“WHAT’S HAPPENING?”

The University of Tennessee/Agricultural Extension Service

Entomology & Plant Pathology - EPP #60

December 1, 2006

New Agent PSEP Info

by Gene Burgess

When a new Extension Agent, who makes pesticide recommendations, is employed, they should become certified as a pesticide applicator in Category 10, Demonstration, Research and Regulatory and Category 15, Worker Protection Standards. Each new agent should request the following from my office.

CORE Manual, Applying Pesticides Correctly (General safety standards)

Category 10 manual, Demonstration, Research and Regulatory

WPS manual, How To Comply manual

TN Laws & Regulations booklet

EPP Info #679, PSEP Information Packet

EPP Info #682, The Certification, Recertification and Licensing Process (For TN Extension Agents)

EPP Info #650, PSEP Training Materials & Forms

Extension Agents must take and pass an exam in C10 in order to make pesticide recommendations. They must take and pass an exam in C15 in order to train Workers, Pesticide Handlers and Trainers in the Worker Protection Standards program.

The CORE manual and Cat. 10 manual should be studied for the C10 exam. The How To Comply manual should be studied for the C15 exam.

When an agent has studied and prepared to take the exams, the TDA application, Commercial Certification Exam Application, should be completed and sent to TDA. The agent should write at the bottom of the form UT Employee. UT employees do not have to pay the $15 exam fee. This form may be found in EPP Info #679 or the Pesticide Safety Education Program, PSEP, website.

You should visit and become familiar with the PSEP web site, http://eppserver.ag.utk.edu/psep/psep.htm. The certification and licensing manuals may be ordered from http://ecommerce.cas.utk.edu/agstore/. One may also register for the certification and licensing classes we offer at this site.

If you have any questions about the certification, recertification or licensing process, please contact me.

Decisions Issued for Pyrethrins, Piperonyl Butoxide, MGK-264, and Dimethoate

by Gene Burgess

EPA has determined that all but one use of pesticide products containing pyrethrins, piperonyl butoxide (PBO), and MGK-264 are eligible for reregistration, pending the risk mitigation outlined by the Agency. Pyrethrins dust application with a power duster is not eligible for reregistration. First registered in the late 1940s and 1950s, pyrethrins, PBO, and MGK-264 are used to control many types of flying and crawling insects and arthropods. Pyrethrins are often formulated with synergists, such as PBO or MGK-264 to extend the pyrethrins toxic effect.

Mitigation measures outlined by the EPA address residential, occupational, and ecological risks. To mitigate residential risks, the Agency is restricting carpet dust applications to spot treatment only and prohibiting use of products in metered release devices in residential areas (removing day-car centers, nursing homes, schools, and hospitals from product labels). Pyrethrins and PBO use in outdoor misting systems will be restricted by establishing a maximum use rate and precautionary label statements, while MGK-264 will be prohibited from use in these systems.

Occupational risks are mitigated through repackaging and applicator respirator requirements. To address risks to aquatic and terrestrial organisms, mitigation measures include reducing the amount and/or frequency of outdoor sprays and agricultural applications. For pyrethrins and PBO mixtures with agricultural uses, no more than 10 applications will be allowed per season, and minimum retreatment interval will be three days, except under extreme pest pressure, in which case this period is 24 hours.

On July 12, the EPA announced the availability of the interim reregistration eligibility decision for dimethoate. The document describes mitigation measures to reduce the insecticide’s impact on drinking water, workers, and the environment. Maximum application rates will be reduced, as well as the number of treatments per season/year. Minimum retreatment times will be extended. (Pesticide & Toxic Chemical News, 7/17/06, EPA Pesticide Update, 7/31/06).

Protein LT-B

by Gene Burgess

Researchers at Iowa State University have successfully inserted genetic material into a corn plant that produces the protein LT-B, which is a subunit of a larger protein produced by some strains of bacteria that cause pig diarrhea. The LT-B protein stimulates protective immune antibodies when eaten by test animals. The group is now trying to conventionally cross the transgenic corn with a male sterile variety of corn, so that pollen is not produced. The university is hoping to also patent the process of creating the male sterile/transgenic hybrids. (Pesticide & Toxic Chemical News, 7/3/06).

Decisions Issued for Lindane, PCNB, Arsenicals, Triadimefon, and Carbofuran

by Gene Burgess

The final push towards reregistration that was due in August 2006 has produced some interesting outcomes. Lindane, which has only been used recently as a seed treatment, is no longer allowed to be used in any pesticide products. Once all of the registrants of technical and end use products request cancellation, tolerances for lindane will be revoked.

The fungicide PCNB will not be eligible for registration on turf, residential ornamentals, cole crops (unless for clubroot), green bean, cotton, potato, dry beans and peas, garlic, peanut, tomato, pepper, and ornamentals in commercial production (except for flowering bulbs). Those uses eligible for registration are cole crops (clubroot only), ornamental bulbs for commercial production and seed treatment.

Based on the Agency’s concern that organic arsenical herbicides will transform to a more toxic inorganic form of arsenic in the soil, with subsequent transfer to drinking water, the herbicides MSMA, DSMA, CAMA, and cacodylic acid are ineligible for reregistration. Consequently, all uses will be canceled. The task force for these products believes that the Agency has overestimated exposure by adding inorganic arsenic to the risk assessment, underestimated the benefits to agriculture and turf management, and will “vigorously defend its member company products.”

The popular residential lawn fungicide triadimefon will also be voluntarily cancelled for this site. Tolerances that are associated with this fungicide (apple, grape, pear, pineapple and raspberry) are proposed for revocation, except for pineapple.

As for the pesticide carbofuran, the EPA stated in early August that all uses will be canceled immediately except for corn, pepper, artichoke and sunflower, which will be phased out by 2010. The registrant, FMC Corporation, disputes the Agency’s evaluation of carbofuran and the decision to cancel all uses of the chemical, and would not voluntarily cancel registration while examining legal options. (Federal Register, 8/2/06, 8/9/06 & 8/30/06, Pesticide & Toxic Chemical News, 8/7/06, Chemical Regulation Reporter, 8/21/06).

FIFRA 2(ee) and Supplemental Labels

by Gene Burgess

The FIFRA Section 2(ee) addresses use of any registered pesticide in a manner inconsistent with its labeling. The term “to use any registered pesticide in a manner inconsistent with its labeling” means to use any registered pesticide in a manner not permitted by the labeling, except that the term shall not include:

(1) applying a pesticide at any dosage, concentration, or frequency less than that specified on the labeling unless the labeling specifically prohibits deviation from the specified dosage, concentration, or frequency,

(2) applying a pesticide against any target pest not specified on the labeling if the application is to the crop, animal, or site specified on the labeling, unless the Administrator has required that the labeling specifically state that the pesticide may be used only for the pests specified on the labeling or after the Administrator has determined that the use of the pesticide against other pests would cause an unreasonable adverse effect on the environment,

(3) employing any method of application not prohibited by the labeling unless the labeling specifically states that the product may be applied only by the methods specified on the labeling, or

(4) mixing a pesticide or pesticides with a fertilizer when such mixture is not prohibited by the labeling.

A FIFRA Section 2(ee) recommendation is occasionally submitted to the State Departments of Agriculture and Consumer Services for a pesticide product. These recommendations constitute University research “added” to labels. It is important to note that the manufacturers claim no responsibility to anything on 2(ee) recommendations, which often look like a label. A 2(ee) is not a supplemental label - they are not submitted to EPA and are not approved by EPA, which is stated on all 2(ee) recommendations. Supplemental labels are just like the main label and they are submitted and approved by EPA. Certain manufacturers combine 2(ee) recommendations into the main label every few years. (IR-4 email dialogue, 9/5/06, Chemically Speaking, 10/2006).

Methyl Bromide Stock Being Correctly Managed

by Gene Burgess

The U.S. EPA released data in September regarding existing stocks of methyl bromide in the United States. The data shows a steady decline in the inventory since 2003, when the Agency began collecting values. The stockpile has decreased from approximately 36 million pounds in 2003 to about 29 million pounds in 2004 to nearly 22 million pounds in 2005. The values present the aggregate inventory held by 35 companies during the period 2003 to 2005.

The release of the data came a little over a week after the U.S. Court of Appeals for the D.C. Circuit rejected a lawsuit brought by the Natural Resources Defense Council (NRDC) which claimed that EPA’s rule implementing critical use exemptions for methyl bromide in 2005 violated the Montreal Protocol, under which the gas is being phased out. “The phaseout of new production and import and the orderly reduction in the existing inventory that facilitates transition to alternatives are proceeding in a manner consistent with previous successful phaseouts of ozone-depleting substances, such as the chlorofluorocarbons (CFCs) and halons,” said the EPA. The Agency also stated that since 1994, $150 million has been invested in research for methyl bromide alternatives. (Pesticide & Toxic Chemical News, 9/18/06).

Most Widely Used Organic Pesticide Requires Help to Kill

by Gene Burgess

The world's most widely used organic insecticide, a bacterium known as Bacillus thuringiensis or Bt for short, requires the assistance of other microbes to perform its insect-slaying work, a new study has found. A team of researchers from the University of Wisconsin-Madison reports that without the help of the native bacteria that colonize the insect gut, Bt is unable to perform its lethal work. The new insight into the workings of one of the most important and environmentally friendly weapons in the human arsenal against insect pests has significant implications not only for the control of insects in agriculture, forestry and human health, but for understanding microbial disease in humans and other animals. “The take-home message is that we've shown that the mechanism of killing for Bacillus thuringiensis is facilitated by the normal gut community,” says the lead author of the study, Nichole Broderick. “This is a mechanism that was not previously known.”

First discovered in 1911, Bacillus thuringiensis was developed as a commercially important insecticide in the 1950s. It is by far the most widely used natural agent to control important insect pests, and the genes that make Bt's toxic proteins have been engineered into numerous crop plants. Transgenic crops using the bacterium's genes are the most prevalent of any engineered plants, and are planted on millions of acres in the United States alone. Although Bt and the toxic proteins it makes have been studied for decades, how the microbe goes about killing the insects it infects has been assumed to be a simple toxin-mediated disruption of the cells that line the insect gut. The damaged cells, according to the prevailing hypothesis, lead to starvation. An alternative hypothesis holds that the spread of the bacterium in infected insects leads to blood poisoning and death.

Virtually all animals, including humans, depend on the interplay of numerous species of bacteria that, beginning at birth, routinely colonize the stomach and intestines. The larvae of moths and butterflies have anywhere from seven to twenty species of gut bacteria. Humans have between five hundred and one thousand species of micro flora that take up residence in the intestinal tract. “In moths and butterflies, the complexity is much lower than in mammals, and even some other insects," Broderick explains. The study was conducted using antibiotics to clear all of the native bacteria that colonize the gut of gypsy moth caterpillars. Exposed to Bt, the caterpillars whose intestinal tracts had been cleared of their native microbial communities showed none of the agent's toxic effects. When the insect's microbial gut flora were reestablished, Bt's insecticidal activity was restored. To further test their results, the Wisconsin team used a strain of live E. coli engineered to carry the Bt toxin to infect caterpillars, a lethal treatment whether or not the insect gut contained its normal complement of microbes. However, if the engineered E. coli was killed before administration, it only killed those caterpillars whose microbial gut flora were intact. “The significance of the microbial community has been overlooked,” Broderick asserts. “Ultimately, this is a toxin-mediated septicemia (blood poisoning) modulated by the gut community.” The exact role played by the microbes to promote the Bt toxin's lethal effects remains unknown.

The upshot of the new work may have immediate application in designing strategies to manage insect pests by enhancing the killing effects of BT using indigenous insect gut microbes or other bacteria known to promote blood poisoning. “The work also raises the possibility that the genes encoding the (Bt) toxins could be deployed more effectively in transgenic crops by exploiting the role of insect-borne bacteria that enhance insecticidal activity,” concludes the research team. (UW-M Press Release, 9/25/06).

DDT - Back by Popular Demand

by Gene Burgess

The Word Health Organization (WHO) has endorsed the indoor spraying of dichlorodiphenyltrichloroethane (DDT) to control malaria-carrying mosquitoes, reversing a 30-year policy. The Organization said there is little risk from the insecticide when it is used appropriately and that any risks are far outweighed by the effectiveness of DDT in controlling a disease that kills one million people annually. Said one WHO official, “The scientific and programmatic evidence clearly supports this reassessment. DDT presents no health risk when used properly.”

New data that suggest minimal effects to the environment or health from indoor spraying of DDT have largely eliminated the concerns which led to the ban on DDT in the early 1980s. The 2001 Stockholm Convention on Persistent Organic Pollutants implemented a global ban on DDT, but allowed about 25 nations to keep using the insecticide for vector control to combat malaria under strict conditions. The WHO said of the dozen insecticides WHO has approved for house spraying, DDT is the most effective. For about $5, a household of five people can be protected for a year, during which time the incidence of the disease is being reduced by 90%.

One of the proponents of the use of DDT is South Africa, which reintroduced DDT for indoor use several years ago after finding that malaria-carrying mosquitoes had developed resistance to other insecticides. Since then, malaria case and fatality numbers have fallen to all-time low levels and South Africa has moved towards malaria elimination. Currently, 14 countries in Sub-Saharan Africa are using indoor spraying programs and ten of those are using DDT.

Activist organizations are split in their reaction. Environmental Defense, which launched the anti-DDT campaign in the 1960s, now endorses the indoor use of DDT for malaria control, as does the Sierra Club and the Endangered Wildlife Trust. Others are less enthusiastic. (Pesticide & Toxic Chemical News, 9/18/06).

Cal-Q-Later

by Darrell Hensley

Do you have a Texas Instruments TI-84 Plus or TI-84 Plus Silver Edition??? If not, they may be purchased from $99 to $139 depending on the retail outlet. If you have one, you may be on the way to solving some of your production problems. Vernier, has developed several probes that work with the TI-84 Plus series calculators and some older TI-83 models. Vernier’s software “Easylink” connects a host of sensors to the calculators, allowing pH, soil moisture, soil temperature, salinity, and conductivity analysis. Each probe varies in pricing. You will need to purchase the interface box ($58) and probe of choice. The software is free to download see http://www.vernier.com/probes/ or http://www.ti.com for more information.

OTHER UT NEWSLETTERS WITH PEST MANAGEMENT INFORMATION

Fruit Pest News

http://web.utk.edu/~extepp/fpn/fpn.htm

Tennessee Crop and Pest Management Newsletter

http://www.utextension.utk.edu/fieldCrops/cotton/cotton_insects/ipmnewsletters.htm

This and other "What's Happening" issues can be found at http://web.utk.edu/~extepp/whatshap.htm

Precautionary Statement

To protect people and the environment, pesticides should be used safely. This is everyone’s responsibility, especially the user. Read and follow label directions carefully before you buy, mix, apply, store or dispose of a pesticide. According to laws regulating pesticides, they must be used only as directed by the label.

Disclaimer

This publication contains pesticide recommendations that are subject to change at any time. The recommendations in this publication are provided only as a guide. It is always the pesticide applicator's responsibility, by law, to read and follow all current label directions for the specific pesticide being used. The label always takes precedence over the recommendations found in this publication.

Use of trade or brand names in this publication is for clarity and information; it does not imply approval of the product to the exclusion of others that may be of similar, suitable composition, nor does it guarantee or warrant the standard of the product. The author(s), the University of Tennessee Institute of Agriculture and University of Tennessee Extension assume no liability resulting from the use of these recommendations.

Visit the UT Extension Web site at http://www.utextension.utk.edu

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