262 Rangelands 10(6), December1988 and only development of appropriate local technology can tries. Therefore, there appearsto be a need for an approp- solve the problems. riate term which portrays the grazing situations in develop- Becauseof setbacks which rangemanagement has received ing countries. This will lay a foundation for research and In pastoral situations, many donoragencies are now reluc- development in a new direction: pastoralism, nomadism, tant to invest in range management projects in developing transhumance, or mixed farming systems. It is suggested countries. Grazing lands are there, and havegrazed that development and managementof rangelands in devel- on these lands and would continue to do so whether range oping countries be called Pastoral SystemsManagement. management programs succeed or fall. There is a need to Literature Cited develop a rangeland anthropology and sociology course in ofthe on the range schools forthose interested in international work GOWP. 1970. Report working group range management. fail Governmentof West PakistanPlanning and DevelopmentDepart- and for the international students. Programs simply ment (Project Wing), Lahore, PakIstan. 42 p. becauseprescriptions are madewithout a proper diagnostic RafI, MM. 1965. Maslakh range project, Quetta, West Pakistan (a analysis of the problem. reviewof its first ten years). Pak. J. Forest.15:319-338. Most think of the read Syal, M.N., and A. Hameed. 1984. Soil potential assessment in rela- people range management waythey in forest areas of D. G. Khan Forest about It in text books have seen it in the coun- tion to plant production or developed Division. Soil Surveyof Pakistan.

Viewpoint: Comments on the Proposed Use of Native for Biological Control of Snakeweeds J.P. Cuda

As ascientist currentlyinvolved in researchon the biologi- reduced to a level such that it is no longerconsidered eco- cal control of weeds on rangelands.I would liketo comment nomically important. Also, becausethis methodof control is on the conclusions and recommendationsof an articlepub- species specific, its effects are not detrimental to non-target lished in the April 1987 issue of Rangelands entitled "The species or to the environment. Potential of Two Insects forControlling Broom Snakeweed" The use of biological control on rangelands has been (Gonzales 1987).Although I agree with the author that bio- examined in detailby DeLoach (1978, 1981) and DeLoachet logicalcontrol would bean appropriate method for control- al. (1986).The two approachesof biological control that are ling broom snakeweed,Gutierreziasarothrae(Pursh) Britt. & currentlyavailable are (A) introduction offoreign organisms Rusby, I question the feasibilityof the augmentation ap- not already present (classical biological control), and (B) proach recommendedby theauthor and also hisassessment augmentation of the effectiveness of organisms already of one of the insects purported to be an important natural present in an area.The key issuehere concerns theselection enemy of broom snakeweed. ofthe biological control methodthat is appropriate for usein I would also liketo pointout that a project on thebiological a low-value per acre agricultural system such as rangelands control of snakeweed is already in progress at Temple, where snakeweeds(perennials) and broomweeds(annuals) Texas. The program was developed in 1975 by Dr. C. Jack are important weeds. DeLoach(1981) states that"biological DeLoach, who is affiliated with the USDA, Agricultural control is ideally suited to control rangeland weeds and ResearchService (ARS). Dr. DeLoachis one ofa small group brush of whichthe major pests are perennialsgrowing in a offederal and university scientists working full-or part-time relatively undisturbed habitat and in areas where the low on biological controlof weeds at several locations acrossthe economic return per unit area makeschemical and mechan- United States. ical controls relatively expensive." He further states that the For the purpose of this discussion, biological control of introduction of foreigncontrol agents is more suitable than weeds is defined as the use of insects, plant pathogens,or augmentation for use on rangelands because of its lower otherorganisms to control weeds (Huffaker 1959). It must be cost. DeLoach et al. (1986) recently compared the relative emphasizedthat "control" is notsynonymous with "eradica- cost ofbiological controlby augmentation and introduction. tion"; the weed species controlled biologically is simply They clearly showed thatthe augmentation approach would betoo expensivein a rangeland system becausethe cost for Author isresearch entomologist at the Biological Control ofWeeds Facility, is tothe area treated. U.S.Department ofAgriculture, and Plant HealthInspection Service, anaugmentation program proportional Science and Technology, South 7th Avenue, Montana State University, In this regard, the total cost and cost per acre is basically Bozeman,MT 59717. The author Is grateful to Paul Boldt, C. Jack DeLoach, and Hyrum B. similar to controlwith herbicides. In contrast, the total cost Johnson,Grassland, Soil and WaterResearch Laboratory,USDA, ARS, Tem- of biological control by the introduction method is inde- ple, TX, forcritically reviewingan earlierdraft ofthis manuscript. I also want to acknowledge W.F. Barr, Department of Entomology, University of Idaho, pendent of the area treated and the cost per acre actually Moscow, and D.E. Foster, Departmentof Entomology,Iowa State University, decreasesover timeas the introduced agentsreproduce and Ames,for providing valuable information on the biology of E. coccinous. Rangelands10(6), December 1988 263 actively seek out the weed. and as a groupare considered to be predaceous in both the DeLoachet al. (1986) identified several important weeds of larval and adult stages (Balduf 1935). Current specialists in rangelands of the southwestern U.S. and northern Mexico clerid still supportthe predatory behavior of the that are possible candidatesfor classical biological control. larval stage and suggestthe larvaeof E. coccineus are prob- Snakeweedsand broomweeds headed the list of priority ably feeding on the immature stages of otherbeetles (W.F. weeds becauseconflicts of interest would be minimal in both Barr, D.E. Foster, pers.Comm.). Itis also noteworthy thatthe countries. DeLoach (1981) and DeLoachet al. (1986) consi- report of Dr. Gonzales does not exclude the possibility that dered broom snakeweed and threadleaf snakeweed, G. the snakeweed plants examined were previously infested microcephala (DC.) Gray, tobe the best candidatesfor clas- with other root-feeding insects. sical biological control because the amount of damage I suggest that the larvae of E. coccineus were probably caused by these snakeweedsexceeds any beneficial value feeding on the root-boring larvae of Crossidius puichellus these plants may have inthe rangeland ecosystem.Also, the LeConte (Cerambycidae)or possibly otherinsects. Richman success potential of introduced biological control agents is and Huddleston (1981) reported that larvae of C. puichellus favorable for snakeweeds.Several root-boring insects have were often sufficientlyabundant in eastern and central New been found in Argentina that have good control potential Mexico to kill snakeweedplants over 15 cm in height. They becausethey severely damage the taproots offour species of also found Enoclerus larvae associated with root tunnels Gutierrezia that are similar ecologically toour North Ameri- constructed by Crossidius larvae. Furthermore, Falkenha- can snakeweeds (Cordo 1985, Cordo and DeLoach, in gen (1978) observed larvae of E. Iaetus nexus Barr inside press). Host range testing of two of the more promising borer tunnels in theroots of broom snakeweedin Arizona; 88 insects is in progress under quarantine conditions at the percent of these larvae were associated with larvae of the Temple laboratory. root-boring weevil Myrmex lineolata (Pascoe)(Curcu lioni- From the previous discussion it can be argued that the dae). Falkenhagen (1978) also suggested the larvae of E.I. augmentation approach as proposed by Gonzales (1987) nexus were predaceouson the larvae of M. lineolata. would probablynot be economical to the rancher. Increas- Adiscovery that E. coccineus is infact feeding on theroots ing the effectiveness of the native phytophagous insects ofsnakeweed would representan important exception toour already attacking snakeweed by mass rearing and then present knowledge of the Cleridae and in particular the releasing them would not be competitive with commercially genus Enoclerus. Further documentation of such a pheno- available herbicides and, in all likelihood, would be prohibi- menon, under controlled conditions where the opportunity tive in the rangeland system where the production per unit of prior infestation by otherroot-feeding insectswere elimi- area is very low. Although thereare numerous examples of nated, would be of great interest to researchers studying native insectsoccasionally controlling weeds (Ueckert1973), clerid and snakeweed ecology and to those interested in to date only one augmentation program utilizing existing biological control of snakeweeds. weedfeeding insectshas beenattempted. Frick and Chandler Literature Cited (1978) mass reared and releasedthe moth Bactra verutana Zeller to control rotundus in Balduf, W.V. 1935. The bionomics of entomophagousColeoptera. purple nutsedge, Cyperus L., Swift Inc. New York. cotton fields The results this John S. Co., in Mississippi. of pilot study Cordo, H.A. 1985. Host-specificity studies of the argentine weevil, showed that even though augmentation was technically Heilipodus ventralis, for the biological control of snakeweeds feasible, a large scale augmentation program would not be (Gutierreziaspp.) in the U.S. pp. 709-720. In: E.S. Delfosse(Ed.). cost effective in the current cotton production system and Proc. VI Internat.Symp. Biol. Control Weeds,Vancouver, Canada was not Aug. 19-25, 1984. consequently implemented. and C.J. DeLoach. Insects and a The an is Cordo, H.A., (In press). pathogen rationale for augmenting indigenous population that attack snakeweeds (Gutierrezia) app. in Argentina. J. Range that the population to be augmented has a characteristic Manage. abundance that is maintained by some density dependent DsLoach, C.J. 1978. Considerations in introducing foreign biotic natural control factor(s) (e.g., predators, parasitoids, or agents to control nativeweeds of rangelands.pp. 39-50. In:T.E. and when that Freeman (Ed.). Proc. IV Internat. Symp. Biol. Control Weeds, pathogens), augmentationceases, population Gainesille, Fla. Aug. 30-Sept. 2, 1976. will revert to its former level (Huffaker etal. 1971). The DeLoach, C.J. 1981. Prognosis for biological control of weeds of fauna associated with snakeweeds clearly illustrates this southwesternU.S. rangelands.pp. 175-199. In: E. Delfosse (Ed.). principleof natural control. Proc.V Internat. Symp. Biol. Control Weeds, Brisbane,Australia. Snakeweedsare attacked a of insects July 1980. by variety (Falken- D.Loach, C.J., P.E. Boldt, HA.Cordo, H.B. Johnson, andJ.P. Cuda. hagen 1978, Foster et al. 1981, Richman and Huddleston 1988. Weedscommon to Mexicanand U.S.rangelands: Proposals 1981, Wangberg 1982). The inability of the native insects to for biological control and ecological studies. USDA For. Serv., effectively control snakeweeds over large areas without Gen. Tech. Rept. R-135:49-68. augmentation that and predators are Fallienhagen, T.J. 1978. Root-boring insects in Gutierrezia saro- suggests parasitoids thrae. M.S. Thesis, Univ. of Arizon. Tucson. 60 pp. operating ina density-dependent fashion to keepthese natu- Foster, D.E., D.N. Ueckert, and C.J. DeLoach. 1981. Insects asso- ral enemies of snakeweedsin check. This is an important ciated with broom snakeweed[Xanthocephalum sarothrae] and pointbecause Gonzales (1987) identifiedthe checkered bee- threadleaf snakeweed[Xanthocephalum microcephala] in West tle Enoclerus coccineus (Schenk.) (Cieridae) as a potential Texas and Eastern New Mexico.J. Range Manage. 34(6):446-454. Frick,K.E., and J.M. Chandler. 1978. Augmentatingthe moth(Bactra biological controlagent ofbroom snakeweedin New Mexico in field for of basedon the of the a verutana) plots early-season suppression purple presence larvaefound in roots of high nutsedge(Cyperus rotundus). Weed Sc 26:703-710. percentageof dead or dyingplants. This observation is sur- Gonzales, G.J. 1987. The potential of two insects for controlling prising because the cierids rarely consume plant material broom snakeweed. Rangelands 9(2):59-61. 264 Rangelands10(6), December 1988

Huffaker, C.B. 1959. Biological control of weedswith insects.Ann. Ueckert, D.N. 1973. Effects of leaf-footed bugs on mesquite repro- Rev. Entomol.4:251-276. duction. J. Range Manage. 26:227-229. Huffaksr, C.B., P.S. Messenger, and P. DeBach. 1971. The natural Wangberg,J.K. 1982. Destructiveand potentially destructiveinsects enemycomponent in natural controland the theory ofbiological of snakeweedin WesternTexas and Eastern New Mexico and a control. pp. 16-17. In: C.B. Huffaker (Ed.). Biological Control. dioristic model of their biotic interactions. J. Range Manage. Pienum Press, New York. 35(2):235-238. Rlchman, D.B., and E.W. Huddleston. 1981. Rootfeeding by the Crossidiuspulchellus LeConteand other insects on broom snakeweed(Gutierreziaspp.) in Easternand Central New Mexico. Env. Entomol. 10:53-57.

Rebuttal: Running the Gauntlet of Scepticism and Resist- ance in Scientific Research G.J. Gonzales

Editor's Note: Readers maywish torefer tothe paper'The Potential Institute indicates that farmers and workers exposed to her- oftwo insectsfor controlling broom snakeweed,"by G.J. Gonzles, bicides face a much higher risk of lympathic cancer than Rangelands 9(2):59-61. others (NM Occupa, Healthand SafetyBureau 1986). Farmers The comments concerning scientific research are the individual exposed to herbicides 20 or more days a year were 600% opinions ofthe authors anddo not representthe official positions of more likelyto contract lympathic cancer. The highest cancer the for or its Society Range Management representatives. risk was associatedwith 2,4-D. Other carcinogens including Itis seldom possible to design an experiment thatanswers cigarette smoke, radiation, and heredity were ruled out. all research questions nor is it realistic to ignore potentially Thus, even where the "total [financial]cost [of a biological important oddities that may be observed in the course of control method] is similar tocontrol with herbicides," biolog- scientificresearch. In acommentary on "The potential oftwo ical control warrants further consideration. insects for controlling broom snakeweed", research which The high correlation between dead or dying snakeweed had been proposed on the biological control of broom plants and evidence of E. coccineus in snakeweed roots snakeweedwas questioned forvarious reasons. (Gonzales 1987) must be put into perspective. While the The majority of concern in using the checkered beetle E. likelihood of this insect being herbivorousor omnivorous is coccineus asa biological control agent is basedon the pre- minimalas discussed by Cuda (1988),the oddity of the corre- misethat the augmentation methodwould be used.Although lation should not be ignoredfor reason of not being inaccord E. coccineus is native to the southwest, an extensivesurvey with current beliefs. Furthermore, while not assuming that ofinsects associatedwith snakeweed in easternNew Mexico becausethe two factorswere correlated therelationship was and western Texas revealed E. coccineus to be present in necessarilyone of cause and effect, I couldnot rule out that only 3 of 47 (6%) of the surveyed sites (Foster et al. 1981). possibility on the basis of instinctive mental resistance to This may indicatethat E. coccineus is relatively "foreign"to new ideas. snakeweed populations and, therefore, possibly should be In deciding whether a line of researchshould be followed, researched as a classical biological control agent for the one should not be put off it merely because the idea has snakeweeds.In addition, inthose sites in which E. coccineus already beenthought of or tried withoutleading to expected was present its abundance was common.This may indicate results (Beveridge 1957). If, forexample, native snakeweed- thatonce invasioninto snakeweed communites had occurred destroying insectsare being regulatedby density-dependent E.coccineus prospered.This warrants further consideration. natural control factor(s), it may be that their populations Assuming that E. coccineus would be used in an augmen- could be regulated using pheromone "confusion". Finally, tation approach, Cuda (1988) concluded that the financial whilenot encouraging abandonment of the critical attitude cost would be prohibitive compared to traditional herbicide or hasty acceptanceof ideasuntil they have beenwell proved control. Regardless of the approach of any pest control and tried, successful research may include conventional method, "cost" can no longerinclude only monetary values and/ornovel approaches (Beveridge1957). but must now consider environmental and health costs.Even Literature Cited rapidlybiodegradable herbicidesthat have beenused in very large volumes worldwide without causing health problems Beverldge,W.I.B. 1957. TheArt of Scientific Investigation.Random and House, Inc. New York. (Guthrie Perry 1980, Ware 1978), are now suspect of Comments on the health Cuda, J.P. 1988. Viewpoint: proposed use of causing problems. Forexample, theNational Cancer native insects for biological control of snakeweeds. Rangelands 10(6) :262-264.