Pesticide Potpourri

• An unusually durable fungus that was first spotted on tiny insects feeding on eggplants in Texas may become a new biological control for the widespread and costly whitefly.  The fungus was first isolated by USDA Agricultural Research Service (ARS) entomologists at the ARS Beneficial Insects Research Unit, Weslaco, Texas.  The new fungal species has been named Isaria propawskii.  In the Lower Rio Grande Valley of Texas, it has been shown to kill both larval and adult stages of silverleaf whitefly.  In fact, since 2001, it has periodically wiped out whiteflies at the ARS insect-rearing facilities in Weslaco.  Notable aspects of I. propawskii include its natural establishment in a semiarid region where temperatures can reach 107 degrees Fahrenheit and its continuing persistence, even in the absence of insect hosts.  A high spore production in common culture media makes this fungus comparatively easy to grow in vitro in the laboratory.  These features, plus its high pathogenic potential against a second major insect pest - the glassy-winged sharpshooter, Homalodisca vitripennis - make the fungus a promising candidate for practical biological control of two major U.S. farm pests.  (ARS News, 5/11/07).
•  A virus technology with potential to control red imported fire ants (Solenopsis invicta) is available for licensing from the ARS.  Scientists in the Imported Fire Ant and Household Insects Research Unit at the ARS Center for Medical, Agricultural and Veterinary Entomology in Gainesville are working with an ant-infecting virus called Solenopsis invicta virus-1, or SINV-1.  They have found it to occur in about 20 percent of red imported fire ant fields, where it appears to cause the slow death of infected colonies.  The SINV-1 virus is the first virus to be recovered from red imported fire ants.  In the laboratory, SINV-1 has proven to be both self-sustaining and transmissible.  Once introduced, it can eliminate a colony within two to three months.  That's why the researchers think it has potential for cultivation and development into a viable biopesticide for controlling S. invicta.  Cooperators are being sought to develop methods for growing and packaging the virus commercially, and for applying it under field conditions.  (ARS News, 4/17/07).

•  The oomycete Phytophthora capsici is the plant pathogen responsible for Phytophthora blight, a devastating disease of bell pepper, cucumber, pumpkin, and related crops occurring worldwide.  This pathogen caused major losses in Florida vegetable production during the past decade, especially on bell pepper and summer squash.  UF/IFAS researchers studied the survival of the oospore during two separate years of study under three different soil treatments: soil solarization, soil fumigation with methyl bromide-chloropicrin (67:33), and a non-treated soil control.  No P. capsici was detected in the fumigated treatments during any sampling date.  In both the solarization and non-treated soils, viable P. capsici was detected at all sampling periods.  However, populations of P. capsici were lower in the soil solarization treatments than in the non-treated soil.  These data indicate that oospores of P. capsici have the potential to survive for at least a year in Florida farming soils and may serve as initial inoculum for future Phytophthora blight outbreaks.  (Plant Disease, Vol. 91 No. 5, May 2007). 

•  Crop to weed transmission of glyphosate resistance via gene flow has been frequently researched but little information is available on weed to weed interactions.  To determine the possible occurrence of weed to weed transfer of the glyphosate resistance, researchers at the Iowa State University and University of Delaware examined hybridization in Conyza, a prevalent weed species in the Midwestern United States.  The researchers observed that hybridization and transfer of herbicide resistance can occur between C. canadensis and C. ramosissima.  The researchers have determined that approximately 3 percent of ova were fertilized by pollen of the opposing species and produced viable seeds.  The interspecific hybrids were found to have intermediate phenotype between the parents but exhibit superior resistance to glyphosate.  The possibility of introgressive hybridization suggest complications in the management of glyphosate resistant weed populations in glyphosate resistant crops and the containment of glyphosate resistance genes within these agroecosystems.  The researchers reiterated that weed control should be combined with alternative management tactics to mitigate the evolution of herbicide resistance in the current agroecosystems.  (CropBiotech Update, 4/27/07). 

•  Makteshim Agan Industries, Inc., Israel, has acquired the Guthion® brand insecticide from Germany-based Bayer CropScience Ag.  Raleigh, NC-based Makteshim Agan Industries of North America received the product line of Guthion Solupak in the U.S. and Canada.  The insecticide is still labeled for apple, pear, cherry, blueberry, almond, pistachio, walnut, and parsley.  (Citrus & Vegetable Magazine, April 2007).

•  The No Spray Coalition and New York City reached a settlement agreement in mid-April over the use of pesticide spraying to combat mosquitoes during West Nile Virus alerts.  The coalition claimed that the city had violated the Clean Water Act.  As part of the settlement, the city has agreed to admit that the pesticide sprayed may harm human health and the environment.  The city has also agreed to pay activist groups $80,000.  (Pesticide & Toxic Chemical News, 4/30/07). 

•  Recent results of a large study indicated that farm workers exposed to paraquat had twice the expected risk of developing Parkinson’s disease than the general population.  A second study found that rodents exposed to paraquat have a build-up of the protein alpha-synuclein, a situation which can lead to destruction of dopamine-producing cells.  (Pesticide & Toxic Chemical News, 4/30/07). 

•  United States revenues in 2006 from agricultural and household pest control chemicals reached $13.8 billion according to a new report.  The gross profit on this was reported to be $8.5 billion, or 61 percent.  Total import value of such products into the U.S. in 2006 fell 10 percent (compared to 2005) with Canada, the U.K., Germany, France, and China the top exporters into the country.  On the other side, U.S. exports to other countries grew 19 percent over 2005 values, with Canada, Brazil, Mexico, China, and France the top recipients.  (Pesticide & Toxic Chemical News, 4/23/07). 

•  Venezuelan President Hugo Chavez Frias has announced that the cultivation of genetically modified crops will be prohibited on Venezuelan soil, possibly establishing the most sweeping restrictions on transgenic crops in the western hemisphere.  Though full details of the administration's policy on genetically modified organisms are still forthcoming, the statement by President Hugo Chavez will lead most immediately to the cancellation of a contract that Venezuela had negotiated with the US-based Monsanto Company.  Before a recent international gathering of supporters in Caracas, Chavez admonished genetically engineered crops as contrary to interests and needs of the nation's farmers and farmworkers.  (Reuters, 4/29/07).

•  The operation to sabotage a UK potato trial was planned with care and under conditions of great secrecy.  Nearly 250 protesters swooped down on the 16-hectare site outside Hull, armed with shovels.  In less than an hour they had moved to invalidate the trial, planting thousands of organic potatoes.  Mission accomplished.  If only they had got the right field.  Activists from Mutatoes.org apologized to farmer David Buckton after it emerged that they wrongly identified his land as the site of the potato trial.  The field they planted was sown with beans.  (Guardian Unlimited, 4/25/07). 

•  Voters at three town meetings in Berkshire County Massachusetts will be considering resolutions seeking an end to the use of genetically engineered seeds on farms.  The resolutions in Becket, Great Barrington, and Savoy all call for legislation in state and federal government that would institute a moratorium on the use of the seed.  Three other Berkshire County towns - Windsor, Sandisfield, and Williamstown - have passed similar resolutions in the past four years.  A total of 21 Massachusetts towns have passed the resolution, and another nine are considering it this year.  In Vermont, 85 towns passed similar resolutions, and the legislative effort that resulted was vetoed by Vermont Gov. Jim Douglas in 2006.  (Berkshire Eagle, 5/7/07).