agrichemical and environmental newsaenews.wsu.edu/dec99aenews/decaenews99.pdf · 1999-12-03 ·...

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Agrichemical &Environmental News

¿¿¿¿¿Dec. 1999No. 164

In This Issue

Comments to: Catherine DanielsWSU Pesticide Information Center

2710 University DriveRichland, WA 99352-1671

Phone: 509-372-7495Fax: 509-372-7491

E-mail: [email protected]

The newsletter is on-line atwww2.tricity.wsu.edu/aenews,or via the Pesticide InformationCenter (PICOL) Web page at

http://picol.cahe.wsu.edu

Hard-copy subscriptions are $15 ayear. Mail check to above address,ATTN: Sally O’Neal Coates, Editor.

Chlorpyrifos Risk Assessment,Part 1: A Tale of Two Sciences .... 1

Making the Connection: SkagitFarmers and the Public ............... 5

Pesticide Applicator Training ....... 8

“Endangered Species” at 4thPesticide Issues Conference....... 9

Biocontrol of Yellow Starthistle .. 11

UW Hosting Course onPesticide Effects ........................ 14

Know Your Enemy: Proper PestIdentification is Good forEnvironment and Bottom Line ... 15

PNN Update .............................. 16

Federal Register Summary ....... 17

Tolerance Information................ 18

As mirrors reflect an obverse reality,popular accounts of EPA’s recentlyreleased risk assessment for chlor-pyrifos seemed to be objective butsomehow wrong. An AssociatedPress release contended thatchlorpyrifos was so pervasive that “amajority of Americans, includingchildren, face potential health risks.”As if pervasiveness was somehowsynonymous with hazard. TheWashington Post on-line declaredboldly, “EPA Says Dursban MayHarm Health.” The Post went on tosay that exposure to Dursban on theskin, in food, or by inhalation couldbe harmful to human health. And ofcourse, the Environmental WorkingGroup (EWG) always enters the fraywith its press release de résistance,subtitling it “Children Found Espe-cially Vulnerable” as it demandedchlorpyrifos be banned. Echoing theWashington Post (or was it the otherway around?), EWG stated thatchlorpyrifos “poses excessive safetyrisks to millions of Americans eachyear who are exposed when theyuse the chemical to kill bugs in theirhomes or gardens, or consume foodcontaminated with the compound.”

OK, let’s clear the air right away. I’veread quite a bit of the released draftchapters of the Re-Registration

Eligibility Decision Documents(REDs) in dreaded detail, and I cancategorically state that the popularaccounts are more reflections ofwishful perspective than faithfulreportage of the documents. Themost egregious misinterpretation isthat EPA concluded excessive riskfrom eating chlorpyrifos residues infood (a.k.a. dietary risk). In fact, EPAsaid that levels of both acute andchronic exposure were not ofconcern. As a matter of fact, chlo-rpyrifos breezed through the mostrigorous of dietary exposure assess-ments, and passed with flying colorsdespite being saddled with a 300-fold safety factor.

So what is all the hoopla about? Ifanything, chlorpyrifos has acquiredthe honor among pesticides of beingthe first one deemed “too risky” byvirtue of residential exposure. Inshort, it’s okay to eat it, but don’tuse it around the house. But theconclusion is just the beginning ofour tale. The real story is aboutwhose science is more sound.

Risk Assessmentfor DummiesBefore delving further into our tale,let’s level the playing field with aquick primer on what is in the RED.

The ChlorpyrifosRisk AssessmentPart 1: A Tale of Two SciencesDr. Allan S. Felsot, Environmental Toxicologist, WSU

...continued on next page

Agrichemical andEnvironmental News

A monthly report on pesticides and related environmental issues

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¿¿¿¿¿Dec. 1999No. 164

The RED consists of chapters cobbled together byEPA’s Health Effects Division (HED). Within thosechapters, the basic elements of a risk assessment—hazard identification, dose-response relationships,exposure assessments, and risk characterization—canbe found. All human health hazards from weight loss toenzyme changes to death are considered. EPA scoursthe pile of submitted manufacturer’s data to find themost sensitive hazard, i.e., the one occurring at thelowest dose tested. Once this hazard is identified, thenEPA decides which dose causes no effect (the NOEL) inthe most sensitive animal tested, usually rats or dogs.Possible exposure scenarios are derived generally byany combination of three methods: (1) directly fromsituation-specific studies by the pesticide manufacturer;(2) indirectly from previously compiled databases ofother worker exposure studies; or (3) calculated fromone of several mathematical models simulating pesticideresidue behavior in surface and ground water.

The estimated exposure is compared to EPA’s predeter-mined level of concern, the Reference Dose (RfD). TheRfD is calculated by dividing the NOEL by some uncer-tainty factor (usually 100), and then adjusting the resultto account for exposure of children, if they are deemedmore sensitive than adults. The final safe exposure,known as the Population Adjusted Dose (PAD), repre-sents the maximum milligrams of pesticide exposure perkilogram of body weight per day (mg/kg/day) that EPAjudges will cause no unreasonable adverse health effectof any kind in any age group. PAD is calculated for bothsingle-day (acute) exposure and 70-year lifetime(chronic) exposure.

Cholinesterase Inhibition: WhichOne Is the Best for Hazard ID?Applying these principles to chlorpyrifos, EPA concludedthat all of Dow AgroSciences (DAS) submitted datapointed to inhibition of cholinesterase enzyme as themost sensitive toxicological endpoint upon which to basethe RfD. However, cholinesterase, which helps modulatenerve activity, comes in many forms and occurs in manytissues. Inhibition of the form known as acetylcholinest-erase (AChE) in rat and dog brains is without doubtrelated to its toxic effects. But an alternative form knownas pseudo- or butyrylcholinesterase (BChE) is inhibitedin the plasma without any toxic effects. EPA says BChE

inhibition matters. DAS says it is irrelevant and onlyindicates exposure. Inhibition of true acetylcholinest-erase in red blood cells (RBCs) is the best predictor oftoxic effects stemming from inhibition of brain AChE.

The science argument between EPA and DAS maysound like a barroom discussion about how manyangels can dance on the head of a pin, but recall thatthe level of acceptable risk is basically decided when theNOEL of the most sensitive hazard is identified. Theeffect of choosing this endpoint is aptly illustrated by acomparison of the NOEL and LOEL (Lowest ObservedEffect Level) observed after feeding dogs for two yearswith different doses of chlorpyrifos (Figure 1.)

If inhibition of RBC AChE rather than plasma BChE ischosen as the most important hazard to use as a bench-mark for risk characterization, then DAS can fit threetimes more exposure into the metaphorical exposurerisk cup. Needless to say, EPA’s viewpoint prevailed.

The Infant Factor and Hazard IDConcerning other hazards, both EPA and DAS agreedthat chlorpyrifos does not cause gene mutation, chromo-somal breakage, or cancer. EPA agreed with DAS thatthe tests used to determine whether children are moresensitive than adults indicated there is no difference insensitivity. Nevertheless, EPA thought that publishedscientific literature suggested some increased sensitivityin infants, and therefore decided to apply an extrathreefold safety factor to the RfD to produce the PAD.

Chlorpyrifos, cont.

FIGURE 1

Dose Associated with Cholinesterase Inhibition in Dogs (mg/kg/day)

The dose at which cholinesterase inhibitionoccurs varies with the type of tissue tested.

Plasma

RBC

Brain

0.001 0.01 0.1 1 10

NOEL

LOEL


Dr. Allan S. Felsot, Environmental Toxicologist, WSU

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¿¿¿¿¿Dec. 1999No. 164

DAS vehemently dissented, supplying plenty of reasons.The argument is worthy of its own essay (stay tuned forPart 2).

Cherry Picking theDose-Response RelationshipChlorpyrifos is one of the few pesticides that has beenstudied under controlled conditions in human volunteers.DAS argued that the dose-response information from itsthree separate human studies provided valid, reliabledata for the NOEL. EPA had accepted the DAS humandata until 1998. But during early 1999, the agencydecided the studies were not adequate to support thetoxicity endpoints (i.e., the NOEL). Instead EPA reevalu-ated the rat and dog dose-response toxicity studies anddecided that an acute single dose rat study sufficed foran acute NOEL of 0.5 mg/kg. The chronic NOEL of 0.03mg/kg/day was derived from a two-year dog-feedingstudy.

The switch from the use of human data to rat and dogdata obligated EPA to divide the NOELs by a safetyfactor of 100-fold to derive RfDs for acute and chronicexposure of 0.005 and 0.0003 mg/kg, respectively.When only animal toxicity data are available, the safetyfactor of 100 accounts for a hypothetical tenfold potentialdifference in sensitivity between rats/dogs and humansand an additional tenfold factor for differences in sus-ceptibility among humans.

EPA justified its fall back on animal data with two mainreasons. First, the agency argued that humans weremore sensitive to cholinesterase inhibition than eitherrats or dogs. But DAS pointed out that EPA failed torecognize they were comparing inhibition of the moresensitive BChE that predominates in dog and humanplasma with the less sensitive AChE that is most preva-lent in rat plasma. In fact, when inhibition of the sameform of cholinesterase was considered, humans were nomore sensitive than other animals, perhaps even lessso. As evidence, DAS agreed with the EPA that theacute NOEL should be 0.5 mg/kg/day, but their supportcame from two of their human studies.

EPA’s second concern about human studies was thatthe one earmarked for supporting a chronic RfD usedonly four humans per dose group in a relatively short-

term test of twenty-eight days. Ironically, two dog studiesthat EPA relied upon only used three or four dogs perdose group. Although the studies lasted one or twoyears, inhibition of cholinesterase was observed afteronly seven days, proving that both short and longperiods of exposure gave the same magnitude of effect.

The worldwide regulatory community, as represented bythe World Health Organization (WHO) in addition to theEuropean Union and Canada, has long accepted thepractice of applying only a tenfold factor to the NOELwhen human testing data were available. Not only didDAS argue for consideration of the human data, but thecompany also held fast to scientific opinion that plasmaBChE inhibition was not a toxic endpoint, only a mea-sure of exposure. DAS wanted the RfDs to be based oninhibition of RBC AChE, making them 0.05 and 0.01 mg/kg/day for acute and chronic exposure, respectively.

It’s Everywhere, It’s Everywhere!Real World Exposure AssessmentNow comes the last piece of the puzzle before risk canbe characterized. How much exposure do consumers,workers, and residents suffer? EPA used a combinationof empirical exposure studies submitted by DAS, datafrom the Pesticide Handler Exposure Database (PHED),and assumptions from draft residential Standard Operat-ing Procedures (SOPs) to estimate exposures forcommercial and private applicators, residential (home-owner) applicators, and residents post-application.

Professional applicators were assumed to wear long-sleeved shirts, long pants, nitrile gloves, and chemical-resistant boots. In contrast, EPA assumed residentialapplicators were only wearing shorts, short-sleevedshirts, and no gloves. Thus, exposure for homeownerswas assumed to be worst-case, not what is prudent orrecommended.

Risk Characterization:Rigged to Fail?The last step of risk assessment involves overlaying theacceptable exposure benchmarks (in this case, the RfDor PAD) on the estimated exposures. For determiningapplicator and residential risk, EPA uses a margin ofexposure (MOE) method in which estimated exposuresare compared to the acute or chronic NOELs. But the



Chlorpyrifos, cont.

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¿¿¿¿¿Dec. 1999No. 164

method turns out to be the sameas if exposure was expressed asa percentage of the RfD or PAD.Any exposure less than the RfDor PAD are considered belowlevels of concern.

The calculated risk is highlydependent on the choice ofbenchmark: RfD or PAD. Theeffect of this choice is aptlyillustrated by comparing tworesidential exposure scenarios tothese benchmarks. In Figure 2, Igraphed measured exposuresreported by DAS for broadcastlawn treatments, one with achlorpyrifos spray and one with agranular formulation. Low, aver-age, and high exposure charac-terizations are shown for each ofthe two formulations. I then overlaid the EPA acute PAD(0.0017 mg/kg/day), which incorporates a 300-foldsafety factor, and the acute RfD (0.05 mg/kg/day) thatDAS has submitted and extensively supported withpublished scientific papers.

Because the exposure bars crossed the line indicatingthe EPA PAD, the risk was characterized as exceedingthe levels of concern. EPA found many such incidencesof worker and residential exposure that were unaccept-able. However, from the DAS viewpoint, EPA’s calcu-lated exposures were well under the RfD. Furthermore,DAS submitted revised calculations for exposure thatwere much lower than EPA’s estimates.

To gain a perspective of how safe the estimates ofexposure are compared to actual observations of noeffects, a line representing the mutually agreeable acuteNOEL (0.5 mg/kg/day) based on both rat and humanstudies was drawn across the graph.

Whose Risk Is It Anyway?One really can’t fault EPA for setting conservativestandards for acceptable risk. After all, the agency isunder tremendous political pressure to “do the rightthing.” But that doesn’t make their interpretation of “the

right thing” sound science. DASsubmitted to EPA a one-inchthick document of rebuttal, citinga number of independent analy-ses that run counter to theagency’s views and analyses.

Regardless of whose science ismore sound, I see a philosophi-cal argument here. If we weretalking about dietary exposures,perhaps EPA might have someground to be so conservativebecause the risk would beessentially involuntary andunavoidable.

But worker and residentialexposures are voluntary risks.Workers are free to choose theiremployer, but more importantly,

they are trained to handle the pesticides and are fullyinformed of the consequences when they are sloppy.Residents choose to purchase a product to use aroundthe home, but they are also free to question a hiredprofessional pest control service about the products theyuse and to demand products they feel would be the leasthazardous. The principle of caveat emptor has longbeen used for the voluntary purchase of pharmaceuticalchemicals over the counter. Perhaps the principle shouldbe applied to residential use of pesticides. Consideringthe wealth of information available for chlorpyrifos, theexistence of human testing data, and plenty of scientificdissent, EPA’s concerns about risk may have exceededreasonable levels.

Dr. Allan S. Felsot is an Environmental Toxicologist withthe Food and Environmental Quality Laboratory atWashington State University. He can be reached [email protected] or (509) 372-7365.

REFERENCES: All references used to prepare thisarticle are contained in documents downloaded from theEPA’s OP insecticide website for chlorpyrifos, (http://www.epa.gov/pesticides/op/chlorpyrifos.htm).


Chlorpyrifos, cont.

Low

Average

High

0.0001 0.001 0.01 0.1 1

GranularSpray

FIGURE 2EPA’s PAD DAS’ RfD NOEL

Risk characterization of residential exposurefollowing lawn treatment with chlorpyrifosspray or granular formulation. Exposures arecategorized as low, average, or high basedon actual DAS measurements.

Exposure (mg/kg/day)

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¿¿¿¿¿Dec. 1999No. 164

Agriculture contributes to the quality of life throughoutthe state of Washington and the nation. But evidencesuggests that while there is widespread appreciationof open space, greenbelts, wildlife, and recreation,the non-farm community does not connect theseassets with the presence of farms. In a 1996 study,seventy percent of the respondents said the quality oflife in Skagit County is very important. Sixty-sixpercent consideredopen space veryimportant. Fifty-sevenpercent said protectingwildlife habitat wasvery important. Yetonly thirty-six percentviewed agriculture asvery important. Forwhatever reason, people are not making the connec-tion between farming and the quality of life, openspaces, and wildlife habitat they enjoy.

With less than two percent of the U.S. populationinvolved in farming, few people have direct experi-ence in agriculture. U.S. citizens enjoy the low cost offood, yet they frequently lose sight of the link betweenthe farm and the freezer case in the local grocerystore. Town and city dwellers sometimes seek out arural atmosphere for their homes, yet they expressconcern about pesticide use, noise, dust, odors, andinsects. They may even support increased regulationof farmers, due to lack of understanding of the reali-ties and complexities of farming.

One effort to address the need for increased opportu-nities to link agriculture and consumers was launchedby Washington State University (WSU)/Skagit CountyCooperative Extension in 1998. The project, Sharingthe Skagit: People, Agriculture, & Wildlife, is fundedby part of a $113,000 grant from United States De-partment of Agriculture (USDA) Sustainable Agricul-ture Research and Education program. Its purpose isto increase community knowledge of agriculture andthe economic and aesthetic benefits it provides. Thegoal is to increase the long-term sustainability of thewider community, its landscape attributes, and its

economic and agricultural bases. Skagit County is aprime area for such a project. Located within anhour’s drive of the major metropolitan city of Seattle,the county is under extreme pressure for the conver-sion of farmland to other uses, primarily housing.Between 1960 and 1997, the population of SkagitCounty increased by 89%. In that same time frame,34% of the county’s farmland was lost to other uses.

The population is expected to grow another50% by the year 2020.

Skagit County has deep roots in its agricul-tural heritage, but many newer residents donot share those roots and the accompanyingvalues. A major thrust of Sharing the Skagithas been to reach these newcomers throughprograms that appeal to the wider audience

of consumers in general. This article describes twosuch programs: 1) the Skagit Agricultural SpeakersBureau and 2) Celebrating Skagit Agriculture: AFestival of Family Farms.

Agricultural Speakers BureauThe idea for an agricultural speakers bureau startedaround a breakfast table in the tiny town of LaConner,which sits on the western edge of thousands of acresof agricultural land in Skagit County. I called togethera diverse group of about a dozen people, including acounty commissioner, the director of a farmlandpreservation organization, the director of the localeconomic development association, the manager of aleading agrichemical dealership, the conservationchair of the local Audubon society, local farmers, andWSU faculty and staff. Discussion focused on waysWSU Extension might provide leadership for linkingthe farming and non-farming communities. Over thecourse of the next year and a half, we prioritizedprojects and the WSU members of the team wroteand submitted a grant proposal. An agriculturalspeakers bureau was one of the projects supported inthe grant award.

Volunteers were solicited through extension newslet-ters, personal contacts and letters, and announce-ments at community events to serve on a speakers

Making the ConnectionFarmers and the General Public

Dyvon Havens, WSU/Skagit County Horticulture Extension Agent

Outreach programsin Skagit Countyeducate the publicabout farming.


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¿¿¿¿¿Dec. 1999No. 164

bureau advisory committee (“core team”). In the fall of1998, we held a kick-off event to explain and promotethe larger Sharing the Skagit project and to invite partici-pation. Press packets were provided to the media priorto the event. Three hundred members of the communitywere invited to the event and seventy attended, each ofwhom received a colorful packet of information and asign-up card on which to indicate the aspects of theproject in which they were interested in committing time.

The core team organized and managed the structure ofthe speakers bureau. They developed vision and mis-sion statements, as well as a plan for implementing theprogram. A major outreach effort yielded a total ofseventy residents who indicated an interest in beingmembers of the larger agricultural speakers bureau.Our orientation session included a welcoming ice-breaker exercise, a demonstration speech and evalua-tion, and presentations on such topics as expectationsof speakers bureau members; purpose and meaning ofthe vision and mission; operating structure and functionof the speakers bureau; and an overview of the speakertraining sessions to be held later in the month. In latespring of 1999, speakers bureau members participatedin six hours of speaker training, conducted by a profes-sional speech educator and coach. Fifty-four people,including livestock farmers, crop farmers, dairy farmers,shellfish farmers, forest managers, bankers, Realtors,FFA students and teachers, university researchers,farmland preservationists, and environmentalists com-pleted the program and are now trained members of theSkagit Agricultural Speakers Bureau. The core teammembers and I developed a scripted speech with slideson Skagit Valley agriculture. The speech is available toany member who wishes to use it. A list of a wide rangeof other speech topics related to agriculture is availableto the public.

To date, speakers bureau members have delivered morethan twenty presentations, reaching more than 300individuals. A promotional postcard was widely distrib-uted during the annual Tulip Festival in April, whichbrings about one million visitors to Skagit County. Oneof the future goals of the program is to reach a largepercentage of these visitors with educational informa-tion. We plan to promote the program throughoutwestern Washington.

Celebrating Skagit Harvest:A Festival of Family FarmsThis community education project was in part an out-growth of Sharing the Skagit, although it was separatelyfunded through donations from local businesses. It wasmodeled after a similar event conducted through theClallam County Cooperative Extension.

On October 2, 1999, ten Skagit County farms openedtheir gates to the public for farm tours, food, children’sactivities, educational displays and videos, music, andother activities. The goals of the event were to increasepublic understanding of agriculture and to improve goodwill between the farming and non-farming communities.Celebrating Skagit Harvest offered consumers anopportunity to meet farmers, experience first-hand whatit feels like to be on a real working farm, and re-connectwith the source of their food and fiber.

As WSU/Skagit County Extension Agent, I led a team oftwenty-two volunteers in organizing and implementingthe event. Community businesses, organizations, andSkagit County government contributed over $10,000 incash and in-kind goods and services to help make theevent a success. Skagit County commissioners pro-claimed the first Saturday in October as “CelebratingSkagit Harvest Day.” The local daily newspaper contrib-uted toward sponsorship of a four-page, full-colornewspaper insert promoting the event to 21,000 house-holds. Elementary school children carried home 7,000promotional flyers. Approximately 4,000 people werecounted at the ten farm entrances on October 2. Manypeople visited from two to four farms during the day.

Farm open houses were held in seven other counties inwestern Washington on the same day through a coordi-nated effort by WSU extension faculty and members ofthe Cascade Harvest Coalition.

It is important to educate the general public about theirconnection to farms and farmers. If you are interested instarting outreach programs similar to ours in SkagitCounty, please feel free to contact me.

Dyvon Havens is a County Extension Agent with WSU/Skagit County Cooperative Extension. She can bereached at (360) 428-4270 or [email protected].

Dyvon Havens, WSU/Skagit County Horticulture Extension Agent

Making the Connection, cont.

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Pesticide ApplicatorTraining Courses for 2000

Washington State University offers PRE-LICENSE courses (for those who do not have a license and need one)and RECERTIFICATION courses (for those who need to renew their current licenses). Fees are $35 per day ifpostmarked 14 days before the program, otherwise $50 per day. This fee DOES NOT include WSDA license testfees, which range from $25 to $170; for information on testing and fees, contact WSDA at (360) 902-2020 orhttp://www.wa.gov/agr/test/pmd/licensing/index.htm. Recertification courses offer 6 credits per day. FOR MOREINFORMATION or REGISTRATION: (509) 335-2830, [email protected] or http://pep.wsu.edu.

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¿¿¿¿¿Dec. 1999No. 164

The conference room of the Yakima, Washington,Doubletree Hotel was filled to capacity for the fourthannual Pacific Northwest Pesticide Issues Confer-ence. The event, held October 19, 1999, drew partici-pants from around the state (and beyond) to hearpolicy makers, research scientists, and industryrepresentatives discuss the topic “Threatened andEndangered Species: PesticideScience, Issues, and Policy.”The conference was spon-sored by Washington StateUniversity (WSU) CooperativeExtension.

Getting OurBearingsEvent Chair Carol Ramsay,WSU Pesticide Education Coordinator, opened theconference promptly at 8:00 a.m., with meetinglogistics and credits. Her superb organization andsubtle gestures kept the day’s speakers on track andensured the jam-packed agenda moved alongsmoothly and stayed on schedule. Perhaps we canget Carol a big gong for next year, or one of thoselong, shepherd’s-crook-style “hooks” to enhance heralready fine facilitation skills.

Dr. Allan Felsot, Environmental Toxicologist withWSU’s Food and Environmental Quality Program,began the presentations with a spate of definitionsdesigned to help attendees get up to speed with thelingo of the day. In a fast-paced fifteen-minute pre-sentation entitled “Refresher Course: Numbers andAlphabet Soup,” Dr. Felsot outlined the EndangeredSpecies Acts (federal and state), risk assessment vs.risk management (the former is scientific, the lattermore socio-political), pesticide residue detection(reminding us about detection methods and limits,and that detection does not equal hazard), and riskguidelines (what is tolerable and why).

Water and What’s In ItThis was followed by an update on “Eastern andWestern Washington Water Quality,” presented byJames Ebbert of the United States Geological Survey

(USGS) Water Resources Division. Ebbert spokeabout the various USGS National Water-QualityAssessments (NAWQAs) being conducted in Wash-ington, detailing aspects of the Central ColumbiaBasin, Puget Sound Basin, and the just-begunYakima River Basin projects. He explained thatNAWQAs look at issues beyond, but including, pesti-

cides. Nationwide, urban areasfrequently show pesticide levelsexceeding aquatic life standards;our Puget Sound Basin is noexception.

Dr. Matt Kadlec continued theexamination of water quality inurban (west-of-the-Cascades)streams, from a Washington

State Department of Ecology perspective. PugetSound Basin is almost three-quarters forested, withonly eleven percent classified as “urban,” yet fiftypercent of pesticide use occurs in the urban areas.Species formerly present in urban streams havedisappeared or the population numbers have de-clined. Other factors may be responsible, but pesti-cide residues may play a role. Department of Ecologymeasured levels of 100 pesticides in ten Puget SoundBasin creeks at high and low flow periods.Macroinvertebrate and fish tissues were sampled.Seven of the streams showed indications of herbi-cides, while six showed insecticides. All levels wereunder both acute and chronic fresh water qualitycriteria.

Speaking of fresh fish—few things smell better than afresh salmon steak on the grill. But salmon don’t justsmell good, they also smell well—which is to say, theyhave a keen olfactory sense. In fact, salmon relyheavily on olfactory (smell) clues for key behaviorsincluding homing, breeding, and defense. So ex-plained Dr. Nathaniel Scholz, a research zoologist atthe National Oceanic and Atmospheric Administration/National Marine Fisheries Service (NOAA/NMFS)Northwest Fisheries Science Center. Neurotoxicpesticides including diazinon have been linked to lossof nervous system function. Research to determine

“Endangered Species” ThemePacks ’Em In at 4th Annual

Pesticide Issues Conference

The October eventwas well attendedand jam-packed withinformation.


Sally O’Neal Coates, Agrichemical & Environmental News Editor

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¿¿¿¿¿Dec. 1999No. 164

levels of effect is ongoing; initial experiments seem toshow the potential for effect at environmental concen-trations.

Risk Assessment DefinedThe morning’s final presentations focused on riskassessment. Dr. John Stark of WSU’s Department ofEntomology provided an overview of the topic, andDr. Allan Felsot returned to the podium to discussprobabilistic risk assessment. Echoing Dr. Felsot’scomments from earlier in the day, Dr. Stark remindedus that risk assessment isn’t wholly science—it’s alsointerpretation, judgement, probability. Steps leadingup to risk assessment include (1) hazard identifica-tion, (2) dose-response assessment, and (3) expo-sure assessment. These are followed by the charac-terization or assessment of risk. This can be achieveddeterministically via a simple quotient, dividing theestimated environmental concentration by the toxico-logical endpoint concentration, or by probabilisticmethods. Deterministic risk assessment is based on asingle exposure estimate, usually a worst-casescenario, and tends to result in very conservativeresults. Probabilistic methods allow for factoring morerealistic variables into assessment equations.

The Urban PerspectiveThe post-lunch panel presentation focused on pesti-cide impacts in urban environments. David Galvin,Hazardous Waste Management Program Manager forKing County, pointed out that (1) more varieties ofpesticides are applied in urban areas, (2) morepounds of pesticide are applied per acre in urbanareas, and (3) some pesticides found in urbanstreams exceed aquatic life concentration limits. Heshared recent developments, issues, and accomplish-ments of the city, county, and tri-county (King, Pierce,Snohomish counties) area, including the October 6,1999, announcement by King County and the City ofSeattle of a comprehensive plan to (1) phase out useof certain pesticides by June 2000, (2) reduce totalvolume of pesticides used in Seattle by thirty percent,and (3) adopt a county Integrated Pest Management(IPM) policy.

Peter Dervin, Executive Director of the WashingtonAssociation of Landscape Professionals (WALP),continued the urban discussion. He admitted thatlandscape contractors have historically been reactiverather than proactive about regulations, waste, andrunoff issues. Governmental regulations have hurt hisindustry and angered many landscape professionals.Now, WALP is working to mend fences and changeattitudes, in part by adding the option of an Environ-mental Advanced Endorsement to its Certified Land-scape Technician (CLT) program.

Conference Chair Carol Ramsay wrapped up theurban segment by stating and amplifying WSU Pesti-cide Education Program’s goal: risk mitigation througheducation. As Pesticide Education Coordinator,Ramsay oversees diverse education projects includ-ing the Master Gardener program, the Hortsensewebsite, the Urban IPM and Pesticide Safety Educa-tion Project, and the Pesticide Applicator (pre-licenseand recertification) Training programs.

The Many Facets of Buffer ZonesBuffer zones were the topic for the next panel. LeeFaulconer from Washington State Department ofAgriculture (WSDA) began by emphasizing that“providing functional riparian habitat is probably thesingle most important thing…in helping recover listedsalmon.” Buffer zones—admittedly political in natureand ill-defined—are part of that riparian strategy. Hedescribed two buffer models, one developed for forestlands and one for the Conservation Reserve En-hancement Program, and discussed the processesunderway for further defining buffers.

Lisa Lantz, Executive Director of Washington StateNoxious Weed Control Board, explained that persis-tent, non-native weeds can foul riparian habitat byimpeding water flow, competing for nutrients, andaltering habitat physiology. Pesticide use can bereduced by detecting weeds early, preventing seedproduction, and employing non-chemical controls.

Establishment of appropriate buffer plants was ad-dressed by The Nature Conservancy’s Jonathan



Issues Conference Packs ’Em In, cont.

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Merz. The seemingly simple concept of re-establish-ing native plants proved complex in The NatureConservancy’s initial eastern Washington efforts.Seed origin, soil quality, weeds, establishment time,and timing of plantings each presented challenges.Over time, his organization has developed workingmethods and models for native plantings in this partof the state.

Finally, Dr. Doug Walsh, WSUAgrichemical and EnvironmentalEducation Specialist, discussedpotential buffer zone impacts onarthropods, both pest andbeneficial (see related article inNovember AENews, Issue No.163, pp. 9–13.) He concludedthat pest insects may wellproliferate in buffer zones, but beneficials are equallylikely to establish and thrive.

ESA Section VII: Everybody HoldHands and Hum Along, NowThe final panel addressed Section VII of the Endan-gered Species Act (ESA), specifically, the mechanismof interagency cooperation known as “consultation”(full text of the U.S. code describing this process canbe viewed at http://www4.law.cornell.edu/uscode/16/1536.html). Consultation is designed as a struc-tured process through which federal agencies conferand cooperate to further ESA objectives. Jodi Bush ofthe United States Fish and Wildlife Service (USFWS)gave some general background on the EndangeredSpecies Act, and an overview. She outlined the act’svarious sections, emphasizing Section VII. JakeMacKenzie, representing the EPA, acknowledged thatthe consultation process is frequently acrimoniousand always time-consuming, but is effective. LeeFaulconer returned to the podium to present WSDA’sperspective. He expressed concerns about an up-coming consultation involving the U.S. Fish andWildlife Service and National Marine Fisheries Ser-vice that may not include WSDA, but will definitelyaffect WSDA. A spirited question-and-answer sessionfollowed, centering around various private parties’ and

non-federal agencies’ concerns about not beinginvolved in ESA consultation processes that directlyaffect them.

Along these lines, the day’s final speaker, WSDA’sJoel Kangiser, addressed some challenges with stateinvolvement in ESA-related consultations. Specifically,EPA’s requirement that WSDA consult with USFWS or

NMFS prior to issuing Section18 exemptions and Section24(c) (Special Local Needs or“SLN”) registrations is problem-atic, especially in the case oftime-sensitive Section 18s.WSDA has developed a matrixof default restrictions that takeinto account commonalitiesamong various ground, airblast,

chemigation, and aerial application techniques atseveral levels of pesticide toxicity. Such a matrix,suggests WSDA, could be essentially pre-approved,eliminating the need for an after-the-fact consultationduring the urgent process of approving an emergencyexemption or special needs registration. WSDA hassubmitted a “Memorandum of Understanding” regard-ing this proposed process to USFWS, and plans to dosomething similar with NMFS.

Without benefit of gong or crook, Carol Ramsaybrought the information-packed day to a closepromptly at 4:00. Conference proceedings may bepurchased for $10 by contacting Carol [email protected]. Those interested in serving onthe planning committee for the 5th Pacific NorthwestPesticide Issues Conference, likely to be held inOctober 2000, should also contact Carol at thataddress or (509) 335-9222. Watch for news aboutnext fall’s conference in this newsletter and on thePesticide Education Program’s website at http://pep.wsu.edu.

Sally O’Neal Coates is an Editor of Research Publica-tions for WSU. She is Editor of this newsletter, andcan be reached at [email protected] or (509)372-7378.

Watch for the 5thPesticide IssuesConference, to beheld fall of 2000.

Issues Conference Packs ’Em In, cont.


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Most people have no use for weeds. Weeds interferewith our use of land and water resources, they com-pete with desired crop and non-crop plants, and theyharm our livestock (or even us, upon occasion). Weedscientists and researchers are continually searchingfor the most efficient and economical, and the leastenvironmentally disruptive, methods to reduce lossescaused by weeds. During the latter part of the twenti-eth century, great progress has been made in dealingwith weed problems more consistently and efficiently.However, these intrusive plants still result in seriouseconomic losses and demand our continued attentionand financial resources.

Various combinations of pre-ventive, physical, cultural,chemical, and biological meth-ods are used to suppress weedpopulations. Biological controlis the planned use of livingorganisms such as insects,mites, vertebrate animals, andplant pathogens to reduce thevigor, reproductive capacity,density, or effect of undesirable plants. Most biologicalweed control projects target non-native plant species.A substantial percentage of the noxious weeds inWashington have been accidentally (or, in somecases, intentionally) introduced from Europe and Asia.These unwanted plant colonists were not accompa-nied by the biotic organisms that typically kept theirpopulations under control in their native homelands.As a result, such weeds have spread throughoutwestern North America.

The biological control practitioner attempts to reducethe abundance of undesirable plants by increasingthe number of weed predators. To biologically controla weed, destructive biotic organisms must be ob-tained from the weed’s native range and subjected toan extensive overseas and domestic testing programlasting from three to five years. This ensures that theorganisms damage only the targeted weed or itsweedy relatives and will not be injurious to non-targetvegetation. If judged safe by federal and state regula-

Biological Control ofYellow Starthistle

with Introduced Insects

tory agencies, the bioagents are then introduced intothe field. Ideally, the biocontrol agents eventuallybecome abundant and reduce the severity of theweed problem.

Yellow Starthistle is Ripefor BiocontrolYellow starthistle (Centaurea solstitialis), also knownas St. Barnaby’s thistle and golden thistle, is anEurasian weed that is believed to have been intro-duced into Washington as an alfalfa seed contami-nant. The weed presently infests an estimated150,000 acres of semiarid rangeland, pasture, crop-land, transportation rights-of-way, and wasteland in

the state. More than 90% of thisacreage is located in Asotin,Columbia, Garfield, Walla Walla,and Whitman counties. The plantis highly invasive in disturbed soilsites and is still expanding itsnaturalized range.

In rangeland areas, yellowstarthistle is very competitive.

The dense canopy formed by a monoculture of theweed blocks light penetration to the soil surface andeffectively eliminates the emergence or growth ofcompeting, edible forage species, reduces grazingcapacity, and diminishes native plant species diver-sity. The long, sharp spines of the flower heads mayphysically injure browsing animals and deter humanaccess to heavily infested recreational or other lands.If ingested by horses, the plant can cause a chronicand potentially fatal neurological disorder called“chewing disease” or equine nigropallidal encephalo-malacia. The dried plant skeletons can also providefuel for late summer fires.

Yellow starthistle normally behaves as a winter an-nual. Depending upon moisture availability, seedsgerminate in the fall or spring and develop rosetteswhich eventually produce the flowering shoots duringlate May and June. Mature plants are highly branchedand bear solitary flower heads at the branch ends.Flowers are bright yellow and the middle and lower

Dr. Gary L. Piper, Entomologist, WSU

The outlook forbiological control ofyellow starthistle isexcellent…


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floral bracts are armed with spines. Since yellowstarthistle is an annual, its only method of year-to-year survival is through the production of seeds.Several thousand seeds may be produced by a plantunder optimal conditions. Seeds are both plumed andplumeless; plumed seeds are spread short distancesby the wind whereas plumeless seeds fall to the soilbeneath the parent plant to reinfest the site. Nearly allseed is viable at maturity, but about 10% of the seedmay remain dormant in the soil for up to 10 years.

Effective management of existing infestations mustinvolve a systematic and persistent application ofmultiple methods over several years. The manage-ment approach will vary according to the extent anddensity of the infestation, theterrain, the equipment available,the budget, and the planned usefor the site. Yellow starthistlesuppression methods includecultivation, mowing, burning,grazing management, encourag-ing or reseeding desirable peren-nial replacement plant species,treating with herbicides, and useof biological control organisms.

Bioagent SpecificsBiological control of yellow starthistle in Washingtonwas begun in 1985 when the beetle Bangasternusorientalis from Greece was introduced. Adults arefound on the budding plants in early summer andmated females affix individual eggs to leafy bractsbeneath the immature flower heads. A female canproduce over 400 eggs during a three-month period.Upon hatching, the larva enters and mines throughthe bracts, mines up the stem, and penetrates thebasal portion of the flower head. One or more larvaecan develop within a head and each larva can con-sume and/or damage 40 to 60% of the seeds. Oncefeeding has been completed, the larva pupates withina cell it constructs within the injured head. Newlyformed adults escape from the heads in late summerand seek protected overwintering sites. There is butone generation annually. This insect has been re-

leased and become established in all yellowstarthistle-infested counties.

A second bioagent released in 1985 was the flyUrophora sirunaseva. This insect completes twogenerations a year. First-generation adults appearduring May and early June; second-generation indi-viduals emerge in early July. Females deposit one ormore eggs amongst the partially exposed florets of abud. Larvae (maggots) burrow through the florets andfeed upon immature seeds. In response to U.sirunaseva presence, the plant produces tissue whichsurrounds each larva to form a gall. Flower headscontaining multiple galls yield only about 50% of theirpotential seed crop. Second-generation larvae over-

winter within the galls in theseed heads. Pupation occursduring late spring. This fly hasbeen released in severalWashington counties but, forunknown reasons, has notdeveloped large populations.

A third insect, Chaetorelliaaustralis, was released in1989. This fly has three gen-erations a year, with adults ofthe first generation usually

infesting cornflower, a yellow starthistle relative, andadults of the other generations attacking both corn-flower and yellow starthistle. Females deposit theireggs beneath the bracts of the flower heads, layingonly one egg per head. The larva tunnels through thebracts into the head where it feeds upon the soft,developing seeds, usually destroying the majority ofthem. Up to 10% of the yellow starthistle seed headsthroughout a site can be infested by this insect.Pupation occurs within the damaged head. Thirdgeneration larvae overwinter within the old seedheads. This fly initially was released in Walla Wallaand Whitman counties but it rapidly spread to othersoutheastern Washington counties.

A fourth insect species, Chaetorellia succinea, hasrecently been found attacking yellow starthistle. A

Biocontrol of Yellow Starthistle, cont.

Six distinct insectspecies—three fliesand three beetles—have proven effectiveagainst this highlyinvasive weed.



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shipment of Chaetorellia from Greece containing C.australis and C. succinea, which very closely re-sembles C. australis, was released in southernOregon. C. succinea readily established and hasquickly spread to infest yellow starthistle in otherwestern states, including Washington. This fly’sbiology is similar to that of C. australis except that itdoes not attack cornflower. Larvae of C. succineadestroy all the developing seeds in a yellow starthistleflower head. This accidentally introduced fly will be avery important biocontrol agent.

A fifth insect, Eustenopus villosus, was first releasedin 1990. Adults of this beetle are found on the weedduring late June and July where they feed upon anddestroy many (75+%) small buds prior to seed forma-tion. Mated females lay eggs in medium-sized, un-opened buds during July. Upon hatching, the larvafeeds on the developing seeds, consuming 90 to100% of them over a sixteen-day period. Pupationoccurs in a chamber constructed from chewed seedsand pappus hairs within the damaged head. Adultsexit the heads in late summer, disperse, and overwin-ter amongst soil debris. There is but one generation ayear. Eustenopus villosus is undeniably the mosteffective insect released against yellow starthistlethus far and is responsible for noticeably reducing theoverall density of the weed—by as much as 70% inareas where it is well established. It has been redis-tributed to every yellow starthistle-plagued county inWashington.

AEN Y2K Subscription ReminderTime is running out to renew your Agrichemical and Environmental News subscription fornext year. Send your check for $15, made out to WSU, to Pesticide Information Center,WSU Tri-Cities, 2710 University Drive, Richland WA, 99352-1671, ATTN: Sally O’NealCoates, Editor. Please include full name and address of newsletter recipient. Should yourequire an invoice, just let us know by phoning (509) 372-7378. Internet access to AENews remains free; the URL is www2.tricity.wsu.edu/aenews.

A sixth species, the beetle Larinus curtus, was initiallyreleased in 1992. Adults are active during late Juneand July and can be observed feeding upon yellowstarthistle flowers and pollen. Eggs are laid betweenthe flowers of a partially opened head and up to threelarvae feed on the ripening seeds over a three-to-four-week period. Seed destruction levels may ex-ceed 96%. Pupation occurs within the damagedheads. Adults escape from the heads in the early falland seek protected overwintering sites amongst soilsurface debris. Larinus curtus completes a singlegeneration each year. This control agent is wellestablished in Klickitat County and new releases arebeing made in other counties to enhance the beetle’sdistribution.

The outlook for the biological control of yellowstarthistle in Washington and other areas of thewestern United States appears to be excellent. Thesuccessful use of insect biological control agents willlessen the weed’s invasiveness and abundance.Biocontrol represents an effective, low cost, long-term, and ecologically sound form of suppression,especially when it is integrated with other availablemanagement methods.

Dr. Gary L. Piper is an Entomologist at WashingtonState University, Pullman. He can be reached [email protected] or (509) 335-1947.


Biocontrol of Yellow Starthistle, cont.

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Local and national experts on pesticide exposure willspeak at a one-day course entitled “Pesticide Medi-cine” early next year in Yakima.

“Topics covered will be relevant for practicing clini-cians and other professionals who interact withpeople exposed to pesticides,” said Dr. MatthewKeifer, co-director of the course.

The University of Washington’s Pacific NorthwestAgricultural Safety and Health Center (PNASH) ishosting the course, which will be held in the WestBallroom at Cavanaugh’s at the Yakima Center onFebruary 11, 2000.

The objectives of the one-day course are to:

¿ Increase knowledge of pesticide toxicity.¿ Review acute and chronic health effects ofpesticides.¿ Learn about exposure to pesticides.¿ Discuss actual poisoning cases in WashingtonState.¿ Understand the workers compensation claimsprocess.

The course is designed for physicians, industrialhygienists, nurses, labor and management represen-tatives, and attorneys, as well as other professionalswho deal, either directly or indirectly, with pesticidesor the human health effects of pesticides.

The course will be co-chaired by Dr. Lucio Costa,director of the UW’s Department of EnvironmentalHealth Toxicology Program, and Dr. Matthew Keifer,director of the Occupational Medicine Program at the

University of Washington. During the course, Dr.Keifer will give tips to clinicians on how to recognizeand treat symptoms of pesticide overexposure. Dr.Allan Felsot, Environmental Toxicologist at Washing-ton State University, will add his unique perspectiveon the importance of pesticides in relation to humanhealth.

A discussion of pesticide exposure in children will bethe focus of a talk by Dr. Richard Fenske, who, alongwith Dr. Keifer, directs the Pacific Northwest agricul-tural Safety and Health Center. A special guestspeaker from the University of California at Davis, Dr.Michael O’Malley, will share his expertise on pesti-cides and dermatological conditions.

Speakers representing government agencies includeDr. Jerry Blondell, a health statistician from EPA’sOffice of Pesticide Programs, who will discuss theepidemiology of pesticide poisoning. BarbaraMorrissey, a toxicologist from the Washington Depart-ment of Health Pesticide Program, will present casestudies from Washington, and Vicky Skeers, anoccupational health nurse consultant from the Wash-ington Department of Labor and Industries, will helpattendees understand the process of filing a workerscompensation claim.

The cost of the course is $165 for those who registerbefore January 14. After that date, the registrationfee is $195. To register, call (206) 543-1069, e-mail [email protected] or visit our website at http://depts.washington.edu/envhlth/conted.html. ThisInternet site also provides information about otherUniversity of Washington courses on occupationaland environmental health.

UW Hosting Course onPesticide Use, Exposure,

and Health EffectsNorm Herdrich, PNASH Outreach Coordinator

The Pacific Northwest Agricultural Safety and Health Center, funded by NIOSH, is one of eight such centers in the UnitedStates. The Center’s mandate is to study occupational health and safety issues in farming, forestry and fishing in the fourRegion X states of Idaho, Washington, Oregon and Alaska. Dr. Richard Fenske is the Center Director, Dr. Matthew Keiferis Co-Director, and Sharon Morris is Associate Director. Adrienne Hidy is the Center’s Administrator, and Marcy White isthe Program Coordinator.

This article was prepared by Norm Herdrich, PNASH Outreach Coordinator. To obtain additional information, he can becontacted at (509) 926-1704, or e-mail him at [email protected].

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With thousands upon thousands of insect speciesfound in the Northwest, it is amazing how few areactually pests of any significance. In fact, the greatmajority of insects are either of no concern or arebeneficial as pollinators, decomposers, or biologicalcontrol agents. It is, therefore, very important to beable to recognizepests and differenti-ate them from non-pests.

The general agricul-tural community hasbecome very awareof recognizing truepests and applyingmanagement (princi-pally chemicals) only when warranted. Not only doesthis make good sense from an environmental stew-ardship standpoint, it makes good economic sense.Why pay to control a non-pest or to manage a pestthat is not causing enough damage to warrant thecosts of control? Pest management, like allother aspects of business, ultimately is amatter of balancing costs and benefits.

Sweet corn is grown on almost 100,000acres in central Washington. The cornearworm, Helicoverpa zea (Boddie), is a keypest of sweet corn throughout the UnitedStates, including Washington. They deposittheir eggs in developing ears. The mothlarvae feed upon the ears and foul them with theirexcrement. If not controlled, this pest can easilydestroy a complete crop. Consumers have a lowtolerance for insects in food and producers have alow tolerance for corn earworm larvae in their crops.In order to plan management of the pest, populationsare monitored through the use of traps baited with afemale sex pheromone. This pheromone is attractiveto male corn earworm but also attracts males of aclose and very similar-appearing relative, the falsecorn earworm moth (Heliothis phloxiophaga Grote &Robinson). False corn earworm larvae feed on avariety of non-agricultural vegetation and are not

Know Your EnemyProper Pest Identification Is Good forthe Environment and the Bottom Line

Dr. Richard Zack, Gary Pelter, & Todd Adams, WSU, and Dr. Peter Landolt, USDA

pests. Unfortunately, because the moths are verysimilar and the false corn earworm is attracted to thepheromone used in corn earworm traps, the captureof this “wrong” species gives field personnel aninflated impression of the true numbers of corn ear-worm present and can lead to insecticide applications

when none are needed.

In 1998, individuals representing the Colum-bia Basin sweet corn industry and WSUCooperative Extension agents Gary Pelterand Erik Sorensen approached Rich Zackabout conducting a training session thatwould help field personnel separate the twomoths so that they could make more refinedand better decisions concerning manage-ment of corn earworm. Although the two

species are difficult to separate, we developed anillustrated, one-sheet flyer that pointed out differencesand could be carried into the field. Most left themeeting feeling that they could differentiate betweenthe two moths (at least enough to make significant

differences in theircounts). In asurvey taken at theend of the fieldseason by Pelter,most growersreported that theyhad decreased thenumber of spraysapplied, especially

in the early season when false corn earworm is morecommon, resulting in an estimated $160,000 savingsin pesticide applications.

In late 1998, we decided to expand the project andenlisted the aid of Dr. Peter Landolt, a researchentomologist at the Yakima United States Departmentof Agriculture (USDA) entomology lab. Dr. Landolt isa leading scientist in pheromone research and ininsect attractants in general. In a cooperative en-deavor between WSU, the USDA, and numerouscentral Washington sweet corn processors (withfunding from the processing industry and the EPA) we

…growers saved anestimated $160,000in the first year.

By differentiatingbetween the cornearworm and falsecorn earworm…


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PNN Update

The Pesticide Notification Network (PNN) is operated by WSU's Pesticide Information Center for the Washing-ton State Commission on Pesticide Registration. The system is designed to distribute pesticide registration andlabel change information to groups representing Washington's pesticide users.

PNN notifications are available on our web page. To review those sent out in October either access the PNNpage via the Pesticide Information Center On-Line (PICOL) Main Page, http://picol.cahe.wsu.edu/, or directly,at http://www.tricity.wsu.edu/~mantone/pl-newpnn.html.

We hope that this new electronic format will be useful. Please let us know what you think by submitting com-ments to Jane Thomas at (509) 372-7493 or [email protected].

Jane M. Thomas, Pesticide Notification Network Coordinator

are now looking for a pheromone that will be morespecific for true corn earworm and eliminate the needfor the identification of trap specimens, which areoften in poor shape and difficult to identify. The projecthas several additional objectives:

¿ finding a feeding attractant that would lureboth male and female moths, making possiblepredictions of seasonal population growth anddamage (only females really need to be controlledand they may have different abundance peaksthan males);

¿ conducting season-long surveys to get abetter idea of when the moths actually appear andin what numbers; and,

¿ testing a number of different trap types so thattrap costs can be balanced with effectiveness.

Todd Adams, a WSU graduate student from theYakima area, is conducting most of the field research.Connie Smithhisler at the USDA lab is providingformulated pheromone blends.

Our preliminary results are promising. We now havea much better understanding of when each species ofmoth is active and a better understanding of whichtypes of areas are favored by the false corn earworm.We have tested several different trap designs buthave yet to evaluate these data. We are currentlyevaluating the different pheromone formulations andfeeding attractants. We hope that within the next fewyears, the need to differentiate these two moths willbe significantly decreased. However, just the fact thatfield personnel now recognize that two different mothswill be taken in their traps and that they have theability to differentiate between the two, has lead tosignificant changes in management practices—goodenvironmental stewardship and saving money!

Dr. Richard S. Zack and Todd Adams are with WSU’sDepartment of Entomology in Pullman. Gary Pelter iswith WSU Cooperative Extension of Grant/AdamsCounties. Dr. Peter J. Landolt is with the YakimaUSDA Entomology Research Division located inWapato, Washington. Dr. Zack can be contacted [email protected] or (509) 335-3394.

Know Your Enemy, Save Money, cont.Dr. Richard Zack, Gary Pelter, & Todd Adams, WSU, and Dr. Peter Landolt, USDA

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Federal Register Summary


In reviewing the October postings in the Federal Register, we found the following items that may be ofinterest to the readers of Agrichemical and Environmental News.

In the October 6 Federal Register, EPA announcedthat the revised risk assessments for naled andtemephos were available for review and comment.These documents can be accessed through URL:http://www.epa.gov/pesticides/op/status.htm.Comments must be submitted to EPA on or beforeDecember 6, 1999. (Page 54298)

In the October 6 FederalRegister, EPA announced thatthe preliminary human healthrisk assessments and relateddocuments for chlorpyrifosmethyl are available for reviewand comment. These docu-ments are avialble on-line atthe following URL: http://www.epa.gov/oppsrrd1/op/chlorpyrifos-methyl.htm. Comments must besubmitted to EPA on or before December 6,1999.(Page 54296)

In the October 14 Federal Register, EPA announcedthat the revised risk assessments for fenthion wereavailable for review and comment. These documentsare available electronically at the following URL:http://www.epa.gov/oppsrrd1/op/fenthion.htm.Comments on these documents should be submittedto EPA by December 13, 1999. (Page 55712)

In the October 15 Federal Register, EPA establishedan exemption from the requirement of a tolerance forresidues of Rhizobium inoculants (pure strains ofRhizobium spp. bacteria [e.g. Sinorhizobium,Bradyrhizobium & Rhizobium]) when used as inertingredients in pesticide formulations applied to allleguminous food commodities. (Page 55838)

In 1994, EPA issued a proposed rule on containerdesign and residue removal requirements for refill-able and nonrefillable pesticide containers andstandards for pesticide containment structures. (59FR 6712, Feb. 11, 1994). In the October 21 Federal

Register, EPA announced that it is reopening thecomment period to obtain public comment on threespecific issues. EPA is considering changes thatwould reduce the scope of the container standards,add an exemption for certain antimicrobial pesticides,and adopt some of the Department of Transportation(DOT) hazardous materials regulations. EPA is also

seeking comment on thedefinition for small businessused to identify small pesti-cide formulators, agrichemicaldealers, and commercialpesticide applicators in thesmall entity impact analysis.EPA believes that thesepotential changes would

support pollution prevention by promoting the use ofrefillable containers and that they would decrease theestimated economic impact of the proposed rules byreducing the number of pesticide products subject tothe container requirements. Comments on theseissues should be submitted to EPA on or beforeDecember 20, 1999. (Page 56917)

In the October 27 Federal Register, EPA announcedthat a revised version of the pesticide science policydocument entitled "Threshold of Regulation (TOR)Policy--Deciding Whether a Pesticide With a FoodUse Pattern Requires a Tolerance" is availble. Anelectronic copy of this document can be accessed viaEPA's OPP Science Policy Web Page on http://www.epa.gov/pesticides/trac/science/. (Page57881)

In the October 27 Federal Register, EPA announcedthat the preliminary human health and ecological riskassessments and related documents for chlorpyrifosare avilable for review and comment. Electronicallythese documents can be accessed on: http://www.epa.gov/pesticides/op/chlorpyrifos.htm.Comments must be submitted on or before December27, 1999. (Page 57876)

EPA Information isavailable on-line at:http://www.epa.gov

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Tolerance Information


Tolerance InformationChemical Federal Tolerance Commodity (raw) Time-Limited(type) Register (ppm) Yes/No New/Extension Expiration Dateimazapic-ammonium 10/6/99 page 54218 30.00 grass forage Yes New 31-Jan-01(herbicide) 15.00 grass hay

0.10 milk0.10 fat, meat, mbp of cattle, goats, hogs, horses, and sheep1.00 kidney of cattle, goats, hogs, horses, and sheep

tebuconazole (fungicide) 10/8/99 page 54777 0.40 sunflower oil Yes Extension 31-Jan-000.20 sunflower seed

ethalfluralin (herbicide) 10/8/99 page 54779 0.05 canola Yes Extension 31-Jan-01

tebufenozide (insecticide) 10/21/99 page 56690 0.10 legume vegetable foliage Yes New 30-Sep-030.50 forage, fodder, hay, and straw of cereal grains0.50 grass forage, fodder, and hay0.50 forage, fodder, hay, and straw of non-grass animal feed

sethoxydim (herbicide) 10/21/99 page 56697 10.00 buckwheat Yes New 31-Dec-01

metolochlor (herbicide) 10/21/99 page 56678 0.30 spinach Yes Extension 31-Dec-0110.00 grass forage

0.20 grass hay

pyriproxyfen (insecticide) 10/21/99 page 56681 0.02 tree nuts No N/A N/A0.02 fruiting vegetables except cucurbits

compound to control leafy spurge on pastures, rangeland, and CRP lands.

tebuconazole to control sunflower rust in sunflowers grown in the plains states.

of ethelfluralin to control kochia in canola.

tebufenozide.

volunteer grains, foxtail, and quackgrass in North Dakota buckwheat.

of metolachlor on spinach and grass grown for seed