ringens), a caterpillar food plant for Common Buckeye butterflies

and Wild Petunia.

Fringeleaf Wild Petunia (Ruellia humilis) a caterpillar food plant for Common Buckeye butterflies

The coloration of the Common Buckeye’s outside hind wing early in the season is mostly tan, with prominent eye spots.

Common Buckeye drinking nectar from Short-toothed Mountain Mint (Pycnanthemum muticum). Note the tan color and eyespots of the hind wing.

The wing color can be quite different in late summer and fall, taking on a rosy hue.  This may be an adaptation that helps Common Buckeyes blend in with the changing color of the surrounding foliage.

Common Buckeye in autumn. Note the rosy color of the hind wing.

Keep an eye out for Common Buckeyes on these last warm days of fall!

Common Buckeyes on goldenrod

 

Resources

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.

Glassberg, Jeffrey.  Butterflies through Binoculars A Field Guide to Butterflies in the Boston-New York-Washington Region.  1993.

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

Wagner, David L.;  Caterpillars of Eastern North America, 2005.

Canadian Biodiversity Information Facility: Butterflies of Canada

Butterflies and Moths of North America