Monarchs Abound

Monarch butterflies have suddenly become more abundant than ever before at Blue Jay Barrens.  During a typical summer, I’m used to seeing a few Monarchs each week.  Things pick up a bit during the fall migration, but this property is outside the primary Monarch migration route, so I usually don’t see multiple butterflies during that time.  This year I’ve been seeing Monarchs on a daily basis, sometimes several at once.  Many of those sightings are centered around the Milkweed plants in front of the house.  The flowers have passed, so that’s not the reason why they are drawn here.

The Monarchs circle the Milkweeds, occasionally setting down for several seconds before moving on.  It’s not always easy to see what they’re up to.

This is a common perching position.  While clinging to the edge of the leaf, the Monarch probes the underside with the tip of its abdomen.  Just a brief stop and then it moves on.

In most cases, an egg is left behind.  With luck, this will be an adult Monarch by next month.

Monarchs depositing eggs on the Common Milkweed near the house is something that happens every year.  This year the Monarchs are leaving their eggs on several other members of the milkweed family, which is something I’ve rarely seen them do.  I watched this Monarch visiting a patch of Butterfly Weed and noticed that its brief visitations to the flowers had nothing to do with nectaring.  I headed over to see if I could find any eggs.

I got sidetracked by the discovery of Monarch caterpillars already present on the Butterfly Weed.  These plants are growing in an area that was mowed in late May as part of a Sweet Clover control plan, so the plants are at an earlier stage of growth than most others in the area.

There were a lot of droppings on the leaves beneath the caterpillars, but it was difficult to see where they had been feeding.  Then I noticed the short stubs at the base of the flower clusters and realized they were all that was left of the consumed flower.

Uncommon at Blue Jay Barrens is the Swamp Milkweed.  That’s to be expected in an area that is primarily classified as a xeric environment.  A few Swamp Milkweed plants survive in sand and gravel deposits along the creek.  This is a shaded, mostly wooded environment that normally doesn’t attract open field travelers like Monarch Butterflies.

The Swamp Milkweed flower head is more erect and less dense than that of the Common Milkweed.  Each flower in the cluster has room to display itself as an individual.

The side veins in the leaf come away from the main vein in an acute angle that’s plain to see.  While admiring the leaves, I noticed that most were displaying some familiar holes.

Monarch caterpillar on the Swamp Milkweed.  This is the first time I’ve ever found Monarch caterpillars on this species.

I went on to count eight caterpillars on this single plant.  I wish them luck in their development.  Their survival depends much on the weather.  A heavy rain storm can quickly bring the creek to flash flood condition and that would lay this plant flat.  The plant can survive that type of treatment, but the caterpillars would probably be lost.  This unprecedented breeding effort by Blue Jay Barrens Monarchs would almost make you believe that the butterflies were aware of their declining numbers and were doing their best to turn the trend around.  I’m just happy to have this opportunity to enjoy such a marvelous creature.

Monarch Butterflies

The spring Monarch Butterfly migration passed without a single Monarch sighting at Blue Jay Barrens.  My earlier disappointment has been abated with a summer season Monarch count surpassing any in recent years.  The Milkweed stands are receiving frequent visitations from this colorful butterfly.

Of course, this is the real reason for maintaining patches of Milkweed plants.  Monarch larvae are Milkweed eaters.  Recent declines in the Monarch population make it more important than ever that this plant be readily available.

Having Milkweed plants snug up against the house makes it easy to monitor the progress of leaf eating insect larvae.  Because of a beating they took during a spring thunderstorm, a few of the plants are unable to maintain an upright position.  Most, however, are standing tall, even though a few needed some propping up and stem support to achieve this condition.

Landscape designers probably wouldn’t recommend crowding the entrance to your home with seven foot tall Milkweed plants.  I would agree, especially when the flower visiting bees during the day or moths at night get sucked into your home every time you open the door.  This Milkweed thicket was not actually intentional.  A single plant that became established beside the water garden was allowed to remain.  Within a couple of years that one plant became two dozen.  For the benefit of the Monarchs, I let them remain.  I must admit that I am also fascinated by the vast array of insects attracted by these plants.

I’m currently finding larvae of all ages.  The youngest are just beginning to show their characteristic black filaments.  Small larvae are easiest to see by looking from below a sunlit leaf. 
 

Midsized larvae show short stubs where the long black filaments will eventually be.  Larvae can also be located by examining holes in the leaves.  Feeding sites are more regular in appearance than hail damage left by the early storm.

Leaf damage causes the Milkweed plant to ooze its thick white sap.  The sticky sap can make it difficult for the larva to feed.  The larva overcomes this obstacle by systematically severing the veins leading to the leaf, this stopping the flow of sap.

In small leaves, the midrib is often cut to halt sap flow to the entire leaf.  On larger leaves, a series of lateral veins might be cut as seen here.

Once the sap stops flowing, eating commences.

The larvae seem to practice an eat-and-run technique that minimizes time spent in any one location.  A section of leaf is consumed and then the larva moves on to another location.  Many predators are attracted to leaf damage in search of prey.  Despite the Monarch’s unpalatability due to accumulating toxins from the Milkweed plant, some predators have to learn the lesson first hand to the detriment of the larva.  Even though they are bad to eat, the best survival strategy is to avoid the predators.

The excess rainfall experienced this spring has really benefited the Milkweeds in the field.  The plants bloomed early and are continuing to produce new flower buds.

This large stand of Purple Milkweed continues to attract Monarch Butterflies as well as other insects dependent on the Milkweed plant for their survival.

It appears that Blue Jay Barrens will contribute a large number of Monarchs to the masses that will make their way south later this summer.  I just hope that conditions at their wintering grounds are favorable for the species continued survival.

Milkweed and Monarch

Judging by the numbers of larvae currently present, Monarch butterflies are going to be particularly abundant this summer.  Strong southerly winds and warm temperatures brought this migratory butterfly to Blue Jay Barrens much earlier than normal.  I’m looking forward to having this species as company through the summer.

The Monarch butterfly was partly responsible for what people referred to as my poor attitude towards school.  In our fifth grade science text, the developmental stages of a butterfly from egg to adult were exclusively portrayed by the Monarch butterfly.  When the teacher distributed drawing paper and asked us to draw those stages, the entire class reproduced the illustration of the Monarch.  Except for me.  I chose to illustrate a Black Swallowtail, a species that I had raised on Wild Carrot during the summer.  The teacher used the text illustrations to show how inaccurate my drawing was and explained that what I portrayed could not exist.  I decided that if she could be that wrong about butterflies, she was probably just as wrong about everything else she was telling us, so I stopped listening to her. 

Monarch caterpillars feed on Milkweed leaves.  A single Common Milkweed sprouted near the Water Garden a few years ago and has since developed into a nice clump.  I see it every day, so it’s easy keep track of any changes.

Fras accumulation on the leaves told me that there were caterpillars at work. 

Fras is also known as caterpillar poop.  Caterpillars spend their lives taking in plant material and expelling waste.  In a search for caterpillars, it’s often easier to find the fras and then trace that back to the animal.

Loss of plant parts is another indicator of caterpillars at work.  Newly hatched caterpillars often have trouble eating mature leaves.  Newly formed leaves, like those found sprouting from the leaf base, are much easier to consume.  A missing sprout is often caterpillar sign.

Holes or missing sections of leaf can also be the work of caterpillars.

Just looking on the other side of the leaf reveals the culprit.

The pattern of feeding is often a deliberate attempt to stop sap flow into the portion of leaf being consumed.  A damaged Milkweed leaf often releases the sticky sap.  By isolating a section of leaf, the caterpillar can feed undisturbed by the sap.

Not all holes in a leaf represent feeding damage.  Jagged tears or holes, especially those with ragged bits of leaf remaining, are examples of physical damage.  In this case, the leaves were battered by a hail storm.

Flowers are also a choice target for smaller larvae.  Some species of moths and butterflies actually lay their eggs on the flower buds. The young can begin feeding on more delicate parts before moving onto the tougher leaves.

Many insects avoid detection by remaining on the under side of leaves, so always get your head down and look up.  I watch many people examine a plant by staring at it as though it was a picture.  Plants are three dimensional objects that require examination from various angles.  Don’t forget that our bodies are supposed to twist and turn.  Use that ability to avoid missing some of the wonderful things in nature.

Far East Field

This is a good time of year to visit areas to assess management success and future needs. I’m in year one of my five year management plan renewal, so I’m identifying activities that should be accomplished within the next few years, as well as those things that urgently need to be completed during the coming winter. This field is roughly four acres in size. It was last cropped around 1976 and was being used for hay when we bought the property. Bedrock is shale and the pH is low throughout the entire soil profile. It has an amazing amount of diversity for such a small field. Wet conditions at the low side of the field transition to super dry conditions as you travel up the slope toward the high ground.

Encroaching woody growth was cut out of this field two years ago. This Tuliptree probably got missed when I was marking the cut trees for herbicide treatment. Multiple sprouts have created a thick bush in place of the single trunked tree. This definitely needs to be cut this winter.

The majority of trees in the field are ones that I have purposely left in place. These are White Flowering Dogwoods. Disease eliminated the dogwoods from their rightful place in the woodland understory. In order to keep White Flowering Dogwoods on the property, I’ve allowed them to stay in the fields. They’re spaced far enough apart that they don’t hinder growth of the prairie species.

The township road boarders the long side of the field and makes this a likely place to discover non-native invasive species. I found just a few Johnson Grass plants near the fence. These must have been too small for me to notice when I did my normal Johnson Grass search earlier in the year. Since they would have been difficult to spray without killing everything around them, I just pulled them up. I’ll check this spot more closely next year to see if I can catch the plants when they’re smaller.

From the looks of the roots, these are probably young plants that came up from seed this year. That’s why they weren’t noticeable earlier. Johnson Grass spreads by way of rhizomes, so it’s hard to control the plant by pulling. Any bit of rhizome left in the soil produces a new plant. Most of the plants I pulled had not yet begun to form rhizomes and showed no signs of having arisen from an established rhizome. The plant second from the left shows some rhizome development and had a break showing that it had left something beneath the surface. Pulling may not have eliminated the infestation, but it certainly thinned it out. If you can’t kill an invasive plant outright, the next best thing to do is cause it severe stress.

The Dwarf Sumacs are bowed under the weight of some tremendously successful seed heads. One more growing season and they’ll reach the stage where they must be cut back to the ground.

There are three large Virginia Pines in this field. Their shade does suppress some prairie growth around the base of the trunk, but they add a bit of diversity that is worth the loss of a few sun loving plants. They’re really turning into some lovely trees.

Several of the Butterflyweeds are blooming here. Unfortunately, there are virtually no swallowtails or other large butterflies to take advantage of the flowers. This has been a dismal year for large butterflies.

This caterpillar is evidence that a Monarch butterfly did come by. I’ve seen scattered Monarchs, but I think they all moved north as quickly as possible. The reports from farther north indicate an abundance of Monarchs up there. I’m looking forward to a very impressive southern migration this fall.

Wild Senna is scattered across the field. All were developing an impressive set of seed pods. It’s amazing how quickly this plant has spread during the past few years.

The bulk of the field is open and developing into a fine prairie. There are a few woody plants that need to be removed and a minor need for some invasive plant control, but there are no big problems to deal with. In a few years, this field should need nothing more than occasional maintenance.

Wet Weather Prairie Growth

I headed out with the idea that I was going to walk through the winter mowed fields to check on their growth rates. Then I decided to look for the Blue Grosbeaks and their recently vacated nest. No signs of any nest in what I thought was a likely spot, so I wandered off in the direction the birds had taken to see if I might locate them in another field. Birds displaying blue coloration were not to be found, except for the Blue Jays of course, but I did find a nice bluish flower. The Scaly Blazing Star, Liatris squarrosa, seem to have synchronized their bloom period this year and are all flowering at once.

This is probably my favorite of the many Blazing Stars. The blooms on squarrosa are spaced far enough apart to allow appreciation of each individual component of the flower heads. I especially like the stiffly pointed bracts that surround the base of the flower head. The whole arrangement looks like a tiny bouquet wrapped in fancy paper.

The plant is rather short and can get hidden by even moderately tall grasses. You can be almost on top of them before you notice the splashes of violet among the grass leaves.

The prairie grasses, adapted to surviving extremely dry conditions, are taking full advantage of the frequent rains. Areas that normally show patches of bare ground are now completely covered by grass.

It’s the Big Bluestem that’s taking over the slopes this year. The density of Big Bluestem in the stand has been increasing steadily over the last 20 years. In a dry year these dry hillsides can grow Big Bluestem that reaches ten feet tall. I’m wondering what kind of height they’ll reach this year.

Years like this really help to boost the organic matter content of the soil. The decaying grass leaves will invigorate the soil biota and the soil will show a slight improvement. I’ve noticed that many prairie wildflowers show increased vigor in the second year following a rainy season. I’m guessing that’s the point at which the nutrients from the decomposing grass become most available.

The flowers are working to keep up with the grass. This Western Sunflower, Helianthus occidentalis, maintains most of its leaves near the ground, but the flower stalk may reach six feet into the air. These plants took advantage of plentiful sunlight before the grasses started to grow. They’ve just reached the stage where they are beginning to produce the flower stalk.

I found this Monarch caterpillar feeding on a Green Milkweed, Asclepias viridiflora. This milkweed species is smaller and has much less leaf mass than the Common Milkweed. Some of the plants could easily have their leaves stripped by a hungry caterpillar. This particular plant didn’t show any signs of feeding activity other than this one leaf. It’s possible that the caterpillar moved to this plant after stripping the leaves from another nearby milkweed. Leaving one plant to find another can be a risky venture. I wonder if the caterpillars have some way of sensing the best direction to go in search of a new food source.