Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Predators delay pest resistance to Bt crops

05.03.2014

Crops genetically modified with the bacterium Bt (Bacillus thuringiensis) produce proteins that kill pest insects. Steady exposure has prompted concern that pests will develop resistance to these proteins, making Bt plants ineffective.

Cornell research shows that the combination of natural enemies, such as ladybeetles, with Bt crops delays a pest’s ability to evolve resistance to these insecticidal proteins.

“This is the first demonstrated example of a predator being able to delay the evolution of resistance in an insect pest to a Bt crop,” said Anthony Shelton, a professor of entomology at Cornell University’s New York State Agricultural Experiment Station in Geneva, N.Y., and a co-author of the paper. Xiaoxia Liu, a visiting scientist from China Agricultural University who worked in the Shelton lab, is the lead author on the paper published in the journal PLoS One.

Bt is a soil bacterium that produces proteins that are toxic to some species of caterpillars and beetles when they are ingested, but have been proven safe to humans and many natural enemies, including predaceous ladybirds. Bt genes have been engineered into a variety of crops to control insect pests.

... more about:
»Agricultural »ISDN »crops »genes »insect »larvae »proteins »resistance »species

Since farmers began planting Bt crops in 1996 with 70 million hectares planted in the United States in 2012, there have been only three clear-cut cases in agriculture of resistance in caterpillars, and one in a beetle. “Resistance to Bt crops is surprisingly uncommon,” said Shelton.

To delay or prevent insect pests from evolving resistance to Bt crops, the U.S. Environmental Protection Agency promotes the use of multiple Bt genes in plants and the practice of growing refuges of non-Bt plants that serve as a reservoir for insects with Bt susceptible genes.

“Our paper argues there is another factor involved: the conservation of natural enemies of the pest species,” said Shelton. These predators can reduce the number of potentially resistant individuals in a pest population and delay evolution of resistance to Bt.

In the study, the researchers set up large cages in a greenhouse. Each cage contained Bt broccoli and refuges of non-Bt broccoli. They studied populations of diamondback moth (Plutella xylostella) larvae, a pest of broccoli, and their natural enemies, ladybird beetles (Coleomegilla maculata), for six generations.

Cages contained different combinations of treatments with and without predators, and with and without sprayed insecticides on the non-Bt refuge plants.  Farmers commonly spray insecticides on refuge plants to prevent loss by pests, but such sprays can kill predators and prey indiscriminately.

The results showed that diamondback moth populations were reduced in the treatment containing ladybird beetles and unsprayed non-Bt refuge plants. Also, resistance to Bt plants evolved significantly slower in this treatment. In contrast, Bt plants with no refuge were completely defoliated in treatments without ladybirds after only four to five generations, showing rapid development of resistance in the pests. In the treatment with sprayed non-Bt refuge plants and predators, diamondback moth populations were reduced, but the larvae more quickly evolved resistance to the Bt plants.

“These results demonstrate the effectiveness of Bt plants in controlling the pest population, the lack of effect of Bt on the predators and the role predators play in delaying resistance to Bt plants in the pest population,” said Shelton.

The study was funded by United States Department of Agriculture and the Special Research Projects for Developing Transgenic Plants in China. 

Cornell University has television, ISDN and dedicated Skype/Google+ Hangout studios available for media interviews.

Melissa Osgood | EurekAlert!
Further information:
http://mediarelations.cornell.edu/2014/03/04/predators-delay-pest-resistance-to-bt-crops/

Further reports about: Agricultural ISDN crops genes insect larvae proteins resistance species

More articles from Agricultural and Forestry Science:

nachricht Better soil data key for future food security
21.06.2016 | International Institute for Applied Systems Analysis (IIASA)

nachricht New plant engineering method could help fill demand for crucial malaria drug
14.06.2016 | Max-Planck-Institut für Molekulare Pflanzenphysiologie

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: First experimental quantum simulation of particle physics phenomena

Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...

Im Focus: Is There Life On Mars?

Survivalist back from Space - 18 months on the outer skin of the ISS

A year and a half on the outer wall of the International Space Station ISS in altitude of 400 kilometers is a real challenge. Whether a primordial bacterium...

Im Focus: CWRU physicists deploy magnetic vortex to control electron spin

Potential technology for quantum computing, keener sensors

Researchers at Case Western Reserve University have developed a way to swiftly and precisely control electron spins at room temperature.

Im Focus: Physicists measured something new in the radioactive decay of neutrons

The experiment inspired theorists; future ones could reveal new physics

A physics experiment performed at the National Institute of Standards and Technology (NIST) has enhanced scientists' understanding of how free neutrons decay...

Im Focus: Discovery of gold nanocluster 'double' hints at other shape changing particles

New analysis approach brings two unique atomic structures into focus

Chemically the same, graphite and diamonds are as physically distinct as two minerals can be, one opaque and soft, the other translucent and hard. What makes...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ERES 2016: The largest conference in the European real estate industry

09.06.2016 | Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

 
Latest News

Nanoscientists develop the 'ultimate discovery tool'

24.06.2016 | Materials Sciences

Russian physicists create a high-precision 'quantum ruler'

24.06.2016 | Physics and Astronomy

Hubble confirms new dark spot on Neptune

24.06.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>