Navigation Links
Biological clocks of insects could lead to more effective pest control
Date:8/12/2009

CORVALLIS, Ore. 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."


'/>"/>

Contact: Jadwiga Giebultowicz
giebultj@science.oregonstate.edu
541-737-5530
Oregon State University
Source:Eurekalert

Related biology news :

1. Keck Foundation funds study of biological interactions with nanomaterials
2. New insight into the mechanisms of voltage sensing and transduction in biological processes
3. Biological warfare: What do you need to know?
4. A mechanism to explain biological cross-talk between 24-hour body cycle and metabolism
5. Story ideas from the Journal of Biological Chemistry
6. Emerging field of neuroecology is showcased in December issue of the Biological Bulletin
7. Story ideas from the Journal of Biological Chemistry
8. Systems biologist finds novel solutions to fundamental biological problems
9. MIT applies engineering approach to studying biological pathways
10. Lensless camera uses X-rays to view nanoscale materials and biological specimens
11. Systems biology approach identifies nutrient regulation of biological clock in plants
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/26/2016)... DUBLIN , April 27, 2016 ... of the  "Global Multi-modal Biometrics Market 2016-2020"  report ... ) , The analysts forecast ... a CAGR of 15.49% during the period 2016-2020.  ... a number of sectors such as the healthcare, ...
(Date:4/14/2016)... TEL AVIV, Israel , April 14, 2016 /PRNewswire/ ... in Behavioral Authentication and Malware Detection, today announced the ... has already assumed the new role. Goldwerger,s ... for BioCatch, on the heels of the deployment of ... In addition, BioCatch,s behavioral biometric technology, which discerns unique ...
(Date:3/29/2016)... , March 29, 2016 ... "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased to ... ink used in a variety of writing instruments, ensuring ... of originally created collectibles from athletes on LegacyXChange will ... analysis of the DNA. Bill Bollander ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ON , June 27, 2016 /PRNewswire/ - BIOREM Inc. ... has been advised by its major shareholders, Clean Technology ... United States based venture capital ... shares of Biorem (on a fully diluted, as converted ... the disposition of their entire equity holdings in Biorem ...
(Date:6/27/2016)... ... June 27, 2016 , ... Newly created 4Sight Medical ... to the healthcare market. The company's primary focus is on new product introductions, ... strategies that are necessary to help companies efficiently bring their products to market. ...
(Date:6/24/2016)... 2016  Regular discussions on a range of subjects including ... two entities said Poloz. Speaking at a lecture ... , he pointed to the country,s inflation target, which is ... "In certain areas there ... common economic goals, why not sit down and address strategy ...
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, a ... eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering with experienced clinical research ... by providing practical tips, tools, and strategies for clinical researchers. , “The landscape ...
Breaking Biology Technology: