Saturday, June 9, 2018

Ramble Report June 7 2018


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.
28 Ramblers met today.
We were happy to welcome Don back. He’s looking slim and healthy and is ready to go!
Today's reading: Dale read part of the May 31 entry from An Almanac for Moderns, by Donald Culross Peattie.
Each evening, when the young crickets are tuning up and the thirsty grass is longing for the dew, I walk out to watch the little linkmen of the field and garden come out and dance a soundless farandole just above the earth. When the firefly's wings are closed for an instant he appears to glide in darkness, this Puck of the air, but let him turn his back and lift his wings and his tiny greenish lamp is lit.

Does he light his own way? Does he affright his foes, or spy his enemies with his lantern? Or does he signal to the women-folk of his kind? This last is the general impression which has been held-that the light enables the sexes to find each other. This were a device so handy and pleasant that it is a pity that all nocturnal animals should not possess it.

Fruits of Green Ash
Show & Tell: Linda continued the theme of “twigs with fruits” by showing us a terminal branch of Green Ash replete with “seeds.” Technically, these are fruits, not seeds. This type of fruit is called a samara and it is similar to the fruit of maple trees. Samaras are a fruit type that is dry, winged, and doesn’t open. Just as with maple fruits, ash samaras are adapted for wind dispersal, helicoptering their way some distance from the parent plant.

Today's route: From the Visitor Center we walked down the road and turned right on the White Trail, walking to the power line right-of-way, and then turned right again and went a short distance up the hill. We retraced our steps on return.

Today’s ramble was a perfect illustration of our motto: “Seeking What We Find.” Plants are rooted in place and you can depend on them to be there the next day, unless some disaster has struck. But animals are a different story. With a knowledge of their natural history you can increase the probability of finding one. You can learn in what habitat they are likely to be found, when in the course of a year they are likely to be active, but those are no guarantees that you’ll encounter them. Most of our animalsdiscoveries today were serendipitous; we happened to be in the right place at the right time.

Cool animals and their stories:

Caterpillar of the Tiger Swallowtail butterfly
Tom noticed a large Tiger Swallowtail caterpillar sitting on a dead leaf on the ground next to the path. This is not a typical place to find such caterpillars. They usually rest on the upper surface of the leaves of their food plant, which, in our area, is most likely to be Black Cherry or Tuliptree. In their resting position the head is tucked down and not very conspicuous. The most noticeable feature is a pair of eyespots (not real eyes) located on the third thoracic segment. Some people think that this gives them the appearance of a snake’s head and might frighten off bird predators. Another odd thing about this species: the early caterpillar stages look completely different, with no suggestion of green or eyespots. The caterpillars of most butterflies molt (shed their skins) five times before forming a chrysalis, which is the pupal stage of a butterfly. In the case of the Tiger Swallowtail, and several other swallowtails, the first three stages of the caterpillar are brown with a whitish saddle near the head end. When they curl up on a leaf they look just like a bird dropping. But after the third molt they turn all green and have the phony eyespots. The individual Tom found was in either the last or next to last stage of development before making a chrysalis.


Lightning Bug or Firefly
It's really a beetle
 

The light organ at the end of the abdomen
This is the time of year when Fireflies or Lightning bugs can be seen in your back yards if you haven’t doused it with harmful chemicals. During the day they hang out on vegetation and will fly only if disturbed. We caught one today and enjoyed playing catch with it as it flew from one person’s hand to another’s, landing on it and flying off again.
Lightning bugs are neither flies nor true bugs, they are beetles with dark, leathery forewings and membranous hind wings. When they fly the forewings are held up and out of the way and the hind wings do all the work. To find out what a “true bug” is visit this post.
Why do they produce light? As today’s reading suggests, the light is a signal emitted by males when seeking out receptive females. Each kind of firefly has its own, species-specific, flash pattern. The most common species in a suburban backyard, Photinus pyralis, sometimes called the “Big Dipper,” emits a yellowish light in a single long pulse as the male flies in a J-shaped pattern. First he descends a little bit, turning the light on, and then, keeping his light on, he swoops upward, completing the vertical part of the “J.” He is looking for a lady firefly hiding in the shrubbery. She will answer his flash with a flash of her own, but she must do it within a few fractions of a second after he finishes showing off. She also answers with a species-specific flash pattern. If her timing is off he doesn’t recognize that she is an appropriate mate. If she does answer within the correct time frame he flies to her location and they mate.
But that’s not the end of the story. There is another kind of firefly in the genus Photuris that can imitate the female response of several different Photinus species. The female Photuris lures a Photinus male in, having deceived him by mimicking the flash of the female of his species. When he lands he approaches her and, instead of mating, she eats him. Not only does she acquire food to assist her in egg production, she also gets distasteful compounds that make her distasteful to potential predators.
How is the light produced? The light organ occupies the last few segments of the firefly abdomen. This article discusses some of the chemistry of light production and how it is controlled in fireflies.
Are there other bioluminescent organisms? The ability to produce light is widely distributed across the tree of life. Light production can be found in organisms ranging from bacteria, protozoa, deep sea fish, insects, crustaceans and fungi. The chemistry behind this ability seems to depend on the same or similar mechanisms, at least in those organisms that have been studied. Some deep sea fish use it in specialized “lures” that attract prey in the otherwise pitch black depths of the ocean. Some squid have specialized organs that house bioluminescent bacteria. The light they emit is thought to make the squid less visible to predators swimming beneath them by matching the overall glow of the sky above. Without the light the squid would be silhouetted against the sky and easily noticed by lurking fish.
More mysterious is the emission of light by single celled animals in the ocean. They respond to disturbance of the water by producing light. When their density is high they mark the passage of boats with a phosphorescent wake that extends 50 or more feet behind the boat. While traveling by motorboat to an offshore island in El Salvador I once amused myself by dipping my hand in the water, creating a mini-wake of delicately silver blue from each finger. The light was probably caused by a Dinoflagellate, Noctiluca scintillans, that sometimes reaches astounding numbers in tropical waters.
In some species of firefly flashing becomes synchronized and the display of thousands of fireflies simultaneously blinking on and off is truly awesome. One place to see this is the Elkmont campground area in the Great Smoky Mountains National Park. The event attracts thousands of people and is tightly regulated, but it is truly a once in a lifetime experience. (Jeff told us that he had once seen synchronous flashing in Oglethorpe County.) The phenomenon appears to depend on the density of the fireflies and the configuration of the physical environment, because the same species, Photinus carolina, that flashes synchronously in the Elmont campground doesn’t do so in other places in the Park or elsewhere.

Egg mass of Eastern Tent Caterpillar moth
Someone found the egg mass of an Eastern Tent Caterpillar moth. It looks like a piece of tar wrapped around a Black Cherry twig. This weatherproof container holds perhaps 150+ eggs that will not hatch until next spring, just as the leaves of the host plant, Black Cherry, emerge from their buds. The caterpillars are social, building a communal nest by weaving silk threads around the crotch of the cherry tree. From that home base the caterpillars travel in a group to the ends of branches that have tender new leaves. There they feed on the leaves and travel back to the nest to digest their meal. As the caterpillars grow they molt and add more silken layers to the nest. After molting 5 times they abandon their nest and wander off looking for a place to pupate (build a cocoon). The adults emerge several weeks later, mate, and the female lays her eggs in a single mass, coated with the shiny black weatherproofing substance. The egg mass endures the remainder of the summer with its heat and thunderstorms, fall and winter with their freezes, snow and ice and then they hatch and emerge in the spring of the following year.

Hatched eggs and nymphs of a bug, possibly a Stink Bug
Katherine discovered another kind of insect egg mass, a group of eggs deposited together on a blade of grass. They were in the process of hatching, with many eggs already emptied. Katherine thinks these may be the eggs of a Stink Bug (a true bug, by the way). True bugs are unlike insects like butterflies and moths that undergo complete metamorphosis. Those insects have four very different looking stages in their life history: egg, larva, pupa and adult. On the other hand, true bugs hatch from the eggs looking like tiny versions of the adult form. They just lack wings, but they otherwise act like their parents, feeding as they do and on the things their parents would eat. With each molt they grow larger and their future wings begin to develop. At the last molt they have reached their adult stage and they can reproduce. This post further explains what a “true bug” is.

Japanese Beetle
James and Nathan went exploring and in tangle of blackberries they discovered a number of Japanese Beetles. These beetles have a bad reputation and, when they are very abundant, they can severely damage shrubbery and other plants like roses. They also lay eggs in the soil, which hatch into grubs that feed on the roots of grasses. When numerous they can produce large bare patches in a lawn. This insect doesn’t appear to be as much of a problem in this part of the South as it does up north, but that is just my subjective experience.

Magnolia Green Jumping Spider
We found an unusual Jumping Spider on the leaf of a Chinese Pistache tree. It’s green in color and doesn’t jump as well as other Jumping Spiders. I carelessly identified as a Lynx Spider, which is also green, but had I looked carefully, I would have realized it was a Magnolia Green Jumping Spider, AKS Magnolia Green Jumper. Jumping spiders do not build a web to capture their prey. Instead they hunt using their extraordinary binocular vision. Spiders have multiple eyes arranged on their head, some as many as eight. In only a few of these are the eyes capable of forming images and the Jumpers are excellent at seeing. If you keep one in a jar you’ll soon fall in love with it. It will turn and look at you when you walk into the room.
Like all spiders, they rely on silk, just not to trap their prey. When they walk about the continuously let out a drag line of silk. If they see a small insect they stalk it until they come within striking distance. Then they leap. Sometimes they miss and then is when the drag line is useful. They fall until the silken line stops them and they crawl back up it to resume hunting. The other way they make use of silk is to weave a small blanket, beneath which they shed their exoskeleton when molting. They also construct a sturdy bag into which they lay their eggs. The egg sac is firmly attached to an object like a folded leaf.

Multicolored Asian Lady Beetle
Asian multicolored lady beetle variation ©entomart Wikimedia commons
Another mis-named insect, a Ladybug, properly known as the Asian Multicolored Lady Beetle (AMLB), was found. This beetle is so variable in color and pattern that it is difficult to identify. The best feature is to look for a black “M” or “W” outlined in white on the front end. As you can see in the composite photo above, this doesn't always work.
Our native Ladybugs have been declining in abundance for a number of years and there is evidence that the AMLB might be responsible. Ladybugs are voracious eaters of aphids and, whey they discover a colony, they lay a lot of eggs. Their larvae also eat aphids. But our ladybugs have a cannibalistic habit; they often eat any eggs they come across. The AMLB also eats eggs, but it coats its own eggs with a toxin that kills or seriously sickens our native ladybugs when eaten. 
The AMLB was introduced the the US to control scale insects in citrus groves. It was very successful in that task, but we're now experiencing the unintended consequences of that introduction.

Today some of the ramblers were discussing the importance of Mycorrhizal Fungi in connecting the trees in a forest. This interview with Susan Simard, one of the pioneers in the development of the “Wood Wide Web” concept, is well worth reading if you are interested in the subject.

Hophorbeam leaf showing the biserrate margin.
(The larger teeth have smaller teeth)
American Hophornbeam is the commonest understory tree in the natural areas of the garden. The trunk of older trees has "cat scratch" bark and the leaf edge is saw-toothed. The larger teeth also bear tinier teeth, making it biserrate.


Winged Elm, showing the "wings" on the branches.

Winged Elm leaf showing the weakly biserrate leaf edge. It takes a sharp eye to see the smaller serrations.
Winged Elm leaves are elliptical, shaped like an eye or an almond. They are biserrate, but the larger teeth are coarser than those of the Hophornbeam. It gets its name from the corky ridges that are seen on the branches, but sometimes you have to hunt to find them.

American Beech leaves with their wavy edges.
American Beech leaves have a papery texture and a curved or wavy edge. Each "wave" has a small bristle. You can remember the tree because you find waves at the beech. The tree has smooth, gray bark, often carved with the initials of young men declaring their love for someone.

Young Water Oak leaves are elongate and only slightly wider at the tip.

A somewhat older Water Oak with distinctly lobed leaves.
Water Oak is a popular oak to plant in suburban yards. It is fast growing, for an oak. It's easily recognized by its spatula shaped leaves. But young saplings have quite different looking leaves.


Black Cherry; its fruits are black, not red.
Black Cherry is an early flowering fruit tree. James didn't hesitate to sample one of the ripe fruits. His conclusion: "It's a little bitter."

Wild Onion with sprouting bulblets
Wild Onion reproduces two ways: it flowers, producing seeds, and it also produces bulblets that sprout before falling off.

The young, developing leaves fo Redbud are pigmented red to prevent damage from sunlight.
Eastern Redbud is a prolific seeder and the shoulders of the path are covered with young plants. The youngest leaves are red but soon lose that pigment. The red color is produced by a chemical called "anthocyanin." It is thought to act as a sunscreen, protecting the developing leaves from "sunburn." Many plants show this red pigmentation on their youngest leaves. It can be seen in new oak leaves.
Queen Anne's Lace

Woodland Coreopsis
The Woodland Coreopsis flower nicely illustrates the pattern of development in composite flowers discussed in last week's post. The outermost whorl of florets are the ray florets and are sterile. The oldest florets in the disk are found on the outermost whorl and these are blooming, while the innermost florets are still in bud. The dark structures in the photo are the anthers that produce pollen. They appear before the pistil matures, a condition called protandry (male first). In some plants the female structures appear first: protogeny.

Yellow Star Grass
It has grass-like leaves, but it's not a grass.


Sensitive Brier
Sensitive Brier has leaves that fold up and collapse when touched or roughly handled. The flowers lack petals. The colorful purple structures are the stamens. Each stamen is tipped with a yellow anther that produces and holds the pollen.

SUMMARY OF OBSERVED SPECIES:

American Hop hornbeam
Ostrya virginiana
Tiger Swallowtail (caterpillar)
Papilio glaucus
American Beech
Fagus grandifolia
Water Oak
Quercus nigra
Southern Black Haw/
Rusty Black Haw
Viburnum rufidulum
Winged Elm
Ulmus alata
Lightningbug, Firefly
Photinus pyralis ??
Post Oak
Quercus stellata
Black Cherry
Prunus serotina
Yaupon Holly
Ilex vomitoria
Smooth Spiderwort
Tradescantia ohioensis
Tent Caterpillar (egg mass)
Malacosoma americanum
Stinkbug (egg mass and hatchlings)
Family Pentatomidae
Japanese Beetles
Popillia japonica
Multicolored Asian Lady Beetle
Harmonia axyridis
Magnolia Green Jumper Spider
Lyssomanes viridis
Chinese Pistache
Pistachia chinensis
Brown Headed Cowbird
Molothrus ater
Wild Onion
Allium canadense
Deptford Pink
Dianthus armeria
Eastern Redbud
Cercis canadensis
Queen Anne's Lace
Daucus carota
American Queen Anne's Lace ??
Daucus pusillus
Woodland Coreopsis
Coreopsis major
Hairy Skullcap
Scutellaria elliptica
Geometer Moth Caterpillar (Inchworm)
Family Geometridae
Yellow Star Grass
Hypoxis hirsuta
Sensitive Brier
Mimosa microphylla
Wild Bergamot/Bee Balm
Monarda fistulosa
Rough Daisy Fleabane
Erigeron strigosus

<insert table here>

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