UE Biology Major Chase Boyles watches for pollinators — normally eastern bumble bees — on the uncovered Thai Lavender Eggplants being used in the study on urban pollination. The "veiled" plants cannot be access by pollinators, but can still grow fruit without them. Overall, plants accessibly by pollinators grew significantly more fruit than the covered plants.
(Tim Jagielo / WNIN News)
The Biology department of the University of Evansville used 60 eggplants to study the effect of local urban pollinators, which helped double the plant’s output; part of growing interest in urban ecology
A simple tool is used to measure for mature eggplant fruits for harvesting. (Tim Jagielo/WNIN News)
It’s early on a Thursday morning and University of Evansville (UE) students and faculty are out picking eggplants — specifically Thai Lavender Eggplants.
“We're looking for 20 grams for the size of the fruit,”said sophomore Kasey Martin. He’s with sophomore Chase Boyles and Biology Professor Cris Hochwender.
They’re methodically moving from plant to plant near the native plant garden at UE, snipping small purple fruits and dropping them into specially labeled bags.
They’re using pre-made loops of zip tie to select the mature fruits, to the din of crickets, cicadas and the distant police siren and nearby traffic from Weinbach Avenue.
UE has undertaken a study which further emphasizes the importance of urban pollinators, and the study of urban ecology. They are studying whether their local pollinators will change the yield of eggplant fruits in the open plants.
There are 60 of these plants. Half are covered with mosquito netting. The other plants are open. The Thai Lavender Eggplant is self-pollinating – meaning it will create fruits regardless of pollinators.
“Our prediction on the open and closed pollinated plants is we're going to have more fruit and flowers set on the plants that are open pollinated, compared to the closed pollinated plants, due to the access of bees,” Martin said.
They’ve been doing this for the past seven weeks — harvesting early on Thursdays and counting the bees later in the morning.
UE also chose Thai Lavender eggplants because of the difficulty in accessing the plant’s pollen.
An eastern bumble bee can pollinate plants in the nightshade family despite difficult to reach pollen. (Tim Jagielo/WNIN News)
Bumble Bees are native pollinators. They use vibration at a certain frequency to shake the pollen from the deep-set anther of the plants. Honeybees can’t do this.
They also aren’t native to North America. While vitally important for honey and almost singlehandedly propping up California almond production, local growing plants need these local pollinators.
The need for native pollinators is especially true in an urban setting. Hochwinder said this experiment is fairly unique. He’s only aware of such a study being done with the Thai Lavender Eggplant in its native India.
“This really focuses on urban questions in North America,” he said. “Because one of the things as an ecologist that I want to do is motivate people to grow native (plants). And one really big benefit of growing natives is you bring in the native bees, and then they give us the pollination benefits in and food gardens in urban areas.”
This points to a growing area of study — urban ecology. It was a big focus of the annual meeting of the Ecological Society of America (ESA) in August held in Long Beach, California.
The more than 15 topics included “Solutions to Urban Ecological Restoration and Management,” “Lessons Learned Managing Vacant Land as Pollinator Habitat,” and “How is Success Defined in Urban Afforestation Initiatives.”
Susannah Lerman, research ecologist with the USDA Forest Service said the study of Urban Ecology is increasingly mainstream. When she first attended ESA meetings in the early 1980s, there was little to no mention of this.
It’s a hot topic because most humans live in urban and suburban settings.
The development of these urban and suburban settings are a leading cause of native pollinator habitat loss.
“However, when we look at these urban and suburban areas, there's a lot of green space, and so there's a lot of potential for us to provide pollinator habitat, to provide habitat for other species, like birds and bees and other pollinators.”
She said 30-percent of the continental US is backyard space — seven times the amount of area allocated for forests.
So, front yards of backyards can be used to attract and support native pollinators and plants — or the robust, active native plants garden roughly the footprint of a medium-size garage like the one at UE.
“I think it's really cool to see how much diversity there actually is, especially in an urban area like this where we've lost a ton of diversity,” biology major Chase Boyles said of the native garden.
“It's really cool to see what just the small area has brought in and what we can see pollinating on these eggplants.”
After more than seven weeks, they recently ended the experiment. There were two-times the number of fruits produced compared to netted plants. The total yield of eggplant biomass when bees had access, was more than three-times compared to the covered plants, with one-third larger fruit.
And these were mostly eastern honeybees right from the native plant garden, with a few sweat bees. Hochwender and his two students netted 17 pounds of eggplants, which he says is great with olive oil, lemon and tahini.
“These make the best Baba Ganoush,” Hochwender said. “They just pick up that smoky flavor.”
Hochwender said his next step is to write a paper to report his findings to the scientific community.
University of Evansville sophomores Chase Boyles, (furthest) and Kasey Martin (center), with professor Cris Hochwender (left) harvested fruits of the eggplant on Thursdays through out the summer. While these plants can self-pollinate, they are far more successful when pollinated by insects — mostly eastern bumblebees. (Tim Jagielo/WNIN News)
