Researcher Studies How Flowers Fight Back Against Damaging Insect Visitors

Aug 03, 2010

Though summer's flowers appear delicate and carefree to us, in fact plants must be tough enough to defend their blossoms against antagonists including florivores and nectar robbers, that is, insects who eat, steal or destroy nectar and flowers without performing beneficial pollination services.

Many plants use and other strategies to stop or punish marauding insects from threatening their flowers, according to doctoral student Nicole Soper Gorden in plant, soil and insect sciences. She recently received a $14,998 National Science Foundation dissertation grant to bring new methods to the investigation of how flowers defend themselves against robbers and florivores and explore how they interact with beneficial such as bees, to assure .

Only 12 such grants were funded nationwide from 140 applications, a compliment to the significance of Soper Gorden's research topic and recognition of her skills in chemical analysis. She is the first to use advanced chemical analysis to study the woodland flower Spotted Touch-me-not, Impatiens capensis, also known as jewelweed.

Chemical defenses in have been well studied, but that's not true for flowers, Soper Gorden explains. Many nectars contain alkaloids and phenolics to deter pests, and flower petals can contain the same chemical defenses as leaves. She is investigating in detail how plants defend not only their leaves but their blooms.

"Flowers are closely linked with plant fitness and floral defensive compounds are common, so understanding the role of floral chemistry mediating interactions is essential," she says. "Pollinators are estimated to provide $100 billion in services each year, and insects that damage flowers can devastate crops, carry diseases, cause invasions or act as biological control agents. Understanding how floral competitors interact with one another and their is critical for managing crop yield and ."

Flowers face a surprising variety of antagonists. For example, some bees cut holes in blooms to steal nectar, while other bee species, flies and ants steal nectar without damaging the blossom. Beetles, including the gardener's nemesis, the Japanese beetle, are florivores, which means they eat the entire flower and are not interested in the nectar. This summer and next, Soper Gorden is observing interactions between these pests and jewelweed and conducting experiments with insect visitors in garden plots at the nearby Hampshire College farm.

Right now, Soper Gorden and three undergraduate assistants are collecting nectar, flowers and leaves and counting numbers of insect visitors by species interacting with 200 plants in the experimental garden. They're assessing pollination in 15-minute sessions once per week, recording the number of flowers visited and time per flower as well as visiting numbers of nectar robbers, thieves, florivores and flower-galling insects.

Further, she's looking at numbers of fruits, seeds per fruit, seed mass and percent germination as markers of reproductive success. In the laboratory, Soper Gorden is measuring anthocyanins, condensed tannins, nectar production and sugar composition using spectrophotometry and high performance liquid chromatography.

Next summer, the young researcher will set up an array of 160 jewelweed plants at Hampshire Farm and use three treatments which manipulate pollinators, nectar robbers and florivores to compare groups under the three manipulated conditions, under all possible combinations of the three, plus a control group with no treatments.

One treatment involves hand-pollination to increase pollination success. For a second, Soper Gorden will simulate nectar robbing by cutting a small hole near the flower's spur, where nectar robbers typically do the same, and removing nectar. Finally, she'll simulate florivory by allowing Japanese beetles to eat approximately 50 percent of floral tissue. Reproductive and other measures will be compared to a control group with no manipulations.

"We'll use these data to model how all the insects interact with each other and the plant, as well as the plant's defenses and its nectar rewards, to better understand the flower's role and the overall implications for plant reproduction," she summarizes.

Explore further: Male monkey filmed caring for dying mate (w/ Video)

add to favorites email to friend print save as pdf

Related Stories

Nectar is not a simple soft drink

Feb 27, 2007

The sugar-containing nectar secreted by plants and consumed by pollinators shares a number of similarities to fitness drinks, including ingredients such as amino acids and vitamins. In addition to these components, nectar ...

Plant hormone regulates nectar production

Mar 29, 2010

Rapeseed is one of the ten most important agricultural crops worldwide. In spring, the rapeseed fields with their bright yellow flowers are widely visible: this year winter rapeseed is being cultivated on ...

Probing Question: Why are flowers beautiful?

Jan 24, 2008

In the 1930s, American artist Georgia O'Keefe wrote: "What is my experience of the flower if it is not color?" O'Keefe is best known for her vibrantly colorful close-ups of petals and stamens on large canvases.

Honeybees not fooled by cheating flowers

Apr 15, 2009

(PhysOrg.com) -- Flowers that want to cheat pollinators by not paying them for their services shouldn’t try to lure them in using floral scents, scientists at Newcastle University have shown.

Are bees also addicted to caffeine and nicotine?

Feb 10, 2010

A study carried out at the University of Haifa has found that bees prefer nectar with a small concentration of caffeine and nicotine over nectar that does not comprise these substances at all. "This could ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.