Friday, July 24, 2015

Ramble Report July 23 2015



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.

Sixteen ramblers braved the humidity and temperature today.

Today's Reading: I read a piece about scientific names from Alpine Plants of the Northwest Wyoming to Alaska, p. 12:

If we can no longer argue for scientific names on the basis of stability, we can still make an argument for clarity. After all, even after scientific names change, there is still only one official scientific name-the new one. (Numerous common names usually remain.) You can also learn scientific names to impress people, around the barbeque or at other social gatherings. Inexplicably to some, Carla Bruni* married former French president Nicolas Sarkozy. She explained that, after a courtship stroll in the Elysee Palace gardens, it struck her that "He knows all the Latin names, all these details about tulips and roses. I said to myself, 'My God, I must marry this man.'"
* Carla Bruni is a former European fashion model.

Today's Route: We went through the formal garden in search of butterflies, pausing whenever we encountered them. We passed through the Heritage garden on the way and stopped to look at the insects on sorghum. From there we walked through the Flower garden and examined the plantings for butterflies. It was getting hot so we gladly entered the Purple trail at the bottom of the Flower garden to enjoy the cool shade and returned back to the Conservatory via the Herb and Physic Garden.

The Arbor: The ever-observant George spotted an ant carrying a dead insect three to four times its size across the pavement.

American South section: Only a few of the wild bergamot and Virginia spiderwort are still blooming, but more of the crimson beebalm still have flowers. A small number of ironweed have started blooming. 

Native American Meadow section: Two tiger swallowtail butterflies were seen visiting flowers in this section. I succeeded in capturing one and showing it to the group. The swallowtail butterflies get their name from the tail-like projections at the rear edge of the hind wings. Some people think that these projections make a "false head" that attracts the attention of possible predators. There is even a different colored spot at the base of the tail that could be interpreted as resembling an eye. Sometimes older swallowtails show damage to this area, supporting the idea that predators like birds directed their attacks toward the tails, allowing the butterfly to make its escape.

Immature Five-lined skink
As we started across the bridge someone noticed a five-lined skink basking in the sun. A skink is a kind of lizard and this one must have been cold because it allowed many of us to gather around it. Usually a skink will run for cover when a human comes within 10 feet of it. But it stayed still in its sunny spot and we were able to get a good look. Its most obvious feature is the bright blue tail, which indicates that this was immature because the tail loses this coloration at sexual maturity. The 5 yellow stripes that run from the head to the base of the tail are also lost as the animal matures and the black background changes to gray. The colorful tail attracts the attention of predators. Skinks can auto-detach the tail if it is grabbed. The detached tail twists and thrashes about and occupies the attention of the predator while the skink makes its escape. There are actually three species of skink in this area of Georgia that look alike, especially as immatures: the five-lined, broad-headed and southeastern five-lined skinks. They can be distinguished by technical details of their scale patterns, but you have to capture them to determine this. 

Dragonfly eyes
The next surprise was a dragonfly that settled on the brickwork at the side of the path. It must have been cold because it allowed me to get close enough to capture it with a net. Most people don't get a close look at a dragonfly so I took the opportunity to point out some of its interesting features. The eyes are enormous and cover most of its head, which is why dragonflies are normally so difficult to capture – they can see almost 360 degrees around themselves. Each eye is composed of thousands of facets, each of which is an independent photoreceptor. These eyes are very sensitive to movement which enables the dragonfly to not only detect predators (or net-wielding entomologists) but also prey like mosquitoes or other flying insects. Their legs have many bristles that form a basket of sorts that can scoop up and hold their prey, allowing them to consume it while they fly.
Bristly dragonfly legs

Dragonflies start life as a wingless aquatic nymph that lives at the bottom of ponds or streams. The nymph is a voracious predator and has an unusual mouthpart it uses to capture its food. This mouthpart has a pair of clasping jaws at the end and is carried folded up below the head. When a prey is spotted the nymph stalks it until within striking range. Almost quicker that you can see the jaws are unfolded and project forward, grabbing the hapless prey. They fold back up, carrying the food to the real jaws where it is eaten. You can see how this works if you imagine your shoulder is the dragonfly head. Hold your arm so that the elbow is next to your chest and your hand is twisted so that your fingers can touch your shoulder. Your fingers represent the jaws and your arm represents the support for the jaws that folds up under the head. Now, when a fly passes overhead, quickly extend your arm and grab it. That's what a dragonfly nymph would do! (This prey capture mechanism is only found in the aquatic nymph; the adult dragonfly can chase down any flying insect and doesn't need the accessory jaws.)

On the other side of the bridge Sue noticed a nymphal stage praying mantis about the same size as the one we saw on a ramble last month.

Mystery caterpillar -- look at the weave of Tom's shirt to get an idea of its size.
Mystery caterpillar: Tom noticed a tiny creature that had fallen on his shirt and asked me if I knew what it was. I needed a hand lens to really see it and it turned out to be one of the most bizarre things I've seen -- it looked like a cross between a caterpillar and an elk. I had no idea what it was. After Don posted his photograph on facebook the mystery was solved by Carmen Champaigne, the superb naturalist at Sandy Creek Nature Center. Carmen had photographed the same kind of caterpillar back in 2010 and she tentatively ID'd it as a newly hatched caterpillar of the White-blotched heterocampa moth (Heterocampa umbrata). This sent Tom searching the internet and he found a picture of the early larva of the Saddled Prominent (Heterocampa guttivitta) that is a dead ringer for our bug. 

Heritage garden: Yesterday Emily and I stopped in the Heritage garden to look at a planting of what I first thought was corn – but something was strange about it. The plants were tall enough for corn, but they had no ears. They also did not have tassels on the top. (The tassels of corn are the pollen producing flowers.) Instead each plant had a spray of what appeared to be grain of some sort. I was stymied. 
Sorghum grain

We were told, much to my surprise, that these tall plants were sorghum. The sorghum of my childhood in Kansas was a short plant, rarely growing more than knee high; these plants are six to eight feet tall. At that height they do resemble corn and this similarity fooled many of the ramblers today.

Sorghum used to be grown in the South for syrup and perhaps it still is. It was processed in much the same way as sugar cane is – the stalks are crushed and the sap collected and boiled to concentrate the sugar. We stopped to look because many insects seemed to be attracted to the leaves but were not actually eating them. There were yellow jackets, flies, a ladybug and at least three kinds of paper wasps. What was the attraction? I'm not sure, but it is possible that they could be looking for sweet sap oozing from injured leaves. Sorghum is an interesting plant – you can read more about it here.

Insects on Sorghum

Ladybug (or, more properly, lady beetle):. The ladybug we found on the Sorghum is an imported species that goes by many common names, but is usually referred to as the Asian multicolored lady beetle (Harmonia axyridis). It is an avid consumer of aphids and related plant pests, but is also implicated in the decrease in our native Lady beetle populations. A good discussion of its benefits, drawbacks and life history is here. This lady bug was introduced to the United States to control scale insects in the citrus fruit industry. It was highly successful but then spread from the citrus orchards across the country, feeding on aphids in addition to scale. It is now directly competing with our native lady beetles and the native species seem to be losing the competition.

Asian multicolored lady beetle variation
©entomart Wikimedia commons

Identification of the Asian multicolored lady beetle is made difficult by its high degree of variability, as the accompanying photo from Wikipedia shows. The best characteristic is to look for a black "M" (or "W," depending on how you look at the beetle) on the head end. In the photograph each beetle has two conspicuous white spots on either side of the first thoracic segment (the part just behind the tiny head). In the center of this segment you can see a small white spot on the front and another white spot on the back of the segment. Together these white marks divide up the black area so that it takes the shape of an "M" when you view the beetle from the back or a "W" when you view it from the front. (Note that this doesn't work with the mostly all black beetles.)
  
Polistes species 1

Polistes species 2

Polistes carolinus
Paper wasps: We saw three kinds of paper wasps on the sorghum leaves. Paper wasps are social insects with three types of individuals in the colony: a single "queen" who is the only wasp laying eggs, workers, who are females but do not reproduce, and males, who appear late in the season. A colony is founded by one or more overwintering, mated female wasp. A single female, the foundress, begins construction of her nest in a sheltered area, frequently under the eaves or gutter of your house. She first builds a stem from which the nest will be suspended, using wood fibers she scrapes up from the environment. When the stem is complete she molds a small cup on the end and lays a single, fertilized egg in the cup. She then continues to extend the walls of the cup and to add new cups next to it. When the egg hatches she has to divide her labor between searching for food for the young larva and enlarging the nest. As the larva (pl. larvae) grow the foundress must extend the walls to keep up with increasing size of her offspring. They finally reach a mature size and then spin a silken cap over their chamber. Within they metamorphose into a pupal stage and a few days later the adult wasp emerges by biting a hole in the silken cap. This newly emerged wasp is sterile and works as a worker, foraging for food for her developing sisters, and increasing the number of cells in the nest. As more and more workers emerge the nest increases in size rapidly and the foundress is able to devote her time to egg laying. The foragers explore the adjacent area, looking for caterpillars. When found, the wasp reduces to caterpillar into a small ball of chewed up flesh, the equivalent of ground beef, which is fed to the developing larvae. Later in the season the foundress of the colony begins to lay unfertilized eggs. These will develop into males. Male wasps hand around the nest or fly off and visit flowers, sipping nectar. At the same time the new females that emerge become sexually mature and fly off and mate the males. These fertilized females will become the foundresses of new colonies the following spring, if they survive the winter. 

Sometimes a colony is founded by multiple females, each of which has been fertilized. When that happens there is quarreling over who will be the reproductive female of the colony. One female emerges as dominant and the other, subordinate, females become workers. Their ovaries atrophy and they can no longer lay eggs. Because such colonies have many workers from the start they grow quickly and produce more offspring than single foundress colonies. So the overwintering females have to make a choice: should they go it alone and produce a smaller number of offspring or should they join a group of females, at the risk of not being able to reproduce. It is unknown how such a choice is made.

And last, but not least, Don found a leaf footed bug on top of one of the sorghum stalks. Those bugs seem to be attracted to developing seeds.

Flower garden: The most productive plantings for butterflies today were the beds of Lantana and spearmint. The mint was especially attractive to the skippers and several kinds of solitary wasps.

Butterflies and Skippers: Skippers are butterflies, just like dogs are carnivores. Skippers are different from other butterflies in several ways – they have stouter bodies and smaller wings in relation to their body size and their antennae have a small hook on the end. They get their name from their very rapid, erratic flight that someone, in a flight of fancy, thought resembled aerial skipping. And it does! 

There are several different subgroups of skippers; in our area we just have to deal with 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 later). 

Spread-wing skippers, as their name implies, hold their wings horizontally when they are resting or nectaring. But some of the spread-wings just hold their wings apart in a V-angle that may range from 90 to just a few degrees. 

The grass skippers are the sparrows of the butterfly world – there are many brown species and they are hard to identify. Come to think of it, a similar thing could be said of the spread-wing skippers; they are the fall warblers of the butterfly world.

Firey skipper basking pose
Basking skippers hold their wings in a characteristic pose: both wings are held open, but the hind wings are opened almost horizontally while the forewings are only slightly opened. The body is oriented so that maximal wing surface is exposed to the sun. This enables the skipper to gain heat rapidly and keep its body temperature high.

Silver spotted skipper
Firey skipper (L); Ocala skipper (R)
There were two common Skippers nectaring in the Flower garden today: Silver spotted skipper, a spread-wing skipper and a fiery skipper, a grass skipper. The silver spotted skipper is a large skipper with a prominent silver spot on the hind wings and a large orange spot on the front wings. The fiery skipper is yellowish-tan with black dots scattered across the underside of both wings. Some of us saw a third skipper, the ocala skipper.

Solitary wasps: We saw at least two different solitary wasps visiting the spearmint blossoms. Unlike the paper wasps, solitary wasps do not form social colonies. Instead mated females construct nest sites by digging in loose, sandy soil or building a mud container (e.g., mud daubers). They then hunt their prey, which may be spiders, grasshoppers, crickets, etc. which they paralyze by stinging. The still living, paralyzed prey is then carried back to the nest site. When sufficient food has been stored in the nest an egg is laid on the still living prey and the nest sealed. This leaves the egg to hatch, the larva to feed on the larder provided by its mother and complete development on its own. Meanwhile, the mother wasp builds another nest and keeps hunting.

Red Admiral butterfly: A delightful surprise was to find a Red Admiral. They 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 nettle! The red admiral is not a rare butterfly here in the Athens area, but it is not common, either. 

Red Admiral
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. (Bed rest was the only treatment at the time; penicillin was not available to the civilian population during WWII.) During that time 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 half I was in bed and I had forgotten how. 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 couldn't walk, so I crawled over to the pole to see it better and to try to catch it. But, of course, it flew off. I didn't know what it was, other than a butterfly, but three years later I found in a book a picture of a dark butterfly with bright orange bands on its wings – the caption read: Red Admiral. 

Purple Trail: By this time (about 9:30AM) we were getting uncomfortably hot so we decided to go into the woods via the Purple trail at the bottom of the Flower garden. The temperature dropped about 10 degrees as soon as we entered the shade of the trees. It's not only the shade, it's the presence of the trees that cools the atmosphere. Water constantly evaporates from tree leaves, a process called transpiration. This is what draws the mineral nutrients from the roots up to the leaves – the constant stream of water being pulled through the trunk into the leaves where it evaporates. Evaporation takes energy and loss of energy lowers the temperature. Trees are the original air conditioning units.

Sericia lespedeza
Growing on either side of the Purple trail there are sericea lespedeza plants (also called Chinese bush clover). These don't appear to be invasive in our area but they are in other parts of the country. Avis spotted St. Andrew's cross growing here. 

Further along the trail, illuminated in a sun fleck, we found a large white mushroom, identity unknown to us, but possibly an Amanita. Near there was a small spider beginning its web – a triangulate orb weaver.

Ed discovered the remains of a cicada which raised the question as to when cicadas call. The common cicada in our area calls during the day and into dusk. Here's a cicada song that I've heard outside my house. I find it really hard to describe insect sounds, partially, I think, because I've lost so much high frequency hearing. Your best bet to identify a sound that you think might be produced by an insect is to browse this website and play a bunch of the recordings.

The most prominent insect chorus outside my house at night is the katydid. Here's a website where you can listen to the call of a Katydid from the southeast US. The first call is for a northeastern race, the second is the call that I hear at night outside my house. If your night sounds are different then you've got something else.

Female tiger swallowtail (non-melanic)

Female tiger swallowtail (melanic)



Male tiger swallowtail (reduced blue dusting)

Herb and Physic garden: Back at the formal garden I was able to capture a female tiger swallowtail and to show everyone how to tell the male from the female. In our area most of the female tiger swallowtails are melanic (dark in color, with little or no yellow striping visible). The butterfly I caught is an uncommon yellow striped female tiger. She looks just like a male tiger swallowtail but for one difference: she has a dusting of blue on the margin of her hind wings. You can see in the photos that the melanic female tiger also has the same blue scales, but the male tiger lacks this blue coloration.


SUMMARY OF OBSERVED SPECIES:
Virginia spiderwort
Tradescantia virginiana
Wild bergamot
Monarda fistulosa
Crimson beebalm
Monarda didyma
Wolf spider
 Family Lycosidae
Eastern tiger swallowtail
Papilio glaucus
English five-lined skink
Plestiodon fasciatus
Common whitetail skimmer
Plathemis lydia
Praying mantis
Order Mantodea
Sorghum
Sorghum sp.
Red wasp
Polistes carolinus
Paper wasp
Polistes fuscatus
Paper wasp (brown eyes)
Polistes exclamans (tentative)
Eastern yellow jacket
Vespula maculifrons
Eastern leaf-footed bug
Leptoglossus phyllopus
Solitary wasps

Fiery skipper
Hylephila phyleus
Silver spotted skipper
Epargyreus clarus
Ocala skipper
Panoquin ocala
Red Admiral butterfly
Vanessa atalanta
Ruby throated hummingbird
Archilochus colubris
Chinese bush clover
Lespedeza cuneata
St. Andrews cross
Hypericum crux-andreae
Amanita
Amanita sp.
Slime mold
Not identified to species
Hophornbeam leaf miner
Phyllonorycter tritaenianella
Triangulate orb weaver spider
Verrucosa arenata
Cicada (shed exoskeleton)
Family Cicadidae


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