Ramble Report September 21 2017

Ramble Report September 21 2017

Today's Ramble was led by Dale Hoyt.

The photos in this post, except where noted, came from Don's Facebook album (here's the link).

Today's post was written by Dale Hoyt.

27 Ramblers met today.

Announcements:

1.     Saturday, Sept. 23, 8AM, Audubon Society Birdwalk, free. Park in Day Chapel lot.

2.     Saturday, Sept. 23, 9:30-12:30PM, Insectival.

3.     Sunday, Sept. 24, 3-5PM, is Pie Day at Sandy Creek Nature Center. Come sample free pies, bid on items in the silent auction, listen to live music, etc.

4.     Tuesday, Sept. 26, 7PM, Jaret Daniels will speak on Backyard Bugs at the State Botanical Garden.

Today's reading: Bill Pierson brought a short Chinese poem

and the calligraphy to accompany it.

The English translation is: "Clear water runs through the rocks." Bill also says "This actually is an old Chinese saying that comes from a book about a famous general who was sitting by clear water and playing a Chinese instrument called a qin during the Liu Song Dynasty sometime in the 5th century AD. Literally each character says from top down: 'Clear spring rock on flow'."

Dale read a Robert Frost poem, In Hardwood Groves.

Today's route: The mulched path to the White Trail; the White Trail to the power line right of way; Left on the RoW to the river; back to the access road; Right on the road back to the Visitor Center.

Eastern Tiger Swallowtail, yellow phase female;
note the blue frosting on the hind wing border, typical of the female sex.

Eastern Tiger Swallowtail butterflies are sexually dimorphic, a fancy way of saying that you can tell the boys from the girls. In males the margin of the hind wing will be black with no hint of blue. In females there is a prominent dusting of blue scales in the area. This difference holds true for both female color forms, the yellow form the black form. In the black form female the yellow area of the wings is very dark, making it difficult to see the tiger striping that gives the butterfly its name. But it is still there and if you can hold the dark form up to the light you can it.

The dark brown pigment is called melanin and is the same substance that darkens our skin when we tan. The dark form female is thought to be a mimic of another dark swallowtail butterfly found in our area, the Pipevine Swallowtail, which is very distasteful. One bite on a Pipevine Swallowtail will turn a bird off of eating any similarly colored large butterfly. By looking like a distasteful butterfly the dark female Tiger Swallowtail is protected from being eaten by birds.

A Carpenter bee is often mistaken for a large Bumble bee, but differs in having a slick, glistening black abdomen. Bumble bees have fuzzy abdomens. Both have hairy thoraxes.

Honeybees are seen on flowers when it is warm enough for them to fly. Unlike Bumble bees, the honeybee cannot raise its body temperature by contraction of its flight muscles. When it is cool they usually only forage on flowers in direct sunlight. If you carefully watch foraging bees you will notice that some are only collecting nectar while others collect pollen. The pollen collectors have clumps of collected pollen stored in baskets on their hind legs.

Honeybees are not native to North or South America; they were brought to the western hemisphere by European colonists. They are a domesticated species and some have escaped from apiaries and established colonies outside of human control. They are feral, like other domesticated organisms living independent of human control.

Newly emerged Gulf Fritillary butterfly

Gulf Fritillary caterpillar

Gulf Fritillary egg

Gulf Fritillary butterflies are very common this time of year. This will be the last generation produced in our area as their larval host plant starts to decline. In fact, an egg laid today may not have enough time or food available to emerge from its chrysalis before the first frost. This species cannot survive our winters in any of its life stages, egg, larva, pupa or adult, so where do they come from?

There is good evidence that the Gulf Fritillary is a migratory species. T. J. Walker, an entomologist at the University of Florida in Gainesville, studied the flight direction of butterflies in his area for six years (1984 to 2000). He built a trap that intercepted flying butterflies of all kinds, collecting them in a cage where they could be counted and released. The trap was designed so that butterflies flying north were separated from butterflies flying south, making it possible to detect seasonal patterns in their movements. In the spring (March, April and May) he caught 1346 Gulf Fritillaries, 98% flying northward. In the fall (September, October and November) he trapped 16,003 Gulf Fritillaries, 96% of them flying toward the south. This is the strongest evidence we have that this species is migratory. 

Our local population arrives in our area in late May, about the time that Passionvine, the larval food, begins to emerge. You can tell that they have flown a long way because their color is dull and their wings look worn. They lay eggs on the passionvines, producing the first generation in our area. There is time for two or three more broods before the food plants disappear and winter weather sets in.

Fly sucking juice from injured Gulf Fritillary chrysalis

Speaking of Gulf Fritillary butterflies, you might remember that last week we found a stink bug sucking the juices from a Gulf Fritillary chrysalis. Today Don spotted a small fly feeding on the same chrysalis. There is a very large group of flies that lack a structure of the wing called a calypter. This fly is one of them and we don't know any more about it. Flies are very difficult to identify without having a specimen in hand to examine.

American Bird Grasshopper

American Bird Grasshoppers are common now. We saw several flying away and captured one. Someone wanted to know the difference between grasshoppers and locusts. Locusts are a kind of grasshopper, the most notorious being the Migratory Locusts that periodically erupts in huge swarms that destroy crops over a large area. They are found in Africa, Asia, Australia and New Zealand.

Female Velvet Ant

Velvet Ants aren't really ants. They are wingless wasps. We frequently see the stunningly colored red and black females scrambling over the ground. The males have wings (we found one on a earlier Ramble this year) and fly about, looking for a female. The females have really painful stings and a long, mobile stinger that makes it difficult to hold one without being stung. They seek out the nests of ground dwelling wasps and bees, enter it, and lay an egg on each larva or pupa they find. Their larva feeds as an ectoparasite on its hosts, eventually killing it. Another feature that may be related to their life style is their very solid exoskeleton. The thoracic segments are fused together, making pinning them very difficult. This would be helpful in fending off the stings of their host species.

Spiders & webs

Sheetweb

 

On cool humid mornings many small spider webs are covered with dew, making them highly visible. Most of these small webs look like miniature shallow plates or domes. They are inhabited by equally small spiders, called Sheet Web spiders. These webs are usually not sticky but trap insects by entangling them in a network of fine silken threads. The spider hangs beneath the web and captures its prey by biting it through the web.

Bowl and Doily web

One of the sheet web spiders is called the Bowl and Doily spider because its web consists of two parts: a bowl shaped upper portion and a lower, flat sheet, the doily. The spider lives between the bowl and doily and captures prey that are entangled in the bowl. (For those who are too young to know or remember: a doily is flat piece of decorative lace that is placed under a plate or other object. According to dictionary.com it was named after a London draper named Doily.)

Yellow Garden Spider

A Yellow Garden spider constructed its web in front of the deer fence next to the road. It had captured a small "June bug," which is a type of beetle and wrapped it in silk and hung it from its web. The beetle was still alive, just paralyzed by the spider venom. The spider keeps such prey for consumption later, when it's feeling peckish.

Spinybacked Orbweaver
Note the silk strands with fuzzy sections

Near a privet removal project sign we found the web of a Spinybacked Orbweaver. This spider resembles a crab in shape. The web is a typical orb web but many of the silk lines have "fuzzy" sections whose functions are unknown. They are characteristic of this type of spider.

Great Leopard moth caterpillar

Long tailed Skipper caterpillar

Caterpillars are sometimes difficult to identify with confidence. Today we found these: Tussock Moth, Great Leopard Moth, Long-tailed Skipper and an unidentified individual.

River Cane restoration 

Our local Audubon Society has started a River Cane restoration project in the power line RoW on the NW corner at the junction of the White and Orange Trails. Gary told us that the first step was to remove all the privet, a job done by Audubon volunteers. Then, using Audubon funds specifically raised for this purpose, River Cane plants were purchased from Thomas Peters and planted by volunteers in the cleared area. Re-emerging privet is being controlled by winter applications of a broad-leaf herbicide that is effective against privet but has no adverse effects on the cane.

Thomas Peters was responsible for clearing privet, by hand, from the flood plain by the Orange Trail two years ago. He has also successfully cultivated River Cane and is raising it for restoration efforts at other locations. Dense stands of cane used to grow in the flood plains of southern rivers. They were known as canebreaks and served as favorite habitats for many species that are now uncommon because the habitat has almost vanished.

River Cane has the unusual habit of reproducing only once and then dying. All the cane in a area flowers at the same time, sets seed and dies. Fortunately, the plants flower only after 50-75 years.

Frostweed

 

Wingstem

 

Yellow Crownbeard

The lower part of the flood plain is dominated by a few plants: the yellow flowered verbesinas, Yellow Crownbeard and Wingstem, along with a few Frostweed.

Tall Ironweed

Then there is Tall Ironweed with its purple flower heads and the other big yellow flowered Asteracea: Tall Goldenrod and Rough Leaf Sunflower.

Spotted Smartweed

 

Arrowleaf Tearthumb

Arrowleaf Tearthumb
closeup of stem showing the pointed barbs

Two members of the Smartweed family grow in the moist depressions of the power line RoW: Spotted Smartweed and the aptly named Arrowleaf Tearthumb with stems covered in almost invisible downward pointing barbs. You'll regret trying to pull it up when those points rake across your skin!

Climbing Buckwheat amidst the wingstems

The other Smartweed is Climbing Buckwheat, a vine that clambers over the wingstems and goldenrods. What appear to be spikes of white flowers are really the fruits. Each flower produces a single seed surrounded by a three-angled ovary wall. True to its name the Climbing Buckwheat is also climbing up the newly planted River Cane and will have to be watched to see if it can peacefully coexist.

Bur Cucumber

Bur Cucumber flower

Bur Cucumber tendrils

One interesting vine that was very common two years ago, but is less commonly seen at present is Bur Cucumber. Although in the cucumber family, its fruits are tiny, inedible and covered with very pointed spines. The vine uses tendrils to climb.

Small White Morning Glory

An inconspicuous vine, Small White Morning Glory is more variable than its name implies. Its flower color varies from white to maroon and we saw several different colors.

SUMMARY OF OBSERVED SPECIES:

Yellow Crownbeard	Verbesina occidentalis
Wingstem	Verbesina alternifolia
Frostweed White Crownbeard	Verbesina virginica
Eastern Tiger Swallowtail	Papilio glaucus
Tall Ironweed	Vernonia gigantea
Sheetweb spider (web)	Family Linyphiidae
Tall Goldenrod	Solidago altissima
Bowl-and-Doily spider	Frontinella communis
Spotted Smartweed	Persicaria punctata (=Polygonum punctata)
Arrowleaf Tearthumb	Persicaria sagittatum (=Polygonum sagittatum)
Late-flowering Thoroughwort	Eupatorium serotinum
Small White Morning Glory	Ipomoea lacunosa
Fall Webworm	Hyphantria cunea
Red Shouldered Hawk	Buteo lineatus
Climbing Buckwheat	Fallopia scandens (=Polygonum scandens)
River Cane	Arundinaria gigantea
Gulf Fritillary	Agrulis vanillae
Passion-flower Vine	Passiflora incarnata
Bur Cucumber	Sicyos angulatus
Great Leopard Moth	Hypercompe scribonia
Carpenter Bee	Xylocopa virginica
Velvet Ant	Family Mutillidae
Asiatic Dayflower	Commelina communis
Virginia Dayflower	Commelina virginica
Rough Leaf Sunflower	Helianthus strumosus
Spinyback Orbweaver	Gasteracantha cancriformis
Beggar Ticks	Desmodium sp.
Long Tailed Skipper	Urbanus proteus
American Bird grasshopper	Schistocerca americana
Blue Mistflower	Conoclinium coelestinum
Wild Heliotrope	Heliotropium indicum
Camphorweed	Heterotheca subaxillaris
Yellow Garden spider	Argiope aurantia
Acalyptrate Fly	Order Diptera