Invasive Plants and Giant Woolly Bears!!

Invasive Plants and Giant Woolly Bears!!
November 4, 2016

Autumn was, so far, unseasonably warm, and rather crisp from lack of significant rain. November 4 was a bright, sunny day, with a clear, baby blue sky.

 Canopy over Cottonwood Pond

Because of these rather non-autumnal conditions, autumn color was slow to appear. On November 4, there was still more green in the trees than what is usual for early November, but other colors had been allowed to peak out from behind covers of chlorophyll increasingly since October 31. The woods had begun to take on the warm glow of the yellow-gold to maroon to deep bronze spectrum.

Looking up the slope I had descended

A nearby Sugar Maple, finally turning gold

Blue Beech saplings on the base of the fallen Cottonwood trunk

Sugar Maple sapling on top edge of Root Ball

During the previous three to four days, since I had last been to Cottonwood Pond, the dry leaf layer on the woods floor had become deeper and more varied in texture as a greater variety of trees were letting go of their leaves. 

Creek near Cottonwood Pond

Leaf-filled Creek - looking upstream

 Very Rotten Log over Creek

 Very Rotten Log with dry leaves and new green plant

An insect larva had spun this cocoon when the leaf was green and pliable, attaching silken fibers and pulling them toward itself. It is snug for the winter.

Our shaggy-haired gnome face (the Root Ball Bottom) was looking sleepy, as if resting more deeply into the Mud Pile pillows.

Fallen leaves were gathering into the bowl of earth that is normally Cottonwood Pond. On that day, the bowl, the Inlet, the Isthmus and “little pond” were all dry.

Looking across the main pond bowl toward the Inlet

Northern pond corner, and the Isthmus connecting it with “little pond.”

 “little pond” on the  topside of the Root Ball

A little bit of water from a recent light rain rests on a leaf in the bed of “little pond”

 Interesting designs in the wood at the base of the fallen Cottonwood Trunk, edge of “little pond”

The fallen Cottonwood Trunk was sporting some fresh mushrooms.

A large section of the south-facing side of the Trunk had been rotting significantly, its old wood carved into “apartments” by various small animals, which help break down the wood into soil. New soil could be seen in some of the crevices where it had fallen. The dead leaves that had fallen and nestled into cradled areas would also break down to become part of that soil. I couldn't help but be reminded of Pueblo cliff dwellings.

Something that had been really bugging me for a long time was the existence of Asian Bush Honeysuckle shrubs (various Lonicera species) in the Cottonwood Pond vicinity, very close to “little pond”, the Trunk and the Swampy Spot. These types of non-native shrubs are some of the worst invasive plants in our area. They grow quickly in dense thickets that crowd out native plants and choke out the sunlight that would otherwise reach and enrich herbaceous plants below. Furthermore, they have an allelopathic affect on other plants, preventing them from growing around the shrubs. What eventually appears is a monoculture of Asian Bush Honeysuckle with bare ground underneath.

These shrubs, over the years, have been marching into our woods from either end, and we had only made a small dent in the population with our sporadic efforts to control them. While walking the woods, I pulled up any smaller ones that I could (they pull up easily), but there were many larger ones – some with branches as thick as my wrists – that must be otherwise controlled, calling for a stronger, more consistent effort.

I had only found two of them associated with Cottonwood Pond, so I decided that November 4 was the day I would go do something about them before they spread further. My original plan was to cut the trunks off below the crown. When researching Asian Bush Honeysuckle control methods, my husband had discovered this idea. He tried it out on a few of the shrubs closer to the road and … they died! I thought it would be nice to try this on the Cottonwood Pond shrubs, leaving herbicide behind.

But, I brought the wrong tool. All I brought was my little pruning saw. I have used it to cut thick old Winter Creeper vine on trees. I did not realize the difference.

I first went to the specimen situated on the north side of the fallen Cottonwood Trunk. It was younger, not having produced flowers or fruit, so it was good to catch it so soon.

 Foreground – young Asian Bush Honeysuckle shrub

Mireille insisted on “helping.”

I cleared away leaves and soil from the base, to get to the crown (the part of the plant where the stems meet the roots.)

What I revealed was a beautiful, hairy, curled up caterpillar – and a quite large one.

It had rows of black spines with deep orange-red stripes between. I had been seeing many of these during late summer through early autumn – making their way through the grass near the clothesline, curled up at the base of the Persimmon tree or near some brick garden edging – all over the place. They look much like the familiar Woolly Bear caterpillars that wiggle in droves across our road in September, except for the alternating red stripes and the very large size.

Because I had been seeing so many, I looked them up and learned about them. They are the Giant Woolly Bear Caterpillars! Their Latin name is Hypercompe scribonia. You can learn more about them here ...

http://entnemdept.ufl.edu/creatures/MISC/MOTHS/Hypercompe_scribonia.htm

… where you can also see a photo of the absolutely stunning black-and-white adult that it becomes – the Great Leopard Moth. This is the largest of the Eastern Tiger Moths. With so many of these caterpillars about, I am hoping to see the moths.

Though the caterpillar looks like a “don't touch!” type (indeed, some caterpillars have venomous spines or hairs), this one is safe to touch. The hairiness and bold stripes, though, serve as a warning to possible predators that might consider this one to be venomous, therefore being more likely to avoid it.

This caterpillar, and others I have seen of its kind, stays very tightly curled up when disturbed (so much so that I've wondered if they were still alive.) When I have moved them to safer places, they have stayed stiffly in this position, not even uncurling after I set them down. The above web site article shed light on this phenomenon:

“When threatened, giant woolly bears curl up tightly to protect their vulnerable undersides. When picked up, their stiff, smooth spines are bent backward and they tend to push the caterpillars forward and out of the grip (Wagner 2009). Because of this, it is virtually impossible to forcibly uncurl them when they are in the defensive posture. Also, in this defensive posture, their bright red inter-segmental areas are highly visible  “

By the way, by perusing this article you can learn other fascinating things about this animal, such as (with the moth) where its ears are located and how they are used, and how they produce high frequency clicks in response to bat sonar (bats are one of their greatest predators), and also how the larvae (caterpillars) resist freezing.

The site also has a list of host plants (plants favored in this species' larval diet.) Many of those plants grow at our place, in the woods, gardens, yard, fields, etc. This caterpillar is resourceful. There are some species of caterpillars dependent on only one to three species of plants for food (such as Paw-Paws for Zebra Swallowtail, and Yucca for the … Yucca moth), but the survival of a species can be more assured if it has a more diverse diet (more chances that food is available somewhere.) One of the plants on the list is Tatarian Honeysuckle (Lonicera tatarica), one of the non-native, invasive species of Asian Bush Honeysuckle. I don't know that this is the species near Cottonwood Pond, but I also wondered if other species of Asian Bush Honeysuckle serve as food for this caterpillar.

So, I got out my pruning saw and got down on the ground. It became evident that this tool was too puny for the job as I started to saw into the thick, hard area below the crown. Maybe it would work, but it would take all day.

All I could do was go ahead and saw the trunks above the soil line. The little saw when through them like butter – well, partially frozen butter – much easier. I wanted these things gone. But, after doing this, my choices for killing off the whole plant would be to either go back later with the right tool and attack the crown, or go back later with the right herbicide to smear on the cut parts (which, if I waited too long, I would have to re-cut.) If I did neither, the shrub would come back with vengeance, sprouting numerous new, vigorous stems, as if to say, “Hah! I'll show YOU who's boss!”

Here are before-and-after photos:

Next, it was time to address the one to the south side of the Cottonwood Trunk, next to the Barkless Log extension.

This one was further along, having flowered in the spring, and then producing berries, which would probably be eaten by birds who would spread the seed elsewhere, adding to the huge Asian Bush Honeysuckle problem we already had.

Asian Bush Honeysuckle in fruit - berries between pairs of opposite leaves

Asian Bush Honeysuckle berries on the ground

Again, I moved leaves and soil away from the shrub's base to expose the crown …

… but saw that this would also be too formidable for my little saw. So, in the time it takes me to say “get rid of this Asian Bush Honeysuckle", I cut the trunks.

It had been growing next to a young tree. Here are before-and-after photos, taken from the other side of that tree:

After I had finished, I took all of the trunks and branches from both shrubs and piled them in a nearby, out-of-the-way spot on the slope. They could then become cover for small woodland animals.

Cut Asian Bush Honeysuckle branches piled near base of tree

Close to the second Honeysuckle shrub was the grove of Elderberry shrubs. How could I tell the difference, so that I didn't cut down valuable, native Elderberry plants? First of all, the difference in the leaves.

Leaves of Elderberry shrubs

Elderberry has compound leaves, meaning a leaf shaft is composed of several leaflets. These are arranged oppositely, and each leaflet has a toothed edge.

On the other hand, though Asian Bush Honeysuckle has opposite leaves, they are single leaves, and are paired with the red berries between each pair. The leaves have smooth edges and stay green longer than any other leafy plant in the woods (see previous Honeysuckle photos.)

Another way to distinguish them is through the bark on their trunks. Asian Bush Honeysuckle has a distinctive streaky look. Elderberry bark is smoother in comparison, with distinctive lenticels - the dark, bumpy spots that are scattered about on it.

After accomplishing this task, I wandered up the back slope for a nice walk in the now colorful autumn woods, dry leaves crunching underfoot, November light slanting through the woodland. I looked back down at the site of Cottonwood Pond, which looked so different from that vantage point. I felt I had helped the area by cutting away the invasive shrubs, though I would have to be sure to go back sometime soon to truly finish the job.

Meanwhile, I was sure the Giant Woolly Bear caterpillar was still curled up in the safe place where I had moved it, waiting for winter.