You catch (and kill) more flies with this sweetener

Jun 04, 2014

In a study that began as a sixth-grade science fair project, researchers at Drexel University have found that a popular non-nutritive sweetener, erythritol, may be an effective and human-safe insecticide.

Erythritol, the main component of the sweetener Truvia, was toxic to Drosophila melanogaster fruit in a dose-dependent manner in the Drexel team's study, published in PLOS ONE. The flies consumed erythritol when sugar was available and even seemed to prefer it. No other sweeteners tested had these toxic effects.

Based on this discovery, Drexel and the researchers are pursuing a patent on erythritol as an insecticide and are continuing to study its effectiveness.

"I feel like this is the simplest, most straightforward work I've ever done, but it's potentially the most important thing I've ever worked on," said Sean O'Donnell, PhD, a professor of biology and biodiversity, earth and environmental science in Drexel's College of Arts and Sciences, who was a senior author of the paper.

Erythritol is a naturally occurring sugar alcohol that is present in small amounts in many fruits. It has been tested in humans at high doses and found safe to consume; it has been designated as a generally recognized safe food additive by the U.S. Food and Drug Administration since 2001 and is also approved as a food additive in many other countries.

And the new evidence that it is toxic to flies, which are drawn to its sweet flavor even when other foods are available, makes it a killer combination. It is particularly promising because it is safe for human consumption, unlike other pesticides that have caused tragic accidental poisonings such as one that killed 23 Indian school children last year.

This line of research would not have started without the curiosity of one of the paper's co-authors, Simon D. Kaschock-Marenda, who is now in the ninth grade. Three years ago, Kaschock-Marenda questioned why both of his parents had stopped eating white sugar when trying to eat healthier.

"He asked if he could test the effects of different sugars and on fly health and longevity for his science fair, and I said, 'Sure!" recalled Daniel Marenda, PhD, Simon's father and an assistant professor of biology in Drexel's College of Arts and Sciences – and now co-senior author of the study. Father and son proceeded to buy supplies at their local supermarket – as many types of sugar and sugar substitutes as they could find. Marenda's lab supplied "baby" flies and growth medium for his son to raise flies in each of the different types of sweeteners at home, in preparation for the science fair at the Julia R. Masterman School in Philadelphia.

"After six days of testing these flies in our house, he came back to me and said, 'Dad, all the flies in the Truvia vials are dead...'" Marenda said. "To which I responded, 'OK...we must have screwed up somehow. Let's repeat the experiment!'"

Under more rigorous testing conditions in the lab, they replicated their result and knew they were onto something – and could use a hand. "I only use insects to study the brain, so I needed someone who knew something about insects," said Marenda. So he brought the find down the hall to O'Donnell, whose background in entomology suited him to the task.

Working together, the team further pursued the question of how fruit flies responded to sweeteners – testing flies grown feeding on each of multiple non-nutritive sweeteners as well as sucrose (table sugar) and corn syrup.

Flies raised on food containing Truvia lived for only 5.8 days on average, compared to 38.6 to 50.6 days for flies raised on control and experimental foods without Truvia®. Flies raised on food containing Truvia also showed noticeable motor impairments prior to their deaths.

"Indeed what we found is that the main component of Truvia, the sugar erythritol, appears to have pretty potent insecticidal activity in our flies," Marenda said.

They found that the toxic effect did not come from stevia plant extract, which is present in both Truvia® and the non-nutritive sweetener PureVia. PureVia was included in their experiments and had no on the flies.

"We are not going to see the planet sprayed with erythritol and the chances for widespread crop application are slim," O'Donnell said. "But on a small scale, in places where insects will come to a bait, consume it and die, this could be huge."

The scientists haven't yet confirmed which insects erythritol might kill, other than fruit flies, or how its toxic effects take hold.

The compound is even naturally produced in some insects, which use it as anti-freeze to protect their bodies against cold conditions – but that may not mean much, as their experiments bear out that the dose makes the poison. The researchers plan to conduct further experiments on other insects such as termites, cockroaches, bed bugs and ants. They will also test erythritol's toxicity as it moves up the food chain by experimenting on praying mantids, which eat .

Until further research helps refine the safest and most effective uses of erythritol for insect pest control outside of the lab, can a supermarket dose of Truvia® help get rid of fruit fly infestations in the kitchen? The scientists aren't sure. That might be an experiment to try at home, or for the next science fair.

Explore further: Caffeinated fruit flies help identify potential genes affecting insecticide resistance

More information: Paper: dx.plos.org/10.1371/journal.pone.0098949

add to favorites email to friend print save as pdf

Related Stories

Fruit fly's 'sweet tooth' short-lived, research finds

Oct 16, 2012

While flies initially prefer food with a sweet flavor, they quickly learn to opt for less sweet food sources that offer more calories and nutritional value, according to new research by University of British ...

Fruit flies medicate their larvae with alcohol

Feb 22, 2013

(Phys.org)—A new study in the U.S. shows that fruit flies lay their eggs on a food source with a high alcohol content if they see parasitic wasps in the area, instead of a non-alcohol food.

'Diabetic flies' can speed up disease-fighting research

Nov 06, 2013

In a finding that has the potential to significantly speed up diabetes research, scientists at the University of Maryland have discovered that fruit flies respond to insulin at the cellular level much like ...

Recommended for you

Science casts light on sex in the orchard

5 hours ago

Persimmons are among the small club of plants with separate sexes—individual trees are either male or female. Now scientists at the University of California, Davis, and Kyoto University in Japan have discovered ...

Four new dragon millipedes found in China

7 hours ago

A team of speleobiologists from the South China Agriculture University and the Russian Academy of Sciences have described four new species of the dragon millipedes from southern China, two of which seem to ...

Scientist creates automatic birdsong recognition app

10 hours ago

Dr Dan Stowell, an EPSRC Research Fellow in QMUL's School of Electrical Engineering and Computer Science, has used a grant from Queen Mary Innovation to develop a prototype for an app that turns his research ...

New research reveals fish are smarter than we thought

11 hours ago

(Phys.org) —A new study from researchers in our Department of Psychology with colleagues at Queen Mary University of London has reported the first evidence that fish are able to process multiple objects ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

EyeNStein
5 / 5 (1) Jun 05, 2014
If it causes motor impairment it might be a good time to re-test on human nerve cells.
It may bind to something other than taste buds sensory nerves.
Jimee
not rated yet Jun 06, 2014
What other critters might be harmed?
Osiris1
not rated yet Jun 23, 2014
Ahhhh, now I get my revenge on the famous Florida fruitfly (gnat). I'll have this with my morning coffee on da porch so when they bite me or crawl up my nose and/eyes, MY body fluids will bite those nasty buggers BACK!!!
otero
Jun 23, 2014
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.