Today's
report was written by Dale Hoyt. The photos that appear in this blog are taken
by Don Hunter; you can see all the photos Don took of today's
Ramble here.
NOTE: This blog will go on hiatus for the
next three rambles. Don will send out links to his facebook album for each
ramble to everyone on our email list, so you'll still be able to enjoy the
photographic record of each ramble.
Sometime in
late July Silvio will be departing for graduate study at UCLA. Let's all bid
him good luck and farewell!
Nineteen
ramblers appeared today.
Today's reading:
Today's route:
Through the Shade garden and Dunson Native Flora garden to the White trail;
across the road to the power line RoW; up the hill to the dogwood, then back
down the hill to the river. Left on the Orange trail to the Orange trail spur
which we took back to the parking lot.
Dunson Native Flora
Garden: We passed the Black cohosh
that has been blooming for several weeks and discovered that there are no
flowers left on the inflorescence. Another plant, visible in the distance,
still had a few flowers left at the very top of the flowering stalk.
At the edge of the Dunson garden there was a Wild petunia in bloom, one of several
we would see later on today's ramble. The Beauty
berry just inside the new fencing was covered with flowers. Each cluster of
blooms will produce a cluster of shining purple berries this fall.
White Trail to power
line: I like to walk this segment of the White trail frequently just to
check on the fruits that are developing on two trees: American Beech and Hophornbeam.
We last were here three weeks ago and the Beech fruits were large and swollen.
Today most of them have split open but the two nuts inside each fruit are still
green and tightly held. The Hophornbeam fruit clusters appear to be about one
third larger than three weeks ago. Each papery sack that makes up the cluster
has a very small seed inside. Ted
wanted to know how these were dispersed. Wind
has a limited effect as the sacks can only be carried a short distance by heavy
gusts. But for trees growing near streams and rivers the sacks are buoyant,
allowing the seeds to be carried downstream. But there must be another way that
they disperse because the Hophornbeam is the most common understory tree in the
garden's natural areas. It is found almost everywhere, from streamside to dry
ridges. There is one in my backyard and small saplings appear everywhere, even
at considerable distances from their possible parent. Something moves the seeds
around, but I don't know what it is.
 | |
| Beech fruit with two nuts |
 | |
| Hophornbeam fruits |
There are other trees in this area of the White trail that
are young and small enough that we can easily see their leaves to identify
them. One is a Green ash sapling
that has opposite, compound leaves, which is an uncommon combination. Only the
Box elder could be confused with it and Box elder usually has only three
leaflets (Green ash has 5-7). Near the
Ash is a Hawthorn with splotchy leaves caused by a rust fungus. There is
also a small Yaupon holly, with tiny, rounded leaves that don't even resemble
the spiny leaves of the American holly or the Oriental hollies. Don spotted a Winged elm with unusual galls on
several of the leaves – they were produced all along the mid-vein of the leaf.
Nearby is a small post oak with its
characteristic Maltese cross shaped leaves.
 | |
| Galls on Winged elm leaf |
 |
| Praying Mantis |
 | |
| Wood boring beetle |
There was a dual surprise – a katydid sitting out in the open. Katydids resemble green
leaves and are
usually very difficult to find because they are so well camouflaged. But this
one was very conspicuous and I had no trouble popping her into a plastic box to
pass around. But as soon she was in the box we saw the reason why she was so
easy to capture – a large maggot was crawling about the box, having emerged
from a hole in the side of the katydids abdomen. There is a whole family of
flies, Tachinidae, that parasitize other insects. They lay an egg or eggs on an
unsuspecting host. The egg hatches into a small maggot that burrows into the
body of the host where it begins to feed on the host's tissues. When it reaches
the appropriate size it eats its way out of its host body and falls to the
ground where it pupates. Do you remember the movie Alien?
Some wanted to know how I could tell that the katydid was a
female. At the end of her
abdomen there is a large, sickle-shaped structure.
This is an egg-laying apparatus, an ovipositor.
Only females have them. Katydids lay eggs in the stems or twigs of plants by
using the ovipositor to cut a slit. The egg emerges from the end of the ovipositor
into the slit. It develops, protected by being tucked away inside the stem,
until it hatches into a miniature version of its parent, minus the wings. This immature stage
is called a nymph. The nymph feeds on leaves and molts (sheds its skin) five
times, growing larger with each molt. The tiny wing pads grow with each molt
until they reach adult size after the last molt. This kind of development is called incomplete metamorphosis and is typical of insects like crickets, grasshoppers, katydids and praying mantis.
 | |
| Female Katydid |
By the way, the katydids are the insects you can hear at
night calling from your trees. They make that rasping "zit-zit-zit"
noise. Only the males call; the females are silent.
 | |
| Agreeable tiger moth |
The last insect find in this area was a small bagworm caterpillar. We didn't actually
see the
caterpillar – it was inside the silken bag it had made and decorated
with pieces of the plant it was eating. Bagworms are more commonly found on
evergreens, but they do feed on deciduous trees as well. The "bag" is a
protective home that the caterpillar carries with it, enlarging it as it grows.
It even pupates inside the bag. In fact, the female moth never leaves the bag.
She has no wings and is barely more than a sack of eggs. Male bagworm moths do
have wings and they fly around looking for "bag ladies." When they
find one they mate with her while she remains inside the bag. After she mates and
her eggs are fertilized she dies, never having left her bag – the ultimate
homebody. The eggs hatch and the tiny caterpillars crawl out of their mother's
body and climb about on the surface of the bag. They produce a thread of silk and
they are so tiny that the wind can pick up the silken thread with its attached
caterpillar and carry it off to a new food plant.
 | |
| Bagworm |
There is a Bottlebrush buckeye growing on this section of
the White trail. If you read last week's blog post you'll remember that Hugh
and I were unsuccessful in finding complete flowers (those with both male and
female parts) on the plant in the International garden. We looked on this plant
and failed to find any flower with both stamens and pistil.
Upper Power line
(above road): The contrast with a few weeks ago was dramatic. Then,
the Daisy fleabane was abundant in the
grassy area and at the sides of the path. Today there is scarcely any of the
fleabane still in bloom. Carolina Desert
Chickory is about the same – a few solitary flowers scattered about here
and there. The new arrival is the Mountain
mint; it's upper leaves are beginning to take on a frosted white appearance
just below where the flowers will be. But the most abundant and prominent plant
now blooming is Wild bergamot – it is
all over the grassy areas and well attended by bees and butterflies (another
common name for this plant is Bee Balm). The bergamot can be found in a variety
of colors, white, pink and red. Bob thought he could detect a difference in the
odor of some of the different colored plants.
 | |
| Mountain mint |
 | |
| Wild bergamot |
Some of the other flowers that are currently blooming in
this area
are: Sensitive brier(on
its last legs), Heal-all (just
starting), Rabbit tobacco (just
starting), Queen Anne's lace (only a
few left) and Trumpet vine (one open
flower, but several buds; an old seed pod).
 | |
| Sensitive brier |
In the middle of the path we discovered a large bird
feather, clearly one primary flight feathers. (You can identify primaries by
their asymmetry: the barbs on one side of the shaft are longer than those on
the other side. Birds molt their feathers periodically, but not all at once. If
they were to do so they wouldn't be able to fly. The only clue we had to
identify the bird was the size and color: the tip was black and toward the base
the color was white. The most likely candidate is the Pileated woodpecker, our largest woodpecker. Ronnie found a stick
and was able to create a banner of sorts by sticking the feather in the end.
 | |
| Pileated woodpecker feather |
One of the butterflies seen nectaring on the bergamot was a
dark-colored female Eastern Tiger
Swallowtail. Many people recognize the yellow with black striped form of
the tiger swallowtail, but the dark form is usually thought to be something
else. If you have a specimen in hand you can see the dark stripes, just as they
are in the yellow and black form, but the area between the stripes is dark
instead of yellow. This is caused by the presence of melanin, the same
substance that is produced in our skin when we tan. This extra melanin is found
only in female tiger swallowtails; the gene that controls its production is
only active in the female sex. Not all female tiger swallowtails are melanic,
some have the same color pattern as the males, but the proportion varies from
one part of the country to another. Here in the south melanic females are most
common, but as you go north, they become less so. In Canada and the northern
states the melanic form is very rare. The reason for this turns out to involve
another species of swallowtail butterfly, the Pipevine swallowtail. The
caterpillars of pipevine swallowtails feed on Pipevines (genus Aristolochia)
that contain many toxic substances. This makes the adult pipevine butterfly distasteful
or poisonous. Pipevine swallowtails are very dark colored with blue coloration
on the upper side of the hind wings. The melanic female tiger swallowtail is also very
dark and has blue coloration on the upper surface of its hind wings – it is a mimic
of the pipevine swallowtail.
Catherine found the cast off exoskeleton of a grasshopper
nymph. We looked at it with the hand lens and were amazed at all the bristles
and bumps on the molt and even more amazed at the thought of how this small
insect was able to pull its legs out of their old skin and still leave it
intact.
Power line (road to
river): About this time of year the cicadas
begin to emerge and start their droning choruses in the trees. I have tinnitus,
so I carry my own private cicada chorus with me year round. That makes it hard
for me to tell if I'm hearing something outside my own head, but, if it's loud
enough, I can tell the difference. Yes, cicadas are beginning to sing right now
in Georgia. These are annual cicadas – appearing every year – not the 17 year
or 13 year cicadas that only appear after long intervals (17 or 13 years, duh).
But calling them "annual" hides the fact that they spend as much as 5
years underground, sipping juices from the roots of trees and other plants.
A common misnomer for cicada is "locust." (This
may be more prevalent in the Midwestern states than it is here.) The locust of
the Bible is a kind of grasshopper in the order Orthoptera. (Cicadas belong to a
completely unrelated insect order: Hemiptera, the bugs, cicadas, aphids, etc.)
The confusion arose because early European settlers first experienced the
massive emergence of 17 year cicadas and could only relate it to the plagues of
locusts written about in the Bible. It may also have been enhanced by the sound
of one of the cicada species: "Pharaoh," continuously repeated.
More bergamot is growing here and Don was able to get photos
of the yellow and black
form of the Eastern Tiger Swallowtail as it sipped
nectar. I waded out into the grass and confirmed that this was a male and
picked up a tick as my reward. To sex the tiger swallowtail you need to look at
the upper surface of the hind wings. If the rear border has a prominent amount
of blue you are looking at a female. Males have very little or no blue
coloration on the rear border of the hind wings.
 | |
| Tiger swallowtail nectaring on bergamot |
 | |
| Anglepod flowers |
 | |
| Spinypod flowers |
We had been seeing grasshoppers jumping all over and someone
finally caught one, a Carolina grasshopper, I think. I spread open its fan-like
hind wing to reveal its black and yellow bands, visible only when the
grasshopper jumps and flies to a distant location.
In the flood plain the vegetation is growing taller by the
day. The most obvious and abundant plants are the wingstems, the ironweed and
the goldenrod, although none is flowering yet. And, of course, there is lots of
pokeweed just starting to set fruit.
We found two types of galls on the goldenrods: an apical
leaf rosette gall and a spherical
stem gall. Each of these galls is caused by a
different fly. The apical leaf rosette
gall is produced by a fly laying an egg in the growing tip of the goldenrod
(the apex, where the apical meristem is located). This halts the vertical
growth of the stem, but not the production of leaves. Because the stem does not
elongate between leaves the leaves all cluster together into a tight bundle.
When the egg hatches the maggot feeds on the tissue of the gall.
 | |
| Apical rosette gall |
The spherical stem
gall is likewise produced by an fly egg,
but it is inserted into stem of
the plant, below the apex. This causes the stem to swell into a hard sphere
with the egg inside. When it hatches the larva, a maggot, feeds on the leaf
tissue. If the gall is not too close to the apical meristem the plant will
continue to grow vertically. This fly pupates within the gall, raising the
question of how it gets out of the gall. Adult flies don't have chewing
mouthparts. But the maggot can chew and just before it gets ready to pupate it
chews an exit tunnel up to the surface of the gall, leaving a thin layer of
plant epidermis covering the end of the tunnel. It then crawls back inside to
pupate. When the adult fly emerges it climbs up the tunnel and then breaks it
open using a balloon on its head that is expanded by hydraulic pressure using
its body fluid. As soon as the tunnel cover pops open the fly emerges, allows
the balloon to collapse and harden, and then flies off to seek fresh goldenrod.
 | |
| Spherical stem gall |
One of the small flowers seen bordering the path caused a
lot of people to wonder what the plant with a flower that looks like a bluet is. The flower they
were looking at is Virginia buttonweed,
a member of the Rubiaceae family, as are the more familiar bluets. Both have
tiny, four-lobed flowers, so the similarity indicates an actual relationship.
Another shed exoskeleton was discovered, this time from a praying mantis.
Orange trail: In
the Orange trail lots of plants released by the removal of the privet, esp.
wingstems and another large stemmed we think might be Fireweed. On vegetation by the
river we encountered another unusual insect
– a net-winged beetle (family Lycidae). Most beetles have hard, tough forewings
that protect the delicate, membranous hind wings. In this beetle the front pair
of wings are thin and flexible with a fine network of veins, hence the name:
net—winged beetle. These beetles are distasteful and advertise it by their
coloration and raising their colorful forewings to advertise their
unpalatability. [Note: beetles are so diverse and abundant that identifying
them to species takes an expert. An amateur should be satisfied with a
Family-level identification, except for some of the very common and most
widespread species.]
 | |
| Net-winged beetle |
 | |
| Eggs on River oats |
Tom got a surprise when a large, dangerous looking insect
flew up onto his shirt. Some people thought it was a Dobson fly but it turned
out to be something different and harmless, but similar: a Stonefly. Stoneflies belong to the order Plecoptera. Dobson flies, the
females of which look a little like stoneflies, are variously considered to be in
the order Megaloptera or a family in the order Neuroptera. Both have predatory aquatic
larvae.
 | |
| Stonefly |
Further along the Orange trail we found Bur cucumber clambering over piles of chopped down privet, a few Leafy elephants foot,Dwarf St. John's wort and a tall,
coarse, thick stemmed plant that appears to be Fireweed (we'll have to wait for it to bloom to be certain).
And so after a ramble that stretched out to a full two hours
we took the Orange spur trail back to the parking lot and Donderos' for
beverages and conversation. We've got to stop finding so many things to look
at. Not.
SUMMARY OF OBSERVED SPECIES:
Common Name
|
Scientific Name
|
Black cohosh
|
Actaea racemosa
|
Wild petunia
|
Ruellia humilis
|
America beautyberry
|
Callicarpa americana
|
American beech
|
Fagus grandifolia
|
Green ash
|
Fraxinus pennsylvanica
|
Praying mantis
|
Order Mantodea
|
Hawthorne
|
Crataegus sp.
|
Post oak
|
Quercus stellata
|
Wood boring beetle
|
Family Cerambycidae
|
Winged elm
|
Ulmus alata
|
Hophornbeam
|
Ostrya virginiana
|
Katydid
|
Family Tettigoniidae
|
Agreeable Tiger moth
|
Spilosoma congrua
|
Prairie fleabane
|
Erigeron strigosus
|
Bagworm moth caterpillar
|
Family Psychidae
|
Carolina horse nettle
|
Solanum carolinense
|
Carolina desert chicory
|
Pyrrhopappus carolinianus
|
Pileated woodpecker
|
Hylatomus pileatus
|
Mountain mint
|
Pycnanthemum incanum
|
Sensitive briar
|
Mimosa microphylla
|
Bee balm/Wild bergamot
|
Monarda fistulosa
|
Heal-all
|
Prunella vulgaris
|
Rabbit tobacco
|
Pseudognaphalium obtusifolium
|
Queen Anne’s lace
|
Daucus carota
|
Bottlebrush buckeye
|
Aesculus parviflorum
|
Tiger swallowtail
|
Papilio glaucus
|
Trumpet vine
|
Campsis radicans
|
Poison ivy
|
Toxicodendron radicans
|
Ox-eye daisy
|
Leucanthemum vulgare
|
Spinypod
|
Matelea carolinensis
|
Anglepod
|
Gonolobus suberosus
|
Pokeweed
|
Phytolacca americana
|
Carolina grasshopper
|
Dissosteira carolina
|
Common whitetail dragonfly
|
Plathemis lydia
|
Virginia buttonweed
|
Diodia virginiana
|
Bluebird eggs
|
Sialia sialis
|
White avens
|
Geum canadense
|
Japanese beetle
|
Popillia japonica
|
Stonefly
|
Order Plecoptera
|
Common yellow wood sorrel
|
Oxalis stricta
|
River oats
|
Chasmanthium latifolium
|
Pennsylvania smartweed
|
Polygonum penslyvanicum
|
Bur cucumber
|
Sicyos angulatus
|
American burnweed/Fireweed
|
Erechtites hieracifolia
|
Leafy elephants foot
|
Elephantopus carolinianus
|
Dwarf St. Johns wort
|
Hypericum mutilum
|
