Monday, May 21, 2018

Common Milkweed Hosting Larvae of Unexpected Tiger Moth

My first encounter with the Blue Jay Barrens population of the Ohio endangered Unexpected Tiger Moth, Cycnia collaris, formerly Cycnia inopinatus, was seven years ago.  My encounters with this species have increased each year since then, and this year is no exception.

Unexpected Tiger Moths are a milkweed dependent species.  Last fall, a few larvae were found on Common Milkweed, Asclepias syriaca, growing in the narrow strip between my driveway and Water Garden.  When larvae of this species are ready to pupate, they move into the plant litter at the base of the host plant and pupate near the soil surface.  I am assuming that this is exactly what occurred last September.  This spring, the adults emerged and apparently laid masses of eggs on the young milkweed plants emerging at the time.

The larvae are present in numbers many times greater than what I saw last year.    The amount of plant damage occurring from feeding larvae is readily apparent.

Most of the feeding is occurring on the young leaves at the growing tip of the plant.  There are about 10 larvae working on the particular plant.

Plants with more larvae show more leaf damage.

There are at least 20 larvae working on this plant.  The milkweed can’t grow quickly enough to stay ahead of these ravenous caterpillars.

Many of the larvae are moving out to begin feeding on the older leaves.  This intensive feeding won’t harm the milkweed.  This batch of larvae, the first of two yearly broods, will soon mature and leave the plant to pupate.  The plant will recover and be ready to hopefully host another batch of larvae in August.

The video shows feeding activity in one of the areas of highest larvae concentration.  Click HERE to view the video on YouTube, which usually provides a clearer image.  Click HERE to view earlier posts concerning this species.

Saturday, April 28, 2018

The Barrens Garden

Eighteen years ago, as the first act of creating a water garden, I dug a large hole near my front porch. Approximately 55 cubic yards of material was removed from the hole and placed in a pile here, near the east side of my barn.  First came slabs of sod a couple of inches thick that were placed in the upper left-hand corner the above photo. Next came the removal of a half foot of clay subsoil that found a permanent residence in the upper center of the photo. Following that, I chiseled through 2 feet of fractured limestone bedrock and added that to my spoil pile. Over the years the material has settled down to become a solid fixture in the landscape.

After several years, the gravel area began to closely resemble the gravelly barrens found tucked away in some of the steeper hillside prairies of Blue Jay Barrens. I then began considering the idea of introducing into this gravel pile seed from some of the rarer winter annuals found growing in the gravelly barrens. My last year’s crop of captive Leavenworthia uniflora and Draba cuneifolia produced such an abundance of seed that I had plenty to invest in this new project that I am calling the Barrens Garden.

In July 2017, I scattered seed over the entire spoil pile.  The results did not disappoint. Shown above are some of the hundreds of rare Draba cuneifolia that resulted from that seeding.

Drabas and Leavenworthia are both members of the mustard family and their flowers show the standard four petal arrangement. These plants are annuals and will not survive past Midsummer. All of the plant’s energy goes into the production of flowers and seeds. Seeds that fall to the ground in June will begin to germinate in October or November. Rosettes of basal leaves will form and grow through the winter. Flower stalks and blooms typically arrive in April.

Leavenworthia uniflora usually follows the same growth pattern of the Draba, although a greater proportion of the seeds tend to wait until February to germinate.

In other wildflower gardens I’ve created, my primary problem is the habit of plants developing much more robustly than they do in their natural setting. It appears that I’ve managed to provide conditions in this Barrens Garden that closely mimic the natural conditions. Above are three Leavenworthia uniflora bracketing a standard dime. The basal rosettes are hardly much larger than that ten cent piece.

Here’s that same dime beside two Leavenworthia uniflora growing in the natural barrens. The size of the plants is almost identical to that found in my Barrens Garden. I have high hopes that this project is going to prove to be a long term success.

Tuesday, April 3, 2018

Split Season Wood Frog Breeding

During roughly the third week of February, the Wood Frogs of Blue Jay Barrens swarmed into the pond for their annual mating event. The behavior is typical for that time of year; however, weather conditions and the intensity of the mating activities were not what I have come to expect.

February 17 – Six inches of snow falls. February 18 – Temperatures struggle to reach the low 40s. Snow melts slowly and is nearly gone by evening. Wood Frogs begin to enter the pond. February 19 – High temperature reaches 75°F. Wood Frogs continue courtship activities through the day and into the night. February 20 – High temperature reaches 80°F. Wood Frog courtship activities can almost be described as frantic and continue through the day. February 21 – high temperature around 35°F. Three inches of snow falls. Wood Frogs have disappeared.

On March 28 Wood Frogs returned to the pond and were heard calling for the next three nights.  Weather was rainy and cool through the period.  This is the first time Wood Frog breeding activities divided in this manner.

The swimming frogs seem to pull in their eyeballs when swimming with head submerged.

In order to project the sound of their calls, the Wood Frogs inflate air sacs located on each side of the body.  The sacs act as resonating chambers for the call. In the above photo the frog is seen from behind, showing the twin air sacs in the foreground and the two bulging eyes behind.

Surface tension causes the water to curve and ride up the frog’s body. The water then reflects the sky and the surrounding landscape, making it difficult to see the frog itself. I wonder if this might afford the frog a degree of camouflage and protection from water level predators.

The short video above offers a view of a calling Wood Frog and a broader view of activity in the pond. The video can also be seen on YouTube by clicking HERE.

Wednesday, November 8, 2017

Fall Project 2017

Each year during September and October, I tend to embark on a large scale management project at Blue Jay Barrens.  This year I worked to systematically eliminate all invasive shrubs from a 16 acre block that was historically used as a crop field in the early 1900’s.  Since all invasive shrubs of seed bearing age appear to have been eliminated from the property, I thought the next step should be to aggressively pursue the youngsters.  My primary problem shrubs are Multiflora Rose, Bush Honeysuckle, Japanese Barberry and Autumn Olive as shown in the lineup in the photo above.  I also find a few Privet and a couple of Winged Wahoo.

My project area sits on a long south facing slope and is a roughly rectangular shape measuring 900 by 800 feet.  The area is currently a patchwork mix of large Eastern Red Cedars, mixed hardwoods, and barrens openings.  I began work at the east property line and worked my way west in a series of strips paralleling the fence line. Each strip ran from the creek up to the hill top, an elevation difference of about 140 feet.  The neighboring property has a growing population of invasives and birds bring plenty of seeds across the property line.  Invasive shrubs were especially within 100 feet of the fence.

To make my search as thorough as possible, I produced a grid pattern by using marking flags to establish the strips and to show the corners of each cell within the strip.  Strips were about 20 feet wide and each cell was about 35 feet long.  This resulted in around 1,000 cells developed within the project area.  I began by establishing two strips using three lines of flags; one red, one blue, and one yellow.  As I completed each strip, I would move the line of flags west to make a new strip.  Within each cell I would walk a line about three feet in from the side, cross over at the end and walk about three feet in along the other side, and then travel up the center until I reached the next cell.  There’s no place within that 16 acres that I wasn’t within a few feet of while searching.  Every invasive shrub found was cut off at ground level and the resulting stump treated with glyphosate.  Most of the treated individuals were less than two feet tall.  If I could see it, I would treat it.

Of course, that doesn’t mean I found every invasive shrub there was to find.  Surrounding native vegetation often hid the invaders.  Dappled sunlight could also be effective camouflage.  Despite these obstacles, I drastically reduced the number of unwelcome shrubs.

Even shrubs that appear impossible to miss can be hidden from view.  This Bush Honeysuckle could not be seen from the other side of the tree.

The concentration of invasives was greatest beneath trees used by roosting or resting birds.  The photo above shows an Autumn Olive, a Bush Honeysuckle and a Multi-flora Rose, three of a larger collection of similar specimens all inhabiting the same small area of ground. 

The cause of the infestation was a large Sycamore, the trunk of which can be seen here in the background.  Flocks of Robins and Cedar Waxwings seem to spend considerable time in the upper branches of towering Sycamores, often after making a large meal of fruits from surrounding shrubs.  While resting, they are also dropping seeds into the fertile soil beneath the tree.

It’s common to find a clump of seedlings that has developed on the site of a seed filled bird dropping.  This jungle of Autumn Olive seedlings resulted from a single bird drop.  

The seedlings must now compete among themselves for survival.  The plants at the edge of the cluster stretch out to capture sunlight.

The clump may appear to be spread over a rather wide space, but clipping the tops reveals that all stems are originating from a single small spot.

Invasives were cut and treated in this area in a slightly less intensive search conducted four years ago.  These two Bush Honeysuckle stems and the stump from which they were cut are a result of that management effort.  I was concerned when I found many Bush Honeysuckle seedlings growing in a roughly 10 foot diameter circle centered around the dead stump.  Could seeds from fruit that fell uneaten to the ground germinate after several years of natural stratification?  If so, this could cause another complication in the battle to control these invasives.  Hopefully, this is just the result of some seed laden birds that just happened to roost above this old bush site.

Multiflora Rose growing on the dry, rocky slopes show an interesting growth pattern.  Most have been growing for many years as indicated by the thick stump found at ground level, but the plants display only the current year’s growth.  Dieback due to harsh conditions seems to be a perennial problem for these roses.  That doesn’t stop them from trying anew each year.  The plant shown above has one live stem produced this year, one dead stem produced last year, and numerous scars on the stump from previous years.

Multiflora Roses also have a habit of sending out a horizontal stem that stays hidden from view.  Cutting and applying herbicide above this branch could cause the treatment to fail and the rose to survive.  The horizontal branches also have the annoying habit of rooting at the leaf nodes so that a series of individual plants develops along the length of the stem.

I know the property will never be completely free of invasive plants, but it would be nice to reach a point where I could walk around without having their presence so obviously displayed everywhere I look.  As my supply of non-native invasive shrubs dwindles, the populations on neighboring properties is expanding, so new seeds will always be finding their way across the fence.  At one point during my work, I was thinking of one of my favorite books, The Day of the Triffids by John Wyndham.  I didn’t realize it when I read the book for the first time nearly 50 years ago, that the story is basically about a non-native invasive plant species that swarms over the countryside wreaking havoc on the human population.  At one point in the book, Triffids crowded outside barrier fences while the people inside hunted and destroyed any invading seedlings.  It was the scene just outside my fence line that brought that book to mind.  Of course, the invasive plants that I’m dealing with can’t walk and they’re not going to strike me dead if I exhibit a moment of carelessness.  That’s something I can be grateful for as I continue my work.

Monday, September 18, 2017

Eliminating Invasive Plants – Summer Activities

As the seasons change, my management activities change.  Summer is a time to hunt and eliminate invasive forbs and grasses.  Sweet Clover was my initial target several years ago.  As Sweet Clover numbers dropped, I added other species that could be controlled by pulling prior to setting seed.  Now, Yellow and White Sweet Clover, Wild Carrot, Teasel, and Oxeye Daisy are all on my summer pulling schedule.  Not all invasive species can be controlled by pulling.  Sometimes, like in the case of Crown Vetch, the aid of a chemical herbicide is necessary to eliminate the plant.

This is my second year using the chemical Clopyralid in the treatment of Crown Vetch.  Clopyralid kills only broadleaf plants, and is particularly effective on legumes.  Grass is left unharmed, so no bare spots are left in the field after treatment.  The areas I treated this year were fewer in number and much smaller than what I dealt with last year.  Shown above is the largest patch of Crown Vetch I had to spray this year, and it covered only about 40 square feet.

Crown Vetch found its way into my fields as seed that was produced along the edges our township road.  I eliminated the roadside vetch last year, but some of the affected field areas are going to take a bit more work.  Crown Vetch growing beneath the canopy of tall Indian Grass is hard to spot.  The best time to search is when the plants begin to flower.

Unfortunately, peak flowering time for Crown Vetch coincides with flowering of other lavender bloomed plants such as Monarda.  Shown above is Crown Vetch on the left and Monarda on the right.  Colors are almost identical.

Monarda flowers are held above the Indian Grass leaves.  Good luck trying to spot a couple stalks of Crown Vetch hidden down in the grass.

Johnson Grass is another species that requires some herbicide assistance if it is to be eliminated.  I’ve been after this species for several years and only found seven small clumps growing this year.

When dealing with Johnson Grass, I first cut the stalks down to a manageable height and trim back any long, flowing leaves.  This allows me to spray the complete plant with glyphosate, without spraying a lot of neighboring plants.

Johnson Grass is another invasive species that can trace its origin back to the roadside.  Even though the roadside along my property is free of this invasive grass, seed produced along other sections of the road are easily caught and transported by vehicles traveling the roadway.  I expect passersby will replenish my seed supply on an annual basis.

Johnson Grass is hard to miss when it sends up a flower stalk.  This species puts on height in late July, long before the tall prairie grasses, so it doesn’t take much searching to identify new infestations.

When the plant is blooming, tops can be cut and just left in the field.  There is no chance that these flowers will produce viable seed if removed from the plant at this stage.  If treatment is done after seed has formed, it is best to remove the seed heads from the field to eliminate any viable seed being left behind.

I began pulling Wild Carrot six years ago.  I’ve had a lot of success in reducing the numbers of this plant.

Areas that once yielded hundreds of plants, are now producing only a few plants each year.

With fewer plants to pull, I can cover more area.  This is the last of the Wild Carrot infested barrens, an area that I have never had time to get to before.  I was able to finish off this field just as the pulling season came to a close.

Wild Carrot seeds were just beginning to darken during my last week of pulling.  Not knowing if these seeds were developed enough to finish ripening on a pulled plant, I removed the seed heads and bagged them for disposal somewhere other than the middle of my field.

A single Black Swallowtail caterpillar was found on one of the pulled carrots.  I transplanted it to a domesticated carrot variety in my vegetable garden.  It ate for several days and then disappeared.  I hope it went off to find a secure place to pupate. 

Friday, September 15, 2017

Cycnia inopinatus Caterpillars

I’m always pleased when an uncommon plant or animal species shows up in unusually large numbers. This year, I am finding the caterpillars of the Unexpected Tiger Moth, Cycnia inopinatus, to be several times more abundant than they have ever been in any past year. Having a bright orange body decorated with tufts of black hairs, this species is hard to miss when it’s around.

The Unexpected Tiger moth is listed as an endangered species in the state of Ohio. Its caterpillars feed exclusively on milkweeds, with Butterflyweed, Asclepias tuberosa, probably being the most common host plant. So far this year, I’ve found caterpillars on Butterflyweeds scattered over about a 30 acre area.

In late spring and early summer I’ve seen the caterpillars feeding on Spider Milkweed, Asclepias viridis. Recently, I’ve found several caterpillars feeding on the leaves of Common Milkweed, Asclepias syriaca.

A five-year-old clump of Butterflyweed growing next to my driveway is currently hosting a half dozen caterpillars. Later this year the caterpillars will move into the leaf litter at the base of the plant and pupate. They will remain there through the winter and emerge as adults next spring.

The Common Milkweed being used as a host plant is growing at the edge of my water garden. So far, this is the only Common Milkweed plant that I have found hosting any Unexpected Tiger Moth caterpillars.

Oleander Aphids have been abundant on all of the milkweeds this year. Caterpillars seem to avoid leaves that are excessively covered with aphids and honeydew, but there are enough clean leaves that the caterpillars do not seem to be lacking an adequate food supply. I hope this abundance of caterpillars results in record numbers of adult moths next spring.

The above video shows some of the typical caterpillar activities.