Today's Ramble was led by Dale Hoyt.
Here's
the link to Don's Facebook album for today's Ramble. (All the
photos in this post are compliments of Don.)
Today's post was written by Dale Hoyt.
24 Ramblers met today.
Today's reading:
Don read a poem, Dance of the Butterflies by his Facebook friend Kristina Plaas.
Dance of the Butterflies
There’s a place where the endless
ridges are blue
and hills are covered in green;
where orange and yellow, purple and white
paint the hillsides with color.
This is the place where the butterflies dance
among towering Turk’s cap lilies
and bobbing bracts of bee-balm.
Purple spots and green stars
entice skippers and swallowtails to feast
upon the bounty of the Blue Ridge.
I sit in wonder, watching fluttering wings
waltz from blossom to blossom,
undeterred by pesky bugs or distant claps of thunder.
Divine nectar-- granted a protected place
to feed earth’s tiniest creatures
and the starving souls of mankind.
and hills are covered in green;
where orange and yellow, purple and white
paint the hillsides with color.
This is the place where the butterflies dance
among towering Turk’s cap lilies
and bobbing bracts of bee-balm.
Purple spots and green stars
entice skippers and swallowtails to feast
upon the bounty of the Blue Ridge.
I sit in wonder, watching fluttering wings
waltz from blossom to blossom,
undeterred by pesky bugs or distant claps of thunder.
Divine nectar-- granted a protected place
to feed earth’s tiniest creatures
and the starving souls of mankind.
Show and Tell:
 | |
| Ginkgo "fruits" (Not yet ripe or they wouldn't be held like this.) |
1.
Carla brought a handful of Ginkgo “fruits” to
show us. Since Ginkgo is a gymnosperm, it doesn’t really have true fruits,
which are found only in angiosperms and derive from the fertilization process.
The fleshy layer surrounding the Ginkgo’s seed is an outgrowth of the stem that
grows around the developing seed called an aril; it is not the result of
fertilization (some Ramblers may be familiar with the fleshy red tissue
partially enclosing the seeds of Yew trees–that is also an aril). Once mature,
the Ginkgo aril is very smelly! Several folks recounted stories of encountering
ripe and rotting Ginkgo arils. The culprit is a compound named butyric acid,
found in putrefying butter and cheese. Somehow, a Chinese cook got past the disgusting
aril and discovered that the seeds are choice and edible: https://www.nutrition-and-you.com/ginkgo-nuts.html
2.
Martine and James shared their story of an
encounter with a green lacewing larva.
He was bitten or more correctly punctured by the larva after picking it
up. They have puncturing mouth parts for
injecting a liquefying substance into their aphid prey. The dried body of the
aphid is then tossed onto its back, disguising it so that it may pass unnoticed
by the ants tending the aphids. A true wolf in sheep’s clothing.
3.
It is James birthday today and also his four
year anniversary as a Nature Rambler (and Martine’s, as well).
Today's route:
We went through the Visitor Center and exited from the back door, then took the
first right into the Herb and Physic Garden. From there we walked past the
Pawpaws to the Heritage Garden and from the Heritage Garden we descended into
the Flower Garden and walked as far as the bed of Lantana, returning from there
to the Visitor Center
As soon as we entered the Herb and Physic Garden we saw a
Monarch butterfly flying rapidly about. It failed to land, so we never got an
unhurried look.
Herb and Physic
Garden.
Nectar Robbery:
Even though we had overcast skies the bumblebees and carpenter bees were very
active in the beds of salvia and mints.
The carpenter bees were nectar robbing.
As they visited each blossom they avoided the opening of the corolla, instead
heading toward the base of the flower. The nectar gland, or nectary, is inside
the flower, at the base of the corolla. If the blossom has been previously
visited by a nectar thief there will be a hole there and the carpenter bee will
insert its mouthparts and sip up the available nectar. If there is no hole the
bee makes one by biting the flower with its mandibles. Carpenter bees use those
mandibles to chew out a nest hole in wood, so they have no difficulty biting a
hole in a flimsy petal.
 | |
| Carpenter nectar robbing Salvia |
 |
| Bumblebee nectar robbing Salvia |
The smaller bumblebees were visiting the flowers in the “legitimate”
way, thrusting their head into the opening at the front of the blossom to reach
the nectar at the base.
By this action they come in contact with the anthers
and pick up a load of pollen on their head and thorax. They also contact the
stigma, the flower structure that receives pollen, and the pollen they carry
from visiting other flowers gets deposited on that stigma.
 |
| Smaller Bumblebee entering Salvia the "correct" way. It has to brush past the anthers that stick out of the flower on the way in. |
You might think that nectar robbery would harm the
ability of the robbed plant to produce fruits or seeds. Several studies have
shown that there is no difference between the productivity of robbed and
unrobbed plants. In some cases, there may even be benefits from being robbed.
How can robbery be beneficial? It has been suggested that
by depleting the nectar supply of a flower it stimulates subsequent visitors to
travel a greater distance before they visit another flower. This would increase
the frequency of outbreeding by reducing the likelihood of self-fertilization.
(Self-fertilization can occur when a bee carries
pollen to another flower on the same plant. It can result in offspring with
lower fitness.)
Mutualistic relationships, like that of plants and their pollinators,
can be sensitive to cheating. The only way each participant has of responding to
a cheater is through evolution or behavioral change. If nectar robbing were
really damaging to a plant then plants that could reduce it would be at an
advantage. They would produce more offspring than plants that experienced more
robbery and their offspring would be more resistant to it. You also have to remember
that a relationship is not isolated, it exists in a complex web of
relationships. There are many kinds of bees and flowers in an ecological community
and each of them interacts, directly or indirectly, with all the others. As long
as there are bumblebees around to pollinate a flower it may not matter that
carpenter bees steal nectar. But if the only pollinator present was the carpenter
bee, the long term presence of the plant would be in doubt.
This
discussion of nectar robbery in Wikipedia shows how complex such an
apparently simple behavior can be.
 |
| Purple Conflower infected with Aster Yellows phytoplasma |
 |
| Another Purple Coneflower infected with Aster Yellows phytoplasma (This plant was not in the Garden; photo by Dale Hoyt) |
Another bed in the Herb and Physic Garden has a number of
Purple Coneflower, one of which has a disease known as “Aster Yellows.” This disease causes dramatic changes in the
flowers, altering the form and color of flower parts (see the accompanying
photos). It is caused by a member of an unusual group of bacteria called “phytoplasmas.” They are similar to
mycoplasmas, bacteria that cause several diseases in humans and other animals,
but genetic analysis shows that they are only distantly related. (I mistakenly stated that Tuberculosis was caused by a mycoplasm; it is caused by a Mycobacterium.)
The Aster Yellows phytoplasma is transmitted to and by
leafhoppers, insects that suck sap from plants. The phytoplasma is imbibed
along with the sap and becomes resident in the salivary glands of the insect
host. When an infected leafhopper feeds on a new plant the disease is
transmitted. You can think of this as a case of plant malaria with the
leafhopper playing the role of the mosquito.
 | |
| A Zinna flower head with only two whorls of ray florets. The yellow disk florets in the center produce nectar and attract pollinators. The ray florests are sterile and produce no nectar. |
In other beds there are a number of different cultivars
of Zinnias. Zinnias are members of
the Aster family, Asteraceae, and have typical composite flower head made of
ray florets and disk florets. Plant breeders have been at work with Zinnia for
many years and they have succeeded in creating an enormous variety of forms
with different colors and, especially, different numbers of ray florets. The
original Zinnia looked very much like a daisy: a single ring of ray florets
surrounding a cluster of disk florets. (You should remember that the “petals”
of a daisy are the ray florets and the disk florets make up the central, yellow
part of the daisy flower. Also, remember that the ray florets are usually
sterile and serve to visually attract pollinators.)
One of the breeder’s goals was to make the Zinnia more
colorful. They did this by growing thousands of plants and looking for ones
that had more ray florets. These became the starting point for the large headed
zinnias we have today. But these additional ray florets came at the expense of
the disk florets. Florets that would normally have become disk florets instead
developed into sterile ray florets. The end result was the giant headed zinnia
with almost no disk florets. These flowers are never visited by bees or
butterflies. Why? Because they lack the nectar producing disk florets. If you
want to attract pollinators to your garden and want to use zinnias to do so,
then grow the older forms that still have disk florets.
 |
| An ornamental Nicotiana flower with long corolla tube. Only hummingbirds or hawkmoths could legitimately reach the nectar at the bottom of the flower. |
 | |
| A Nicotiana flower split open to show where the anthers and stigma are located. A hummingbird or hawkmoth bumps its face into the anthers and stigma when inserting its beak or tongue into the flower. |
Another bed in the Herb and Physic Garden is filled with
flowers that have a very long, tubular corolla. These are in the same genus, Nicotiana, as the tobacco plant. This Ornamental Nicotiana is pollinated by
agents that have long enough tongues or beaks to reach all the way down the
length of the corolla tube. Only two organisms, hummingbirds and hawk (or
sphinx) moths fit the bill here.
 | |
| Two Pawpaw fruits this year |
Pawpaws: Earlier
this year we passed by the pawpaw patch and noted a few fruits were developing.
Today we found them again just to see how much they had grown. Pawpaw flowers
are pollinated by flies. Some sources say these are fungus flies, but other
sources suggest that flesh flies do the job. Some who have pawpaw patches have
hung road kill from the trees in the hope that the attracted flies will
increase the number of flowers that are pollinated. You will remember that
pollination not only produces seeds but results in the fruit that holds those
seeds.
Pawpaws tend to produce many root suckers – that’s how
you get a pawpaw patch. The problem is that pawpaws are self-incompatible,
meaning that pollen from one tree cannot successfully produce fruit and seeds
on the same tree. Since the root sprouts in the patch are genetically identical
to the original tree they cannot produce fruit unless there is a source of
pollen from a genetically different tree nearby.
Pawpaw fruit is known as “custard apple” and is
delicious, with a flavor that defies description. It is too delicate to be
shipped, which is why you can’t find pawpaws in your supermarket. You can sometimes
find them at local farmer markets. There is a seller at the Athens Farmers
Market at Bishop Park who has a few for sale in September or October.
 |
| A male Eastern Tiger Swallowtail "mud puddling" in wet gravel in the Heritage Garden. The absence of blue scales on the black margin of the hind wing indicates it is a male. |
In the Heritage Garden we noticed a male Eastern Tiger Swallowtail butterfly
sitting on the gravel between the beds. Some of the Ramblers wanted to know how
I knew it was a male. There are three reasons:
1)
It was yellow with black stripes. In our area
most, but not all, female tiger swallowtails lack the yellow wing coloration.
2)
Female tiger swallowtails have a dusting of blue
scales on the edge of the upper surface of the hind wings. This butterfly
lacked those blue scales.
3)
Only male butterflies do what this one was
doing: sucking up the moisture from the recently watered gravel.
This behavior, no. 3, above, is called mud puddling. You can see a large group of tiger
swallowtails actively mud puddling in this video. Look carefully at the
butterflies in the video, keeping mind item 2, above. Do you see any females? At
the edges of mud puddles or other places where a lot of moisture is present butterflies
can find many nutrients dissolved in the water. By sucking up that fluid the
butterflies are getting not only water, but especially sodium and nitrogenous
compounds. Only male butterflies are known to mud puddle and this is why: During
mating the males transfer a package of material, called a spermatophore, to the
female. The spermatophore contains not only sperm, but nutrients, including the
sodium acquired by mud puddling. The more of these nutrients the male can
supply his mate with the more eggs she can lay.
In addition to the tiger swallowtail on the gravel, James
also spotted a tiny, newly metamorphosed American
Toad. The unusual thing about this toad was its color, it was brick red and
matched the color of the gravel it was found on. American toads vary in their
coloration, ranging from reddish through brown.
 | |
| A developing Birdhouse Gourd |
There are two kinds of gourds growing in the Heritage
Garden, a Birdhouse Gourd and
another type of decorative gourd. Gourds are members of the cucumber family,
Cucurbitaceae, along with melons, squash and pumpkins.
 |
| Female gourd flower; in the upper right background there is another female flower with a swollen ovary -- the beginning of gourd development. |
 |
| Male gourd flower |
 |
| Squash Lady Beetle on gourd leaf with feeding damage from the beetle. |
An interesting beetle was seen on the Birdhouse Gourd
leaves – a Squash Lady Beetle. This
insect in in the same family as the well known Ladybugs (more accurately called
“Lady Beetles.” Most gardeners know that Lady Beetles and their larvae eat
aphids and are, therefore, considered to be beneficial insects. This beetle
belongs to a subfamily of the Lady Beetles knows as “plant-eating lady
beetles.” You can see the kind of damage they do to the leaves of their host
plant, in this case the leaf of a birdhouse gourd.
 | |
| Cotton flower with Bordered Plant Bug The cluster of stamens surrounding the style is typical of the mallow family. |
 |
| Cotton flower showing the epicalyx bracts that are typical of mallow flowers. |
 |
| Developing cotton boll split open to show developing cotton fibers. |
Cotton: Also
in the Heritage Garden is a row of decorative Cotton plants, Red Foliated White Cotton. Cotton is in
the mallow family, Malvaceae, and the flowers have all the characteristics that
Linda showed us last week in the Hibiscus flower. Linda cut open a young flower bud and you can
see the cotton fibers developing among the seeds.
Where does the actual cotton come from? Some of the cells
of the outer layer of the developing seed begin to elongate. These fiber cells
eventually reach a length of about 1 to 2 ½ inches, depending on the kind of
cotton. Each fruit, called a boll, will contain around two dozen seeds. The
total number of cotton fibers per boll is an astonishing one half to three
quarters of a million fibers. You can do the division to determine how many
fibers are produced by each seed. Here is
a more technical description of how cotton fiber develops.
Everyone living in the South is aware of how the Boll
Weevil destroyed the cotton economy of the south. Given that background, It’s a
little surprising that the town of Enterprise, Alabama, erected a monument to
the Boll Weevil. The commemorative plaque reads:
“In profound
appreciation of the boll weevil and what it has done as the herald of
prosperity, this monument was erected by the citizens of Enterprise, Coffee
County, Alabama.”
The full story of how a southern town came to sing the
praises of a devastating pest can be read in this article in the Smithsonian
Magazine. It's
a great read and well worth your time.
 |
| Insect trap used to see if harmful insects are attracted to the cotton. |
At the end of the row of cotton is an insect trap, set up
to capture flying insects. Such traps are “baited” with synthetic pheromones,
the scents that many insects give off to attract mates. Insects attracted by
the pheromones fly up into the inverted funnel and out into the top of the
trap. There they can’t find their way out and remain until they die or the trap
is emptied. Such traps are used to determine the level of infestation in the
field as well as to identify the insects present. Control measures can be taken
based on the number of type of insects trapped.
 |
| Lantana flower head with a skipper getting nectar out of a yellow flower. The purple flowers are no longer producing nectar and are ignored by pollinators that have learned to associate yellow with the nectar. |
Flower Garden:
My main purpose in visiting the Flower Garden was to demonstrate the Lantana –
butterfly interaction. Lantana flowers are reliable nectar producers and very
popular with butterflies. Today the visitors were mostly Skippers, the Fiery
Skipper and what are jokingly called LBJs. (LBJ is an acronym borrowed from
birders; it means “Little Brown Jobs” and is a term applied to difficult-to-identify
sparrows and other brown colored birds. Botanists have a similar acronym: DYC –
Da**ed Yellow Composites).
The variety of Lantana planted here has flowers of two
different colors, yellow and purple. When the flowers open they are yellow and
when they have been pollinated they change color to purple. If you look
carefully at the flower head you’ll notice that the yellow flowers are close to
the center of the head while the purple ones are closer to the outer edge. This
is because the unopened flowers in the head mature from the outside inward, so
the older flowers have been exposed to pollinator visits longer.
A pollinated flower stops producing nectar, so the
yellow-purple color difference indicates which flower is worth visiting. But
you have to be smart enough to learn the difference. And butterflies and other
insects that visit the Lantana are up to the task. While we watched Skippers
visiting the flower heads each one would extend its proboscis into a yellow
colored flower. When finished it moved on to the next yellow flower, ignoring
the purple ones. After the last yellow flower was visited the skipper flew to
another flower head.
Martha Weiss, now at Georgetown University, showed that
butterflies could learn to identify the flowers with the nectar reward after
only two days of experience. She also surveyed the flowering plants and found
that color changing flowers were found in 77 different plant families, so it is
not an uncommon occurrence.
SUMMARY
OF OBSERVED SPECIES:
Sleepy
Orange Butterfly
|
Abaeis nicippe
|
Monarch
Butterfly
|
Danaus plexippus
|
Eastern
Carpenter Bee
|
Xylocopa virginica
|
Bumblebee
|
Bombus sp.
|
Salvias
|
Salvia sp.
|
Purple
Coneflower
|
Echinacea purpurea
|
Pawpaw
|
Asimina triloba
|
Birdhouse
Gourd
|
Lagenaria siceraria
|
Squash
|
Cucurbita sp.
|
Eastern
Tiger Swallowtail
|
Papilio
glaucus
|
American
Toad
|
Bufo (Anaxyrus)
americanus
|
Red
Foliated White Cotton
|
Gossypium hirsutum
|
Bordered
Plant Bug
|
Largus sp.
|
Zinnia
|
Zinnia sp.
|
Fiery
Skipper
|
Hylephila phyleus
|
LBJ
Skippers
|
Family
Hesperiidae
|
Cupid's
Shaving Brush
|
Emilia fosbergii
|
Ornamental
Nicotiana
|
Nicotiana sp.
|
Squash
Lady Beetle
|
Coccinellidae:
Epilachna sp.
|
Lantana
|
Lantana strigocamara
|
