Tag Archives: pesticides

Beekeepers Ask EPA to Remove Pesticide Linked to Colony Collapse Disorder, Citing Leaked Agency Memo

Beekeepers Ask EPA to Remove Pesticide Linked to Colony Collapse Disorder,
Citing Leaked Agency Memo

Pesticide Already Illegal in Germany, Italy & France Based on Scientific Findings

SAN FRANCISCO and WASHINGTON, D.C – Beekeepers and environmentalists today called on EPA to remove a pesticide linked to Colony Collapse Disorder (CCD), citing a leaked EPA memo that discloses a critically flawed scientific support study. The November 2nd memo identifies a core study underpinning the registration of the insecticide clothianidin as unsound after EPA quietly re-evaluated the pesticide just as it was getting ready to allow a further expansion of its use. Clothianidin (product name “Poncho”) has been widely used as a seed treatment on many of the country’s major crops for eight growing seasons under a “conditional registration” granted while EPA waited for Bayer Crop Science, the pesticide’s maker, to conduct a field study assessing the insecticide’s threat to bee colony health.

Bayer’s field study was the contingency on which clothianidin’s conditional registration was granted in 2003. As such, the groups are calling for an immediate stop-use order on the pesticide while the science is redone, and redesigned in partnership with practicing beekeepers. They claim that the initial field study guidelines, which the Bayer study failed to satisfy, were insufficiently rigorous to test whether or not clothianidin contributes to CCD in a real-world scenario: the field test evaluated the wrong crop, over an insufficient time period and with inadequate controls.

Original post at Pesticide Action Network.

Contacts:Heather Pilatic, Pesticide Action Network
cell: 415.694.8596

Jay Feldman, Beyond Pesticides
202.543.5450, ext 15

Less is more for greener insecticide.

Romanelli, GP, EG Virla, PR Duchowicz, AL Gaddi, DM Ruiz, DO Bennardi, E del Valle Ortiz and JC Autino.  2010.  Sustainable synthesis of flavonoid derivatives, QSAR study and insecticidal activity against the fall armyworm, Spodoptera frugiperda (Lep.: Noctuidae). Journal of Agricultural and Food Chemistry 58:6290-6295.

Synopsis by Evan Beach
Aug 23, 2010

No solvent and no corrosive acids. That’s part of the recipe for a new, less polluting method of making chemicals that kill an important crop pest. Taking their inspiration from natural plant chemicals called flavones, the authors of the study developed a way to make, compare, and test the insecticides, and used the information to create a predictive computer model.

The cleaner synthesis was used to control fall armyworms, one of the main threats to corn crops in many parts of the world. The new method avoids toxic solvents and strong mineral acids that were needed in earlier processes.

Instead, it relies on a metal catalyst that works at low levels: one catalyst molecule per 200 molecules of starting material. The catalyst could be easily recovered at the end of the chemical reaction and recycled several times, reducing waste.

Flavones protect plants against a variety of bacteria and insects. Some flavones also show beneficial effects in humans as antioxidants, anti-inflammatory agents, antimicrobials and anticancer agents.

The researchers made synthetic flavones using the greener technique and found that the chemicals were effective against the armyworm larvae. Based on these results, the researchers then created a computer model to predict which natural flavones might be worth testing as pesticides. They analyzed the structures of more than a dozen plant flavones and found two with characteristics in common with the chemicals that worked against armyworms.

One of the natural flavones, luteolin, occurs naturally in the human diet, in carrots, peppers, celery, and some spices. The other, apigenin, is common in citrus fruit, tea, and a variety of vegetables. Both chemicals are often cited for their therapeutic effects in humans.

The next step is for scientists to test whether these two natural flavones do indeed kill insects, as predicted by the model. While the natural flavones would probably have minimal environmental impacts if applied as pesticides, the synthetic flavones reported in the study were not tested for environmental persistence or toxicity to organisms besides armyworms. Those experiments would confirm whether the greener preparation leads to greener pesticides.

Mosquito Spray Affects Bird Reproduction.

Mosquito spray affects bird reproduction

House martin numbers hit by ‘environmentally friendly’ insect control.

Natasha Gilbert

Anti-malarial spraying: A biological pesticide, containing  Bacillus thuringiensis, is sprayed onto stagnant water which is a  potential breeding site for the mosquito vectors of malaria. 1990Spraying Bti to control mosquitoes may hit bird populations.WHO/TDR/Pasteur Institute

A widely used microbicide may not be as environmentally friendly as previously thought.

The bacteria Bacillus thuringiensis israelensis (Bti) is now the most commonly used microbicide to control mosquitoes worldwide and is considered to be the least toxic alternative to chemical pesticides. But a new study has revealed adverse effects on the reproductive success of birds.

When ingested by water-inhabiting mosquito larvae, toxic proteins produced by Bti cause pores to form in the guts of the larvae, destroying their digestive tract and eventually killing them. The microbicide has been in use for more than 25 years and is the favoured method of mosquito control in West Africa, the United States and Europe. The handful of previous field studies on its toxicity to vertebrate populations have not found significant adverse impacts.

But work1 — by Brigitte Poulin, a bird ecologist at the Tour du Valat research centre in Arles, France, and her colleagues — in the Journal of Applied Ecology provides evidence that mosquito control has effects further up the food chain. The team shows that the breeding success of house martins (Delichon urbicum) in Bti-treated areas in a national park in the Camargue, France, dropped dramatically compared with that of birds living in untreated sites. The fall in reproductive success was due to the loss of mosquitoes — the birds’ preferred food source.

“We demonstrated that Bti clearly has an impact on house martins,” says Poulin.

Read the full story at NatureNews