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

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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

Sleepy Orange Butterflies Overwintering in Pennsylvania

As I write this, it’s 30°F and snowing lightly, with snow, ice and rain predicted for the next few days.  It’s December in New Jersey.  Oddly, I like winter.  So what am I doing thinking about butterflies?

Sleepy Orange Nectaring on Pickerelweed (Pontederia cordata)

Sleepy Orange Nectaring on Pickerelweed (Pontederia cordata)

Since summer I’ve been puzzling over the fact that a butterfly species that is primarily tropical, the Sleepy Orange (Eurema nicippe or Abaeis Nicippe), has been seen regularly in summer across the Delaware River at Bowman’s Hill Wildflower Preserve, just south of New Hope, Pennsylvania.  (See Sleepy Orange Butterflies are Back)  This species is not thought to overwinter farther north than North Carolina.  How is it that Sleepy Oranges have consistently been at the Preserve for the past four summers, and before that in 2006 and 2008?

Is it random chance?  Are they successfully overwintering here?  Or have they evolved to be able to migrate south in the fall and back north in the summer, returning to the same location?  Inquiring minds want to know (ok, I want to know), so I gave myself the assignment of observing them throughout the fall to see if I could learn anything that could help answer this question.

Throughout August the Sleepy Oranges could be seen mating, with the females taking the lead in selecting the location, usually on or near their favorite caterpillar food plant, Wild Senna (Senna hebecarpa).

Sleepy Oranges mating on Wild Senna

Sleepy Oranges mating on Wild Senna

Naturally, this activity was followed by the females laying eggs.

Sleepy Orange laying an egg (ovipositing)

Sleepy Orange laying an egg (ovipositing)

Their efforts were pretty successful, treating me to many caterpillar

Sleepy Orange Caterpillar

Sleepy Orange Caterpillar

and chrysalis sightings throughout September.

Sleepy Orange Chrysalis

Sleepy Orange Chrysalis

Empty Sleepy Orange Chrysalis - the butterfly has already emerged

Empty Sleepy Orange Chrysalis – the butterfly has already emerged

The chrysalises masqueraded perfectly as leaflets loosing their chlorophyll and changing to shades of tan, yellow and orange.

By late September, I still saw fresh-looking adult butterflies in their summer coloration form.

Sleepy Orange, summer color form

Sleepy Orange, summer color form

In the south, where Sleepy Oranges are known to overwinter as adults in reproductive diapause, they have a different, darker coloration for this overwintering generation. I observed my first individual with this coloration at the Preserve on September 24.

Sleepy Orange, winter color form

Sleepy Orange, winter color form

This butterfly had just emerged from its chrysalis.  The tan leaf-like thing hanging behind and between the two leaves to the right of this butterfly is the recently vacated chrysalis, positioned perfectly as if it were a leaflet.

Empty Sleepy Orange Chrysalis

Empty Sleepy Orange Chrysalis

Throughout October, every time I looked on a warm enough day I eventually saw adult Sleepy Oranges.  They usually made their appearance by flying up from the ground, first one butterfly, then two, maybe three or four, flying constantly, circling around each other, flitting back and forth, until they disappeared back down to the grasses and fallen leaves on the ground.  I no longer saw mating, caterpillars or chrysalises.

Occasionally a Sleepy Orange basked from a tree branch, safe in the camouflage of the changing fall leaves.

Sleepy Orange basking on Willow Oak - Can you see the butterfly?

Sleepy Orange basking on Willow Oak – Can you see the butterfly?

Only very rarely did I see them nectaring, although they may have been feeding more than I was able to observe, possibly on blossoms of young plants at nearly ground level, like this aster.

Sleepy Orange nectaring on aster

Sleepy Orange nectaring on aster

The spot where I saw the butterflies most frequently is a small meadow area with lots of young plants (including Wild Senna, their caterpillar food plant) and exposure to afternoon sun.

My last sighting of an adult was on November 2, a mild sunny day with a high in the mid-60s.  Given the current temperatures, I’m pretty sure that will be my last sighting until next year.

So it appears that the Sleepy Oranges are at least attempting to overwinter here, probably as adults, and probably in the shelter of the plants and fallen leaves on the ground.  Lets see if they’re successful.  This fall and winter is starting out a bit colder than normal, so even if they have survived the winter here in the past, it doesn’t necessarily mean they’ll make it this year.  I hope they do!

Even if they do overwinter here, it doesn’t exclude the possibility that they might also have a second strategy that involves migration.

I’ll keep you posted.

Sleepy Orange, winter form

Sleepy Orange, winter form

Resources:

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