Thursday, August 3, 2023

Ramble Report August 3, 2023

Authors of today’s Ramble report: Linda and Don. Comments, edits, and suggestions for the report can be sent to Linda at Lchafin@uga.edu
All photos are by Don Hunter except where otherwise indicated. His complete set of photos from today's Ramble are on Facebook
here.

Rainy morning at the Botanical Garden
Photo of Impatiens by Aubrey Cox
Today was a “rainy-day ramble,” practicing the new Nature Ramble weather policy: we meet regardless of the weather and see what happens. We’re pretty sure that, rain or shine, we will have a good time. About 15 ramblers met in the Visitor Center and swapped stories for a while.

Don shared an exciting piece of news with us. As many of us know, Don has collaborated with Becky Hunt Griffin, Coordinator of the Great Southeast Pollinator Census and UGA Extension entomologist, for several years, providing detailed photographs of Georgia pollinators and insect identifications during the census and throughout the year. Becky just posted this announcement on the Pollinator Census Facebook page: “I am excited to announce that the 2023 Great Southeast Pollinator Census Grand Marshal is Don Hunter. Don has been an incredible advocate for the Census and pollinators. He enjoys helping educate others about insects.  He was the obvious choice for this year's Grand Marshal and I was honored to present him the a plaque recognizing his role. Thank you, Don Hunter, for all you do for pollinators! Look for Don's video opening this year's Census early on August 18th.”

Don proudly displaying his award


Don joined the Nature Ramblers in the spring of 2013 and quickly took on the role of photographing and recording each ramble. Before then, he'd had no interest in insects but has since taught himself through studying field guides, iNaturalist, BugGuide.net, and other online sources. What is the secret to his success with photographing insects? "Just practice, practice, practice and picking up hints and techniques from friends and fellow photographers."

The Great Southeast Pollinator Census is a community science project created by UGA Extension, now in its sixth year with thousands of participants all over the SE. The census will take place this year August 18-19.

Sandy shared highlights from her recent butterflying trip in Costa Rica. Below are  seven photos of some of the butterflies, plants, snakes, and birds she encountered. The complete set of her photos are here.

 

Linda shared this article about living in the natural world in a time of change.

Around 9:30, Ramblers ventured outside into a barely detectable mizzle. Most of us wandered around the Herb and Physic Garden as the sun came out, admiring the pollinators that were visiting the medicinal and culinary herbs curated by Garden Curator Carol Dyer Rudow.

Bumblebee on Oregano flowers
photo credit

Meanwhile Don was photographing in the nearby beds and in the Heritage Garden, employing his new macro flash diffuser to spectacular effect. All of Don’s photos are here on Facebook and a selection are below.

As members of the Aster family, Zinnia flower heads are a combination of small fertile flowers (in this photo, five-lobed yellow flowers) held on a central disk and outer whorls of pink ray flowers. Many of the Zinnias at the Garden show a tendency to have oddly shaped and colored ray flowers popping up among the disk flowers.
Versute Sharpshooter resting on a Zinnia’s ray flower.
Ocola Skipper visiting the disk flowers on a Coreopsis flower head.
Large Milkweed Bug on Butterfly weed flowers.

Large Milkweed Bugs exhibit aposematic coloration – bright orange or red colors that warn potential predators that an insect is poisonous. Adults (above) are patterned with black and reddish-orange markings, juveniles are mostly red with a few black spots (below), and even their eggs are bright orange.

Ailanthus Webworm Moth visiting the small fertile flowers of a Hydrangea inflorescence. The large showy flowers in the foreground are sterile, existing only to attract insects who quickly discover that pollen and nectar are available only in the small flowers.

Job’s Tears is an odd-looking grass with wide, clasping leaves and bulbous swellings at the base of the seed head. It is native to Southeast Asia and cultivated there at high elevations where other grain crops do not grow well. The stem at the base of the flower cluster is swollen into a hard, round ball called a pseuodocarp ("fake fruit"). Some varieties of Job’s Tears have hard pseudocarps that are used to make beads; other varieties have soft pseudocarps that are harvested and sold as Chinese pearl barley.


Carpenter Bee “robbing” a Salvia flower by chewing a hole in the base of the flower and sipping nectar.

Don saw quite a few Western Honeybees and one Eastern Carpenter Bee visiting Salvia flowers in search of nectar. Dale wrote the following mini-essay (lightly edited) about nectar robbing by bees in the Ramble Report of July 19, 2018. At that time, we’d been watching large Carpenter Bees and small Honeybees visiting Salvia flowers.

Dale: “The larger Carpenter Bees were ‘nectar-robbing,’ piercing the narrow bottom of the tubular flower, while only the [smaller] Honeybees were attempting to access the nectar through the flower opening. While visiting the flower in the ‘legitimate’ way, the smaller bee thrusts its head into the opening at the front of the blossom to reach the nectar at the base, thereby coming in contact with the anthers and picking up a load of pollen on their head and thorax. They also contact the stigma, the flower structure that receives pollen, and the pollen they carry from other flowers gets deposited on that stigma, effecting pollination.

As the Carpenter Bee visited each blossom, it avoided the opening of the corolla, instead heading straight to the base of the flower. The nectar gland is inside the flower, at the base of the corolla. If the blossom has been previously visited by a nectar thief, there will be a hole there and the bee will insert its mouthparts and sip up the available nectar. If there is no hole, the bee makes one by biting the flower with its mandibles.

You might think that nectar robbery would harm the ability of the robbed plant to produce fruits or seeds. But several studies have shown that there is no difference between the productivity of robbed and unrobbed plants. In some cases, there may even be benefits from being robbed. How can robbery be beneficial? It has been suggested that by depleting the nectar supply of a flower it stimulates subsequent visitors to travel a greater distance before they visit another flower. This would increase the frequency of outbreeding by reducing the likelihood of self-fertilization. Self-fertilization can occur when a bee carries pollen to another flower on the same plant – self-fertilization can result in offspring with lower genetic fitness.

Mutualistic relationships, like that of plants and their pollinators, can be sensitive to cheating. The only way plants have of responding to a cheater is through evolution or behavioral change. If nectar robbing were really damaging to a plant, then plants that could reduce or prevent this behavior would be at an advantage. They would produce more offspring than plants that experienced more robbery and these offspring would be more resistant to robbing. Remember that a plant-pollinator relationship is not isolated, it exists in a complex web of relationships. There are many kinds of bees and flowers in an ecological community and each of them interacts, directly or indirectly, with all the others. As long as there are smaller bees around to pollinate a flower, it may not matter that Carpenter Bees steal nectar. But if the only pollinator present was a Carpenter Bee, the long-term presence of the plant would be in doubt. This discussion of nectar robbery in Wikipedia shows how complex such an apparently simple behavior can be.” Thanks, Dale!

SUMMARY OF OBSERVED SPECIES

Oregano                                   Origanum vulgare
Bumblebee                               Bombus sp.
Chamber Bitters                       Phyllanthus urinaria

Creeping Charlie, Ground Ivy  Glechoma hederacea
Plumeria, Frangipani                Plumeria sp.
Asparagus                                Asparagus officinalis
Lawn Pennywort                      Hydrocotyle bowlesioides
Zinnia                                      Zinnia elegans
Versute Sharpshooter Leafhopper    Graphocephala versuta
Ocola Skipper
                            Panoquina ocola
Coreopsis, Tickseed                Coreopsis sp.
Black-eyed Susan                   Rudbeckia hirta
Long-tailed Skipper                 Urbanus proteus
Fiery Skipper                           Hylephila phyleus
Lantana                                   Lantana camara cultivar
Transverse-banded Flower Fly
       Eristalis transversa
Carpenter-mimic Leafcutter Bee    Megachile xylocopoides
Fennel                                  Foeniculum vulgare
Large Milkweed Bug            
Oncopeltus fasciatus
Ailanthus Webworm Moth    Atteva aurea
Job's Tears                            Coix lacryma-jobi
Hydrangea                            Hydrangea sp.
Blue-green Bottle Fly            
Lucilia coeruleiviridis
Salvia 
cultivar 'Heatwave Blaze'     Salvia microphylla   
Common Eastern Bumble Bee       Bombus impatiens
Eastern Carpenter Bee                  Xylocopa virginica
Carpenter-mimic Leaf Cutter Bee    Megachile xylocopoides