On this beautiful cool Sunday morning, UW Arboretum naturalist Susan Carpenter met the group of 7 Friends who gathered for her Pollinator Tour at the entrance to Picnic Point. She prepared us for our observations of these important pollinators by reviewing the life cycle of a bumble bee colony.  I was fascinated by her description of the hardworking queen bumblebee, who emerges in the spring from her solitary underground hibernation, collects nectar from flowers and sets up a nest nearby. Working alone, she lays her first batch of eggs, fertilized in the previous summer, and sits on them to warm them. The queen has to leave the nest to gather more nectar and pollen to feed the hatched larvae which mature into adult female worker bees. As the season progresses, the queen lays unfertilized eggs which develop into haploid males that leave the nest in search of other queens to fertilize. Susan gave each of us a laminated copy of the Bumble Bee Brigade Field Guide to Females and Males of 21 bumblebee species. She also gave us a Rusty Patched Bumble Bee Midwest Plant Guide to native plants that will attract most of the other bumblebee species, too.  

Susan encouraged us to take our own photos of bees and submit them to the Wisconsin DNR’s Bumble Bee Brigade, wiatri.net/inventory/bbb.  As the insects' territory is squeezed by climate change, and they face threats from pesticide use, loss of habitat and disease, the DNR and the Xerces Society can use our observations to guide their bumblebee conservation efforts.  
Bumblebees sighted today:
Bombus auricomus       black and gold
Bombus bimaculatus    twospotted
Bombus griseocollis      brownbelted
Bombus impatiens        common eastern
Bombus vagans            half-black
The federally-listed-as-endangered bee that we were hoping to see, but did not:
Bombus affinis        rusty patched
​
​Many thanks to Susan for her very engaging and informative tour. Report by Doris Dubielzig and Friends host Steve Sentoff, Photos by Glenda Denniston, Doris Dubielzig, Seth McGee, Steve Sentoff

​On a beautiful Saturday afternoon, Professor Glen Stanosz shared his knowledge of trees with five enthusiastic guests. As attendees strolled through the shaded paths near Picnic Point, Glen identified ash, oak, red pine, and white pine trees among other woody species. 
Each tree species was paired with a remarkable tale of conquest by fungal or insectivore invaders… occasionally intertwined with hopeful twists of perseverance as researchers discover some tree species are beginning to develop resistance against their pesky assailants:

• Ash trees face adversity from two fronts: emerald ash borer (EAB) insects and the Candidatus fraxinii bacteria which can harm ash trees’ ability to store and transfer water and nutrients, respectively. Glen noted that most ash trees in the Preserve have succumbed to the forces of Candidatus fraxinii, displaying the characteristics of Ash Yellow disease (a sparse crown, with leaves that exhibit a “cupped” shape as you look at higher branches of the tree, and a “witches broom” in newer branches) which reflect the consequences of a failing root system. However, the future of ash trees is not necessarily bleak according to Glen, as new research indicates that ash trees are developing resistance to both EAB and Candidatus fraxinii. 

 

• Oak trees commonly fall victim the coordinated acts of the Bretziella fagacearum fungus and their sap beetle accomplishes. The Bretziella fagacearum fungus can colonize in wounds of oak trees and create a mat of sweet-smelling spores under the oak bark to attract sap beetles. Fresh oak tree wounds also release a sweet smell and attract sap beetles— so sap beetles can effectively spread the Bretziella fagacearum fungus from oak tree to oak tree if as they alternate visits to alluring sweet-smelling fungal pads and equally appealing oak wounds. Researchers have discovered that sap beetles can detect oak wounds just 15 minutes after a wound is created— an impressive skill, but extremely problematic in the eyes of scientists who want to mitigate spread of oak wilt disease. Once established in the oak tree, Bretziella fagacearum spreads through the root system of the tree until it ultimately kills the oak.

While trees face incredible feats against fungal and insect invaders alike, Glen described how this harassment is a result of trees’ tempting design. Trees are made of two main components: cellulose and lignin… in other words, trees are made of sugar and glue! So, if trees have the audacity to grow tall and advertise their sweet composition to the decomposers in their ecosystems, that must mean trees have some secret defenses of their own. Indeed, Glen skillfully pointed out trees using their defensive ability to compartmentalize their trunks; these trees created a seal that trapped an invading fungus on the interior of the trunk, allowing the living outer region of the trunk to service the tree unharmed. 
 
Finally, Glen referenced a non-fungal threat to forests: climate change. With observed warming trends in Wisconsin, Glen said it is possible that the composition of forests may change over time. Glen hypothesizes that Wisconsin may lose its maple and conifer trees, but retain hickory trees as hickory trees can be found in southern/warmer regions of the US. ​​Report and Photos by the Friends' host Olympia Mathiaparanam.

My first day…as a water quality monitor—Doris Dubielzig reports:
"In our first year as a Lake Forecasting Steward with Clean Lakes Alliance, the Friends recruited a team of volunteers, each of whom committed to collect near-shore data twice a week for a month. Our site is the floating pier at the boat launch on University Bay across from parking lot 60. Steve Sentoff was the first to make observations, beginning shortly after Luke Wynn, Watershed specialist for CLA, trained our 7 member team in late April.  Nicole Miller and Genevieve Murtaugh continued in June. I had signed up for July. On Monday night, I drove to Nicole’s home, where she handed me the Instruction Book, the digital thermometer and the turbidity tube.