Sunday, June 26, 2016

Ramble Report June 23 2016



Today's Ramble was lead 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.

Seventeen Ramblers met today.

Today's readings: We had two readings today. Sue read this article from the Athens Banner Herald on the beneficial aspects of spiders. Dave read the poem Piute Creek by Gary Snyder:

One granite ridge
A tree, would be enough
Or even a rock, a small creek,
A bark shred in a pool.
Hill beyond hill, folded and twisted
Tough trees crammed
In thin stone fractures
A huge moon on it all, is too much.
The mind wanders. A million
Summers, night air still and the rocks
Warm. Sky over endless mountains.
All the junk that goes with being human
Drops away, hard rock wavers
Even the heavy present seems to fail
This bubble of a heart.
Words and books
Like a small creek off a high ledge
Gone in the dry air.

A clear, attentive mind
Has no meaning but that
Which sees is truly seen.
No one loves rock, yet we are here.
Night chills. A flick
In the moonlight
Slips into Juniper shadow:
Back there unseen
Cold proud eyes
Of Cougar or Coyote
Watch me rise and go.

(Snyder began as an early, important member of the "Beat" movement. His poetry is heavily influenced by Zen Buddhism, Japanese Haiku and Chinese verse.)

Today's route:
We left the arbor and made our way down the paved walkway towards the International Garden, taking the sidewalk to the left, just before the Flower Bridge.  We walked close to the Visitor Center, following the path through the hop arbors to the gazebo in the Heritage Garden.  At this point we made our way directly back to the Visitor Center and Donderos'.

On the way down the sidewalk we spotted two spiders, a Triangulate Orbweaver and Orchard Orbweaver. The Triangulate was still small, but illustrates why we seldom see spiders until later in summer and early fall – they are simply too small. Most hatch out in the spring from eggs that overwintered and it takes time for them to grow to the size where they become noticeable.

Bottlebrush Buckeye; mostly staminate (male) flowers
A Bottlebrush buckeye still had some racemes with lots of flowers. If you look carefully at each raceme with its hundreds of flowers you may notice that most of them have only stamens. Only a small percentage of the flowers are perfect (that is, contain stamens and pistils, the male and female parts). The perfect flowers are difficult to find because the style of the pistil is long, thin and the same color as the filaments of the stamens. It lacks the small brown anther at the end, but some older stamens have lost their anthers also. There is another Bottlebrush buckeye near this one – it is on the sidewalk just beyond the Flower bridge and has dropped most of its petals. The perfect flowers on that plant stand out as their swollen ovary at the base of the pistil still bears the style. If you're interested you can count the number of perfect flowers and the total number of flowers on a raceme. It should come out to about 4% perfect. This condition of bearing some perfect and some male flowers is called andromonoecious. The andro- prefix means male and the –monoecious suffix means one house – both sexes on the same plant.

Today's focus was on pollinators, especially bees, but, as ever, we were open to anything that creeps, crawls or flies upon or around flowers.

How many kinds of bees are found in the SBGG?
A two year study (2006-2007) in the garden found 122 species of bees. (To give you a perspective on this number there are only about one half as many kinds of trees found in the garden.) The vast majority of these bee species are solitary. Only 7 of the species collected were social bees: the Honey bee and 6 kinds of Bumble bee.

Common, easily recognized bees.
Today we saw four kinds of easily identified bees:
1.  
Carpenter bee
Carpenter bee – large bee with a fuzzy yellow thorax and a smooth, glistening black abdomen. A solitary bee.
2.  
Bumble bee
Bumble bee – variable in size, some almost as large as Carpenter bees. Both thorax and abdomen are fuzzy. Various amounts of yellow fuzz on either thorax and/or abdomen. (There are at least six species of Bumble bee to be found in the garden.) A social bee.
Honey bee robbing nectar from a Salvia
3.   Honey bee – smaller than the Carpenter bee or Bumble bee; abdomen with alternating orangish-yellow and black rings. Baskets on hind legs hold pollen and will look like colorful saddlebags if the bee is collecting pollen. (Color depends on the color of the pollen.) A social bee.
4.   Leaf-cutter bee – about the size of a honey bee, but fuzzier and with alternating gray and black bands on the abdomen. Lacks the saddlebags for pollen collecting on the hind legs. (Pollen is collected on the belly of the abdomen. These bees are highly effective pollinators, possibly because the ventral surface is where the pollen is collected. As the bee scrambles over the flower the pollen is more likely to come in contact with the flower's stigmas. Leaf-cutters are solitary bees.

Difference between social insects and solitary insects.
Social insects live in a communal nest, like a honey bee hive, in which only one individual is reproductive (the queen). The other individuals in the colony are her daughters and do not reproduce. They perform other activities: foraging for nectar and pollen, defending the hive, feeding the brood (and the queen), building and maintaining the hive and storing food.

Solitary insects live isolated lives. A fertilized female constructs her own nest, often by digging a tunnel in the ground or excavating a cavity in a stem or piece of dead wood. She then provisions the nest with food that she gathers herself. In bees this is a mixture of nectar and pollen. After the nest is provisioned she lays an egg on nectar-pollen mixture and closes off that portion of the nest. Her egg will hatch and the larva will feed on the food provided by its mother, and then pupate, all the while living in the same chamber. Meanwhile, the mother repeats this process until the nest is filled with partitioned chambers, each with their single developing progeny. The original female continues to build and provision nests until she dies. Her young may emerge from the nest in the same year or over winter and emerge in the following spring. The emerging males and females mate, the males die soon after and the fertilized females do as their mother did.

The difference between bees and wasps.
Bees generally have branched hairs on their body, the better to gather pollen with. Wasps have few, in any hairs, but if they do have hairs they will not be branched. Adult bees feed on nectar and gather pollen to feed to their larvae (along with nectar to make "bee bread"). Adult wasps also feed on nectar but feed freshly killed and minced insects to their larvae. To some this makes wasps beneficial insects because they hunt and kill the caterpillars that eat our garden plants.

 Wasps can be social or solitary, just like bees. Examples of social wasps are: paper wasps, yellow jackets, and hornets. Paper wasps build the small, flat paper nests that are often found under the eaves of houses. Yellow jackets build similar paper structures, but typically build them underground or in cavities like hollow trees. Hornets build large, paper enclosed nests that can be as large as a basketball.. The paper enclosure that surrounds the nest protects the inhabitants from the elements, enabling hornets to put their nests in exposed areas.

Why do the stings hurt so much?
The nest of social bees and wasps is a concentrated resource of valuable food for other animals. Bee hives have, in addition to their store of honey, wax and pollen lots of juicy larvae that many animals, especially bears and skunks, would love to eat. Wasp nests don't contain stored food but their larvae would make a tasty, protein-rich meal for another animal. Where ever such a concentrated resource is present defensive measures have evolved and in the social wasps and bees this is a potent sting. In the distant past those bees or wasps with milder stings suffered greater damage to their nests and failed to produce as many offspring as those with more powerful stings. As a result the social bees and wasps have very painful, long lasting stings.

The solitary bees and wasps have no such concentrated resources to defend and their stings are much less severe than those of their social relatives. In fact, most solitary bees and wasps will only sting if physically restrained.

The social bees we saw today were Honeybees and Bumblebees. The other bees we saw, Carpenter bees, Leaf-cutter bees and numerous tiny bees were all solitary. We also saw several different kinds of solitary wasps feeding on the nectar of flowers in the Physic Garden: a Great
Great Golden digger wasp
Golden digger wasp
, Great Black wasp and Scoliid wasps. The scoliids are interesting. Their prey is the grubs of beetles in the scarab family (June bugs, Japanese beetles, etc.) that feed buried in the soil feeding on the roots of grasses. The female scoliids somehow can sense where these beetle larvae are, dig down into the soil, and lay an egg on the grub after paralyzing it with a sting.

Organ pipe mud dauber nests 
We didn't actually see one of the solitary wasps – we only saw it's nest and it wasn't possible to determine if it was active. This wasp builds long hollow tubes made from mud. Several are created side by side suggesting the pipes of an organ and giving the common name of the wasp: the Organ pipe mud dauber. Each tube is stocked with paralyzed spiders. Although the nests may be built together each one is built and maintained by a single female. There are reports that males stand guard while the female is hunting and protect the nest from parasites and other dangers. If true, this one of the only instances in which male wasps play any role after mating. People who have looked at the next contents find that they contain exclusively a single species of spider. This suggests that the wasps are able to seek out a specific habitat in which they can find their prey.

There were also several kinds of flies visiting flowers in the Physic Garden: a big, hairy Tachinid fly and some smaller flies that look very much like bees. The Tachinids are parasitic on other insects. For example, they lay eggs on caterpillars and, after hatching, the larvae eat their way into the body of the unlucky insect and consume it from the inside. Tachinids attack a large range of insects: grasshoppers and praying mantids, to name a few.

The bee mimics are in the Flower fly family (also known as the Hover fly family). They are able to hover motionless in front of a flower and then suddenly dart off. Their color pattern looks very bee-like: alternating rings of black and yellow. To distinguish them from real bees look at how the wings are held at rest. Flower fly wings are held at an angle, making the resting fly look a little like a jet aircraft with swept back wings. Real bees hold their wings straight over their backs when not flying. 

Adult hover flies feed on nectar and pollen but their larvae are vicious carnivores (really insectivores) that feed on aphids. So you should welcome these harmless flies to your garden; they protect your plants from the attacks of sap sucking insects. 

Carpenter bee biting base of Salvia flower

Carpenter bee nectar robbing a Salvia
Bees that cheat.
There are two beds of Salvia on the way to the Visitor's Center and they were being actively worked by Carpenter bees and Honey bees, but not in the way you would think. The Salvia flower has long throat and a narrow opening, so to reach the nectar produced at the bottom of the flower a pollinator would need a long tongue. While we watched the Carpenter bees we noticed that they were cheating. They were getting nectar from the back door. Instead of inserting their tongue into the floral opening they were biting an opening in the base of the corolla tube. Time after time we saw them fly from flower to flower and ignore the front door. The Honey bees were doing the same thing, but they were visiting flowers that the Carpenter bees had already slit open. This activity is anthropomorphically, but accurately, called nectar robbing.

 

Hops:

Developing Hops fruits

Lupulin glands on hops; they supply the flavor in beer
One of the arbors in the garden has some Hops vines growing over it and they are developing the flower clusters that are used to flavor beer. The clusters are superficially similar to the fruits of the tree we know as Hophornbeam, which accounts for the origin of the Hop part of its name. Opening up one of the clusters Linda saw what looked like a yellow dust on the bracts. Our initial thought was that it might be pollen, but that was not the case. Some Google searches revealed that these tiny golden balls are glands that contain a substance called lupulin, which is what gives hops the properties desired in making beer.

An aside: Before hops were used in beer making the plant used for the same purpose in England was Ground ivy, in the Mint family. Another name for Ground ivy is Gill-over-the-ground. The Gill part of the name should be pronounced as if the G is a J, making it sound French. And, in fact, the word Gill is from the French guiller which means to ferment beer. (source)

Flowers of the Aster family:

Zinnia blossom; white ray florets, yellow disk florets are open for pollinators
What appears to be a single flower in a Daisy is really an inflorescence, a group of smaller flowers called florets. In daisy-like plants in the Aster family these florets are of two kinds: ray florets and disk florets. The ray florets are those on the outer edge of the inflorescence – they look like what most people would call petals. In fact, each petal is the single ray of a tiny floret. Inside the ring of ray florets is a large number of florets that lack the prominent ray. Instead these florets each have a tubular corolla of fused petals. These are called the disk florets. If you examine them with a hand lens you can see that the disk is made of hundreds of these tiny flowers. In many of the Aster family flowers the ray florets are sterile; they are the flags that attract pollinators. In these plants the disk florets produce the pollen and seeds. But the pattern I want to call your attention to is the sequence in which these florets open. In plants like the Black Cohosh the oldest flowers are at the bottom of the raceme. They are the first to open and the flowers become mature in a sequence from the bottom to the top of the raceme, from the oldest to the youngest. In the daisy-like Asters the sequence of maturity is from the edge to the center. You can think of the Aster inflorescence as a squashed raceme where the oldest flowers are on the outside and youngest near the center of the disk. If you start with the oldest ray floret and connect it to the next oldest and so on until you reached the youngest floret in the center you would find that you had made a long spiral, like the groove on an old phonograph record. This spiral pattern arises from the way in which a floret is produced by an embryonic tissue at the very tip of a the flower bud – a tissue called the floral meristem. This group of cells produce by successive division the cells that become the florets. As each successive floret is produced the next one arises at a fixed angle from the preceding one. At the same time the distance between the floral meristem and the embryonic florets expands. This is how the spiral arises. A lot has been written about the significance of this angle and the patterns that it gives rise to – more than I can go into here. Two videos by Vi Hart delve into this in a very entertaining way; both are worth watching: first video; second video.

Other insects:

Widow Skimmer dragonfly

Dragonfly eyes and legs
We saw one dragonfly, a Widow Skimmer, today and succeeded in capturing it for a closer look. Dragonflies are visual predators. This life style is reflected in the size of their eyes. They occupy most of the head, giving them 360 degree vision. They are also the speediest and most maneuverable of the flying insects. They catch their prey on the wing and hold it with their spiny legs while devouring it.

Butterflies and Moths
There weren't many butterflies active today, but those we saw were outstanding: two kinds of Hairstreaks and one Skipper.

Hairstreaks get their name from the presence of two short, hair-like projections from the lower edge of the hind wing. Just next to the base of each projection there is a dark spot, usually near a different colored spot. The effect of these is to resemble an eye with antennae projecting from near it – in other words, an imitation head. The illusion is made better by a behavior that many of us observed today: when the butterfly is at rest the hind wings are rubbed together. Put your hands palms together in front of you. Now, keeping your palms together, rock each hand up and down. The hairstreak butterfly moves its hind wings in the same way. This wiggles the hairs – the fake antennae – and, together with the fake eye spots, make the edge of the wing look like the head of the butterfly. A predator like a bird or a lizard will strike at the moving decoy and get a piece of wing, allowing the butterfly to escape with its life, even if its a little tattered.
Juniper Hairstreak

Red-banded Hairstreak
The two Hairstreaks we saw were the Red-banded and Juniper Hairstreaks. There are many different Hairstreak species and identifying them is difficult. You need a good field guide.  The Juniper hairstreak larva feeds on Eastern Red Cedar, otherwise known as Juniper. The Red-banded hairstreak caterpillar feeds on Sumacs, but not on the living leaves. It feeds on the decaying leaves on the ground beneath the plants. Strange habits!

Young Milkweed Tussock moth caterpillars & skeletonized milkweed leaf
Near the Physic Garden was a small bunch of Common Milkweed. One of its leaves was almost completely skeletonized by a large group of young Milkweed Tussock moth caterpillars. These caterpillars are gregarious when young, spreading out and becoming solitary as they get older. The older caterpillars will completely defoliate the small group of milkweeds here – keep watch on their progress over the next week or two. The older caterpillars are quite striking – they are very hairy, covered with tufts of black, orange and white hairs. Like the Monarch butterfly the caterpillar and adult moth sequester the poisonous and distasteful compounds on the milkweed plant and are thus protected from predators. In spite of the common name this moth is in the Tiger moth family, not the Tussock moth family.

PawPaw fruit
Pawpaw fruits
A few weeks ago we noticed some fruits on the Pawpaw trees, so we stopped to see if they had gotten any larger. Most of them were spherical and the Ramblers that are familiar with Pawpaw fruit thought that was unusual. In their experience the fruit is generally more oblong. I suspect that the shape of the fruit is determined by the number of seeds it contains, which, in turn, is a function of how effectively the flower was pollinated. The more seeds, the less spherical the fruit is.

Mississippi Kite
Last, but not least, while we lingered in shade of the Heritage Garden gazebo someone spotted a Mississippi Kite (a bird) soaring over the garden. This beautiful bird has long, narrow wings that remind me of a soaring glider. According to the books they feed on the wing, catching large insects like cicadas, grasshoppers and katydids the make up the majority of their diet.

Then it was back to Donderos' Kitchen for many of us.

SUMMARY OF OBSERVED SPECIES:
Common Name
Scientific Name
Triangulate orb weaver
Verrucosa arenata
Orchard orb weaver
Leucauge venusta
Bottlebrush buckeye
Aesculus parviflora
Bumblebee
Bombus sp.
Hover fly
Family Syrphidae
Yucca
Yucca sp.
Salvia, various cultivars
Salvia sp.
Carpenter bee
Xylocopa sp.
Honeybee
Apis sp.
Widow skimmer dragonfly
Libellula luctosa
Yarrow
Achillea filipendulina
Great golden digger wasp
Sphex ichneumoneus
Great black wasp
Sphex pensylvanicus
Red banded hairstreak
Calycopis cecrops
Milkweed tussock moth
Euchaetes egle
Common milkweed
Asclepias syrica
Large milkweed bug
Oncopeltus fasciatus
Scoliid wasp
Hymenoptera: Scoliidae
Hops
Humulus lupulus
Tachinid fly
Family Tachinidae
Leaf cutter bee
Family Megachilidae
Juniper hairstreak
Callophrys gryneus
Flower fly; Hover fly
Family Syrphidae
Rattlesnake master
Eryngium yuccifolium
Pawpaw
Asimina triloba
American beautyberry
Callicarpa americana
Purple coneflower
Echinacea purpurea
Sachem skipper
Atalopedes campestris
Organ Pipe Mud dauber
Trypoxylon sp.
Mississippi kite
Ictinia mississippiensis

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