Lincoln, Charles

Phillips, Jacob R.

English

UARK (University of Arkansas )

Journal of the Arkansas Academy of Science Volume 24 Article 24 1970 Impact of Resistance to Pesticides on Cotton Insect Problems in Arkansas Charles Lincoln University of Arkansas, Fayetteville Jacob R. Phillips University of Arkansas, Fayetteville Follow this and additional works at: https://scholarworks.uark.edu/jaas  Part of the Entomology Commons, and the Plant Biology Commons Recommended Citation Lincoln, Charles and Phillips, Jacob R. (1970) "Impact of Resistance to Pesticides on Cotton Insect Problems in Arkansas," Journal of the Arkansas Academy of Science: Vol. 24 , Article 24. Available at: https://scholarworks.uark.edu/jaas/vol24/iss1/24 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu. Charles Lincoln and Jacob R. PhillipsThe Impact of Resistance to Insecticides on CottonInsect Problems in ArkansasCharles Lincoln, Professor and Jacob R. Phillips, Associate ProfessorDept. of Entomology, University of Arkansas, Fayetteville, Arkansas 72701Insecticides have been used for cotton insect controlin Arkansas for 100 years. For the 1st half of thisperiod usage was very light, only occasional applicationsfor cotton leafworm control. Then the boll weevil enteredthe picture. Calcium arsenate was developed for con-trol of this pest but usage was relatively light. 1942was a year of heavy infestation by boll weevil and cot-ton leafworm, and yet only 2 million pounds of insecti-cides were used in Arkansas according to our best esti-mates. This is no more than Vi of an application peracre.In 1945 DDT became available for commercial use,an event awaited with great anticipation. In 1946 a boll-worm outbreak in southwestern Arkansas called for thefirst large scale usage of this miracle insecticide oncotton in the state.DDT was not effective on boll weevil but other chlori-nated hydrocarbons came along soon. A very heavy bollweevil outbreak extending from late 1948 through 1950put these new insecticides to a severe test. Results werespectacular. Partly due to these new insecticides andpartly to changing economic and social conditions, useof insecticides as needed became a standard productionitem. Over the past 20 years an average of 5 to 8 ap-plications of insecticides has been made to about 2/3 ofthe cotton crop. Insect hazards are rather low in north-eastern Arkansas. This results in little insecticide usageon about 1/3 of the Arkansas cotton crop.Insect resistance to insecticides has been recognizedfor half a century. Mosquitoes and houseflies promptlydeveloped resistance to DDT. Even so, it was fondlyhoped that field resistance of our major cotton pestswould not develop for many years, if ever.In 1953 and 1954 cotton aphid populations appear-ed to be resistant to BHC in some locations. We wereshortly too busy on other problems of resistance to pur-sue this and it has never been properly documented.Weather conditions in 1955 were unusually favorablefor boll weevil development and unfavorable for effectiveuse of insecticides. By early August this pest was outof control throughout its normal range in the MississippiPublished with the approval of the Director, Agri-cultural Experiment Station, University of Arkansas.Delta. Persistence and a break in the weather enabledfarmers to bring the boll weevil under control, a trulyspectacular save. In adjacent areas in Louisiana and inthe South Delta of Mississippi farmers were not sofortunate. Runaway infestations persisted.After some hasty lab tests, LSU Entomologists announced in early September, 1955 that some boll weevilpopulations were resistant to BHC and certain otherchlorinated hydrocarbon insecticides.Toxaphene was one of the chlorinated hydrocarbonsto which the boll weevil showed resistance in 1955. Asstated earlier, DDT is ineffective at normal field dosagesen boll weevil. Mixtures of toxaphene and DDT provedto be effective on toxaphene-resistant boll weevils, al-though they were no more effective than straight toxa-phene on susceptible weevils.DDT afforded the 1st effective insecticidal control ofthe cotton bollworm, Heliothis zea. In the 40's controlwas spectacular with i/2 Ib/A. By the late 50's controlwas acceptable with 1 Ib/A. This pest went out of con-trol in the Russellville-Dardanelle area in August, 1961.Some time was bought with mixtures of chlorinated hy-drocarbon insecticides and the resistance level was highly variable from one population to another.Organophosphorous insecticides became popular inthe late 50's because of their effectiveness in controllingboll weevil, aphid, and spider mites. At high dosagesthey came into common use for bollworm control.Resistance to an organophosphorous insecticide,methyl parathion, interfered with bollworm control inJackson county in 1969. This had been predicted fromearlier lab work, from problems of control in CentralAmerica, and from problems with a related species, thetobacco budworm.Carbaryl or Sevin is a carbamate insecticide, repre-senting another chemical grouping. Like the organoph-osphorous insecticides it is a cholinesterase inhibitor.In a few years low-level resistance in bollworm has de-veloped.Several caterpillars that are sometimes pest of cot-ton appear to represent cases of non-target species beingselected for resistance. These include tobacco budworm,cabbage looper, and beet armyworm. Spider mites arereadily selected for resistance. In cotton fields in Arkan-sas resistance to organophosphorous insecticides has de-Arkansas Academy of Science Proceedings, Vol. XXIV, 197066Journal of the Arkansas Academy of Science, Vol. 24 [1970], Art. 24Published by Arkansas Academy of Science, 1970loped, apparently another case of a non-target organ-km being selected for resistance.After 25 years of heavy insecticide usage on cottonL Arkansas, several pest insects and mites have deve-Lped resistance to the 3 principal groups of insecticides.,nclmiticides: the chlorinated hydrocarbons, the organ-phosphorous compounds, and the carbamates.The first reaction of the farmer to resistance is toincrease the dosage and frequency of insecticide appli-cation. During the brief period that this approach ispartially effective, it exaggerates the problem of environ-mental contamination.I Cotton is in dire straits economically. Every effortis being made to reduced the cost of production. Butthe resistance problem adds to the cost of production.Cotton insects are the subject of this presentation, butthe situation is similar for many of our food and feedcrops. Furthermore, a pest species may develop a highlevel of resistance from exposure to insecticides on cot-ton, making it difficult to control on other crops. Exam-ples include cabbage looper on greens crops and boll-worm on soybeans.It is neither cheap nor easy to discover new chemi-cal groupings that willcontrol insects and meet accept-able standards of safety and economics. Several yearsand millions of dollars are required to carry out the re-search to serve as the basis for registration. Prospectsare so discouraging that at least 4 major companieshave closed their primary synthesis and screening lab-oratories in the past 3 years.It appears unlikely that new insecticides can be syn-thesized and developed rapidly enough to offset the pre-sent rate of obsolescence of insecticides through re-sistance. More realistic requirements on registration ofnew insecticides would help, but would not solve theproblem. Biological insecticides (bacteria, viruses, etc.)are under more stringent registration restrictions thanare chemical insecticides.There are many exciting possibilities of insect con-trol that do not depend upon conventional insecticides.There are only a few proven successes to date. To ade-quately implement these new approaches in terms ofpractical insect control will require many years, tre-mendous investments in research, and a high level ofcooperation by many disciplines of the biological andphysical sciences.SUMMARYIn 25 years of heavy insecticide usage on cotton inArkansas, resistance has become a problem with severalpest insects and mites to the 3 principal groups of in-secticides and miticides: the chlornated hydrocarbons,the organophosphorns compounds, and the carbamates.Development of control measures, chemical or other-wise, is not proceeding at a sufficiently rapid pace tostay ahead of the problem posed by insect resistanceto insecticides.ARoad-Kill Census ofMammals inNortheastern ArkansasJ. W. Ed Wortham' and Earl L. HanebrinkBox 67, Arkansas State University, State University, Arkansas 72767INTRODUCTIONIIt is the purpose of this study to investigate speciesiposition and numbers of mammals killed on selectediways in northeastern Arkansas. Roadside counts haven used by wildlife personnel to determine populationces for areas under study for a wide variety of gamecies. Hendrickson (1939) was the first to describeroadside census as an inventory method for rabbits,ht (1959) used roadside counts to estimate state-s rabbit population trends in Missouri. Regulardetermined highway routes were driven in an auto-Jile at a prescribed time of day and rabbits werented per mile. Lord (1955, 1961) used the roadsideK(l)Present address: Dept. of Zoology, Southern Illi-Univ., Carbondale, III.census method to count rabbits in Illinois and madecomparisons of censuses taken during early morning andnight. Newman (1959) reported on weather factors in-fluencing the roadside counts of cottontail rabbits.Ornithologists have used the roadside census tech-nique for many years. Nice and Nice (1921) used thismethod to study Oklahoma bird populations as early as1920. Since their pioneer studies, this technique hasbeen used by a number of research workers. Kendeigh(1944) evaluated the roadside census in relation to othertypes of censuses used in studying birds. Dice (1938,1952) thoroughly discussed and compared numerouscensus methods. Howell (1951) made detailed studiesusing relative conspicuousness in determining bird num-bers along roadsides in Tennessee. The roadside censusis used as a method of determining relative abundanceand not absolute abundance. Variability of roadside cen-Arkansas Academy of Science Proceedings, Vol. XXIV,197067Journal of the Arkansas Academy of Science, Vol. 24 [1970], Art. 24https://scholarworks.uark.edu/jaas/vol24/iss1/24

Impact of Resistance to Pesticides on Cotton Insect Problems in Arkansas

ScholarWorks@UARK

Journal of the Arkansas Academy of ScienceVolume 24 Article 241970Impact of Resistance to Pesticides on Cotton InsectProblems in ArkansasCharles LincolnUniversity of Arkansas, FayettevilleJacob R. PhillipsUniversity of Arkansas, FayettevilleFollow this and additional works at: http://scholarworks.uark.edu/jaasPart of the Entomology Commons, and the Plant Biology CommonsThis article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able toread, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking priorpermission from the publisher or the author.This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academyof Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu, ccmiddle@uark.edu.Recommended CitationLincoln, Charles and Phillips, Jacob R. (1970) "Impact of Resistance to Pesticides on Cotton Insect Problems in Arkansas," Journal ofthe Arkansas Academy of Science: Vol. 24 , Article 24.Available at: http://scholarworks.uark.edu/jaas/vol24/iss1/24Charles Lincoln and Jacob R. PhillipsThe Impact of Resistance to Insecticides on CottonInsect Problems in ArkansasCharles Lincoln, Professor and Jacob R. Phillips, Associate ProfessorDept. of Entomology, University of Arkansas, Fayetteville, Arkansas 72701Insecticides have been used for cotton insect controlin Arkansas for 100 years. For the 1st half of thisperiod usage was very light, only occasional applicationsfor cotton leafworm control. Then the boll weevil enteredthe picture. Calcium arsenate was developed for con-trol of this pest but usage was relatively light. 1942was a year of heavy infestation by boll weevil and cot-ton leafworm, and yet only 2 million pounds of insecti-cides were used in Arkansas according to our best esti-mates. This is no more than Vi of an application peracre.In 1945 DDT became available for commercial use,an event awaited with great anticipation. In 1946 a boll-worm outbreak in southwestern Arkansas called for thefirst large scale usage of this miracle insecticide oncotton in the state.DDT was not effective on boll weevil but other chlori-nated hydrocarbons came along soon. A very heavy bollweevil outbreak extending from late 1948 through 1950put these new insecticides to a severe test. Results werespectacular. Partly due to these new insecticides andpartly to changing economic and social conditions, useof insecticides as needed became a standard productionitem. Over the past 20 years an average of 5 to 8 ap-plications of insecticides has been made to about 2/3 ofthe cotton crop. Insect hazards are rather low in north-eastern Arkansas. This results in little insecticide usageon about 1/3 of the Arkansas cotton crop.Insect resistance to insecticides has been recognizedfor half a century. Mosquitoes and houseflies promptlydeveloped resistance to DDT. Even so, it was fondlyhoped that field resistance of our major cotton pestswould not develop for many years, if ever.In 1953 and 1954 cotton aphid populations appear-ed to be resistant to BHC in some locations. We wereshortly too busy on other problems of resistance to pur-sue this and it has never been properly documented.Weather conditions in 1955 were unusually favorablefor boll weevil development and unfavorable for effectiveuse of insecticides. By early August this pest was outof control throughout its normal range in the MississippiPublished with the approval of the Director, Agri-cultural Experiment Station, University of Arkansas.Delta. Persistence and a break in the weather enabledfarmers to bring the boll weevil under control, a trulyspectacular save. In adjacent areas in Louisiana and inthe South Delta of Mississippi farmers were not sofortunate. Runaway infestations persisted.After some hasty lab tests, LSU Entomologists announced in early September, 1955 that some boll weevilpopulations were resistant to BHC and certain otherchlorinated hydrocarbon insecticides.Toxaphene was one of the chlorinated hydrocarbonsto which the boll weevil showed resistance in 1955. Asstated earlier, DDT is ineffective at normal field dosagesen boll weevil. Mixtures of toxaphene and DDT provedto be effective on toxaphene-resistant boll weevils, al-though they were no more effective than straight toxa-phene on susceptible weevils.DDT afforded the 1st effective insecticidal control ofthe cotton bollworm, Heliothis zea. In the 40's controlwas spectacular with i/2 Ib/A. By the late 50's controlwas acceptable with 1 Ib/A. This pest went out of con-trol in the Russellville-Dardanelle area in August, 1961.Some time was bought with mixtures of chlorinated hy-drocarbon insecticides and the resistance level was highly variable from one population to another.Organophosphorous insecticides became popular inthe late 50's because of their effectiveness in controllingboll weevil, aphid, and spider mites. At high dosagesthey came into common use for bollworm control.Resistance to an organophosphorous insecticide,methyl parathion, interfered with bollworm control inJackson county in 1969. This had been predicted fromearlier lab work, from problems of control in CentralAmerica, and from problems with a related species, thetobacco budworm.Carbaryl or Sevin is a carbamate insecticide, repre-senting another chemical grouping. Like the organoph-osphorous insecticides it is a cholinesterase inhibitor.In a few years low-level resistance in bollworm has de-veloped.Several caterpillars that are sometimes pest of cot-ton appear to represent cases of non-target species beingselected for resistance. These include tobacco budworm,cabbage looper, and beet armyworm. Spider mites arereadily selected for resistance. In cotton fields in Arkan-sas resistance to organophosphorous insecticides has de-Arkansas Academy of Science Proceedings, Vol. XXIV, 197066Journal of the Arkansas Academy of Science, Vol. 24 [1970], Art. 24Published by Arkansas Academy of Science, 1970loped, apparently another case of a non-target organ-km being selected for resistance.After 25 years of heavy insecticide usage on cottonL Arkansas, several pest insects and mites have deve-Lped resistance to the 3 principal groups of insecticides.,nclmiticides: the chlorinated hydrocarbons, the organ-phosphorous compounds, and the carbamates.The first reaction of the farmer to resistance is toincrease the dosage and frequency of insecticide appli-cation. During the brief period that this approach ispartially effective, it exaggerates the problem of environ-mental contamination.I Cotton is in dire straits economically. Every effortis being made to reduced the cost of production. Butthe resistance problem adds to the cost of production.Cotton insects are the subject of this presentation, butthe situation is similar for many of our food and feedcrops. Furthermore, a pest species may develop a highlevel of resistance from exposure to insecticides on cot-ton, making it difficult to control on other crops. Exam-ples include cabbage looper on greens crops and boll-worm on soybeans.It is neither cheap nor easy to discover new chemi-cal groupings that willcontrol insects and meet accept-able standards of safety and economics. Several yearsand millions of dollars are required to carry out the re-search to serve as the basis for registration. Prospectsare so discouraging that at least 4 major companieshave closed their primary synthesis and screening lab-oratories in the past 3 years.It appears unlikely that new insecticides can be syn-thesized and developed rapidly enough to offset the pre-sent rate of obsolescence of insecticides through re-sistance. More realistic requirements on registration ofnew insecticides would help, but would not solve theproblem. Biological insecticides (bacteria, viruses, etc.)are under more stringent registration restrictions thanare chemical insecticides.There are many exciting possibilities of insect con-trol that do not depend upon conventional insecticides.There are only a few proven successes to date. To ade-quately implement these new approaches in terms ofpractical insect control will require many years, tre-mendous investments in research, and a high level ofcooperation by many disciplines of the biological andphysical sciences.SUMMARYIn 25 years of heavy insecticide usage on cotton inArkansas, resistance has become a problem with severalpest insects and mites to the 3 principal groups of in-secticides and miticides: the chlornated hydrocarbons,the organophosphorns compounds, and the carbamates.Development of control measures, chemical or other-wise, is not proceeding at a sufficiently rapid pace tostay ahead of the problem posed by insect resistanceto insecticides.ARoad-Kill Census ofMammals inNortheastern ArkansasJ. W. Ed Wortham' and Earl L. HanebrinkBox 67, Arkansas State University, State University, Arkansas 72767INTRODUCTIONIIt is the purpose of this study to investigate speciesiposition and numbers of mammals killed on selectediways in northeastern Arkansas. Roadside counts haven used by wildlife personnel to determine populationces for areas under study for a wide variety of gamecies. Hendrickson (1939) was the first to describeroadside census as an inventory method for rabbits,ht (1959) used roadside counts to estimate state-s rabbit population trends in Missouri. Regulardetermined highway routes were driven in an auto-Jile at a prescribed time of day and rabbits werented per mile. Lord (1955, 1961) used the roadsideK(l)Present address: Dept. of Zoology, Southern Illi-Univ., Carbondale, III.census method to count rabbits in Illinois and madecomparisons of censuses taken during early morning andnight. Newman (1959) reported on weather factors in-fluencing the roadside counts of cottontail rabbits.Ornithologists have used the roadside census tech-nique for many years. Nice and Nice (1921) used thismethod to study Oklahoma bird populations as early as1920. Since their pioneer studies, this technique hasbeen used by a number of research workers. Kendeigh(1944) evaluated the roadside census in relation to othertypes of censuses used in studying birds. Dice (1938,1952) thoroughly discussed and compared numerouscensus methods. Howell (1951) made detailed studiesusing relative conspicuousness in determining bird num-bers along roadsides in Tennessee. The roadside censusis used as a method of determining relative abundanceand not absolute abundance. Variability of roadside cen-Arkansas Academy of Science Proceedings, Vol. XXIV,197067Journal of the Arkansas Academy of Science, Vol. 24 [1970], Art. 24http://scholarworks.uark.edu/jaas/vol24/iss1/24

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Impact of Resistance to Pesticides on Cotton Insect Problems in Arkansas

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