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(Environment) (Bio) Pests & Wasps: New Possibilities

 
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PostPosted: Wed Jan 18, 2006 9:26 am    Post subject: (Environment) (Bio) Pests & Wasps: New Possibilities Reply with quote






New Possibilities to Fight Pests with Biological Means
Dr. Jörg Degenhardt
Max Planck Institute for Chemical Ecology
January 18th, 2006

Max Planck researchers in Jena, Germany have identified a gene which produces a chemical "cry for help" that attracts beneficial insects to damaged plants

A genetic mechanism that enables corn plants to "cry for help" and attract beneficial insects has been clarified by scientists from the University of Neuchâtel, Switzerland and the Max Planck Institute for Chemical Ecology in Jena. Corn plants emit a cocktail of scents when they are attacked by certain pests, such as a caterpillar known as the Egyptian cotton leaf worm. Parasitic wasps use these plant scents to localize the caterpillar and deposit their eggs on it, so that their offspring can feed on the caterpillar. Soon after, the caterpillar dies and the plant is relieved from its attacker. In the case of corn, only one gene, TPS10, has to be activated to attract the parasitic wasps. This gene carries information for a terpene synthase, an enzyme forming the sesquiterpene scent compounds that are released by the plant and attract wasps toward the damaged corn plant. Since this mechanism is based only on a single gene, it might be useful for the development of crop plants with a better resistance to pests (PNAS, Early Edition, January 16-20, 2006).

At least 15 species of plants are known to release scents after insect damage, thus attracting the enemies of their enemies. Scientists term this mechanism "indirect defence". A previous cooperation by the scientists in Neuchatel and Jena showed that indirect defence functions not only above ground, but also below the earth’s surface.

To understand the biochemistry behind this plant defence, biologists of the Max Planck institute studied corn plants, caterpillars of the species Spodoptera littoralis (Egyptian cotton leaf worm) and parasitic wasps of the species Cotesia marginiventris. Deciphering the complex mix of scents that the plants release after damage offered clues as to which classes of enzymes might be important for scent production.

The researchers isolated various genes encoding terpene synthases, the enzymes that produce these scents. One of these genes, TPS10, produced the exact bouquet of nine scent compounds that was released by the damaged corn plant. To demonstrate that TPS10 is indeed the important gene, the scientists introduced TPS10 into another plant, called Arabidopsis thaliana, which then released the same scents that have been observed in corn. To test whether these scents do attract the parasitic wasps, these plants were tested in an olfactometer, a device to study insect behaviour.

The researchers placed scent-producing as well as unmodified plants in the six arms of the olfactometer. When the predatory wasps were set free in the central cylinder of the olfactometer, they flew towards the scent-producing plants. The experiments led to an additional, surprising result: in order to react this way, the wasps needed a first exposure to both the corn scent and the caterpillar which led them to associate the two. Young, "naive" wasps without this experience could not distinguish between scent-producing plants and control plants, or failed to move at all.

Original work:

Schnee, C., Köllner, T.G., Held, M., Turlings, T.C.J., Gershenzon, J., Degenhardt, J.
The products of a single maize sesquiterpene synthase form a volatile defense signal that attracts natural enemies of maize herbivores
PNAS, Early edition, January 16-20, 2006

*************************************************************

Questions to explore further this topic:

What are pesticides?

http://www.epa.gov/pesticides/about/index.htm
http://www.pesticides.gov.uk/a.....asp?id=219
http://www.nsc.org/ehc/indoor/pesticid.htm

What are the types of pesticides?

http://www.epa.gov/pesticides/about/types.htm

How do we use pesticides safely?

http://www.epa.gov/pesticides/health/safely.htm

Pesticides and aquatic life

http://www.ext.vt.edu/pubs/wat.....0-013.html

Pesticides and human health

Dietary exposure
http://www.pmac.net/worry.htm

A range of health problems
http://www.pmac.net/pesticides_fertilizers.html

Pesticides and cancer
http://www.pmac.net/pesticide_pollution.html

Pesticides and Parkinson's disease
http://www.pmac.net/parkinson.html

Pesticides and poisoning
http://www.cbsnews.com/stories.....8953.shtml


Why is there a need to look for alternatives for pesticides?

http://www.beyondpesticides.org/about/mission.htm

Here are suggestions for least toxic control of pests:

http://www.beyondpesticides.or...../index.htm

What are pests? (Extensive Libraries for pests)

http://www.ipm.ucdavis.edu/PMG......home.html
http://ohioline.osu.edu/lines/pests.html

Crops and pests

http://www.nysaes.cornell.edu/.....s/english/
http://www.uky.edu/Ag/Entomolo.....fldcrp.htm

Vegetables and pests

http://www.uky.edu/Ag/Entomolo...../efveg.htm

Fruits and pests

http://www.uky.edu/Ag/Entomolo.....ffruit.htm

Livestock and pests

http://www.uky.edu/Ag/Entomolo.....livstk.htm

Common household pests

http://www.uky.edu/Ag/Entomolo.....fstruc.htm
http://www.orkin.com/pestlibrary/default.asp

Pest identification guide

http://www.orkin.com/downloads....._Guide.pdf

Dangerous Pests

http://www.orkin.com/downloads.....ts_Web.pdf

What are the various natural pests' predators?

http://woodypest.ifas.ufl.edu/beneficl.htm
http://www.nysaes.cornell.edu/ent/biocontrol/
http://www.buglogical.com/pest.....gIndex.asp
http://www.ext.colostate.edu/p.....05550.html
http://www.nysaes.cornell.edu/.....intro.html


What are wasps?

http://www.gardensafari.net/en....._wasps.htm

Yard wasps
http://www.uky.edu/Ag/Entomolo...../ef411.htm

Cuckoo wasp
http://www.everythingabout.net.....ckoo_wasp/

Gall wasp
http://www.everythingabout.net.....gall_wasp/

Hornet
http://www.everythingabout.net.....ps/hornet/

Paper wasp
http://www.everythingabout.net.....aper_wasp/

Potter wasp
http://www.everythingabout.net.....tter_wasp/

Sphecid wasp
http://www.everythingabout.net.....ecid_wasp/

Spider wasp
http://www.everythingabout.net.....ider_wasp/

Velvet ant
http://www.everythingabout.net.....elvet_ant/

Parasitic wasps
http://www.ipm.iastate.edu/ipm/iiin/bparasiti.html
http://woodypest.ifas.ufl.edu/249.htm
http://chrisraper.org.uk/Html/parasitica.htm

What are terpenes?

http://en.wikipedia.org/wiki/Terpene
http://www.people.vcu.edu/~asneden/terpenes.htm
http://www.chemie.fu-berlin.de.....ne_en.html

GAMES

http://www.orkin.com/learningc....._games.asp
http://www.orkin.com/downloads.....20Book.pdf


Last edited by adedios on Sat Jan 27, 2007 3:48 pm; edited 3 times in total
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PostPosted: Wed Jan 18, 2006 3:06 pm    Post subject: DA: Pesticide use big challenge to organic farming Reply with quote

This story was taken from www.inq7.net
--------------------------------------------------------------------------------
http://news.inq7.net/regions/i.....y_id=63395

DA: Pesticide use big challenge to organic farming
First posted 01:25am (Mla time) Jan 19, 2006
By Delmar Cariño
Inquirer


LA TRINIDAD, BENGUET—Although the government has recognized the productive and marketing potentials of organic farming, farmers’ dependence on commercial farm inputs pose a challenge to those who want to make organic farming part of mainstream agriculture, officials said.

Cesar Rodriguez, director of the Department of Agriculture in the Cordillera, said such dependence on commercial inputs is one of the challenges they are looking at as they try to formulate policies that will spur organic farming in the country.

In the vegetable producing towns of the Cordillera, researchers found that the use of commercial pesticides and insecticides had become part of a farming culture and an obstacle to efforts to convince farmers to go organic.

Rodriguez said the problem could be solved by providing farmers intensive training on organic farming, support services and planting materials.

Rodriguez represented Agriculture Secretary Domingo Panganiban at the opening of the First Cordillera Organic Agriculture Congress at the Benguet State University here on Friday.

He said the DA is aggressively promoting two programs that complement organic farming—the integrated pest management program and the “Agri-Kalikasan,” a community-based program of producing organic fertilizers.

Dr. Carlito Laurean, BSU research director, said Benguet’s vegetable farms have become acidic due to the extensive use of pesticides and insecticides.

“Soil fertility has been severely damaged due to the long and continuous use of these farm inputs,” he said.

“The practice has become a part of their farming systems and it would take quite sometime to convince them to stop using these inputs.”

But Rodriquez said organic farming was not a new farming practice.
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PostPosted: Tue Mar 07, 2006 6:38 pm    Post subject: Prenatal Pesticide Exposure And High Blood Pressure Reply with quote

Source: Harvard School of Public Health

Posted: March 7, 2006

Prenatal Pesticide Exposure And High Blood Pressure And A Decreased Ability To Copy Shapes

Children in Ecuador whose mothers were exposed to pesticides while pregnant had increased blood pressure and diminished ability to copy geometric figures as compared to a control group, according to an epidemiological study in the March issue of Pediatrics. The results appear to be independent of current exposure to the chemicals. The mothers themselves were reported to be healthy.

A team of researchers led by Philippe Grandjean, adjunct professor in the Department of Environmental Health at HSPH, analyzed data on 72 children aged seven or eight years old in the rural Tabacundo-Cayambe area in Northern Ecuador. The children were examined by a physician and were given a battery of standardized tests for neurobehavioral functions. Thirty-seven of the children had mothers whose self-described occupational histories indicated that the women had been exposed to pesticides during pregnancy, typically by working in greenhouses. Dose-response relationships and the exact timing of the exposures' impact were not established due to the nature of the study design.

In the exposed children, the average systolic blood pressure was higher than in those who were unexposed (104.0 mm Hg versus 99.4 mm Hg). An increase in diastolic pressure was not statistically significant. Hypertension among children and adolescents is defined based on a range of blood pressures in healthy children, and children above the 95th percentile are considered hypertensive. In the Pediatrics study, nine children exceeded the approximate 95th percentile of 113 mm Hg. Seven of those children had prenatal pesticide exposure.

Prenatal pesticide exposure was also associated with a decreased ability to copy figures presented to the children as part of a standardized Stanford-Binet test. Adjusted regression analysis indicated that the exposed children experienced a developmental delay on this aptitude of four years. The authors noted that the confidence interval, or range of value, for this coefficient was relatively wide but was a statistically significant finding in a study of limited size, suggesting that the effect could be substantial.

In the part of Ecuador in which the children live, malnourishment is frequent. The authors used delayed growth, or stunting, to explore the role of nutrients in the study's results. Stunting is viewed as an indicator of malnutrition and is defined according to a height-for-age scale. Stunting was associated with decreased copying ability in both exposed and non-exposed children. The researchers found that stunting had no clear effect on blood pressure. They therefore concluded that prenatal pesticide exposure may add to the already deleterious effects of malnutrition.

Current pesticide exposure was measured by excretion of pesticide metabolites in urine and was associated with increased reaction time, one of the standardized tests given for neurobehavioral function, indicating that current and prenatal exposures result in different outcomes. Effects caused by exposure in utero may last into childhood.

"These results suggest that more attention should be paid to protecting the developing brain and that we should seriously consider adopting and enforcing a greater margin of safety in protecting both fetuses and children from potential toxic exposures," said Grandjean.

This research was supported by the Danish Medical Research Council.

Grandjean was an author on two papers that appeared in the February 2004 issue of The Journal of Pediatrics on the effects of prenatal exposure to mercury.
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PostPosted: Sun Apr 23, 2006 2:27 pm    Post subject: Expert: Synthetic chemicals next cause of destruction Reply with quote

Monday, April 24, 2006
Expert: Synthetic chemicals next cause of destruction
By Jeffrey M. Tupas
SunStar

THE use of pesticides and other deadly chemicals could be the second worst cause of mass destruction next to nuclear explosions, according to one of the country's prominent toxicologists.

Dr. Romeo Quijano, president of the Pesticide Action Network-Philippines, issued this warning as the global community of environmentalists celebrated Earth Day last Saturday.

An anti-aerial spraying campaign called "Stop the Toxic Shower!" was also launched locally by the environmental non-government organization Interface Development Interventions Inc. (Idis) and the Panaghoy sa Kinaiyahan-Coalition for Mother Earth (Panaghoy) against the spraying method practiced by banana plantations to fight fungus that attacks bananas.

"I have seen how people's lives were destroyed by synthetic chemicals. Women with thyroid cancers, men with prostate cancers, children with deformities and other abnormalities because of synthetic chemicals," said Quijano who is also a professor at the University of the Philippines-College of Medicine.

"Imagine a community with many children with cleft lips and palates and severe skin diseases. There were also reports of deaths -- the truth is that pesticides and other synthetic chemicals are poison no matter how the manufacturers and even the government tell us that they are not harmful to human," Quijano added.

Deaths in plantations

Councilor Nenen Orcullo said there were also reports about deaths in many areas where banana and pineapple plantations are located. In her own village in Mandug, Tigato District, Orcullo said, a child was killed after eating a Cavendish banana.

"There were many incidents that were kept secret like this. I know that the synthetic chemicals used by these companies are indeed deadly to people and harmful to the environment. I am aware that we are against giant capitalists and the struggle is a little difficult," said Orcullo who authored in 2004 the ordinance seeking to ban the aerial spraying practice in Davao City.

In 1997, Quijano led a study on the impact of the pesticides used by the Lorenzo-owned Lapanday Development Corporation (Ladeco) on the village of Kamukhaan in Digos, Davao del Sur. The group found out that at least 700 individuals (or 150 families), a number of them children, were allegedly poisoned by the chemicals used Ladeco in their ground and aerial spraying practices.

Among the synthetic chemicals used by the company in their operations were Paraquat, Maneb, Macozeb, Carbofuran, Glyphosate and Diazinon. These synthetic chemicals, Quijano said, were already banned, if not restricted, by other countries.

Mancozeb, for instance, has been identified by California as carcinogenic or cancer causing.

Carbofuran, also known as Furadan, has been banned in New Zealand, Finland and Libya and severely restricted many countries like Canada and the United States and listed as potential endocrine disruptor by the German federal Agency.

Human rights violation

Airing his support to the growing demand to totally ban aerial spraying in the city, Quijano said the people should demand from the government their basic right to health as mandated by the constitution and the international humanitarian law.

"By not doing anything regarding this issue, the government is also violating the constitution which tells that the state must protect the people's health -- we could then say that there is a blatant violation of our rights as human," he said.

"The people have the right against chemical intrusion. The companies do not have the right to invade us if we don't want aerial spraying the government should listen to us because this is what we want. It should be the interest of the general public that should be given more weight," Quijano added. (JMT)
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PostPosted: Sat Jul 15, 2006 9:39 pm    Post subject: Black bug infestation spreads to 4 provinces Reply with quote

Black bug infestation spreads to 4 provinces


By Juan Escandor Jr.
Inquirer
Last updated 02:40am (Mla time) 07/16/2006

Published on Page A15 of the July 16, 2006 issue of the Philippine Daily Inquirer

PILI, CAMARINES SUR—Sparing two provinces for the meantime, the black bug infestation has spread to four Bicol provinces—covering 20 towns and a total of 98 villages, according to a report of the Regional Crop Protection Center (RCPC) of the Department of Agriculture.

The report showed a seven-month spread of the infestation that started in the coastal towns of Sorsogon in November last year. At the end of May, nine of the 16 municipalities and a total of 74 villages had been confirmed black bug infested.

For five months, the black bug infestation was confined only to Sorsogon until the RCPC confirmed its spread to Albay in April with infestation verified in two villages of Legazpi City, two villages of Rapu-Rapu and one village in Manito.

In May, the black bug infestation further spread to Camarines Sur—in the four adjoining towns of Caramoan, San Jose, Sangay and Lagonoy in the Partido District of the province, facing the province of Catanduanes.

From Camarines Sur, the black bug infestation spread later that month to Catanduanes with outbreaks in five villages.

But RCPC said it still had to assess and verify whether or not the pest had already infested rice farms in the province.

Only the provinces of Camarines Norte and Masbate remained free from black bug infestation until now.

Balagtas Torres, DA regional executive director, said the black bug infestation does not pose significant harm to the rice production of the region because, he said, it is only destructive to rice plants at the vegetative stage—one to two months old.

Torres said the black bug could do no harm to rice plants that are in the flowering and fruiting stages.

He said the DA does not recommend the use of chemicals against the black bug because, he said, predators of the pest will also die and chemicals could do more harm than good.

Torres said the RCPC had already developed the method for biological control of black bug using a preparation of bacteria called metarrhizium that infests, disables and kills the bug as the bacteria are passed on from bug to bug.

He said the DA regional office cannot handle the infestation alone and called on the local government units to help in financing the war on the bugs.

In a memorandum to Torres, Evangeline C. Dela Trinidad, RCPC chief, reported that her office has already distributed metarrhizium in seven towns affected by the black bug infestation in the provinces of Albay and Sorsogon.

Dela Trinidad said the RCPC had also conducted seminars on how to control the spread of black bugs in the towns of Bacon and Barcelona in Sorsogon.

She said three teams were also dispatched to monitor the rise or fall of the pest’s population by light trapping during and before a full moon.



Copyright 2006 Inquirer. All rights reserved.
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PostPosted: Wed Sep 27, 2006 10:09 pm    Post subject: UGA scientists engineer root-knot nematode resistance Reply with quote

University of Georgia
27 September 2006

UGA scientists engineer root-knot nematode resistance

Athens, Ga. – University of Georgia professor Richard Hussey has spent 20 years studying a worm-shaped parasite too small to see without a microscope. His discovery is vastly bigger. Hussey and his research team have found a way to halt the damage caused by one of the world's most destructive groups of plant pathogens.

Root-knot nematodes are the most economically important group of plant-parasitic nematodes worldwide, said Hussey, a distinguished research professor in plant pathology at the UGA College of Agricultural and Environmental Sciences.

They attack nearly every food and fiber crop grown, about 2,000 plant species in all.

The nematode invades plant roots, and by feeding on the roots' cells, they cause the roots to grow large galls, or knots, damaging the crop and reducing its yields.

Working with assistant research scientist Guozhong Huang and research technician Rex Allen, Hussey discovered how to make plants resistant to root-knot nematode infection.

Eric Davis at North Carolina State University and Thomas Baum at Iowa State University also collaborated on the research.

The discovery "has the potential to revolutionize root-knot resistance in all crops," Hussey said.

The most cost-effective and sustainable management tactic for preventing root-knot nematode damage and reducing growers' losses, he said, is to develop resistant plants that prevent the nematode from feeding on the roots. Because root-knot nematode resistance doesn't come naturally in most crops, Hussey's group bioengineered their own.

The results of the study were published Sept. 26 in the journal, Proceedings of the National Academy of Sciences.

Four common root-knot nematode species account for 95 percent of all infestations in agricultural land. By discovering a root-knot nematode parasitism gene that's essential for the nematode to infect crops, the scientists have developed a resistance gene effective against all four species.

Using a technique called RNA interference, the researchers have effectively turned the nematode's biology against itself. They genetically modified Arabidopsis, a model plant, to produce double-stranded RNA to knock out the specific parasitism gene in the nematode when it feeds on the plant roots.

This knocked out the parasitism gene in the nematode and disrupted its ability to infect plants.

"No natural root-knot resistance gene has this effective range of root-knot nematode resistance," Hussey said.

The researchers' efforts have been directed primarily at understanding the molecular tools the nematode uses to infect plants. This is a prerequisite for bioengineering durable resistance to these nematodes in crop plants.

Through this research, they've discovered the parasitism genes that make a nematode a plant parasite so it can attack and feed on crops, Huang said.

"Our results of in-plant RNA interference silencing of a parasitism gene in root-knot nematodes provides a way to develop crops with broad resistance to this destructive pathogen," Hussey said. "Equally important, our approach makes available a strategy for developing root-knot-nematode-resistant crops for which natural resistance genes do not exist."


###
Funding for the project came from the U.S. Department of Agriculture's Cooperative State Research, Education and Extension Service National Research Initiative and the UGA College of Agricultural and Environmental Sciences.
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PostPosted: Fri Oct 13, 2006 11:46 am    Post subject: Mayo Clinic study could lead to safer pesticides Reply with quote

Mayo Clinic
October 12, 2006

Mayo Clinic study could lead to safer pesticides
Study identifies a new target unique to greenbugs and aphids
ROCHESTER, Minn. -- Each year millions of dollars in crops are lost to two insects notorious for devastating farms: the greenbug (Schizaphis graminum) and the English grain aphid (Sitobion avenae). Although these tiny green insects are 1/16th of an inch long, they are heavyweights in the farm industry. In 2005, the Department of Agriculture reported that $100 million in crops were lost in six states to these pests.

In a new study in the October issue of Bioorganic & Medicinal Chemistry Letters, a Mayo Clinic researcher has published work that opens the door to the possibility of creating safer pesticides to control the greenbug and English grain aphid in crop farms. The key, according to the study's author, Yuan-Ping Pang, Ph.D., director of Mayo Clinic's Computer-Aided Molecular Design Laboratory, was in identifying an insect-specific enzyme that could be used as a direct target for a new insecticide that would not affect humans and animals. The research was done with the support of a powerful terascale supercomputer Dr. Pang designed to develop a three-dimensional model of an enzyme taken from the two insects. (Terascale refers to a computer so powerful it can perform one trillion operations per second.)

"We now have a blueprint that will enable the development of a new generation of pesticides that will not be toxic to humans. Ultimately, the idea would be that we would be able to eat apples without washing them -- even though it may be covered with pesticides," says Dr. Pang.

Greenbugs are found in North, Central and South America, Europe, Africa, the Middle East and Asia. Aphids have been present since 1912 in southern Europe, central Asia, the Middle East and Africa. Greenbugs are the most damaging of aphids because they suck plant juices and inject a toxin into the plant during the process, Dr. Pang says. The toxin causes more injury than the actual physical injury made by greenbugs.

To date a common method of protecting crops from greenbugs and the English grain aphid has been the use of anticholinesterase-based pesticides developed during the World War II era. These pesticides cripple an enzyme called acetylcholinesterase, which decomposes acetylcholine, a neurotransmitter in the brain that sends signals between nerve cells. Disabling acetylcholinesterase causes a chemical imbalance in the brains of insects eventually killing them. The problem is that acetylcholinesterase affects both insects and humans.

"Unfortunately current anticholinesterase-based pesticides target a common residue of acetylcholinesterases that is apparent in both insects and humans. The use of potentially dangerous pesticides developed decades ago is based on the hypothesis that these pesticides are used in low doses that humans can tolerate, but pests cannot," Dr. Pang says.

But according to a report by the Environmental Protection Agency's Office of Inspector General, some anticholinesterase pesticides can enter the brain of fetuses and young children and can destroy cells in the developing nervous system.

To date, safer and equally effective insecticides have not been designed to replace insecticides currently used by farmers, Dr. Pang says.

Anticholinesterase-based pesticides target an amino acid within the acetylcholinesterase enzyme, called serine. Serine is not unique to insects, which is why serine-based insecticides affect both humans and animals. Dr. Pang developed a computer-based three-dimensional model that identified a different amino acid called cysteine, which is unique to insects. It is located at the opening of the active site of acetylcholinesterase.

"My goal was to find an enzyme residue that is unique to insects. Doing so would allow us to design a molecule that would selectively inhibit the insect enzyme. Therefore we could conceivably create a pesticide that is only toxic to insects, not humans," Dr. Pang says.

Dr. Pang analyzed the anticholinesterase protein sequences of 72 species ranging from humans to chickens and other mammals and pests. He found a cysteine amino acid present in the acetylcholinesterase protein sequences of the greenbug and English grain aphid, but absent in comparable human and animal sequences.

Examining the three-dimensional models of both the greenbug and aphid acetylcholinesterase enzymes with the terascale supercomputer he designed was Dr. Pang's crucial next step. He discovered the pest-specific cysteine residue located at the edge of the active site of the insect acetylcholinesterase.

Acetylcholinesterase enzymes have a deep and narrow active site. A cysteine residue is located at the opening of the active site of insect acetylcholinesterases and can react with a small-molecule pesticide. In other words, the cysteine residue serves as a hook that can tether a small molecule in the active site and damage the enzyme.

However, the cysteine is not present in acetylcholinesterase in humans or animals. So the cysteine residue is essentially a species marker for developing new pesticides that would not harm humans because cysteine is not an enzyme active in humans or mammals, Dr. Pang says.

"We inspected the entire active site of the human enzyme and we couldn't find one cysteine residue," he says.

"It is conceivable that a chemically stable molecule could react with insect-specific cysteine residue and irreversibly inhibit the insect acetylcholinesterases upon binding to the active site. This leads me to believe that the cysteine residue can be used as a species marker for developing a new generation of safer pesticides that can inhibit greenbug and aphid acetylcholinesterase, but not human or animal acetylcholinesterases," Dr. Pang says.

"Protein sequences as one-dimensional information can tell us whether an amino acid we are focusing on is unique, but not whether that amino acid is located in the active site of the enzyme. We cannot target the residue if we do not know where it lies. Now, we can examine the location of the residue in three-dimensional space using terascale computers.

"This work offers a structural basis for the possible design of pesticides that are toxic to insects, but not to humans. It demonstrates the benefits in the power of molecular biology that led to the discovery of the functionally important and pest-specific cysteine residue that was hidden in a sea of protein sequences originally reported in 2002," Dr. Pang says.


###
This study was funded by the Mayo Foundation for Medical Education and Research.

EDITOR'S NOTE: A high res image of aphids from Minnesota farms is available upon request.

To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news

MayoClinic.com (www.mayoclinic.com) is available as a resource for your health stories.
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PostPosted: Mon Nov 20, 2006 7:15 am    Post subject: Chemical exchanges show wasps are bad losers Reply with quote

Biotechnology and Biological Sciences Research Council
19 November 2006

Chemical exchanges show wasps are bad losers

Wasps have more than just a sting in their tail according to new research published this week in the Proceedings of the Royal Society B, they also carry the insect version of pepper spray in their heads, which they can release when fighting other wasps. The research not only gives us a fascinating insight into insect behaviour but could also help us to use wasps to kill crop destroying pests.

For the first time scientists, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), have recorded 'chemical exchanges' undetectable by the human nose which take place between females of a species of bethylid wasp - Goniozus legneri, when they fight over larvae on which they lay their eggs. Not only have they discovered that chemical exchanges take place, but also that it is always the losing wasp that releases the potent gas.

While the research was primarily aimed at improving the understanding of animal behaviour, lead researcher Dr Ian Hardy, from the University of Nottingham, explains that there is great potential for applied spin-offs: "Bethylid wasps kill the larvae of many insects that are pests of crops, such as almonds, coffee and coconut, ruining harvests and costing industry thousands of pounds. These wasps could be used as a cheap and effective biological control to kill the larvae, avoiding the use of expensive and polluting pesticides. But for successful biological control, we need a good knowledge of wasp behaviour, including how wasps from the same and different species interact. Understanding these patterns can inform us of the best combinations of species to release against a given crop pest."

The scientists staged 47 separate contests between pairs of female wasps, placing them in a transparent chamber with a larva, which in the wild they paralyse to use as a host to lay their eggs on. One 'owner' female had paralysed the host 24 hours before the other wasp was allowed to intrude.

Making new use of a real-time chemical analysis technique known as Atmospheric Pressure Chemical Ionisation Mass Spectrometry (APCI-MS), as well as recording wasp behaviour on video, the researchers were able to study the visible and chemical behaviour of the wasps in tandem.

Behaviours displayed by the wasps included chasing, biting, stinging and full-on fighting. The video and chemical analysis showed that a volatile chemical, which is a type of spiroacetal, was released by the wasps when losing a particularly aggressive fight.

Dr Hardy said: "Our research suggests that wasps which have lost a fight release spiroacetal to temporarily and partially incapacitate the winner, it could be likened to the insect version of pepper spray. The volatile chemicals released by the wasps may prompt females to disperse away from the target area. If we understand how to reduce chemical release behaviour we can improve the efficacy of these wasps in pest control".

Professor Julia Goodfellow, BBSRC Chief Executive, said: "This research highlights the benefits of understanding animal behaviour and the impact this can have on finding solutions to tackle costly problems such as pest control."

###
The research is being published in the print edition of the Proceedings of the Royal Society B on Wednesday.

Images are available to accompany this story. Please download from: http://www.bbsrc.ac.uk/media/p.....wasps.html

Image 1: Female bethylid wasps fighting
Image 2: Female bethylid wasps on host larva

Please credit: Sonia Dourlot

Contact

Dr Ian Hardy, University of Nottingham, Tel: 0115 9516052, email: ian.hardy@nottingham.ac.uk

Notes to Editors
Volatile emission by contest losers revealed by real-time chemical analysis Marlène Goubault, Tim P. Batchelor, Robert S. T. Linforth, Andrew J. Taylor and Ian C. W. Hardy Proc. R. Soc. B. Volume 273, pp2853-2859 Issue 1603, Print publication date: 22 November 2006

About BBSRC
The Biotechnology and Biological Sciences Research Council (BBSRC) is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £350 million in a wide range of research that makes a significant contribution to the quality of life for UK citizens and supports a number of important industrial stakeholders including the agriculture, food, chemical, healthcare and pharmaceutical sectors. http://www.bbsrc.ac.uk
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PostPosted: Mon Apr 02, 2007 8:17 pm    Post subject: Picky-eater Flies Losing Smell Genes Reply with quote

Picky-eater Flies Losing Smell Genes
April 2, 2007
UC Davis

A UC Davis researcher is hot on the scent of some lost fruit fly genes. According to population biology graduate student Carolyn McBride, the specialist fruit fly Drosophila sechellia is losing genes for smell and taste receptors 10 times faster than its generalist relative Drosophila simulans. The findings could help researchers understand how some insect pests adapt to feeding on a particular plant.

Genes are lost when mutations destroy their function. "Drosophila sechellia may be losing genes that helped its ancestors detect and assess plants it no longer uses," said McBride, whose research was recently published in the journal Proceedings of the National Academy of Sciences.

A native of the Seychelles islands in the Indian Ocean, D. sechellia split from its sister species D. simulans half a million years ago -- just a blink of evolutionary time. While D. simulans feeds on a variety of plants, D. sechellia specializes in eating the Indian mulberry, which repels other fruit flies. D. sechellia has evolved resistance to the toxins of its host fruit, and a strong chemical attraction to its scent.

For her genetic analysis, McBride drew on the recently sequenced genomes of D. sechellia and D. simulans, which are available to the public.

"This is the first time that biologists have been able to compare whole genome sequences from closely related insects that differ dramatically in their ecology," she said. McBride also compared the genes of these two flies to another close relative, the classic lab fruit fly Drosophila melanogaster.

She discovered that not only is the specialist fly losing genes for smell and taste receptors 10 times faster than the generalist, but its remaining sensory genes are also evolving at a more rapid rate. McBride said that the changes in these genes are likely related to the flies' different feeding strategies, because smell and taste are the primary senses that insects use to assess potential host plants.

"My work suggests that changes in these receptors help insects adapt to novel host plants," McBride said. "These genes may therefore be a good place to start looking for genetic changes that underlie host adaptation in other species, including agricultural pests."

McBride's research is supported by grants from the National Science Foundation and the National Institutes of Health.
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PostPosted: Wed Apr 18, 2007 7:49 am    Post subject: Wasps Eat Siblings For Good of the Family Reply with quote

Wasps Eat Siblings For Good of the Family

By Corey Binns
Special to LiveScience
posted: 18 April 2007
08:43 am ET

While most young male wasps are just bags of loosely organized cells, their sterile sisters develop quickly into slender snake-like shapes, grow huge jaws and start chomping on their little brothers.

The sterile sisters' lethal sibling rivalry is downright spiteful, but unusual genetics, not to mention the opportunity to keep living, means that fertile sisters benefit from the nasty behavior in more than one way.

After a mother wasp from the genus Copidosoma lays two eggs—one male and one female—into a host (for instance, the egg of a moth), these eggs divide clonally, producing a thousand genetically identical sisters and a thousand genetically identical brothers. The sisters, therefore, are more closely related to each other than they are to their brothers.

For the full article:

http://www.livescience.com/ani.....diers.html
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PostPosted: Fri Apr 20, 2007 9:58 am    Post subject: Why some aphids can't stand the heat Reply with quote

University of Arizona
19 April 2007

Why some aphids can't stand the heat

For pea aphids, the ability to go forth and multiply can depend on a single gene, according to new research.

An overheated aphid with a mutation in that gene can't reproduce.

The gene isn't even in the insect -- it's in tiny symbiotic bacteria housed inside special cells inside the aphid.

"It's the first time a mutation in a symbiont has been shown to have a huge impact on host ecology," said Nancy A. Moran, Regents' Professor of ecology and evolutionary biology at The University of Arizona in Tucson. "One version of the gene is good if the aphids experience heat, and the other version is good if they are in cool conditions."

Neither organism can survive on its own. The Buchnera aphidicola bacteria, which cannot live on their own, supply the aphids, Acyrthosiphon pisum, with essential nutrients.

UA researchers Helen E. Dunbar, a senior research specialist, Alex C. C. Wilson, now at the University of Miami in Coral Gables, Fla., Nicole R. Ferguson, a member of UA's Undergraduate Biology Research Program, and Moran are publishing their findings in the May 2007 issue of PLoS Biology.

Their research paper is titled "Aphid Thermal Tolerance is Governed by a Point Mutation in Bacterial Symbionts." The research was funded by the National Science Foundation and the National Institutes of Health. Howard Hughes Medical Institute provides funding for the UA's Undergraduate Biology Research Program.

Aphids reproduce asexually, so juveniles are clones of their mothers. The symbiotic bacteria are passed on from mother to child. Moran's lab maintains colonies of aphids, each descended from a single ancestral aphid mother.

The scientists found the heat-intolerant gene by accident.

Wilson, then a UA postdoctoral fellow in Moran's lab, was testing the response of some aphid and bacterial genes from one aphid colony. The bacteria's ibpA gene codes for a protein, called a heat-shock protein, that protects the cell's innards from thermal damage.

Wilson expected all the ibpA genes from one colony to be the same.

She was surprised that, after aphids were heated for four hours, some of their symbiotic bacteria produced about 100 times more of the ibpA-encoded heat-shock protein than others.

"It was a huge difference," Moran said.

A piece of DNA called a promoter switches the ibpA gene on or off. The scientists found some of the bacteria had a disabling mutation in their promoters. Those bacteria could no longer manufacture much of the protective heat-shock protein and were therefore killed by the heat treatment.

In another experiment, the researchers gave a 95 F (35 C) heat treatment to aphids whose bacteria carried the mutated promoter, the regular promoter and to Tucson aphids. For each group, the team measured production of a molecule, RNA, that codes for the protective heat-shock protein.

Tucson genes produced three times more RNA than the normal genes from lab colony aphids. The lab colony genes produced about 50 times more than did the genes carrying the mutated promoter.

Aphids proliferate in the summer, and their predator defense can expose them to additional heat.

"When one is bitten, it releases an alarm pheromone and the others all jump off the plant," Moran said. The ground can be more than 20 degrees Fahrenheit warmer than the cool, shady plant.

To test the effect of heat on aphids themselves, the scientists subjected juveniles to 95 F (35 C) for four hours.

The heat-treated aphids hosting bacteria with mutated promoters lived, but didn't reproduce.

"The heat shock kills the bacteria very quickly, although it doesn't kill the aphid," Dunbar said. "But she's sterilized and doesn't have any babies."

The bacteria provide nutrients essential for aphid reproduction.

Conversely, aphids with bacteria with the mutated promoter reproduced faster at the temperatures, 60-68 F (15 - 20 C), at which aphids are maintained in the lab.

Results from wild aphids suggest the genetic makeup of a pea aphid's bacteria depends on climate. Bacteria from Tucson aphids all had heat-tolerant promoters. Bacteria from Michigan or New York state aphids were five to seven times more likely to have the heat-intolerant, mutated promoter.

The two promoters are barely different -- the heat-sensitive version has 10 adenine molecules in a row, and the other has 11.

"The presence or absence of one (adenine) has a huge effect on how well the host does, how well it can survive and reproduce at different temperatures," Moran said.

When a bacterial cell reproduces, a new DNA molecule is copied from the original. But the many adenine molecules in a row makes it easier for a mistake to delete or insert an adenine, causing a mutation, Moran said.

Pea aphids, native to Europe, are now found worldwide. Many other species of insects have similar symbiotic relationships with bacteria. Such easy-to-arise mutations in symbiotic bacteria could explain how some insect pests can expand into new environments, Moran and Dunbar said.

Moran's next step is working with researchers in Wisconsin to see how the bacterial gene variants affect aphids in the field.

###

Related Web sites:

The Moran Laboratory
http://eebweb.arizona.edu/faculty/moran

UA Department of Ecology and Evolutionary Biology
http://eebweb.arizona.edu

Center for Insect Science
http://cis.arl.arizona.edu

* * * University of Arizona science news is online @ http://uanews.org/science * * *
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PostPosted: Mon May 07, 2007 7:21 am    Post subject: Premature births may be linked to seasonal levels of pestici Reply with quote

Indiana University
7 May 2007

Premature births may be linked to seasonal levels of pesticides and nitrates in surface water

INDIANAPOLIS --The growing premature birth rate in the United States appears to be strongly associated with increased use of pesticides and nitrates, according to work conducted by Paul Winchester, M.D., professor of clinical pediatrics at the Indiana University School of Medicine. He reports his findings May 7 at the Pediatric Academic Societies' annual meeting, a combined gathering of the American Pediatric Society, the Society for Pediatric Research, the Ambulatory Pediatric Association and the American Academy of Pediatrics.

Dr. Winchester and colleagues found that preterm birth rates peaked when pesticides and nitrates measurements in surface water were highest (April-July) and were lowest when nitrates and pesticides were lowest (Aug.-Sept.).

More than 27 million U.S. live births were studied from 1996-2002. Preterm birth varied from a high of 12.03% in June to a low of 10.44% in September. The highest rate of prematurity occurred in May-June (11.91%) and the lowest for Aug-Sept (10.79%) regardless of maternal age, race, education, marital status, alcohol or cigarette use, or whether the mother was an urban, suburban or rural resident. Pesticide and nitrate levels in surface water were also highest in May-June and lowest in August –September, according to the U.S. Geological Survey.

For the past four years, Dr. Winchester and colleagues have focused attention on the outcomes of pregnancy in Indiana and the United States in relation to environmental pesticides and nitrates in surface and drinking water. Last year at the Pediatric Academic Societies' annual meeting, Dr Winchester reported that birth defects peak in Indiana and in the United States as a whole during April through July, the same months as pesticides and nitrates reach their maximum concentrations in surface water. This year's presentation expands upon that work.

"A growing body of evidence suggests that the consequence of prenatal exposure to pesticides and nitrates as well as to other environmental contaminants is detrimental to many outcomes of pregnancy. As a neonatologist, I am seeing a growing number of birth defects, and preterm births, and I think we need to face up to environmental causes," said Dr Winchester, who is also director of Newborn Intensive Care Services at St. Francis Hospital in Indianapolis.

"Preterm births in the United States vary month to month in a recurrent and seasonal manner. Pesticides and nitrates similarly vary seasonally in surface water throughout the U.S. Nitrates and pesticides can disrupt endocrine hormones and nitric oxide pathways in the developing fetus," he said.

"I believe this work may lay the foundation for some of the most important basic and clinical research, and public health initiatives of our time. To recognize that what we put into our environment has potential pandemic effects on pregnancy outcome and possibly on child development is a momentous observation, which hopefully will help transform the way humanity cares for its world," said James Lemons, M.D., Hugh McK. Landon Professor of Pediatrics at the IU School of Medicine. Dr. Lemons is director of the section of neonatal-perinatal medicine at the IU School of Medicine and heads the Riley Hospital for Children of Clarian Health's section of neonatal-perinatal medicine.


###
Collaborating with Dr. Winchester on this study were Akosua Boadiwaa Adu-Boahene and Sarah L. Kosten of the IU School of Medicine, Alex K Williamson of the U.S. Geological Survey, and Ying Jun, Ph.D. of the University of Cincinnati. The work was funded by the Division of Neonatology, Department of Pediatrics of the IU School of Medicine.
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PostPosted: Mon May 14, 2007 10:00 am    Post subject: According to a study conducted by the UGR, 100% of pregnant Reply with quote

According to a study conducted by the UGR, 100% of pregnant women have at least one kind of pesticide in their placenta
14 May 2007

María José López Espinosa. Department of Radiology and Physical Medicine of the Universidad de Granada

- A doctoral thesis written at the Department of Radiology and Physical Medicine reveals an average presence of eight organochlorine contaminants in the organisms of pregnant women, which are usually ingested by means of food, water and air.

- These chemical substances may cause some malformations in the genito-urinary system of the foetus, such as cryptorchidism and hypospadias.


C@MPUS DIGITAL Human beings are directly responsible for more than 110,000 chemical substances which have been generated since the Industrial Revolution. Every year, we “invent” more than 2,000 new substances, most of them contaminants, which are emitted into the environment and which are consequently present in food, air, soil and water. Nonetheless, human beings are also victims of these emissions, and involuntarily (what is known in this scientific field as “inadvertent exposure”), every day humans ingest many of these substances which cannot be assimilated by our body, and are accumulated in the fatty parts of our tissues.

This is especially worrying for pregnant women. During the gestation period, all the contaminants accumulated in the organism have direct access to the microenvironment where the embryo/foetus develops. The doctoral thesis “Maternal-child exposure via the placenta to environmental chemical substances with hormonal activity”, written by María José López Espinosa, from the Department of Radiology and Physical Medicine of the University of Granada, analyzes the presence of organochlorine pesticides –normally used as pesticides- in the organisms of pregnant women. The analysis was developed at San Cecilio University Hospital , in Granada, with 308 women who had given birth to healthy children between 2000 and 2002. The results are alarming: 100% of these pregnant women had at least one pesticide in their placenta, but the average rate amounts to eight different kinds of chemical substances.

Fifteen different pesticides in the organisms of pregnant women

In her study, through the analysis of the placentas, López studied the presence of 17 endocrine disruptive organochlorine pesticides (i.e., pesticides which interfere with the proper performance of the hormonal system). The results showed that the most frequent pesticides present in the placenta tissue are DDE (92.7%), lindane (74.8%), endosulfan diol (62.1%) y endosulfan-I (54.2%). Among these, the most prevalent was endosulfan-diol, with an average concentration of 4.15 nanograms per gram of placenta (156.73 ng/g lipid). Surprisingly, the UGR researcher discovered that some patients’ placentas contained 15 of the 17 pesticides analyzed.

A total of 668 samples from pregnant women were used in this study, which was approved by the Ethical Commission of San Cecilio University Hospital . Mothers were informed of the study’s goals before giving their express consent.

Thanks to gynaecologists, the nurses and the midwives who participated in the study, biological samples were extracted from the blood, the umbilical cord and the placenta during childbirth. The following day, an epidemiological survey was carried out by trained survey statisticians. The survey contained questions on the general data of the parents, their places of residence, profession, medical history, anthropometric information, age, tobacco habits, lifestyle and diet during pregnancy, among other factors.

The study made at the UGR has facilitated research into the association of the characteristics of parents, newborn babies and childbirth with exposure to pesticides found in the mothers’ placenta. Among the aspects associated with a higher presence of pesticides we find an older age, higher body mass index, less weight gained during pregnancy, lower educational level, higher workplace exposure, first-time motherhood and lower weight in babies.

“Serious effects on the baby”

According to María José López, “we do not really know the consequences of exposure to disruptive pesticides in children, but we can predict that they may have serious effects, since this placenta exposure occurs at key moments of the embryo’s development”.
The research group to which María José López belongs, directed by Prof. Nicolás Olea Serrano, has conducted several studies which associate exposure to pesticides with neonatal malformations if the genito-urinary system, such as cryptorchidism (undropped testicles) and hypospadias (total fusion of the urethral folds).

The UGR researcher underlines the fact that, in spite of “inadvertent exposure”, “it is possible to control pesticide ingestion by means of a proper diet, which should be healthy and balanced, through consumption of food whose chemical content is low. Moreover, daily exercise and the avoidance of tobacco (which could also be a source of inadvertent exposure) are very important habits which help to control the presence of pesticides in our organisms.

The UGR researcher’s work is framed within the objectives established in the research project ”Increasing incidence of human male reproductive health disorders in relation to environmental effects on growth-and sex steroid-induced alterations in programmed development” (Environmental Reproductive Health), directed and carried out by a multidisciplinary group of clinicians, basic researchers and epidemiologists at several institutions from countries such as Denmark, Finland or England and financed by the European Union (QLK4-1999-01422).

Reference
María José López Espinosa. Department of Radiology and Physical Medicine of the Universidad de Granada
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PostPosted: Wed Jun 06, 2007 2:03 pm    Post subject: Pesticides choke pathway for nature to produce nitrogen for Reply with quote

University of Oregon
6 June 2007

Pesticides choke pathway for nature to produce nitrogen for crops

Many agrichemicals block a key receptor in soil bacteria, affecting production

Many farmers applying pesticides to boost crop yields may instead be contributing to growth problems, scientists report in a new study.

According to years of research both in the test tube and, now, with real plants, a team of scientists reports that artificial chemicals in pesticides – through application or exposure to crops through runoff – disrupt natural nitrogen-fixing communications between crops and soil bacteria. The disruption results in lower yields or significantly delayed growth.

In a paper appearing online this week ahead of the regular publication by the Proceedings of the National Academy of Sciences (PNAS), the five-member team reports that agrichemicals bind to and block connections to specific receptors (NodD) inside rhizobia bacteria living in root nodules in the soil. Rotation legume crops such as alfalfa and soybeans require such interaction to naturally replace nitrogen levels that, in turn, benefit primary market crops like corn grown after legume rotations.

Legume plants secrete chemical signals that recruit the friendly bacteria, which work with the plants to convert atmospheric nitrogen into ammonia that, then, is used as fertilizer by the plants.

"Agrichemicals are blocking the host plant's phytochemical recruitment signal," said the study's lead author, Jennifer E. Fox, a postdoctoral researcher in the Center for Ecology and Evolutionary Biology at the University of Oregon. "In essence, the agrichemicals are cutting the lines of communication between the host plant and symbiotic bacteria. This is the mechanism by which these chemicals reduce symbiosis and nitrogen fixation."

Fox began the project as a doctoral student with John A. McLachlan, director of the Center for Bioenvironmental Research at Tulane University. She is working at the University of Oregon as a National Institutes of Health and National Research Service Award postdoctoral fellow under Joe Thornton, a professor of biology who focuses on phylogenomics and nuclear receptor genes.

Fox and colleagues began detailing their findings in the journal Nature (2001) and Environmental Health Perspectives (2004), testing more than 50 chemicals, including pentachlorophenol (PCP), in in-vitro assays. The paper in PNAS reports their in-vivo findings using real plants and bacteria.

None of the chemicals used in the research, including PCP, proved to be toxic to either the plants or bacteria, Fox said, "but PCP was unique in that it inhibited both seed germination and nitrogen fixation." More than 20 commonly used agricultural chemicals shared the same mechanism of action as PCP, but with varying amounts of signal disruption.

Fox, McLachlan and colleagues, in their PNAS paper, pointed to two published studies from 2000 that had found significant declines in both crop yield per unit of synthetic nitrogen fertilizer added and also a significant decline in overall symbiotic nitrogen fixation.

The most common explanation for the observations is an overuse of agrichemicals applied to legume crops. That practice sets up "a vicious cycle," Fox said, because it reduces a legume crop's natural need for nitrogen fixation but leaves a shortage of natural nitrogen in the soil for the next year's crop to utilize. Thus, she said, there is the need for yet more fertilizer.

Other reasons, Fox said, have been poor soil quality due to overuse, which strips nutrients such as nitrogen and phosphorous from the soil, and to tillage, which interrupts root structures and disturbs the nitrogen-fixing bacteria when soil is turned.

"Our research provides another explanation for declining crop yields," Fox said. "We showed that by applying pesticides that interfere with symbiotic signaling, the overall amount of symbiotic nitrogen fixation is reduced. If this natural fertilizer source is not replaced by increased application of synthetic nitrogen fertilizer, then crop yields are reduced and/or more growing time is needed for these crops to reach the yields obtained by untreated crops. We feel that this is a previously unforeseen factor contributing to declining crop yields."

The researchers say that field-wide experiments now are needed, in addition to tests to determine the exact elements of pesticides that inhibit natural plant-bacteria interaction.


###
In addition to Fox and McLachlan, co-authors on the PNAS paper were Jay Gulledge of the University of Louisville, Erika Engelhaupt of the University of Colorado and Matthew E. Burrow of the Center for Bioenvironmental Research and the School of Medicine at Tulane University.

Source: Jennifer Fox, postdoctoral research associate, 541-346-1537, jenfox@uoregon.edu

Link: Thornton lab: http://www.uoregon.edu/%7Ejoet/
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PostPosted: Fri Jun 15, 2007 12:49 pm    Post subject: Mysterious Bee Deaths Linked to Pesticides Reply with quote

Mysterious Bee Deaths Linked to Pesticides
By Genaro C. Armas, Associated Press

posted: 15 June 2007 09:44 am ET

LEWISBURG, Pa. (AP) — Scientists investigating a mysterious ailment that killed many of the nation's honeybees are concentrating on pesticides and a new pathogen as possible culprits, and some beekeepers are already trying to keep their colonies away from pesticide-exposed fields.

After months of study, researchers are finding it difficult to tie the die-off to any single factor, said Maryann Frazier, a senior extension associate in Penn State University's entomology department.

“Two things right now ... that are really keeping us focused are the pathogen and the role of pesticides,” Frazier said.

For the full article:

http://www.livescience.com/ani.....ouble.html
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PostPosted: Sun Jul 15, 2007 5:04 pm    Post subject: Outwitting pesky parasites Reply with quote

Crop Science Society of America

Outwitting pesky parasites

Researchers find a shortcut for screening resistant soybean crops
MADISON, WI, July 15, 2007 - Across the southern United States, an invisible, yet deadly parasite known as the root-knot nematode is crippling soybean crops. While plant breeders are racing to develop cultivars resistant to the root-knot nematode, they are being slowed down by current time-consuming and expensive methods of screening for resistant plants. Now, researchers believe they have found a shortcut for screening resistant soybean crops.

Researchers at the University of Georgia report the discovery of several molecular markers that will help soybean breeders to accurately screen for root-knot resistant plants at a fraction of the time and cost of current screening techniques in the July issue of The Plant Genome.

While previous studies of soybean crops helped researchers to locate genes associated with root-knot nematode resistance, University of Georgia scientists recently identified single nucleotide polymorphisms (SNPs), slight variations in the DNA, nearby genetic regions that code root-knot nematode resistance. After linking the identified SNPs to root-knot nematode resistance, scientists developed a marker assisted screening test that used SNPs to determine whether or not plants were resistant to root-knot nematode.

“The basic objective of any breeding scheme is to identify elite individuals that can pass on their desirable characteristics,” explained Bo-Keun Ha, lead author of study. While Ha says most conventional breeders rely on phenotypic evaluations of plants to select the plant with most desirable traits, this process takes time and money. For example, if a breeder wants to select plants with resistance to root-knot nematode based upon a phenotypic evaluation alone, he or she must grow a large population of plants, inoculate plants with nematode eggs, wait until the growth of the nematode and evaluate the damage before selecting the most resistant plants.

Instead of relying on the time-consuming phenotypic screening to determine whether or not the root-knot resistance genes are present in soybean crops, “marker assisted selection can inform breeders about the presence of the resistance gene in individual plants,” said Ha. Also, because marker assisted selection involves the screening of a few markers across thousands of plants Ha pointed out that the marker assisted selection is rather inexpensive and time efficient.

“Our results found SNPs linked to two root-knot nematode resistance genes and developed the resources for a relatively high throughput method of selection for the two genes,” said Ha. “The SNP assays that we have reported will empower soybean breeders to efficiently incorporate root-knot resistance genes into new productive cultivars.”


###
The Plant Genome ( http://www.crops.org/genome/ ) is a peer-reviewed, international journal of applied plant genomics research published four times a year by the Crop Science Society of America.

The American Society of Agronomy (ASA) www.agronomy.org, the Crop Science Society of America (CSSA) www.crops.org and the Soil Science Society of America (SSSA) www.soils.org are educational organizations helping their 10,000+ members advance the disciplines and practices of agronomy, crop and soil sciences by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.
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PostPosted: Tue Jul 24, 2007 4:11 pm    Post subject: In a bug-eat-bug world, researchers are using a unique Chine Reply with quote

University of Minnesota
24 July 2007

In a bug-eat-bug world, researchers are using a unique Chinese import to battle soybean aphids
University of Minnesota researchers are field testing wasps to battle soybean aphids.
University of Minnesota scientists are field testing a beneficial insect, a stingless wasp from China also known as Binodoxys communis, that kills soybean aphids. A successful field test would be a major breakthrough in controlling a damaging crop pest. The U of M received permission from the federal government to conduct this test and is the leading institution in the testing.

The soybean aphid first appeared in Minnesota fields in 2000 and today costs soybean growers an estimated $200 million annually in lost crop yields and spraying costs in Minnesota alone. The national cost is much higher.

“The soybean aphid was imported without any of its natural enemies, the organisms that keeps aphids in check in China,” said Dave Ragsdale, U of M entomologist. “Our researchers and Extension experts are working to provide that check and balance system.”

Multiple stages of evaluation and testing have been completed at the Insect Quarantine Facility, a joint effort between the Minnesota Department of Agriculture and the Minnesota Agricultural Experiment Station on the U of M’s St. Paul Campus. Special security and air filtration systems ensure the insects being evaluated don’t venture out on their own. Field testing will take place in a limited number of grower fields and at Research and Outreach Centers.

Binodoxys communis was approved for release based upon four years of laboratory safety testing. It is an especially promising species for control of soybean aphid, because it comes from a region in China that is a good climate match to Minnesota. The stingless wasp specializes in soybean aphid and has been observed apparently controlling it in China.

A cooperative effort between the U of M, the state and soybean growers, like New Richland farmer Larry Muff, have made this experiment possible.

“The soybean check off is committed to supporting research that will mitigate this devastating pest,” said Muff, co-chair of the Minnesota Soybean Research and Tech Transfer Committee. “Organic growers will also benefit from this biological control of aphids.”

University researchers and Minnesota Department of Agriculture scientists will monitor the ability of Binodoxys communis to kill soybean aphids this summer and continue the attack this fall when soybean aphids move to buckthorn plants and survive the winter to battle soybean aphids in 2008.

The researchers also have a backup plan. Eleven other species and strains of stingless wasps are under evaluation and some of these that have shown promise from both a safety and efficacy standpoint may be field tested in 2008.

###

More information on the field testing, high resolution photos for download and other soybean aphid information is available at www.soybeans.umn.edu
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PostPosted: Mon Oct 01, 2007 12:32 pm    Post subject: Cockroaches Are Not Morning People Reply with quote

Cockroaches Are Not Morning People
By Tuan C. Nguyen, LiveScience Staff Writer

posted: 30 September 2007 10:14 am ET

Cockroaches learn new tricks well in the evening, but they're lousy students in the morning.

A new study, published in the Proceedings of the National Academy of Sciences, showed that while cockroaches were able to pick up and remember lessons taught in the evenings, they might as well have stayed in bed during the morning hours.

For the full article:

http://www.livescience.com/ani.....rning.html
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PostPosted: Mon Oct 15, 2007 10:33 am    Post subject: Satellites help ensure efficient use of pesticides Reply with quote

Satellites help ensure efficient use of pesticides
ESA

15 October 2007
A new service, developed in the framework of an ESA-supported project, is using satellite images to compare agricultural crop sites across Europe in order to ensure the more efficient use of pesticides.

For the full article:

http://www.esa.int/esaEO/SEM2E.....omy_0.html
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PostPosted: Thu Dec 06, 2007 6:29 pm    Post subject: Tiny pest-eating insect fights fruit flies Reply with quote

American Society for Horticultural Science
6 December 2007

Tiny pest-eating insect fights fruit flies

New environmentally friendly way to control fruit flies promotes agricultural sustainability


HARROW, ONTARIO -- Farmers and vineyard owners have a new weapon in their pest management arsenal. A commonly used parasitoid, or parasitic insect that kills its host, has proven to be quite effective in the control of fruit flies in vineyards. These tiny pest-devouring insects are considered to be powerful "biocontrol agents" since they reduce the need for chemical pest management applications.

Jean Pierre Kapongo, Ph.D., an entomologist specializing in environmental health at the University of Guelph in Ontario, Canada, recently published the results of a research study that will aid vintners and fruit farmers in their ability to produce healthier crops. According to Kapongo, vineyard owners and farmers can now control fruit flies (Ceratitis capitata) with Muscidifurax raptor, an insect currently used in the control of other types of pests.

The study investigated the use of Muscidifurax raptor to control fruit flies in vineyards. Until recently, fruit flies were usually controlled with chemical insecticides and selected natural enemies. Kapongo explained that these traditional control methods were not popular with farmers because of the adverse effects of chemicals and the unreliability of using living parasites. "Now we have discovered a parasitoid that is easily produced and effective in controlling fruit flies.", Kapongo commented. He added that insectaries, where parasitic insects are commercially produced and sold, are ready to increase production of the insects in response to market demands from vineyard owners.

Kopongo noted that using the Muscidifurax raptor parasitoid to control flies benefits the environment and promotes agricultural sustainability because the method lessens the need for chemical pesticides. Researchers believe that the study results will have additional application for controlling flies that threaten animals in confined environments such as poultry houses, dairies and horse stables.


###
The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublication.....42/6/1400/

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education and application. More information at ashs.org
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PostPosted: Fri Dec 28, 2007 10:22 am    Post subject: Handling pesticides associated with greater asthma risk in f Reply with quote

American Thoracic Society
28 December 2007

Handling pesticides associated with greater asthma risk in farm women

New research on farm women has shown that contact with some commonly used pesticides in farm work may increase their risk of allergic asthma.

“Farm women are an understudied occupational group,” said Jane Hoppin, Sc.D., of the National Institute of Environmental Health Sciences and lead author of the study. “More than half the women in our study applied pesticides, but there is very little known about the risks.”

The study was published in the first issue for January of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

The researchers assessed pesticide and other occupational exposures as risk factors for adult-onset asthma in more than 25,000 farmwomen in North Carolina and Iowa. They used self-reports of doctor-diagnosed adult asthma, and divided the women into groups of allergic (atopic) or non-allergic (non-atopic) asthma based on a history of eczema and/or hay fever.

They found an average increase of 50 percent in the prevalence of allergic asthma in all farm women who applied or mixed pesticides. Remarkably, although the association with pesticides was higher among women who grew up on farms, these women still had a lower overall risk of having allergic asthma compared to than those who did not grow up on farms, due to a protective effect that remains poorly understood.

"Growing up on a farm is such a huge protective effect it's pretty hard to overwhelm it," said Dr. Hoppin. "[But] about 40 percent of women who work on farms don't report spending their childhoods there. It is likely that the association with pesticides is masked in the general population due to a higher baseline rate of asthma."

Dr. Hoppin also found that most pesticides were associated only with allergic asthma, even though non-allergic asthma is generally more common in adults. “Asthma is a very heterogeneous disease,” said Dr. Hoppin. “This finding suggests that some of the agricultural risk factors for allergic and non-allergic asthma may differ.”

Some legal but rarely used compounds, such as parathion, were associated with almost a three-fold increase in allergic asthma. But even some commonly used pesticides were associated with a marked increase in allergic asthma prevalence. Malathion, for example, a widely used insecticide, was associated with a 60 percent increased prevalence of allergic asthma.

Of all the compounds examined, only permethrin, a commonly used insecticide that is used in consumer items such as insect-resistant clothing to anti-malaria bed-nets, was associated with both allergic and non-allergic asthma.

This is the first study to examine pesticides and asthma in farm women, and it points the way for future research to clarify the relationship. “At the end of the day, you have to remember that we’re looking at cross-sectional data, thus we cannot establish a temporal association between pesticide use and asthma,” cautions Dr. Hoppin. “There is a difference in asthma prevalence between women who did and did not use pesticides but whether it is causal or not remains to be seen.”

Dr. Hoppin and her colleagues are in the midst of planning a large scale prospective study that will better evaluate the links between pesticide exposures and asthma. “We want to characterize the clinical aspects of this disease, as well as lifetime exposures to agents that may either protect against asthma or increase risk,” said Dr. Hoppin. “We hope to start the study in 2008.”


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PostPosted: Mon Jul 14, 2008 9:05 am    Post subject: New "scrubber" speeds removal of powerful anthrax Reply with quote

New "scrubber" speeds removal of powerful anthrax clean-up agent
9 July 2008
Organic Process Research & Development

Researchers in New Jersey report discovery of a fast, efficient method for removing a powerful pesticide used to sterilize buildings and equipment following anthrax attacks. Their chemical "scrubber" removes 99 percent of the pesticide following fumigation and could pave the way for its broader use in anthrax clean-up efforts, the scientists say. Their study is scheduled for the July 18 issue of ACS' Organic Process Research & Development, a bi-monthly journal.

In the new study, Roman Bielski and Peter J. Joyce note that the commonly used pesticide, methyl bromide, is superior to chlorine dioxide for destroying anthrax-causing bacteria and their spores. However, it is highly toxic to humans and may harm the environment by destroying the ozone layer. Researchers thus have sought an efficient method for removing this promising anthrax decontamination agent.

Bielski and Joyce documented the effectiveness of their removal method in experiments with an empty office trailer filled with air containing methyl bromide. They treated air exhausted from the trailer with a solution of sodium sulfide combined with a powerful catalyst. This chemical "scrubber" removed more than 99 percent of the methyl bromide from the air. — MTS

ARTICLE #3 FOR IMMEDIATE RELEASE
"The Use of Methyltricaprylylammonium Chloride as a Phase Transfer Catalyst for the Destruction of methyl Bromide in Air Streams"

DOWNLOAD FULL TEXT ARTICLE
http://dx.doi.org/10.1021/op800016j
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PostPosted: Mon Aug 11, 2008 1:09 pm    Post subject: A new look at the "biobed's" role in pesticide spi Reply with quote

A new look at the "biobed's" role in pesticide spills
11 August 2008
Journal of Agricultural and Food Chemistry

Scientists in Sweden are cautioning about the need for further research as more countries embrace a popular method for preventing pesticide spills. Their review of current scientific knowledge on the so-called "biobed" is scheduled for the August 13 issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry.

In the study, Maria Del Pilar Castillo and colleagues point out that pesticide spills are common when farmers transfer highly concentrated liquid preparations into spray tanks where the pesticide is diluted with water. Even if a small, few-inch wide puddle of this concentrate spilled under the tank, the nearby environment could be exposed to up to one hundred thousand times the normal pesticide dose. "The risk of contamination is obvious," says Castillo.

To remedy the problem, Swedish scientists in 1993 developed the biobed. Built from layers of grass, clay and a biomixture of straw, peat and soil approximately two feet deep, the biobed functions as an absorbent sponge for leaking concentrate from parked spray tanks.

Castillo says the effectiveness and simplicity of biobed systems help them spread worldwide. But as biobeds are modified to suit local conditions and needs, she cautions that it is important to analyze their actual performance in each specific location and evaluate the effects of changes to the biobed's composition and how local temperature and other conditions affect performance.

ARTICLE #4 FOR IMMEDIATE RELEASE
"Biobeds for Environmental Protection from Pesticide Use – A Review"

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http://dx.doi.org/10.1021/jf800844x
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PostPosted: Mon Aug 25, 2008 11:41 am    Post subject: Pop chirp bite crunch chew Reply with quote

Pop chirp bite crunch chew
August 30th, 2008; Vol.174 #5

It turns out that a tree doesn’t have to fall in the forest to make a sound. Upright trees make plenty of sounds, even though human ears can’t hear them. But few aside from botanists would have known about the voices of the trees if two guys had not pounded an old meat thermometer turned ultrasonic microphone into a beetle-infested piñon.

For the full article:

http://sciencenews.org/view/fe.....runch_chew
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