Today's Ramble was lead by Dale Hoyt.
Except where stated otherwise, all the photos in this post were taken by
Rosemary Woodel. (Don Hunter is still indisposed. We miss you, Don! Please get
well soon.)
Today's post was written by Dale Hoyt.
Eighteen Ramblers met today, which started out overcast and cool for July. Good for us but not as good for butterflies!
Today's reading: Rosemary read a poem by John Moffitt from the collection: Teaching with Fire, edited by S. M. Intrator and M. Scribner.
To Look at Any Thing
To
look at any thing,
If you
would know that thing,
You
must look at it long:
To
look at this green and say,
"I
have seen spring in these
Woods,"
will not do - you must
Be the
thing you see:
You
must be the dark snakes of
Stems
and ferny plumes of leaves,
You
must enter in
To the
small silences between
The
leaves,
You
must take your time
And
touch the very peace
They
issue from.
Today's route: We went through the formal garden in search of butterflies, pausing whenever we encountered them. In the Heritage garden we stopped to look at the great variety of insects on the Sorghum. From there we walked a short way through the Flower garden and retraced our steps back to the Conservatory.
Red Admiral
butterfly: The injured tree near the Arbor was still exuding sap and
attracting a variety of insects, including hornets and three Red Admiral
butterflies. Red Admirals are easily recognized by the reddish-orange band on
the upper side of the fore wings and the margin of the hind wings. The
caterpillar feeds on nettles! It is not a rare butterfly here in the Athens
area, but it is not common, either.
Red Admiral; sipping fermented sap |
(Forgive the following personal anecdote; feel free to
skip to the next topic.) This butterfly has a special significance for me. When
I was in kindergarten I contracted rheumatic fever and was confined to bed for
six weeks. The doctor told my mother that under no circumstances was I to exert
myself or leave the bed, so she had to carry me to the bathroom even though she
was pregnant. (In addition to being pregnant my mother was very small woman,
only 4'11" and weighed 95 lbs. Today Rheumatic fever is easily treated by
a round of antibiotics, but at that time bed rest was the only treatment.
Penicillin had been produced was not available to the civilian population
during WWII.) My brother was born in early March and soon thereafter the doctor
decided that I could resume activity. But I discovered that I could no longer
walk – my muscles had atrophied during the month and a half I was bed-ridden and
I had forgotten how to maintain my balance – I could only crawl like a baby.
It was a beautiful March day and my father carried me
outside to join my mother and new baby brother. We were sitting on the steps
enjoying the sun and warmth of early spring when I noticed a butterfly on our
clothes line pole. Like us, it was basking in the warmth of the springtime sun.
I crawled over to the pole to get a closer look at it. It flew off, of course.
I had no idea what it was then, other than a butterfly, but three years later I
saw a picture of a dark butterfly with bright orange bands on its wings – the
caption read: Red Admiral. Every time I see one now I am reminded of the smell
of spring grass and the feeling of awe I felt on that day in March, 1944.
Ecological
consequences of "prettier" flowers.
Plant breeders have succeeded
in producing many "improved" varieties of cutting flowers, selecting
for larger and showier blooms. Take Zinnias as an example. The original form of
the zinnia was like a daisy: a disk of tiny florets surrounded by a flat plane
of ray florets. This was the quintessential composite "flower." The
breeders succeeded in creating plants with pom-pom shaped flower heads. This
transformation was achieved by converting disk florets into ray florets. The
most extremely modified varieties have no disk florets, just a beautiful
hemispherical cluster of ray florets. But a price is paid by this
transformation. In the composite family (Asteraceae or Compositae) the ray
florets with their single, strap-shaped petal (more properly called a ligule)
are usually sterile, lacking both stamens and pistil. Their function is to
attract pollinators, signaling the presence of nectar and pollen that is
produced by the disk florets. So when the outer whorl of disk florets is
converted to ray florets the total number of nectar and pollen yielding florets
is decreased at the expense of doubling the "petals." The more the
breeders selected for the pom-pom shaped flower the fewer fertile florets
remained. The result was a flower that looked beautiful to the human eye but
that gave no pollen or nectar bounty to the pollinators. A similar process
occurred with the non-composite flowers. Selection for doubling the number of
petals actually converts the stamens into petals. Those wonderful tea roses are
mostly sterile. The moral is simple: if you want to attract butterflies to your
garden you should plant the old fashioned varieties of flowers. By walking
through the Botanical Garden you can see for yourself what plants are most
attractive to the type of insects you want to attract.
Praying mantis.
Someone spotted a cast off exoskeleton of a Praying mantis and another
sharp-eyed observer found a newly molted Chinese mantis nearby. It's wings were
fully expanded, but the exoskeleton was still soft and unable to afford it
flight. (It takes a period of time for the exoskeleton to harden after each
molt. During that time the insect is almost defenseless and unable to fly until
it stiffens up.
American Dagger Moth caterpillar - best to not touch it |
Butterflies
Butterflies are flying pointillist art. The beautiful and
often intricate color patterns on the canvas of their wings is made of millions
of tiny, flat scales, each a single color. The scales are so small that a
square 1/25th of an inch on a side contains hundreds. To the human eye the
individual scale is like a mote of dust, but when massed together on the planar
surface of the wing they combine to produce the loveliest color patterns in the
living world, each scale a single color. Like human hair and fingernails,
butterfly scales are not living; each is secreted by a single cell that dies
when its work is done. The resulting scale is only weakly attached to the wing
surface and is easily detached. This property is useful in encounters with
spider webs – the scales stick to the silk but break away, allowing the
butterfly or moth to sometimes escape.
Are Butterflies
and Skippers different? Some lepidopterists treat Skippers a type of
butterfly (like cats are a type of carnivorous mammal). Other regard the
Skippers as a distinct subgroup of the Lepidoptera: Moths, Skippers and
Butterflies. The Skippers don't care.
How are Skippers
and Butterflies different? Most Skippers have stout, husky bodies, i.e., their
body is large in relation to the size of their wings. The butterflies have
comparatively large wings for the size of their body. Skipper flight is very
fast and seemingly erratic, from which the common name "skipper" is
derived. The antennae are clubbed, like a butterfly's , but has a hooked
projection beyond the club. (You need a hand lens to see this in most cases.)
There are several different subgroups of skippers but in
our area we have to deal with just two: the grass skippers and the spread-wing
skippers.
Grass skippers tend to be smaller and their caterpillars
feed on grasses. When they are visiting flowers their wings are usually held
together over their back, except when basking (more on basking below).
Spread-wing skippers, as their name implies, hold their
wings horizontally when they are resting or nectaring. But some of the
spread-wings, like the Silver-spotted skipper, just hold their wings in a
slight V-angle that may range from 90 to just a few degrees.
Fiery skipper; typical basking pose, hind wings almost horizonal; fore wings less open. |
Basking grass
skippers hold their wings in a characteristic pose: both wings are held
open, but the hind wings are held almost horizontally while the forewings are
only slightly opened. The body is oriented so that it is maximally exposed to
the sun. This enables the skipper to gain heat rapidly and keep its body
temperature high enough for rapid flight.
Fiery skipper |
Silver-spotted skipper; note husky body. |
There were two common Skippers nectaring in the Flower
garden today: Silver spotted skipper
(Epargyreus clarus), which is a
spread-wing skipper and a Fiery skipper
(Hylephila phyleus), a grass skipper.
The Silver spotted skipper is a large skipper with a prominent silver spot on
the underside of the hind wings and a large orange spot on the underside of the
front wings. The fiery skipper is yellowish-tan with a scattering of black dots
on the underside of both wings.
Ocola skipper (photo by Don Hunter) |
Long-tailed skipper |
We saw one individual each of the Ocola skipper (Panoquin ocola),
a Long-tailed skipper (Urbanus proteus) and a Duskywing skipper (Katherine said it
might be Horace's duskywing (Erynnis
horatius).
Eastern tiger swallowtail; male - note absence of blue color on the dark border of the hind wings |
The Eastern Tiger
swallowtail is the state butterfly of Georgia. This large yellow butterfly
with black stripes is common and very distinct. The swallowtail in the name
refers to the projections from the hind wings that are reminiscent of the tail
feathers of a swallow. At the base of tails there is a circular marking that,
together with the swallowtail makes this area of the wing resemble a head with
large eye and antennae. Predators may mistakenly attack this pseudo-head and
get a mouthful of wings while the butterfly escapes, a little more ragged but
still alive. At least that is the theory. In support is the frequent occurrence
of damage to this part of the hind wing suggesting that predatory attacks really
are misdirected.
Eastern tiger swallowtail; melanic female The tiger stripes are still faintly visible. |
There is another color form of the Eastern tiger
swallowtail, one that is uniformly dark in color. This results from the
presence of a dark pigment, melanin, the same substance that is produced in
human skin exposed to sunlight. The yellow areas of the wing are black,
obscuring the tiger stripes. (They can still be seen if the wings are back lit
by the sun.) The curious thing is that these melanic forms are only found in
females; the males are always the black and yellow form. In our area about 80%
of the females are melanic. It is thought that the melanic females are mimicking
a distasteful swallowtail, the Pipevine swallowtail, which, like the Monarch
butterfly, acquires a foul taste from its larval food. Support for this idea is
found in the proportion of melanic females: it is highest in the South where
the Pipevine swallowtail is common. In more northern areas, where the Pipevine
is rarer, the melanic tiger swallowtail is less common. And in Canada, where
the Pipevine swallowtail is not found, all the tiger swallowtails are yellow
with black stripes. So it appears that natural selection favors the melanic
form where its model is common. This is thought to be an example of what is
called Batesian mimicry. (A Batesian mimic is harmless and edible but resembles
a poisonous or distasteful species and thereby gains protection from
predators.)
The puzzle is why the melanic condition is restricted to the
females. Some have suggested that the yellow and black pattern is necessary for
mate recognition by females, but this idea has not been tested, so far as I
know.
You can distinguish tiger swallowtail sexes by the
presence or absence of blue scales on the dark border of the hind wing. If it
is densely blue then it is a female, otherwise it is a male.
Speaking of blue -- there was a single Azure butterfly nectaring on some of the flowers, probably a Summer Azure. The Azures are a bit unsettled at present. Some think that there may be at least five different species that differ in their food plants and flight times. Others think that is too many. But all would agree that the blue on the upper surface of the wings is like a piece of the sky.
Summer Azure butterfly |
The surprise for today was a Giant swallowtail, the largest butterfly in North America nectaring in the flower garden. The food plant for this species is citrus. If there are any planted in the garden they may have caterpillars. They also breed on a native plant species, Wafer Ash. I have only seen one of these in the garden, so we'll have to check it out also.
Sorghum ecosystem
Sorghum; looks like corn but no ears in the leaf axils; Flowers are at the top; that's where the seed appears; Corn has tassels (male flowers) on top. |
In the Heritage garden there is a row of Sorghum plants that are infested with
aphids. Right now the aphid population is relatively small, but aphid
populations can grow rapidly and in a few more weeks every plant will be
covered with them. But you won't find them on the upper surfaces of the leaves –
you'll have to lift the leaves to see them. The aphids are sucking the sweet
Sorghum sap and they excrete what they don't use as a tiny droplet of what is
euphemistically called "honeydew." This sweet fluid accumulates on
the leaves below the aphid colonies and attracts many kinds of bees and wasps,
who scurry across the leaves searching for the sweet residue.
Small aphid colony on underside of Sorghum leaf |
Ladybug larva; these beetle larvae are voracious eaters of aphids |
Asian multicolored lady bugs mating; like their larvae, these beetles also eat aphids. |
The attendees at these sugar parties are flies, wasps and
bees. Today the party was dominated by two categories of wasps: social wasps and solitary wasps. The social wasps you're probably familiar with – yellowjackets,
paper wasps, and hornets. They live in nests made of paper and form large colonies
in which only one individual lays eggs, while the others perform
non-reproductive tasks: foraging, nest construction and cleaning, larval
feeding and colony defense.
Social wasps
Polistes carolina; a paper wasp |
Another paper wasp |
Another paper wasp, possibly Polistes fuscatus |
Solitary wasps were by far the most abundant wasps today
and we were able to recognize many distinct kinds, even though we couldn't
identify them.
A solitary wasp |
Another solitary wasp; pretty orange legs |
Yet another solitary wasp |
Male honey bee (Drone); big eyes - the better to find a mate with. (photo by Angeli Menon) |
I think this one is a Mud dauber (photo by Angeli Menon) |
Two more wasps (photo by Angeli Menon) |
Solitary wasp and lady beetle (lady bug) (photo by Angeli Menon) |
Looks like a Yellowjacket, but I don't think it is. (photo by Angeli Menon) |
As the name implies, this type of wasp does not live in
colonies. Each female constructs her own nest, typically a burrow in the soil
or an excavation in a twig. She then searches for food for her offspring and
each kind of wasp seeks a specific type of prey: crickets, spiders,
grasshoppers, caterpillars, etc. Many have very narrow tastes. For example, one
wasp preys only on the queen ants of one species.
When the prey is found it is
paralyzed, not killed, by the sting and then carried back to the nest where the
female lays a single egg on it and closes the nest. The female wasp then
repeats this process until it dies.
When the egg hatches the wasp larva feeds in darkness on
the still living body of its host until it reaches the size to pupate. The
pupal stage may last until the following year or there may be two or more
generations in a single year. When the adult emerges from the pupa it digs its
way out and starts the next generation.
That's it for today's post!