Cotton Boll Weevil An Evaluation of USDA Programs : a Report (1981) / Chapter Skim
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APPRAISAL OF THE OPM AND BWE TRIALS AND PLANS FOR THEIR BELTWIDE APPLICATION
APPRAISAL OF THE OPM AND BWE TRIALS AND PLANS FOR THEIR BELTWIDE APPLICATION
Pages 58-103
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From page 58... ...
The OPM trial was also unreplicated and so limited in size that in-migration of boll weevils from adjacent areas was clearly detected. There were two criteria used by the USDA for success in the OPM and BWE trials (USDA l98lb)
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From page 59... ...
Since North Carolina and Virginia are at the northern limit of the boll weevil's range and weevil populations in the trial zone had been reduced to extremely low levels by two unusually cold winters immediately before the trial, it would be expected that the APHIS program would reduce boll weevil populations more rapidly in North Carolina and Virginia than could be anticipated elsewhere in a beltwide program. A more vigorous program of population suppression
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From page 60... ...
We found that the BWE trial had provided insufficient data and information to resolve several significant issues. The trial did not provide information useful for boll weevil eradication throughout the Cotton Belt, nor was it designed to do so.
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From page 61... ...
Would these differences affect the eradication program? • Do all weevil populations respond in the same way to pheromone traps?
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From page 62... ...
Furthermore, these insect species might vary from location to location in their ability to develop resistance to insecticides. In summary, considerable heterogeneity exists across the Cotton Belt in terms of the cotton insect complex, environmental characteristics, cotton production practices, current insect management practices, and perhaps in boll weevil populations as well.
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From page 63... ...
Estimates of boll weevil population increases during the season were also obtained through the use of traps. Use of Traps in the BWE Trial Pheromone traps provided useful information during several phases of the BWE trial, thus making it possible to determine boll weevil population levels to a degree of accuracy never before possible.
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From page 64... ...
Insect behaviorists have speculated about variations in the response to pheromone traps of individuals within a single population. If significant variation exists, pheromone traps may exert a selection effect on the boll weevil population for those weevils that are least attracted to the traps.
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From page 65... ...
. Migration and Dispersal of the Boll Weevil A key element of a successful eradication program would be keeping zones freed of boll weevils isolated from zones still infested.
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From page 66... ...
Between September l5 and 24, l980, 9 boll weevils were detected by visual examination of cotton bolls, or by trapping, at the same site. Three of these 9 were inside unopened bolls, with one of them in the pupa stage.
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From page 67... ...
The NRC Committee believes that the USDA's biological evaluation team should have considered various scenarios before concluding that the BWE trial had accomplished its objectives. If the team considered other scenarios for explaining nondetection of weevils in the eradication zone and discarded them as unlikely, it should have discussed its rationale for doing so.
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From page 68... ...
Comments by USDA personnel as to the necessity for a sterile male component in the proposed BWE program were conflicting. Effect of Boll Weevil Eradication on Biological Control of Heliothis Insecticide Use A reduction in future insecticide use has been identified as a major justification for a beltwide eradication program (USDA l98lb)
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From page 69... ...
Host Plant Resistance (HPR) Cotton varieties have a number of morphological and biochemical characteristics that confer measurable resistance to insects, and the beneficial insect complex of parasites and predators tends to moderate pest population levels.
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From page 70... ...
70 TABLE 5.1 Host plant resistance (HPR1 factors and their relative effect on cotton yield and susceptibility to key cotton insect pests. Effect of HPR Factor on Boll Plant weevil Heliothis bugs Pest Species Pink bo ll worm HPR Factor Effect on yield Pubescent Increase - + 0 Glabrous Decrease 0 - + Nectariless Neutral 0 -?
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From page 71... ...
Both the BWE and OPM trials demonstrated better management of beneficial arthropods. Careful management and timing of insecticide applications to control boll weevils reduced insecticide loads.
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From page 72... ...
72 e Cotton Belt divided acres of cotton. The 0 The area within the economic status in 4J CO id •H 0 0 fC o H • 4J o rH CO in o O M 0 (4_j in A f]
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From page 73... ...
Failure would not be instantly recognized in any of these situations, but the net result would be to greatly increase the use of insecticides, accelerate pest resistance to insecticides throughout the Cotton Belt, reduce the role of natural enemies, and increase the probability of secondary pest outbreaks. Biological Consequences of Success Initially, a beltwide boll weevil eradication program would have a large and beneficial effect not only because a key pest of cotton had been eliminated but also because cotton growers would become more knowledgeable about integrated pest management methods.
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From page 74... ...
ECONOMIC CONSIDERATIONS The assignment of the USDA's economic evaluation team was to estimate the market consequences of the successful beltwide implementation of each of the proposed boll weevil eradication and control strategies. Cotton yield increases and the cost reductions expected for specific locations were needed to make these estimates.
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From page 75... ...
For example, extension service personnel believe that additional extension service educational activities and technical assistance would result in improved cotton insect management and higher yields (Economics and Statistics Service l98lb)
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From page 76... ...
£./ Includes producers of soybeans, corn for grains, grain sorghum and small grains. £/ Producers were assumed to pay 50 percent of eradication program costs, exclusive of capital costs and follow-up monitoring.
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From page 77... ...
The NRC Committee believes the pattern of the redistribution estimated by the USDA team is correct, but believes that the extent of the redistribution has been overestimated by USDA. The USDA's economic evaluation does not report the consequences of the sequential reduction in production costs that would occur as the eradication program moved across the boll weevil-infested areas of the Cotton Belt.
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From page 78... ...
• The estimated cost of future eradication operations appears to be only a fraction of the operating costs actually experienced in the BWE trial in North Carolina. • The eradication trial in North Carolina -- conducted after two severe winters had reduced the boll weevil population -- lasted three years but beltwide eradication costs include only two years of program costs.
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From page 79... ...
The NRC Committee therefore urges that an accurate estimate of program costs be developed by an independent agency prior to any USDA request for public funding of a beltwide eradication or management program. ENVIRONMENTAL CONSIDERATIONS The USDA environmental evaluation team report (APHIS l98la)
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From page 80... ...
The estimates were strongly influenced by persons familiar with CIC practices who had limited knowledge of new management techniques being developed in the trials. Similarly, it is unclear how the detailed management program from the OPM and BWE trials can be extrapolated to take account of the diversity of regional pest and crop relationships throughout the Cotton Belt.
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From page 81... ...
Long-Term Impacts on Environmental Quality. An intensive beltwide eradication program would involve a trade-off between the ecological risks of short-term increases in insecticide residues and the long-term benefits of an overall reduction in insecticide use once eradication was achieved.
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From page 82... ...
Unfortunately, systematic data to quantify these effects are scarce, but some idea of the prevalence of insecticide residues in the Cotton Belt can be gained from data provided by the national soil and air monitoring programs of the Environmental Protection Agency shown in Tables 5.3 and 5.4. Heavy use of calcium arsenate in cotton-growing areas has left residues that have persisted for 25 years or more.
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From page 83... ...
83 V f> »H ro iH r*
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From page 85... ...
. The national monitoring program for persistent pesticides in human adipose tissues shows that DDT residues among inhabitants of the Cotton Belt are substantially higher than those of other states (Table 5.6)
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From page 86... ...
. Other insecticides used to control cotton insect pests are also hazardous to environmental quality and human health.
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From page 87... ...
Data provided by the USDA environmental evaluation team from Delphi estimates of the insecticides likely to be used and their application rates in a beltwide eradication program, as well as data on the insecticides used in the OPM and BWE trials, indicate that l5 chemical formulations (and diflubenzuron, which is not included in
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From page 88... ...
. Four insecticides -- dimethoate, endrin, fenvalerate, and sulprofos -- were used in the OPM trial but not in the BWE trial (Table 5.8)
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From page 89... ...
Average number of pounds per acre in the OPM applied area 1978 1979 l980 Acephate l.30-2.00 0.04 Az inopho sme t hyl 0.l6-0.25 0.0l Chloridimeform 0.05 0.03 0.l3-0.25 Chlorpyrifos 0.33-0.50 0.01 -- Dicrotophos 0.l0-0.25 0.09 0.35 0.07 Dimethoate 0.02 0.35 0.07 0.l0-0.20 Endrin 0.0l <0.0 0.27 EPN 0.28 0.38 0.22 0.50-0.75 Fenvalerate 0.03 0.l2 0.ll 0.05-0.20 Met homy 1 0.30-0.45 0.22 0.33 <0.0 Methyl parathion 0.25-l.50 0.28 0.82 2.29 Monocro topho s 0.20-l.00 <0.0l 0.0l 0.02 Permethrin 0.l3 0.03 0.03 0.l0-0.20 Toxaphene l.50-2.00 0.05 0.52 Sulprofos 0.50-l.50 0.07 0.0l SOURCE: Carpenter and Miller (l98la)
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From page 90... ...
Average per number of pounds applied acre in the OPM area l978 l979 l980 Acephate l.30-2.00 < 0.0l < 0.0l Azinophosmethyl 0.l6-0.25 0.08 0.06 Chlori dime form 0.l3-0.25 0.03 0.01 Chlorpyrifos 0.33-0.50 0.0l 0.l4 Dicrotophos 0.l0-0.25 0.ll 0.0l EPN 0.50-0.75 0.06 0.ll Methomyl 0.30-0.45 0.07 0.l2 Methyl parathion 0.25-l.50 0.02 0.7l 0.69 Monocrotophos 0.20-l.0 0.l0 0.0l Permethrin 0.l0-0.20 0.02 0.0l 0.06 Toxaphene l.50-2.00 0.0l 0.72 0.l3 SOURCE: Carpenter and Miller (l98la)
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From page 91... ...
Carhamate Lannate Insect growth regulator Mallard duck Quail 15.9 l5.0 Di f lubenzuron Mallard duck Quail >2000 >5000 Organochlorine Toxaphene Mallard duck Ring-necked pheasant 70.7 Organophosphate Azinophosmethyl 40.0 Mallard duck Ring -necked pheasant 136 74.9 Chlorpyrifos Mallard duck Quail 75.6 l6 Dicrotophos Mallard duck Ring-necked pheasant 4.24 3.2l Dinethoate Mallard duck Wild bird 4l.7 50.7 EPN Mallard duck Ring-necked pheasant 3.08 53.4 Malathion Mallard duck 1485 Methyl parathion Mallard duck Wild bird l0.0 50.7 Monocrotophos Mallard duck Ring-necked pheasant 4.76 2.83 Synthetic pyrethroid Permethrin Mallard duck >4640 Fenvalerate Mallard duck >9932 is defined as the lethal dose to 50 percent of the test population. References for the source of these data are given in Carpenter and Miller (l98la)
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From page 92... ...
Carhamate Lannate Insect growth regulator Diflubenzuron Organochlorine Toxaphene Organopho sphate Azinophosmethyl Chlorpyrifos Dicrotophos Dimethoate EPN Malathion Methyl parathion Azodrin Synthetic pyrethroid Permethrin Fenvalerate Mule deer Rat Rat Mouse Mule deer Mouse Mouse Rat Mouse Rat Mouse Rat Mule deer Rat Mouse Rat Rat Mouse Rat Mouse Mule deer Rat Rat Rat ll-22 27 4640 4640 l39-240 ll2 7.l5 l3 l52 l45 11 16 >200 l52 42 8 l400 886 l2-l6 l8.5 25-50 2l 4l0 45l aLD50 is defined as the lethal dose to 50 percent of the test population. References for the source of these data are given in Carpenter and Miller (l98la)
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From page 93... ...
Car hamate Lannate 24-h Channel catfish 0.92 Insect growth regulator Di f lubenzuron 96-h Channel catfish 370 Di f lubenzuron 96-h Rainbow trout 240 Organochlorine Toxaphene 96-h Pinfish 0.0005 Toxaphene 96-h Fathead minnow 0.0l4 Organophosphate Guthion 96-h Brown trout 0.004 Guthion 96-h Catfish 3.29 Malathion 96-h Bluegill 0.103 Malathion 96-h Catfish 8.97 Methyl parathion 96-h Bluegill l.6 Methyl parathion 96-h Catfish 5.7l Methyl parathion 96-h Crayfish 0.003 Synthetic pyrethroid Permethrin 96-h Bass 0.0085 Permethrin 96-h Channel catfish 0.00ll Permethrin 96-h Crayfish 0.00062 Fenvalerate 24-h Rainbow trout 0.02l is defined as the concentration of insecticide in the water that is lethal to 50 percent of the test population. References for the source of these data are given in Carpenter and Miller (l98la)
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From page 94... ...
. The index yielded a significant environmental impact value for the BWE trial in l979, but subsequently Q was set arbitrarily at zero for l980.
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From page 95... ...
Endangered and Threatened Species The most significant environmental impact of a beltwide boll weevil management program would be the direct and indirect effects of insecticides on non-target organisms. Aquatic biota are clearly the most sensitive, and natural ecological processes would ultimately move and concentrate insecticide residues in streams, rivers, and estuaries of the Cotton Belt.
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From page 97... ...
The fact that year-to-year variations in Q for the same trial exceeded, in most cases, the differences between the trials makes the usefulness of this approach doubtful. Conclusions Beltwide boll weevil/cotton insect management programs would pose a number of potential environmental hazards which were not evaluated in the USDA risk analysis (Economics and Statistics Service l98la)
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From page 98... ...
Erosion potential by soil classification Sedimentation rates in rivers and estuaries Ecological toxicology Toxicity thresholds Toxicology to aquatic resources (also estuarine) Toxicology to terrestrial resources Deleterious effects on natural environment Effects on beneficial insect fauna Regional ecology Biological control alternatives Genetic engineering of cotton varieties Alternative hosts - boll weevil refugia Presence of regional aquatic and terrestrial economic resources Compliance with environmental legislation Clean Air Act Clean Water Act Toxic Substances Control Act
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From page 99... ...
Monitoring of bioaccumulation in biota Monitoring of residues in human adipose tissues Climate Annual rainfall Moisture index Evapotranspiration index Annual temperature Min. annual temperature Max.
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From page 100... ...
of lakes/state Major rivers/estuaries Principal drainage basins Surface water runoff Season's highest streamflow Season's lowest streamflow Water resource regions Suspended sediments Annual turbidity Water quality • Unique resources by Water Resource Region Rare and endangered species Wilderness areas Proposed wilderness areas National forests National parks National wildlife refuges National scenic rivers Research national areas Nature conservancy areas
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From page 101... ...
Beneficial insects and spiders would become more important parts of pest management programs, and aquatic life in streams and rivers (especially in the vicinity of fields heavily sprayed in previous years) should benefit from decreased use.
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From page 102... ...
But in either case, grower acceptance would be much more likely if the program selected for implementation allowed flexibility and individual choice, which are always more acceptable to the American farmer than governmental decrees. The data developed in the OPM and BWE trials clearly show that area programs are more successful in maintaining low boll weevil populations than the "each-grower-do-his-own-thing" approach (CIC)
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From page 103... ...
The state Extension Service had a great deal to do with organization of the Texas Pest Management Association, which, along with private consultants, has been very active in bringing about grower acceptance of crop management practices that will provide the best control of cotton pests. All of these practices are economically sound and lead toward reduced insecticide use.
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