Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biological clocks of insects could lead to more effective pest control

17.08.2009
Researchers at Oregon State University have discovered that the circadian rhythms or biological "clocks" in some insects can make them far more susceptible to pesticides at some times of the day instead of others.

With further research, the scientists said, it may be possible to tap into this genetic characteristic, identify the times that a target insect is most vulnerable to a specific pesticide, and use that information to increase the effectiveness, reduce costs and decrease the amounts of pesticide necessary for insect control.

Approaches such as this may also be highly useful in programs of "integrated pest management," the researchers said, which aim to minimize pesticide use, prevent development of resistance to pesticides, and use a broad range of physical or chemical control measures to enhance the long-term effectiveness of an insect control program in crop agriculture.

The findings were just published in PLoS ONE, a professional journal, in work supported by the U.S. Department of Agriculture, National Institutes of Health and National Science Foundation.

"We found that it took triple the dose of one pesticide to have the same lethal effect on fruit flies at the time of day their defenses were strongest, compared to when they were weakest," said Louisa Hooven, a postdoctoral fellow in the OSU Department of Zoology and lead author on the study. "A different pesticide took twice the dose. This makes it pretty clear that the time of day of an exposure to a pesticide can make a huge difference in its effectiveness."

In recent years, researchers have found that the genes which are sensitive to the natural rhythms of day and night can have a wide range of biological effects, on everything from fertility to feeding patterns, sleep, hormone production, stress, productivity, medication effectiveness and many other functions. And they operate in multiple cells in many or most plant and animal species, including humans.

In the newest work, circadian rhythms appear to coordinate "xenobiotic metabolizing" genes, or the genes responsible for breaking down and detoxifying various poisons, such as pesticides. Besides that, it's possible that circadian clocks may also affect absorption, distribution, excretion, and molecular targets of toxicity.

"This rhythmic defense mechanism may have evolved in order to disarm the noxious compounds that plants produce to avoid being eaten by an insect," said Jadwiga Giebultowicz, a professor of zoology at OSU. Other co-authors on this work included OSU undergraduate students Katherine Sherman and Shawn Butcher.

The OSU study found that insect defenses against two commonly used pesticides, propoxur and fipronil, were strongest during mid-day, and weakest around dawn, dusk or the middle of the night. The effectiveness of two other pesticides studied – deltamethrin and malathion – did not seem to be so strongly associated with time of day, at least with fruit flies.

"For this approach to be useful in agriculture or other places pesticides are used, we will need to test specific insects against specific pesticides, and we will probably find differences in time of maximum effectiveness for various pest-pesticide configurations," Giebultowicz said. "In some cases we may be able to greatly improve the effectiveness of pesticides or allow the use of reduced doses."

Although many pesticides have a residual effect, the researchers said, the timing of the first exposure can be critical. Many pesticides are repellent to insects, and if they are not killed immediately they may simply avoid the residue, or in some cases develop resistance to the pesticide – a critical and costly problem in modern agriculture. Pesticide resistance has been a driving force behind the evolution of the field of integrated pest management, as growers realized that sustainable pest control is not as simple as using the same pesticide, year after year, which often becomes increasingly ineffective and more expensive.

The new findings, the OSU researchers said, are also another example of how circadian rhythms are important in other detoxification systems in biology. In human medicine, a field called "chronopharmacology" is already developing, based on the observation that some medications are far more effective if administered at one time of the day instead of another.

Research into the molecular mechanisms underlying circadian rhythms was pioneered in fruit flies, but the OSU researchers hope their future research will shed light on how the biological clock influences responses to chemicals in humans.

"A fundamental understanding of the functional significance of circadian rhythms in chemical exposures may facilitate strategies to reduce adverse events in humans, promote control of pest species and reduce pesticide use," the researchers wrote in their report.

"Our study strongly suggest that time of day should be included in insect control strategies and human risk assessment of chemical exposures, including pesticides," they said. "In some cases, the clock, together with the dose, may make the poison."

Editor's Note: A digital image of the type of fruit fly used in this research, Drosophila melanogaster, can be obtained on Wikipedia at this URL: http://bit.ly/kUcwm

Jadwiga Giebultowicz | EurekAlert!
Further information:
http://www.oregonstate.edu

More articles from Life Sciences:

nachricht What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society

nachricht Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>