Monday, July 17, 2017

Ramble Report July 13 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 and Don Hunter.
Twenty four Ramblers met today.
Announcements:
Today's reading: Bob Ambrose recited one of his new
evolution-themed creations: The First Nursery. (You can find the text of this poem in today's email.)
Bill Pierson read a thought-provoking short quotation from Henry Miller:
"Our destination is never a place but a new way of seeing things."

Today's route: We took the sidewalk next to the conservatory to the various sections and gardens in the International, Heritage and Flower Gardens.

Pollination puzzle
Why is pollen spelled with an "e," but pollination is spelled with an "i"?

Bees and Pollination
Much has been written about the pollination services of bees and other insects, so much that we forget that this really reflects a human perspective of what these insects are doing when they visit flowers. From the perspective of a bee it is merely gathering food for its young. Yes, they are literally stealing nectar and pollen from plants to feed to their offspring. The nectar contains principally carbohydrate (sugars) and is a source of energy, but very poor nutritionally. For the bee larvae to grow they must have protein and this is supplied by the pollen. So when a bee wallows about in a flower it cares not a whit about the fact that it is pollinating that flower; it is merely harvesting as much pollen as it can possibly get to carry back to its nest.

How many kinds of bees are found in the SBGG?
A two year study conducted in 2006-2007 in the garden found 122 species of bees. Of these only 7 are social bees: the non-native Honey bee and 6 kinds of Bumblebee.

Bumblebee nectaring; note pollen baskets on leg (orange mass is pollen)
Social Bees
A social bee lives in a colony of bees that has a single reproductive individual, the "queen," who produces all the eggs. The other bees in the colony are either workers or drones. Workers are non-reproductive bees that perform various duties, e.g., foragers, nurses, etc. Foragers collect nectar and pollen to feed the larvae; nurses feed and care for the larvae. Drones are male bees and are produced only when the colony is making new queens. Only the Honeybee colony survives the winter, using its stored honey and pollen; in the other social bees, the Bumblebees, the colony dies in the fall, only the new, fertilized queens survive over the winter. Each Bumblebee queen begins a new colony in the Spring. Their colonies are much smaller than Honeybee colonies.
Carpenter bee (a solitary bee) stealing nectar by biting through the base of a flower.
Solitary bees
The other 100+ bee species in the Garden are solitary bees. A solitary bee does everything by itself. A fertilized female constructs a nest that may be a burrow in the ground, a hollow twig or a tunnel she excavates in dry wood. She gathers nectar and pollen and brings it back to her nest, making a kind of "bee bread," a mixture of nectar and pollen, on which she lays a single egg. She then closes off that part of the nest, making a chamber in which the larva will grow and develop with no further interaction with its mother. Meanwhile she continues to forage and either adds another chamber to her nest or constructs or finds a new nest.

Franklinia with flower bud
Franklinia
Brad Sanders is a William Bartram expert and accompanied us on our Ramble today. He is the author of Guide to William Bartram's Travels, an exhaustive compendium of the places Bartram visited along with additional information and historical background. It is currently available only on the used book market but Brad is revising it for the second edition.
The Heritage Garden here at the State Botanical Garden has a single specimen of Franklinia alatamaha, a shrub/tree discovered by John and William Bartram, the first botanists in the American colonies. While we gathered in the shade of the gazebo Brad told us about the Bartrams and their discovery of Franklinia.
John and William Bartram discovered it on the banks of the Altamaha river in south Georgia on October 30, 1765. The plant was growing in the vicinity of Ft. Barrington, in a swampy area between sand dunes. The Bartrams returned to Philadelphia and, several years later, William returned to the south, traveling there for a number of years. He later published an account, Travels, of his time in the south. He managed to find the Franklinia that he and his father had previously seen and gather seeds, which he sent back to Philadelphia. His father successfully germinated the seed and all the Franklinia plants known to exist today are descendents of that seed.
Although William Bartram was an exceptional botanist who discovered many new plants during his travels, the only plant he ever named was the Franklinia alatamaha (with the name of the river misspelled). The genus name honors Benjamin Franklin, a close friend of the Bartrams.
The plant was last seen in nature in 1814.
Many people and institutions have plants that grow vigorously, especially in the northern climate, which suggests that Franklinia is/was a relict of past glacial periods.
The specimen we have here at the Garden is growing in a pot because all attempts to grow the species in our soils fail. (The failure may be due to the persistence of pathogens in our soil from the days of cotton farming.
If you'd like to see Franklinia in bloom you'll have to be quick. When a flower bud opens it lasts but a day; the petals have fallen by the next morning.
Franklinia is a close relative of the Camellia and Loblolly-bay; all are in the tea family (Theaceae). Hybridization is in progress. The hybrid forms will be called Gordenias, according to Brad.

Miscellaneous critters

Hentz's orbweaver spider
Spider
Midsummer is when we begin to encounter spider webs. Why? Most spiders are annual species, living only a year. They hatch from overwintering eggs in the spring and start to feed and grow. In early July they have started to reach the size that can construct large, noticeable webs. (When they are smaller the webs are also small and hidden from human view.) Now it is common to see or walk through large orb webs stretching between shrubs or other open areas where humans walk. Today Angeli found the orbweb of a Hentz's orbweaver stretched between two shrubs. She (the spider) had capture a June bug (beetle) and was busy draining its bodily fluids.
Later in the season the spiders will have become fat and egg-laden. Then they will spin silken cases for their eggs and die. The eggs overwinter and hatch the following spring.

A small group of Daddy longlegs on a Pawpaw leaf; there were a lot more on the leaf but they fled before they could be photographed.
Daddy-long-legs
Everyone has seen a daddy-long-legs at one time or another. Their tiny round body seems to bounce around as they run away on their improbably slender, long legs. They are sometimes mistakenly thought to be a kind of spider, but they belong to an entirely different order of arachnids. (Most people recognize three types of arachnids: spiders, scorpions and harvestmen, AKA daddy-long-legs.)
While looking for Pawpaw fruit Angeli came across a group of about two dozen daddy-long-legs gathered together in a tight cluster. They soon dispersed, but only after swaying back and forth as a group right after being disturbed. Why were they clumped together? My first guess was that this might be a mating aggregation – possibly a group of males that were attracted to a female emitting a pheromone. But a bit of sleuthing on the internet showed that is probably not the reason for this aggregation behavior. This website has several videos of harvestmen aggregations and explores some of the possible explanations for the behavior. Few people study harvestmen and much about their natural history is unknown. The upshot is that no one seems to know why they get together in such groups.

Sorghum insects
A black and orange lady beetle larva is attracted to the Sorghum aphids; it is a major aphid predator

A much enlarged Sorghum aphid colony
The Sorghum always plays host to a large number of aphids that cluster beneath the leaves where they suck the sugary sap. The "honey dew," which is really aphid poo, drops down on the leaves below, just as it does on your car when you park beneath a tree. The Sorghum aphid poo has a lot more sugar and it attracts a lot of bees, flies and wasps that eat up as much sugar as they can.
 
Butterflies
Butterflies don't seem to be particularly abundant this year. We only found a few different kinds today: 3 kinds of skippers (spread-wing skipper, Fiery skipper, & Silver-spotted skipper), a Buckeye and a Tiger swallowtail.
Spread-wing skippers
There are several kinds of spread-wing skippers in our area and they are difficult to identify, which is why I'm refraining from attempting to do so. They are sexually dimorphic, which means males and females differ, and it's difficult to tell the sexes apart. They also vary seasonally. Some experts say that the only sure way to identify them with confidence is by examination of the male genitalia. 
Other skippers
 
Fiery skipper

Fiery skipper basking pose
Both wings are flared open; hind wings open further than forewings



Buckeye; photo taken through a plastic container
Buckeye
The Buckeye is a common butterfly and has prominent large eyespots on all its upper wing surfaces. The males are territorial and will chase other buckeyes off. 

Male Tiger Swallowtail
Note the absence of blue color on the black margins of the hind wings
(compare with female below)

Female Tiger Swallowtail
The black margins of the hind wings are heavily dusted with blue
(compare to male above)
Eastern Tiger swallowtail
Tiger swallowtails are our state butterfly and usually pretty common. Their larval food is Tulip tree or Black cherry, both common plants. The males are yellow with black stripes but the females are dimorphic (two forms). One form is nearly all black in color and the other form is yellow with black stripes, the same as the male coloration. The dark females have additional black pigment, melanin, deposited in what would be the yellow areas. This makes them blend in with the black stripes, producing a solid black wing area. Though if you examine a melanic female you can see the faint outlines of the dark stripes. A sexual dimorphism is superimposed on this striped male, melanic or striped female pattern. The posterior margin of the hind wing upper surface is black in males but is black with a frosting of blue scales in females.
It is thought that the melanic female Tiger swallowtail is a mimic of the Pipevine swallowtail. The Pipevine swallowtail's larval stage feeds on Pipevine and accumulates the distasteful, poisonous compounds in that plant, much like the Monarch butterfly larva accumulates distasteful compounds from its milkweed host. Support for this idea is found in the geographic distribution of the two forms. The Pipevine swallowtail is common in the southeastern states, decreasing in abundance as you go north. The frequency of the melanic Tiger Swallowtail is highest in the south, decreasing as you go north. In the northeastern states there are no Pipevine swallowtails and the Tiger swallowtails of both sexes in those areas are all yellow.

Tiger swallowtail
Tongue (proboscis) is coiled up below the head on left

Butterfly "tongues"
The butterfly tongue (proboscis) is used to obtain nectar from flowers and liquids from other sources. The proboscis is held coiled up beneath the head and, when in action, is uncoiled and used to probe the flower for nectar. The end of the proboscis has many taste receptors. (Butterflies also have taste receptors in their feet.) The proboscis is made of two parts that zip together. Each half is a tube with slit along its length. To make the functional proboscis the two tubes meet together along their slits, forming a double straw. In cross-section it's like a figure 8 on its side, with an opening at the point of crossing. A muscular pump in the head provides the suction to sip the fluid up to the mouth.

SUMMARY OF OBSERVED SPECIES:

Red salvia
Salvia greggii
Carpenter bee
Xylocopa virginica
Bumblebee
Bombus sp.
Bog sage
Salvia ulignosa
Honey bee
Apis mellifera
Hentz's orbweaver
Neoscona crucifera
June beetle
Phyllophaga sp.
Black-eyed Susan (?)
Rudbeckia hirta
Solitary bee

Silvery checkerspot butterfly
Chlosyne nycteis
Paw paw tree
Asimina triloba
Daddy longlegs/Harvestman
Order Opiliones
Franklinia
Franklinia alatamaha
Spread-wing skipper, Duskywing
Erynnis sp.
Common buckeye
Junonia coenia
Lady bug, larval stage
Family Coccinellidae
Aphids
Superfamily Aphidoidea
Sorghum
Sorghum sp.
Fiery skipper
Hylephila phyleus
Silver-spotted skipper
Epargyreus clarus
Eastern swallowtail butterfly
Papilio glaucus
Mealybug?
Family Pseudococcidae

1 comment:

  1. Thanks for explaining why we don't get tangled up in spider webs earlier in the year. Perfectly logical when you learn that most spiders are annual species!
    -gc

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