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Environmental IssuesAssociatedwith Enhancing the Impact ofBiological Control AgentsA Student Debate

Fred GouldGeorge Kennedyand Robert KopanicDepartment of EntomologyNorth Carolina StateUniversity Raleigh NC

160

ONEMAJOR GOAL OF GRADUATE EDUCATION IS TO FAMILIARIZE STUDENTS WITH THE CONCEPTS FACTS

and techniques that are essential to progress in a specific discipline An additional goalshould be to prepare students to use their newly acquired knowledge One important challengeto scientists working i1lboth basic and applied fields is to use incomplete and often conflictingsets of facts and theories in formulating public policies with broad impacts or in prioritizingresearch programs at the level of the individual laboratory or at more generallevels

One common means by which public policies and priorities are determined is through theprocess of debate in which individuals with different perspectives on an issue present their viewsin a public forum We feel that it would be useful for student members of the ESA to gain moreexperience with the process of debate To this end we have organized a series of student debatesto be held each year at the national ESA Annual Meeting The topics debated at the last threemeetings were Risks associated with the use of pesticidal transgenic crop plants (IndianapolisIN 1993) Environmental issues associated with enhancing the impact of biological controlagents (Dallas TX 1994) and Issues related to the conservation of insect biodiversity (LasVegas NY 1995) The scheduled topic for debate at the 1996 meeting (Louisville KY) is Issuesin implementing ecologically sound integrated pest management The debates are sponsoredby the ESA Committee on Student Affairs

Format for the debates and methods used to prepare for them have evolved through our ex-perience and also are based on input from participants Currently four specific statements (orquestions) that relate to one broad problem are the focus of the debate For each statement onestudent presents a brief historical background (15 minutes) one student argues that the statementis true (pro position) and one student argues that the statement is false (con position) Each proand con debater has the opportunity to make herhis argument (1 0 minutes) and follows up withone rebuttal statement (3 minutes)

In the past we have solicited the participation of university departments in the debate throughpersonal contacts and by sending invitations and descriptions of the debate to the chairs of allentomology departments (and related departments) in the United States Preparation for thedebate involves seminar and discussion sessions conducted by the participating university teams(at their respective schools) throughout the fall semester In these sessions students examine theissues and debate the pro and con positions The debate organizers randomly assign each teamthe task of presenting at the ESA Annual Meeting a pro con or background presentation for twoof the debate issues Each team selects students to represent their assigned perspective at thenational ESA Annual Meeting

After the debate at the 1994 ESA Annual Meeting the participants decided it would be usefulto publish summaries of their statements These short summaries printed below capture someof the flavor of the debate We want to emphasize that students were randomly assigned pro orcon positions and so the views presented here are not necessarily the views of the students whomade the presentations We also want to emphasize that in debating it is essential for the debaterto present the strongest case possible in defense of a given position In building a case for thatposition a debater will avoid bringing up details that do not support his or her argument unlesstheir relevance or veracity is being challenged It is the job of the opponent to point out thesedetails We welcome any suggestions for future topics or for approaches to improve the programAny university departments desiring to participate in these debates are encouraged to contact theStudent Affairs Committee of the ESA or the organizers

AMERICAN ENTOMOLOGIST bull Fall1996

TopicThe United States Has BeenNegligent in Regulating theImportation Release and Useof Generalist Natural Enemies

BackgroundKatherine SchickDeparbnentofEntomologyUniversity of California Davis CA

Recent theorists in biological control haveadvocated the use of generalist natural ene-mies because they should survive local extinc-tions of target pests by utilizing other prey orhosts When the target pest recolonizes thepatch the generalist biological control agentalready may have effective population levelsin place for control

The risks of using generalist natural ene-mies include pest management risks-dietswitching by the generalist may lead to anincrease in target and secondary pest num-bers-and ecological risks-nontarget species(within and outside the targeted agroecosys-tern) may be impacted negatively

The pest management risks of using gener-alists are illustrated by a study focusing onspecies in three genera of predatory Hemi-ptera Geocoris Nabis and Zelus which preyon cotton aphids (Aphis gossypii Glover)(Rosenheim et al 1993) In cotton fields thesepredators showed a decided preference forlacewing (Neuroptera) larvae which also preyon aphids The result was that aphid popula-tions were larger in the presence of both lacew-ings and predatory bugs than in the presence oflacewings alone

The implications for biological control arethat one cannot assume that the effectsof gener-alist predators are restricted to a single trophiclevel and additional predator species may notadditively suppress a pest herbivore but mayinstead feed upon a predator of the target pestcausing an increase in pest numbers

Ecological risks of using generalist naturalenemies include the possible extinction of non-target arthropod species Some studies suggestthat the introduced sevenspotted lady beetleCoccinella septempunctata L is causing the

AMERICAN ENTOMOLOGIST bull Fa1996

decline in populations of native North Ameri-can coccinellids and could lead to extinctionsFew arthropod extinctions have been demon-strated to be caused by introductions but giventhe large proportion of the arthropod faunathat is yet to be described many extinctionscaused by generalist natural enemies couldremain unnoticed Federal regulation of natu-ral enemy importation is authorized by boththe Plant Pest Act and the Plant Protection andQuarantine Act (US Code SS 147a-167) andenforced by the Animal and Plant Health In-spection Service (APHIS) of the US Depart-ment of Agriculture Congress gave APHISregulatory authority to protect the nationsagriculture

The LaceyAct (16US CodeSS 3371-3378)gives the US Fish and Wildlife Service (USF-WS) authority to regulate importation ofthreatened and endangered biological organ-isms However the USFWS generally defersthe permitting of live arthropod importationsto APHIS

The National Environmental PolicyAct (42US Code SS4321-4370a) requires an initialscoping document publicly announcingplanned projects including the release of animported biocontrol agent and an environ-mental assessment The assessment may resultin a finding of no significant impact or it mayrequire further review in the form of an envi-ronmental impact statement

A few years ago there was concern thatAPHIS policies might not have followed theseenvironmental regulations Lockwood(1993a b) and Carruthers and Onsager (1993)discussed a perceived irregularity in this envi-ronmental assessment process as it related torangeland grasshopper control This discus-sion sparked a major controversy among ento-mologists involved in biological control Theargument centered on releases of an alien En-tomophaga fungus and parasitic wasp bothpossibly generalists to control native grass-hopper species on western rangelands in theUnited States Concerns were expressed thatthese releases might endanger other nativerangeland grasshopper species that were notpests

References Cited

Carruthers R I and J A Onsager 1993 Per-spective on the use of exotic natural enemies forbiological control of pest grasshoppers (Or-thoptera Acrididae) Environ Entomol 22885-903

Lockwood J A 1993a Environmental issues in-

The risks ofusing generalistnatural enemies

include pestmanagment

risks and eco-logical risks

161

middot there isincreasing

evidence thatgeneralistscan directlysuppress orcause localpopulationsof native

nontargets togo extinct

162

volved in biological control of rangeland grass-hoppers (Orthoptera Acrididae) with exoticagents Environ Entomol 22 503-518

1993b Benefits and costs of controlling range-land grasshoppers (Orthoptera Acrididae)with exotic organisms search for a null hy-pothesis and regulatory compromise EnvironEntomol 22 904-914

Rosenheim J A L R Wilhoit and C A Armer1993 Influence of intraguild predation amonggeneralist insect predators on the suppressionof an herbivore population Oecologia 96439-449

Pro PositionEileen A EliasonDepartment of EntomologyMichigan State UniversityEast Lansing MI

I will use three levels of argument to demon-strate that the United States has been negligentin its importation and release of generalistnatural enemies I will explain that (1) at thetheoretical level it is difficult to understand thepotential negative impacts of generalist natu-ral enemies (2) at the regulatory level thesenegative impacts are impossible to preventand (3) at the historical level use of generalistnatural enemies has proven that negative im-pacts are not only possible but in fact fre-quently occur

The ideal classical biological control agentpossesses high host-specificity good searchingability short development time high fecundi-ty and the ability to occupy any host niche(DeBach 1974) Recently however the ideal ofhost specificity has been challenged on boththeoretical and empirical grounds (Miller andAplet 1993) This results in generalists beingconsidered seriously for use in classical biolog-ical control programs (Miller and Aplet 1993)

Biological control often has been practicedas a modern technology without a strong the-oretical foundation The failures of biolog-ical control importations outnumber thesuccesses due to a lack of predictive theory andmodeling Even if adequate theory existed topredict potential for establishment of the bio-control agent and control of target pests it wouldbe difficult to predict the larger community andecosystem level effects of the exotic introduc-tions Lack of host specificity in the introducedorganism magnifies these problems

Numerous regulations exist that are intend-ed to prevent generalist natural enemies from

becoming pests or from having negative im-pacts These regulations have been describedin the Background section None of these actsspecifically addresses the practice of biologi-cal control but each of them is intended toprotect our environment The current federalreview process considers potential harm toeconomically important species but disregardsthreats or damage done to noneconomic spe-cies and to ecosystem integrity (Miller andAplet 1993)

This lack of an appropriate scientific basisand adequate regulation has resulted in eco-nomic social and environmental harm Interms of economic harm time and money havebeen spent to achieve pest control but general-ists have not been cost-effective (Beirne 1985)In terms of social harm some natural enemieshave themselves become nuisances An exam-ple of this is the multicolored Harmonia axy-ridis (Pallas) which enters peoples homes enmasse in late fall to overwinter (Lyon 1994)But most importantly there is increasing evi-dence that generalists can directly suppress orcause local populations of native nontargets togo extinct leading to cascading ecologicalimpacts (Howarth 1983 1991 Wheeler andHoebeke 1996) The first example Cactoblas-tis cactorum (Berg) is a generalist naturalenemy of prickly pear This moth migratedinto Florida from the Caribbean and recentlyhas been found attacking Opuntia spinosissi-ma (Martyn) a native endangered cactus spe-cies (Kass 1990) Another example of ageneralist attacking nontargets is Compsiluraconcinnata (Meigen) a tachinid parasite of thegypsy moth Lymantria dispar L that nowattacks more than 200 species (Hauptman1991) Many other examples exist that supportthe assertion that the United States has beennegligent in its importation and use of general-ist natural enemies

References Cited

Beirne B P 1985 Avoidable obstacles to coloni-zation in classical biological control of insectsCan J Zoo I 63 743-747

DeBach P 1974 Biological control by natural en-emies Cambridge University Press London

Hauptman C 1991 Gypsy moths and general-ists Sanctuary 5 17-20

Howarth F G 1983 Classical biocontrol pana-cea or Pandoras box Proc Hawaiian Ento-mol Soc 24 239-244

1991 Environmental impacts of classical biolog-ical control Annu Rev Entomol 36 485-509

Kass H 1990 Once a savior moth IS now a


scourge Plant Conservation 5 3Lyon W F 1994 Multicolored Asian lady beetle

Ohio State Extension Fact Sheet HYG-2158-94

Miller M and G Aplet 1993 Biological controla little knowledge is a dangerous thing RutgersLaw Rev 45 285-334

Wheeler A G and E R Hoebeke 1996 Coc-cillella Ilovemllotata in northeastern NorthAmerica historical occurrence and current sta-tus Proc EntomoI Soc Wash (in press)

Con PositionPaul WhItaker Amy ChenotMichael Riehle and Kevin VossDepartment of EntomologyUniversity of WIsconsin Madison WI

Over 100 years ago C V Riley importedthe vedalia beetle Rodolia cardinalis (Mul-sant) from Australia and rescued the Califor-nia citrus industry from the ravages of thecottony cushion scale Icerya purchasiMaskell Introduction of this natural enemytook place with no host range studies no per-mits no quarantines and no regulations Thestunning success with this beetle initiated along series of natural enemy introductions thatcontinues today Although a separate regulato-ry and statutory framework has not been devel-oped to specifically address biological controlthis activity has been regulated increasinglyover the past century through provisions in anumber of acts statutes and protocols (seeSchick this article) Regulation has increasedconcurrently with our awareness of the poten-tial negative consequences that these nonindig-enous animals could have in their newenvironments Before arguing that the UnitedStates has not been negligent in regulating theimportation release and use of generalistnatural enemies we will first define the termsnegligence and generalist In legal terms neg-ligence is the failure to exercise that degree ofcare rendered appropriate by the particularcircumstances and which a man of ordinaryprudence in the same situation and with equalexperience would not have omitted (Black1891) For the purpose of this argument wewill consider all natural enemies to be general-ists except those few species that are strictlymonophagous We use this strict definition forthree reasons (1) there is little consensus onhow to assess the host range of natural ene-mies (2) most data available on natural enemy


introductions do not distinguish between gen-eralists and specialists and (3) other defini-tions of a generalist natural enemy areremarkably uncommon in the literature

Several recent papers have questioned thesafety of classical biological control and spe-cifically the use of generalist natural enemies(eg Howarth 1991 Lockwood 1993) Theseauthors cite many examples of introductionsthat allegedly resulted in severe nontargetimpacts extinctions losses of biodiversityand disruptions of native communities How-ever these examples have little relevance tothe main thrust of classical biological controlin the continental United States Often theseexamples involve vertebrate or mollusk naturalenemies which comprise a small proportion ofnatural enemy introductions Most of these ex-amples occurred in tropical andor island eco-systems which differ greatly from thetemperate continental ecosystems of the contig-uous 48 states (Williamson 1981) Finally sev-eral of these examples are based on anecdotal orcircumstantial information (ie that the newlyintroduced natural enemies caused these nega-tive effects is inferred but not proven)

Much of our knowledge of the negativeconsequences of exotic natural enemies derivesfrom cases cited in the papers mentionedabove Yet there is remarkably little evidencethat these consequences have occurred in thecontiguous United States Nearly 400 speciesof beneficial arthropods have been introducedinto the United States during the last 100 yearsand the only documented negative impact hasbeen the accidental introduction of two hyper-parasite species that were introduced prior to1910 before quarantine procedures were insti-tuted (Coulson and Soper 1989) Although it ispossible that exotic generalist natural enemiesin the United States could be imposing impor-tant nontarget effects it would seem that 100years and 400 introductions would be suffi-cient to reveal their negative impacts

Despite the scarcity of documented negativeconsequences arising from the introduction ofgeneralist natural enemies in the United Statesthere has been increasing scrutiny of this activ-ity over the years under a patchwork of regu-lations Although most of these regulationswere designed for other purposes they seem tohave been effective in ensuring the safety ofclassical biological control Despite this theNational Biological Control Institute ofUSDA-APHIS has been developing regula-tions and implementing procedures that ad-dress concerns about the use of biologicalcontrol in the United States (E S Delfosse

This continualtightening ofregulations

before negativeconsequences

have been docu-mented reflectsa prudent cau-tious approachto biological

control

163

K FWallin R W HofstetterS Steffan and T L RabeyDepartment of EntomologyUniversity of Wisconsin Madison WI

Background

The United States ShouldAttempt To Enhance theEfficacy of Biological Controlby Regulating Pesticide Use

The biological and economic interactionsbetween chemical and biological controls arecomplex and difficult to evaluate On the otherhand the use of chemicals as the primary pestmanagement technique is known to influencesome components of biological control forexample environmencal imbalances causedby pesticide application often are detrimentalto the efficacy of arthropod natural enemies(van den Bosch and Telford 1964) However itcould be argued that pesticide use occurs be-cause it effectively and economically fills aneed left by the inability of natural enemies to

restrict the densities of many pests below dam-aging levels Despite the inadequacy of datawith which to fully characterize the interac-tions among pesticides natural enemies cropprotection and economics there appears to beconsensus on one point current methods of pestcontrol are reasonably effective and economi-cal but not ideal The many attributes of pes-ticides and biological control must beexamined carefully before regulations on pes-ticide use are enacted to enhance the use andefficacy of biological control

In the aftermath of World War II the 1950sand 1960s experienced an enormous unre-stricted rise in chemical pest control (Hinkle1993) Although current regulations requirestudies on the potential impacts of pesticides onhumans and environmental health they do notrequire studies examining potential impacts onthe efficacy of biological control Even thoughsuccessful biological control has been docu-mented for more than 100 years negative ef-fects on biological control agents are notconsidered of primary importance when regu-lating pesticide use Some scientists and envi-ronmental groups have concluded that increasedregulation of pesticides supplemented with bio-logical control research may be necessary toenhance biological control efficacy

Widespread use of pesticides is largely theresult of convenience simplicity effectivenessflexibility and economics Despite the advan-tages of pesticides pesticide use may lead toproblems such as insect pest resistance out-breaks of secondary pests adverse effects onnontarget organisms and other externalities(Metcalf and Luckman 1975) There have beennumerous cases in which overuse of broad-spectrum insecticides has resulted in insecti-cide resistance and the development ofsecondary pests as in the cotton-growing areaof the Lower Rio Grande ValleyTexas How-ever when pesticide use is approached basedon sound ecological principles chemical pes-ticides serve as dependable and valuable toolsfor the pest manager

Several effective integrated control pro-grams have been developed in which biologi-cal control and chemical agents arecompatible The elements of these programsinclude knowledge of the insect system mon-itoring of species composition use of manage-ment models and a liaison group enablingimplementation Consideration of these ele-ments can provide guidance for the optimumuse of pesticides in pest management pro-grams For example judicious selection andtiming of chemical application can preclude

References Cited

personal communication) This continualtightening of regulations before negative con-sequences have been documented reflects aprudent cautious approach to biological con-trol We can only conclude that the UnitedStates has not been negligent in regulating theimportation release and use of generalistnatural enemies

Black H C 1891 A dictionary of law LawbookExchange New York

Coulson J R and R 5 Soper 1989 Protocolsfor the introduction of biological controlagents in the United States pp 135 In R PKahn [ed] Plant protection and quarantinevol 3 CRC Boca Raton FL

Howarth F G 1991 Environmental impacts ofclassical biological control Annu Rev Ento-mol 36 485-509

Lockwood J A 1993 Environmental issues in-volved in biological control of rangeland grass-hoppers (Orthoptera Acrididae) with exoticagents Environ Entomol 22 503-518

Williamson M H 1981 Island populations Ox-ford University Press Oxford UK

Topic

middot currentmethods of

pest control arereasonably

effective andeconomical

but not ideal

164 AMERICAN ENTOMOLOGIST bull Fall 1996

direct mortality to natural enemies in a phy-tophagous-predatory mite system (Metcalfand Luckman 1975)

In considering regulation of pesticide use toenhance the efficacy of biological control itwill be necessary to fully consider the cost andbenefits to agriculture and society in general

Acknowledgments

We thank K Raffa and D Mahr (Universityof Wisconsin) for their organization and en-couragement in a departmental seminar andbeyond We also thank the College of Agricul-tural and Life Sciences University of Wiscon-sin-Madison for providing travel support

References Cited

Hinkle M K 1993 Environmental issues of bio-logical control regulation pp 13-21 Itt R CMcDonald J D Harper and W A Dickerson[eds] Biological control developing strategiesfor the 90s Plant Industry Division NC De-partment of Agriculture Raleigh

Metcalf R L and W H Luckman 1975 Intro-duction to insect pest management Wiley ampSons New York

van den Bosch R and A D Telford 1964 Envi-ronmental modification and biological controlIn P DeBach [ed] Biological control of insectpests and weeds Chapman amp Hall London

Pro PositionLisa CarloyeDepartment of Entomology320 Morrill Hall University of Illinois atUrbana-Champaign UrbanalL

Historically government regulation hasbeen used to stimulate a shift toward ecologi-cally-friendly consumer practices Regulation-induced shifts in the auto industry havereduced air pollution and could be used to en-hance the use of biological control Severalexisting government regulations discouragethe use of biocontrol and should be changedFor example government grading standardsare used in part to convey information aboutproduce quality but do not include informationabout pesticide residues By changing gradingstandards to include pesticide informationperfect produce that is obtained through pesti-cide use would have a lower grade and the costof the pesticide would not be regained throughhigher profits Furthermore government grad-

AMERICAN ENTOMOLOGIST bull Fal1996

ing standards for fruits and vegetables are of-ten so high that pesticides are applied solely tomeet these standards Biocontrol agents maynot control pests below government standardsbut they often can control pests at levels beloweconomic injury levels Thus if grading stan-dards were relaxed biocontrol could become aviable alternative (National Research Council1989)

Because biocontrol products have narrowerhost ranges andor are often geographicalIyrestricted (although there are exceptions) theirmarkets tend to be narrower than those forchemical pesticides which are typicalIy lessgeographically restricted and can have abroad spectrum of activity (Cook 1992) Al-though desirable from an environmental view-point such specialization results in smallermarkets which in turn results in lower profitsThis narrower profit margin makes biocontrolunattractive to industry The discrepancy be-tween profit associated with biocontrol andchemical pesticides is widened further becausemany costs associated with pesticide use arenot included in the prices paid Hidden costsinclude decontaminating soil and ground andsurface water monitoring pesticide residuesand some registration costs Furthermorethere are health costs for agricultural workersand communities whose aquifers and wellsbecome contaminated By implementing regu-lations that require market prices of pesticidesto reflect more closely the average cost of theiruse (including both short- and long-term costs)biocontrol will be able to compete better withpesticides

The registration process itself makes devel-opment of biocontrol agents prohibitive Cre-atively reducing costs associated withregistration requirements would achieve thegoal of risk management while minimizing theunintended consequence of deterring biocon-trol development Microbial control agentsthat cannot grow at animal body temperaturesshould not be required to undergo toxicologytests (Cook 1992) and closely related organ-isms that have been shown experimentally tobe specific to a host and environment shouldnot need to undergo rigorous repetitive trialsfor each species or subspecies For example incases where a pathogen is host-specific geo-graphically restricted and poses no humanhealth risks closely related species known tohave similar life histories and restrictionscould be registered under the same umbrellalabel as a pilot species that has undergone ex-tensive registration testing Relaxing registra-tion requirements to eliminate unnecessary

The discrepancybetween profitassociated withbiocontrol andchemical pesti-cides is widenedfurther becausemany costs

associated withpesticide use arenot included inthe prices paid

165

Con Position

While regulatingpesticides may

reduce pesticideuse biological

control interven-tion will not

necessarily occurconcomitantly

tests would also reduce registration obstaclesand costs Templeton (1992) argues

why worry about toxicology when conven-tional wisdom teaches that plant pathogens donot infect animals and why worry about envi-ronmental impact when host-specificity andsta bility assures no risk to anything but theweed host

In calling for relaxation of registration require-ments we must be careful to not imply a relax-ation of risk assessment Careful guidelinesmust be developed to ensure that regulationsminimize risk for both high- and low-risk bio-control products

In conclusion I would emphasize the neces-sity of using pesticide regulation as a tool toenhance biocontrol If we want to enhance theavailability quality and therefore use of bio-control we must require that pesticides incor-porate the long-term costs of their use into theirmarket price and improve government regula-tions that encourage development of biocon-trol products while modifying thoseregulations that encourage pesticide use

References Cited

Cook R J 1992 Reflections of a regulation bio-logical control researcher pp 9-24 In RCharudattan and H W Browning [eds] Regu-lations and guidelines critical issues in biologi-cal control Proceedings USDNCSRS NationalWorkshop 10-12 June 1991 Vienna VA In-stitute Food amp Agricultural Science Universityof Florida Gainesville

National Research Council 1989 Alternative ag-riculture pp 10-20 National Academy PressWashington DC

Templeton G E 1992 Regulatory encourage-ment of biological weed control with plantpathogens pp 61-63 III R Charudattan andH W Browning [eds) Regulations and guide-lines critical issues in biological control Pro-ceedings USDNCSRS National Workshop10-12 June 1991 Vienna VA Institute Foodamp Agricultural Science University of FloridaGainesville

Christopher SansoneDepartment of Entomologytexas AampM UniversityCollege Station TX

The use of pesticides in cropping systemsand the urban environment is a two-edged

sword The impacts of pesticides both negativeand positive are well documented The impactof regulations on pesticide use patterns is not aswell documented but if a product is regulatedprobably less of that product will be used Whileregulating pesticides may reduce pesticide usebiological control intervention will not necessar-ily occur concomitantly

Regulations can take many shapes andforms Regulations imply establishing a set ofrules to perpetuate uniformity or order andmandatory participation Shumway andChesser (1994) concluded that when additionalregulations are imposed on pesticide use farm-ers usually change to alternative crops ratherthan increase their use of alternative pest con-trol tactics such as biocontrol

Many regulation discussions focus on apercentage reduction of pesticides The ques-tion here becomes would the reduction in ki-lograms of pesticide used be biologicallyrelevant Despite an almost 1DO-fold reductionin the amount of active ingredient from theorganophosphates to the pyrethroids the samebiological problems such as pest resurgenceand resistance exist with little movement tobiological control

Another problem associated with the regu-latory approach is the difficulty of developingregulations that do not impede the develop-ment and implementation of alternative tacticsfor pest management The registration historyof pheromones illustrates how regulations cando more harm than good In September 1980Environmental Protection Agencys FederalInsecticide Fungicide and Rodenticide Act(FIFRA) Scientific Advisory Panel presenteddraft guidelines for biorational pesticides thatwere nearly indistinguishable from those forbroad-spectrum pesticides From 1973 to1980 an average of three pheromone productswere registered annually From 1981 to 1987no pheromone products were registered It wasonly after EPA dropped several requirements in1993 that new pheromone products again wereregistered

The strongest case for regulation of pesti-cides is conservation of natural enemies Whenbroad spectrum pesticides are removed fromthe environment natural enemies are allowedto playa greater role in pest managementWell-designed integrated pest management(IPM) systems can and often do achieve thatsame reduction in pesticide use without addi-tional regulations on pesticides (Frisbie andSmith 1989) In Texas alone vegetable IPMprograms have reduced pesticide use by 66on carrots processed for baby food soups and

166 AMERICAN ENTOMOLOGIST bull Fal1996

frozen foods Other states can report similarsuccesses involving the implementation ofproperly designed rPM systems without addi-tional regulations

Even when commitments to pesticide reduc-tion are put into place they do not necessarilytranslate to increased or enhanced biologicalcontrol In 1987 the Government of Ontariomade a commitment to reduce the use of agri-cultural pesticides by 50 by the year 2002(Murphy and Broadbent 1993) An 80 reduc-tion was achieved in chrysanthemums withrPM technology without an increase in the useof biological control

If regulation of pesticides is not the answerthen what alternatives exist Much of the de-velopment of the insecticide industry afterWorld War II was enhanced by subsidies pro-vided by the Defense Department for develop-ing nerve poisons Biological control couldbenefit from the same sort of subsidizationthrough crop insurance for failed biologicalcontrol attempts low interest loans to suppli-ers of natural enemies to enhance the develop-ment of this cottage industry or increasedfunding for biological control research

Stronger ties between research extensionand grower groups are essential Growers ofspecific commodities have the greatest vestedinterest in a biological solution to their pestproblems and stand to gain the greatest returnfrom the economic investment Grower groupscould provide commodity check-off funds forapplied research and for extension in order topromote biological control Grower groupsalso could produce the natural enemies fortheir constituents in situations where the returnon investment is too low to maintain the inter-est of private insectaries

Many other changes such as ecologicallysound amendments to future US farm billsand a decrease in the stringency of cosmeticstandards on produce could be implementedto enhance biological control A public man-date exists to use pesticides more responsiblyAlthough regulation of pesticides may achievethe goal of pesticide reduction regulations willnot necessarily increase the use of biologicalcontrol or help producers maintain sustain-ability and profitability By creating incentivesand designing biologically extensive IPM pro-grams biological control can be enhanced andproducers can maintain their profitability

References Cited

Frisbie R E andJ W Smith Jr 1989 Biological-ly intensive integrated pest management the

AMERICAN ENTOMOLOGIST bull Fa1l1996

future pp 151-164 In J J Menn and A LSteinhauer [eds] Progress and perspectives forthe twenty-first century Entomological Societyof America Lanham MD

Murphy G D and A B Broadbent 1993 Devel-opment and implementation of IPM in green-house floriculture in Ontario Canada In J Cvan Lenteren [ed] Working Group on Inte-grated Control in Glasshouses Bulletin 16 In-ternational Organization for BiologicalControl

Shumway C R and R R Chesser 1994 Pesti-cide tax cropping patterns and water qualityin south central Texas J Agric Appl Econ 26224-240

TopicWe Should Develop andRelease Pesticide-ResistantNatural Enemies

BackgroundBrian BishopDepartment of EntomologyMichigan State UniversityEast Lansing MI

Until recently there has been little researchon pesticide effects on natural enemies (Croft1990) Before 1958 six papers were publishedon direct toxicity assessments on natural ene-mies between 1958 and 1966 17 papers werepublished and between 1967 and 197342 pa-pers were published (Croft and Brown 1975)As a result more is known about the effects ofpesticides on pests than on predators and par-asitoids Croft and Brown (1975) cited five rea-sons for this (1) preferential attention given tocontrol of direct competitors (2) assumptionthat natural enemies and pests respond similar-ly to pesticides (3) more monetary resourcesfor studying pests (4) difficulty in rearing nat-ural enemies and (5) lack of standardized tox-icology test methods for natural enemies

Of 504 cases of recorded arthropod resis-tance in 1989481 (955) involved pest spe-cies whereas 23 (45) involved beneficialsTwo hypotheses the preadaptation hypothesisand the food limitation hypothesis have beenproposed to explain this discrepancy (assum-ing that the discrepancy is not primarily due tobias in research effort)

more isknown aboutthe effects ofpesticides onpests than onpredators and

parasitoids

167

The use of resis-tant naturalenemies is

essentially anal-ogous to the

well-establishedstrategy of

using selectivepesticides

168

The preadaptation hypothesis proposes thatphytophagous arthropods already contain en-zymes such as multifunction oxidases that al-low them to detoxify pesticides because theymust cope with chemical defenses in their foodplants The food limitation hypothesis statesthat the resistant natural enemies that survivea chemical spraying are left with very fewpreyhosts and either starve or emigratewhereas the few resistant pests have an abun-dant food supply and can quickly build uppopulations Two implications of the food lim-itation hypothesis are that (1) natural enemieshave the potential to evolve resistance rapidlyif an abundant food supply is present and (2)under intensive pesticide use resistance innatural enemies will not appear until after re-sistance in the pest has appeared Data alsoindicate that differences may exist betweennatural enemies In comparison with preda-tors parasitoids are thought to be both lessresistant to pesticides initially and limited intheir ability to develop resistance The need forstandardized tests to measure pesticide side-effects on natural enemies is being addressedby the International Organization for Biolog-ical Control Working Group Pesticides andBeneficial Organisms (Hassan 1985)

Several research scientists feel that to beeffective in IPM programs natural enemiesshould have high resistance and should replacesusceptible biotypes in the field (eg Croft andBrown 1975) Genetic improvement of naturalenemies can be accomplished through artifi-cial selection (field or laboratory) hybridiza-tion and recombinant DNA techniquesResults of many laboratory breeding programsindicate that only low levels of resistance areachieved and resistance declines when selec-tion is removed (Croft and Brown 1975) Com-puter simulation models and field tests indicatethat low dosage or reduced chemical applica-tions in the field can lead to the development ofresistance in natural enemies while retarding itin pests However natural enemies selected forresistance in the laboratory would need pesti-cides applied often and uniformly to maintaintheir resistance and remove susceptible bio-types Hence maximizing efficacy of labora-tory- and field-selected natural enemies mayrequire different management strategies in thefield

Headly and Hoy (1987) conducted a studyin the almond industry to determine if the ben-efit received from resistant natural enemieswould be worth the cost of developing andimplementing them They concluded that thealmond industry could see a cost reduction of

$50-8250 per hectare and individual grow-ers could save $60-110 per hectare if integrat-ed mite management using resistant predatormites was adopted

References Cited

Croft B A 1990 Arthropod biological controlagents and pesticides Wiley New York

Croft B A and W A Brown 1975 Responses ofarthropod natural enemies to insecticidesAnnu Rev Entomol 20 285-335

Hassan S A 1985 Standard methods to test theside-effects of pesticides on natural enemies ofinsects and mites developed by the Internation-al Organization for Biological Control workinggroup Pesticides and beneficial organismsBull Organ Eur Pestic Policy 15 214-55

Headley J c and M A Hoy 1987 Benefitcostanalysis of an integrated mite management pro-gram for almonds J Econ Entomol 80 555-559

Pro PositionMichael StoutDepartment of EntomologyUniversity of California Davis CA

In the future agriculture will rely increas-ingly on pest control strategies other than pes-ticides and most management programs willprobably incorporate multiple control strate-gies including biological control Howeverbecause effective biological or alternative con-trol strategies do not exist for many key pestspesticides will remain a part of pest manage-ment programs for the foreseeable future Thispresents something of a dilemma because pes-ticides kill natural enemies as well as pestsand therefore often are responsible for thefailure of biological control Pesticide-resis-tant natural enemies because they allow theapplication of necessary pesticides while min-imizing natural enemy mortality allow theintegration of pesticides and biological con-trol Once pesticides are made compatiblewith biological control it becomes possible todesign pest management programs that rely ona combination of the two strategies (as well asother compatible strategies) rather than onpesticides alone thereby reducing the amountof pesticide use

Resistant natural enemies and pesticideshave been successfully integrated in orchardcrops (Brunner 1994) In apple orchards forexample organophosphates are needed to con-


trol direct pests such as the codling moth forwhich the economic threshold is very lowMites are secondary pests of apple that haveevolved resistance to organophosphates in theabsence of predators resistant to organophos-phates pest mite outbreaks are induced byorganophosphate applications This in turnnecessitates the use of miticides However ifresistant predatory mites are present pestmites are brought under biological control andthe need for miticides is eliminated or reducedEndemic organophosphate resistance in natu-ral enemies has been used in apple manage-ment programs for over 25 years In additionreleases of laboratory- and field-selected pred-atory mites have been made in areas contain-ing susceptible predators and the resistantmites have established and persisted (Croft1976) It is important to note that establish-ment and persistence of resistant predatorymites in orchard crops has not required in-creased use-in terms of rate or frequency ofapplication-of the selecting insecticide andthe introduction of resistant predators has cur-tailed in some cases dramatically the need formiticides

Although resistant natural enemies have tothis point been used only for control of sec-ondary pests induced by necessary pesticidesthey have potential uses in other agriculturalsituations There are undoubtedly many situ-ations in which pesticides natural enemiesand other compatible strategies (eg phero-mone disruption) could be used in concertagainst a key pest Natural enemies and otherstrategies are not always effective at keepingkey pests below their economic thresholdsand pesticides will sometimes be necessaryBecause resistant natural enemy populationsare not decimated by pesticides pest mortalityprovided by resistant natural enemies and pes-ticides should be additive not exclusiveThus in pest-management programs that re-quire pesticides resistant natural enemiesshould provide more consistent biologicalcontrol decreasing the total amount of pesti-cide needed Similarly other managementstrategies if they are compatible with pesti-cides and resistant natural enemies could pro-vide additional sources of mortality andfurther reduce reliance on chemical control

The use of resistant natural enemies is essen-tially analogous to the well-established strate-gy of using selective pesticides or usingbroad-spectrum pesticides in such a manner asto achieve selectivity As such the use of resis-tant natural enemies is a potentially valuablemethod for integrating chemical biological

AMERICAN ENTOMOLOGIST bull Fall 1996

and other forms of control The use of multiplecontrol strategies has of course the primarybenefit of reducing pesticide use Reduced pes-ticide use has the added benefit of retardingpest resistance to pesticides extending thenumber of years a pesticide remains useful Asmethods for producing resistant natural ene-mies improve (eg through genetic engineer-ing [Presnail and Hoy 1994]) developmentand introduction of resistant natural enemiesmay become affordable and feasible for manycrops

References Cited

Brunner J F 1994 Integrated pest managementin tree fruit crops Food Rev IntI 10 135-157

Croft B A 1976 Establishing insecticide-resis-tant phytoseiid mite predators in deciduoustree fruit orchards Entomophaga 21 383-399

PresnailJ K and M A Hoy 1994 Transmissionof injected DNA sequences to multiple eggs ofMetaseiulus occidentalis and Amblyseius fin-landicus (Acari Phytoseiidae) following mater-nal microinjection Exp Appl Acarol 18319-330

Con PositionDaniel R SuiterDepartment of EntomologyUniversity of Florida Gainesville FL

Following are several reasons why the de-velopment and release of pesticide-resistantnatural enemies should not be pursued Firstthe release of pesticide-resistant natural ene-mies might encourage the use of pesticidesBoller (1987) maintained that the use of pesti-cide-resistant natural enemies would encour-age the use of pesticides IPM practicestypically promote conservation of natural en-emies through selective use of pesticides How-ever with the use of pesticide-resistant naturalenemies conservation may not be an issuebecause resistant natural enemies cannot bekilled As a result the frequency of sprayingmight increase

Secondly the introduction via a transpos-able element or virus vector of a gene for resis-tance into a natural enemy might lead tohorizontal transfer of genetic material to a pestinsect Recently the use of transgenic plantshas received a great deal of attention Genesfor a variety of desirable traits such as resis-tance to viruses and herbicides have been in-

the releaseof pesticide-

resistantnatural enemiesmight encour-age the use of

pesticides

169

bullo Ie

MarkA pomerlnkeDepartment of Entomologyamp Nematology

University of Florida Gainesville FL

Genetically EngineeredNatural Enemies Should beRegulated in a DifferentManner Than Other Non-indigenous Natural Enemies

roundckClassical biological control is one of the

oldest forms of pest control known toda y Bio-logical control involves using a natural enemyan organism that feeds on another organism toreduce the number of pests to a noneconomiclevel Natural enemies have been utilized asbiological control agents since 1200 AD

Genetic manipulation is older than mostpeople realize Ancient agriculturalists pickedplants with traits that provided for greaterharvest or insect resistance It has been suggest-ed that interspecific hybridization might pro-vide useful genes for genetic improvement ofbeneficial arthropods Genetic improvementof arthropod natural enemies has beenachieved through artificial selection (eg pes-ticide resistance in phytoseiids) Today recom-binant DNA techniques are being used toimprove arthropod natural enemies (Hoy1992)

Several different laws currently are used toregulate the release of nonindigenous arthro-pods Four of most important laws of concernto entomologists are (1) The Lacey Act (1900)(2) the Plant Quarantine Act (1912) (3) theFederal Plant Pest Act (1957) and (4) Execu-tive Order 11987 (1977) These acts and ordersprovide authority to the USFWS and USDA-APHIS to regulate movement and release ofany nonindigenous arthropod Because theselaws and decrees do not include any informa-tion on the release of genetically engineeredarthropods several regulations have beendrafted concerning these arthropods Guide-lines drafted in 1972-1975 at the Asilomarconferences in California became the Recom-binant DNA Advisory Committee guidelines

References Cited

Boller E 1987 A closer look at the question ofpesticide resistance antagonists InternationalOrganization for Biological Control WesternPaleartic Regional Section Profile no 6 Inter-national Organization of Biological Control

Doebley] 1990 Molecular evidence for gene flowamong Zea species BioScience 40 443-448

serted into crops Crop plants are capable oftransferring genes over relatively long distanc-es to related plants thac differ in their life his-tories Doebley (1990) demonstrated gene flowbetween maize and its nearest wild relatives the teosintes in Central America and MexicoThe underlying concern is that the escape ofgenes through pollen and hybridization couldenhance the vigor of existing weeds The con-cern over the use of transgenic pesticide-resis-tant natural enemies is that if horizontaltransfer were to occur between the naturalenemy and a crop pest this might confer resis-tance in the pest

Another argument against the release ofpesticide-resistant natural enemies is econom-ically based Consider the following scenarioIn a certain agroecosystem there exists anexotic pest among the pest complex Afteryears of costly foreign exploration classicalbiological control specialists discover one ofits primary natural enemies which is thenquarantined where host specificity and naturalhistory data are gathered After mass releasethe parasitoid begins having a significant reg-ulatory impact on the pest In the meantimethe growers only option is to spray on an inter-val basis to control the pest The manufacturerof the product currently being used by thegrower then initiates a research program toestablish a strain of the parasitoid resistantonly to its active ingredient This scenariowould leave growers without a choice of pes-ticide tools It is not unreasonable to expectthat a program of resistant natural enemiescombined with as-needed reduced pesticideapplications would be more effective than ei-ther alone However if there were only onesource of resistant natural enemy its ownermight then have a monopoly on its price

In this short discussion I have identified justa few of the drawbacks that should be consid-ered before embarking on the widescale use ofresistant natural enemies in IPM programsIndeed the permanency of genetically alteredarthropod releases leaves no room for errorThe ecological costs of such a mistake might becatastrophic

The process ofrisk assessment

for classicalbiological con-trol agents iswell definedcompared to

that for geneti-cally engineeredcontrol agents

170 AMERICAN ENTOMOLOGIST bull Fa1l1996

Pro Position

in 1976 These guidelines help to ensure thatresearchers will not genetically engineer or-ganisms that might become hazardous toplants or animals if they escape from the lab-oratory To help regulate genetically engi-neered arthropods the USDA-APHIS de-veloped the following guidelines Federal Reg-isters 7 CFR parts 330 and 340 and 7 CFR part340 final rule These guidelines regulate theintroduction of genetically engineered organ-isms that are plant pests or could potentiallybecome plant pests However the above guide-lines do not allow for permanent release of anygenetically engineered arthropods only limit-ed or test releases of transgenic arthropods areallowed and no such releases have been madeto date When permission to perform a test orlimited release finally is granted two methodsthat may be used to ensure that establishmentdoes not occur are climatic condition and alethal gene Both methods involve the inabilityof an arthropod to survive climatic conditionsto which it is not accustomed

All of the above laws are designed to reducethe risk that a mistake will occur Risk can bedefined as the probability of occurrence multi-plied by the potential consequences of suchoccurrence (Ginzburg 1991 ABRAC 1992)Risk assessment is the process of determining ifor how much harm could be caused to a non-target organism should a control agent start toutilize it The process of risk assessment forclassical biological control agents is well de-fined compared to that for genetically engi-neered control agents Weed biological controlagents require a determination of whether thecontrol agent can complete its development onany plant in the same or related plant family asthe target plant This information can be ob-tained by performing choiceno-choice testsUsing information obtained from these tests amore informed decision can be made on releas-ing the control agent No such guidelines existfor genetically engineered natural enemies

Even with all the laws and regulations inplace and the risks analyzed mistakes in bio-logical control could occur For example oneauthor has expressed concerns about extinc-tion of native arthropods being caused by in-troduced control agents (Howarth 1983)However there appears to be no conclusiveevidence to support his findings Still his pointis valid because there are risks and those risksneed to be analyzed

What arc the risks and how does one definethem for genetically engineered arthropodsAs genetic engineering of arthropods becomesmore common concerns about the additional

risks from genetically engineered arthropodnatural enemies are being discussed more fre-quently A recent conference in GainesvilleFL addressed concerns about releasing genet-ically engineered arthropods (Risks of Releas-ing Transgenic Arthropod Natural Enemiesorganized by Marjorie A Hoy and Ernest SDelfosse 13-16 November 1993) The confer-ence found four areas that should be addressedby researchers who plan to release geneticallyengineered arthropods for short term evalua-tion (1) attributes of the unmodified organism(2) attributes ofthegenetic alteration (3) phe-notype of modified organism compared tounmodified organism and (4) attributes of theaccessible environment

References Cited

[ABRAC] Aricultural Biotechnology ResearchAdvisory Committee 1992 Guidelines for re-search involving planned introduction into theenvironment of genetically modified organ-isms Guidelines recommended to USDA by theAgricultural Biotechnology Research AdvisoryCommittee 3-4 December 1991 USDA Officeof Agricultural Biotechnology Document No91-104

Ginzburg L R [ed] 1991 Assessing ecologicalrisks of biotechnology Butterworth-Heine-mann Boston

Howarth FG 1983 Classical biocontrol pana-cea or Pandoras box Proc Hawaiian Ento-mol Soc 24 239-244

Hoy M A 1992 Commentary Biological controlof arthropods enetic engineering and environ-mental risks BioI Control 2 166-170

Catherine SKatsarDepartment of EntomologyTexas AampM UniversityCollege Station TX

No indication exists that naturally occur-ring genotypes identified and selected viamolecular techniques are inherently differentfrom genotypes selected by more conventionalmeans Rather than concentrate on differencesin methodology it is perhaps more relevant toaddress the potential changes in biology thatmay result when a natural enemy is geneticallymodified The question at hand is not whethera genetically engineered natural enemy is po-tentially more hazardous than a naturally oc-curring one rather the question is whether or

the questionis whether or notthe biology of a

transgenicorganism is

unique enoughto warrant sepa-rate regulatoryguidelines

A~IERICAN ENTOMOLOGIST bull Fa11996 171

An exoticagent and

CEO are onlydifferent in

the same waytwo exoticspecies are

different withregards totheir newhabitat

172

not the biology of a transgenic organism isunique enough to warrant separate regulatoryguidelines

What are the differences in biology associ-ated with a transgenic organism that requirean alternative regulatory approach The con-cept of one gene coding for one polypeptide isfundamental to our understanding of genotyp-ic expression At the organismallevel howev-er phenotype is determined by a complexnetwork of interactions among gene productsInteractions may occur among genes at differ-ent loci among alleles at the same locus oramong genes and the environment Often asingle gene may affect several traits (Barton1990 Gavrilets and de Jong 1993) Rarely isthe relationship between genotype and pheno-type one-to-one

Because changes in genome structure mayresult in phenotypic changes in adjacent geneproducts care should be taken to determine anysecondary effects gene transfer may have onother genetic interactions By focusing only onthe primary gene product important secondaryphenotypic effectsmay beoverlooked Epistasisand pleiotropy often playa major role in deter-mining phenotype (Falconer 1989)

Before we can understand organismal be-havior and gene function as a consequence ofvarying genetic backgrounds we must studyphenotype in the context of the whole organ-ism Nonindigenous natural enemies mayhave characteristics that are expressed only incertain environments or conditions Similarlyonce an indigenous natural enemy has beenaltered genetically its response to its previousenvironment can no longer be predicted ade-quately Still the inner workings of a nonindig-enous natural enemy have resulted as aconsequence of natural selection In contrastthe inner workings of a transgenic organismhave never before operated together and haveonly been subjected to limited selection pres-sure in a laboratory environment

The ability to manipulate and transfer genesinto an array of genetic environments isonly thefirst step in understanding the complexities ofliving organisms Whereas individual genesmay have predictable results genetic interac-tions between nonallelic loci make phenotypiceffects unpredictable Simplyput when dealingwith genetic interactions the old adage thewhole is the sum of its parts isnot entirely trueGenotype does not specifyphenotype unambig-uously Rather it determines only a range inwhich phenotypic expression may occur

It is not whether or not anyone of theseorganisms is inherently more dangerous than

the other but whether or not the characteristicsand potential risks associated with nonindige-nous and genetically engineered natural ene-mies make them different enough to warrantseparate regulatory guidelines The objectiveof the scientific community should be to devel-op regulatory guidelines that maximize bio-logical and environmental stability while atthe same time minimizing counterproductivered tape

References Cited

Barton N H 1990 Pleiotropic models of quanti-tative variation Genetics 124 773-782

Falconer D S 1989 Introduction to quantitativegenetics John Wiley amp Sons New York

Gavrilets S and G De Jong 1993 Pleiotropicmodels of polygenic variation stabilizing selec-tion and epistasis Genetics 134 609-625

Con PositionStephen GaimariDepartment of EntomologyUniversity of Illinois at Urbana-Champaign

UrbanaIL

Genetically engineered organisms (GEOs)for biocontrol should not be regulated differ-ently than exotics because they raise similarquestions and concerns regarding risks

Two important questions for either type oforganism are (1) Will the organism control thetarget pest and (2) Will the introduced agentbecome a pest itself Possible negative effectsinclude pest enhancement effects on humanhealth and attacks on nontargets Any intro-duced organism can potentially feed on allavailable suitable hosts and affect associatedspecies in some way (Howarth 1991) This isprecisely what needs consideration for anypotential agent whether GEOs or exotics

Any organism with combinations of traitsnovel to an environment is likely to play novelecological roles As with an exotic a GEOmay prosper in a new habitat type geograph-ical area or season making it effectively anintroduced exotic likely to enter new bioticand abiotic interactions Therefore the phe-notype of a transgenic organism not the pro-cess used to produce it is the appropriate focusof regulatory oversight (Tiedje et al 1989)

The US Congress Office of TechnologyAssessment (1993) treats GEOs as nonindige-


nous by definition with the central issues forexotics and GEOs being the same

Both involvethe releaseof a livingorganismpo-tentially capable of reproduction establish-ment and ecological effects beyond the initialrelease site The specific characteristics of theorganism and the receiving environment willdetermine the consequencesof either type of in-troduction

Miller and Aplet (1993) pointed outthat mostpublic concern with biotechnology revolvesaround unknown effects of novel organisms onecosystems into which they are released

The proper considerations for either type ofagent are the organism released the organ-isms targeted the surrounding fauna and flo-ra and other environmental attributes Theimportant scientific considerations include thepotential survival and reproductive capacityof the introduced agent its interactions withother organisms and the effects on communitystructure and ecosystem function After re-lease a GEO is subject to the same naturalselection pressures as any other organism(Tiedje et al 1989) and the one or two alteredtraits will not preclude the entire genome fromovercoming selective pressure

Host specificity testing stresses the funda-mental similarities in answering host-relatedquestions Host specificity in the field is onlyknown with certainty after release but pre-release estimates are possible through labora-tory studies Each group of agents must beevaluated by scientists who are familiar withthe unique characteristics of these groups(Maddox 1994) The questions are the sameamong all potential agents for release Does itcolonize or prey on nontargets Does it killnontargets What effects do the agents have onthe community To answer these questionsdifferent approaches must be taken and theexperimental design must fit the agent (ietesting must emphasize hosts that are poten-tially susceptible based on phylogenetic andhabitat considerations) Regulatory require-ments should be broad enough to ensure thatexperiments can be tailored to fit individualcases (Maddox 1992)

The fundamental issues concerned with re-leases of exotic natural enemies and GEOs arethe same Should we be asking the same ques-tions regarding host specificity and potentialinteractions with the surrounding environ-ment Should we be worrying about the samepotential risks and effects associated with anyintroduction Therefore prerelease studies onpotential effects of either type of organism


should be overseen by a single regulating bodyAn exotic agent and GEO are only different inthe same way two exotic species are differentwith regards to their new habitat

References Cited


Maddox J V 1992 The effects of regulations onthe use of insect pathogens as biological controlagents pp 73-81 In R Charudattan and HW Browning [eds] Regulations and guide-lines critical issues in biological control Pro-ceedings National Workshop 10-12 June1991 Vienna VAUniversity of Florida PressGainesville

1994 An evaluation of opposing viewpoints ofclassical biological control pp 43-51 InSLC Fosbroke and K W Gottschalk [eds]Proceedings USDA Interagency Gypsy MothResearch Forum 18-21 January 1994 An-napolis MD USDA Forest Service RadnorPA


Tiedje J M R K Colwell YL Grossman R EHodson R E Lenski R N Mack and P JRegal 1989 The planned introduction of ge-netically engineered organisms ecological con-siderations and recommendations Ecology 70298-315

US Congress Office of Technology Assessment1993 Harmful non-indigenous species in theUnited States OTA-F-565 US GovernmentPrinting Office Washington DC

Acknowledgments

We thank Connie Satterwhite for her helpwith many drafts of this manuscript We thankESA for its support of this venture

bull

Fred Gould and George Kennedy are profes-sors of entomology at North Carolina State Uni-versity Fred Gould teaches insect ecology andconducts research on ecological genetics of in-sects George Kennedy teaches IPM and stud-ies plantinsect interactions Robert Kopanic is agraduate student at North Carolina State Univer-sity He is studying ecology and management ofcockroaches

173

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TopicThe United States Has BeenNegligent in Regulating theImportation Release and Useof Generalist Natural Enemies

BackgroundKatherine SchickDeparbnentofEntomologyUniversity of California Davis CA

Recent theorists in biological control haveadvocated the use of generalist natural ene-mies because they should survive local extinc-tions of target pests by utilizing other prey orhosts When the target pest recolonizes thepatch the generalist biological control agentalready may have effective population levelsin place for control

The risks of using generalist natural ene-mies include pest management risks-dietswitching by the generalist may lead to anincrease in target and secondary pest num-bers-and ecological risks-nontarget species(within and outside the targeted agroecosys-tern) may be impacted negatively

The pest management risks of using gener-alists are illustrated by a study focusing onspecies in three genera of predatory Hemi-ptera Geocoris Nabis and Zelus which preyon cotton aphids (Aphis gossypii Glover)(Rosenheim et al 1993) In cotton fields thesepredators showed a decided preference forlacewing (Neuroptera) larvae which also preyon aphids The result was that aphid popula-tions were larger in the presence of both lacew-ings and predatory bugs than in the presence oflacewings alone

The implications for biological control arethat one cannot assume that the effectsof gener-alist predators are restricted to a single trophiclevel and additional predator species may notadditively suppress a pest herbivore but mayinstead feed upon a predator of the target pestcausing an increase in pest numbers

Ecological risks of using generalist naturalenemies include the possible extinction of non-target arthropod species Some studies suggestthat the introduced sevenspotted lady beetleCoccinella septempunctata L is causing the


decline in populations of native North Ameri-can coccinellids and could lead to extinctionsFew arthropod extinctions have been demon-strated to be caused by introductions but giventhe large proportion of the arthropod faunathat is yet to be described many extinctionscaused by generalist natural enemies couldremain unnoticed Federal regulation of natu-ral enemy importation is authorized by boththe Plant Pest Act and the Plant Protection andQuarantine Act (US Code SS 147a-167) andenforced by the Animal and Plant Health In-spection Service (APHIS) of the US Depart-ment of Agriculture Congress gave APHISregulatory authority to protect the nationsagriculture

The LaceyAct (16US CodeSS 3371-3378)gives the US Fish and Wildlife Service (USF-WS) authority to regulate importation ofthreatened and endangered biological organ-isms However the USFWS generally defersthe permitting of live arthropod importationsto APHIS

The National Environmental PolicyAct (42US Code SS4321-4370a) requires an initialscoping document publicly announcingplanned projects including the release of animported biocontrol agent and an environ-mental assessment The assessment may resultin a finding of no significant impact or it mayrequire further review in the form of an envi-ronmental impact statement

A few years ago there was concern thatAPHIS policies might not have followed theseenvironmental regulations Lockwood(1993a b) and Carruthers and Onsager (1993)discussed a perceived irregularity in this envi-ronmental assessment process as it related torangeland grasshopper control This discus-sion sparked a major controversy among ento-mologists involved in biological control Theargument centered on releases of an alien En-tomophaga fungus and parasitic wasp bothpossibly generalists to control native grass-hopper species on western rangelands in theUnited States Concerns were expressed thatthese releases might endanger other nativerangeland grasshopper species that were notpests

References Cited

Carruthers R I and J A Onsager 1993 Per-spective on the use of exotic natural enemies forbiological control of pest grasshoppers (Or-thoptera Acrididae) Environ Entomol 22885-903

Lockwood J A 1993a Environmental issues in-

The risks ofusing generalistnatural enemies

include pestmanagment

risks and eco-logical risks

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Lanham MD 20706-3115Fax 301-731-4538


bullo Ie








References Cited










Pro Position






References Cited











An exoticagent and




172








References Cited





UrbanaIL














References Cited







Acknowledgments


bull


173

NOW AVAILABLE





E-mailPhoneFax




INSECTS199 7

CALENDAR

2-4 $800 each5-9 $775 each






three-year planner




Lanham MD 20706-3115Fax 301-731-4538


Pro Position






References Cited











An exoticagent and




172








References Cited





UrbanaIL














References Cited







Acknowledgments


bull


173

NOW AVAILABLE





E-mailPhoneFax




INSECTS199 7

CALENDAR

2-4 $800 each5-9 $775 each






three-year planner




Lanham MD 20706-3115Fax 301-731-4538


An exoticagent and




172








References Cited





UrbanaIL














References Cited







Acknowledgments


bull


173

NOW AVAILABLE





E-mailPhoneFax




INSECTS199 7

CALENDAR

2-4 $800 each5-9 $775 each






three-year planner




Lanham MD 20706-3115Fax 301-731-4538










References Cited







Acknowledgments


bull


173

NOW AVAILABLE





E-mailPhoneFax




INSECTS199 7

CALENDAR

2-4 $800 each5-9 $775 each






three-year planner




Lanham MD 20706-3115Fax 301-731-4538


NOW AVAILABLE





E-mailPhoneFax




INSECTS199 7

CALENDAR

2-4 $800 each5-9 $775 each






three-year planner




Lanham MD 20706-3115Fax 301-731-4538


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Transcript of %KKH=C;L?> OCLB )GB;G=CGA LB? -FI;=L H@ &CHEHAC=;E … · XVc XdXX^cZaa^Yh VcY XdjaY aZVY id...