Comparisons Between Resistance Management Strategies for Insects and Weeds

1995 ◽  
Vol 9 (4) ◽  
pp. 830-839 ◽  
Author(s):  
Fred Gould
Keyword(s):  
Population Structure ◽  
Insecticide Resistance ◽  
Herbicide Resistance ◽  
Management Strategies ◽  
Resistance Management ◽  
Basic Research ◽  
Resistance Literature ◽  
Resistance Evolution ◽  
The Commons ◽  
Structure Lead

Problems with insecticide resistance have long plagued the field of economic entomology. Genetic, biochemical, and ecological information on insects has been used to develop strategies to slow the rate of insecticide resistance evolution. Documented cases of herbicide resistance have increased dramatically over the past 10 yr. This paper compares some aspects of insect and weed biology that can be used in determining whether or not resistance management strategies developed for insects are likely to be useful in combating herbicide resistance. Differences between insects and weeds in terms of genetic architecture, mating systems, and population structure lead to differences in the expected efficacy of some resistance management strategies. Because of the localized population structure of some weeds, it may be easier to get farmers to participate in herbicide resistance management programs and avoid a “tragedy of the commons.” A review of the herbicide resistance literature reveals a number of areas of basic research on ecology and genetics of weeds that could help in designing more appropriate resistance management programs.

scholarly journals Mixtures as a Fungicide Resistance Management Tactic

2014 ◽  
Vol 104 (12) ◽  
pp. 1264-1273 ◽  
Author(s):  
Frank van den Bosch ◽  
Neil Paveley ◽  
Femke van den Berg ◽  
Peter Hobbelen ◽  
Richard Oliver
Keyword(s):  
At Risk ◽  
Disease Control ◽  
Fungicide Resistance ◽  
Management Strategies ◽  
Resistance Management ◽  
Relative Effect ◽  
Resistance Evolution ◽  
Modes Of Action ◽  
Selection For ◽  
Effective Life

We have reviewed the experimental and modeling evidence on the use of mixtures of fungicides of differing modes of action as a resistance management tactic. The evidence supports the following conclusions. 1. Adding a mixing partner to a fungicide that is at-risk of resistance (without lowering the dose of the at-risk fungicide) reduces the rate of selection for fungicide resistance. This holds for the use of mixing partner fungicides that have either multi-site or single-site modes of action. The resulting predicted increase in the effective life of the at-risk fungicide can be large enough to be of practical relevance. The more effective the mixing partner (due to inherent activity and/or dose), the larger the reduction in selection and the larger the increase in effective life of the at-risk fungicide. 2. Adding a mixing partner while lowering the dose of the at-risk fungicide reduces the selection for fungicide resistance, without compromising effective disease control. The very few studies existing suggest that the reduction in selection is more sensitive to lowering the dose of the at-risk fungicide than to increasing the dose of the mixing partner. 3. Although there are very few studies, the existing evidence suggests that mixing two at-risk fungicides is also a useful resistance management tactic. The aspects that have received too little attention to draw generic conclusions about the effectiveness of fungicide mixtures as resistance management strategies are as follows: (i) the relative effect of the dose of the two mixing partners on selection for fungicide resistance, (ii) the effect of mixing on the effective life of a fungicide (the time from introduction of the fungicide mode of action to the time point where the fungicide can no longer maintain effective disease control), (iii) polygenically determined resistance, (iv) mixtures of two at-risk fungicides, (v) the emergence phase of resistance evolution and the effects of mixtures during this phase, and (vi) monocyclic diseases and nonfoliar diseases. The lack of studies on these aspects of mixture use of fungicides should be a warning against overinterpreting the findings in this review.

Identification of a point mutation in the ace1 gene of Therioaphis trifolli maculata and detection of insecticide resistance by a diagnostic PCR–RFLP assay

2015 ◽  
Vol 105 (6) ◽  
pp. 712-716
Author(s):  
E. AlSuhaibani ◽  
C.C. Voudouris ◽  
R. Al-Atiyat ◽  
A. Kotzamumin ◽  
J. Vontas ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Insecticide Resistance ◽  
Management Strategies ◽  
Resistance Management ◽  
Resistance Mutation ◽  
Resistance Mechanisms ◽  
Effective Control ◽  
Agricultural Pests ◽  
Resistance Mutations ◽  
Diagnostic Pcr

AbstractAphids are important agricultural pests worldwide. Their control is largely based on chemical insecticides. One species that shows important invasive abilities and host-plant-related differences is Therioaphis trifolii (Monell) (Hemiptera: Aphididae). T. trifolii maculata, also known as spotted alfalfa aphid (SAA), can be very injurious to alfalfa crops in certain regions, such as in Saudi Arabia for effective control it is essential to diagnose and monitor the resistance mechanisms in the SAA populations. In the present study, we analysed acetylcholinesterase (ace) target site insensitivity mechanisms. A 650 bp length DNA containing the putative acetylcholinesterase (ace1) precursor was obtained and compared with other Hemipteran species. The sequences of many individual aphids collected from alfalfa crops in Saudi Arabia were analysed for the presence of resistance mutations: no resistance mutations were found at the resistance mutation loci 302; however, the presence of a serine–phenylalanine substitution (S431F) was identified in one individual. The S431F substitution, has been shown to confer significant levels of both organophosphate and carbamate resistance in other aphid species, and is now found for the first time in T. trifolii. We subsequently developed a simple polymerase chain reaction–restriction fragment length polymorphism assays for the S431F mutation, using a TaqI restriction site destroyed by the S431F mutation. The novel diagnostic assay may support the implementation of Insecticide Resistance Management strategies, for the control of SAA in alfalfa crops in the Kingdom of Saudi Arabia, and other countries worldwide.

The effects of local selection versus dispersal on insecticide resistance patterns: longitudinal evidence from diamondback moth (Plutella xylostella (Lepidoptera: Plutellidae)) in Australia evolving resistance to pyrethroids

2008 ◽  
Vol 98 (2) ◽  
pp. 145-157 ◽  
Author(s):  
N.M. Endersby ◽  
P.M. Ridland ◽  
A.A. Hoffmann
Keyword(s):  
Gene Flow ◽  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Management Strategies ◽  
Resistance Management ◽  
Synthetic Pyrethroids ◽  
Forage Crops ◽  
Microsatellite Variation ◽  
Resistance Evolution ◽  
Local Selection

AbstractWhen strong directional selection acts on a trait, the spatial distribution of phenotypes may reflect effects of selection, as well as the spread of favoured genotypes by gene flow. Here we investigate the relative impact of these factors by assessing resistance to synthetic pyrethroids in a 12-year study of diamondback moth, Plutella xylostella, from southern Australia. We estimated resistance levels in populations from brassicaceous weeds, canola, forage crops and vegetables. Differences in resistance among local populations sampled repeatedly were stable over several years. Levels were lowest in samples from weeds and highest in vegetables. Resistance in canola samples increased over time as insecticide use increased. There was no evidence that selection in one area influenced resistance in adjacent areas. Microsatellite variation from 13 populations showed a low level of genetic variation among populations, with an AMOVA indicating that population only accounted for 0.25% of the molecular variation. This compared to an estimate of 13.8% of variation accounted for by the resistance trait. Results suggest that local selection rather than gene flow of resistance alleles dictated variation in resistance across populations. Therefore, regional resistance management strategies may not limit resistance evolution.

Evidence for resistance to pyrethroids and organophosphates inPlutella xylostella(Lepidoptera: Plutellidae) from Pakistan

2007 ◽  
Vol 97 (2) ◽  
pp. 191-200 ◽  
Author(s):  
A. Khaliq ◽  
M.N.R. Attique ◽  
A.H. Sayyed
Keyword(s):  
Insecticide Resistance ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Plutella Xylostella ◽  
Management Strategies ◽  
Resistance Management ◽  
Resistance Mechanisms ◽  
Laboratory Population ◽  
Multiple Resistance ◽  
Low Toxicity

AbstractThe susceptibility of representative pyrethroid (cypermethrin, deltamethrin, lambdacyhalothrin, bifenthrin), organophosphate (chlorpyriphos, triazophos, profenophos) and new chemistry insecticides (spinosad, indoxacarb and emamectin) was investigated for 18 field populations ofPlutella xylostella(Linnaeus) from three different zones in Pakistan. The LC50(mg ml−1; 48 h) values of pyrethroids for various populations ranged from 0.19–1.88 for cypermethrin, 0.31–2.64 for deltamethrin, 0.08–1.16 for lambdacyhalothrin and 0.07–0.88 for bifenthrin. The LC50(mg ml−1; 48 h) of organophosphates ranged from 0.52–5.67 for chlorpyriphos, 0.37–4.14 for triazophos and 0.03–2.65 for profenophos. The most probable reason for low toxicity of organophosphates and pyrethroids is the evolution of multiple resistance mechanisms; however, further studies are required to establish these mechanisms. When these same products were tested against a susceptible laboratory population (Lab-Pak), the new chemistry compounds were significantly more toxic than pyrethroids and organophosphates. The results are discussed in relation to integrated pest management and insecticide resistance management strategies forP. xylostella.

Modeling Glyphosate Resistance Management Strategies for Palmer Amaranth (Amaranthus palmeri) in Cotton

2011 ◽  
Vol 25 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Paul Neve ◽  
Jason K. Norsworthy ◽  
Kenneth L. Smith ◽  
Ian A. Zelaya
Keyword(s):  
Weed Management ◽  
Management Strategies ◽  
Resistance Management ◽  
Glyphosate Resistance ◽  
Palmer Amaranth ◽  
Case Scenario ◽  
Management Options ◽  
Worst Case ◽  
Resistance Risk ◽  
Resistance Evolution

A simulation model is used to explore management options to mitigate risks of glyphosate resistance evolution in Palmer amaranth in glyphosate-resistant cotton in the southern United States. Our first analysis compares risks of glyphosate resistance evolution for seven weed-management strategies in continuous glyphosate-resistant cotton monoculture. In the “worst-case scenario” with five applications of glyphosate each year and no other herbicides applied, evolution of glyphosate resistance was predicted in 74% of simulated populations. In other strategies, glyphosate was applied with various combinations of preplant, PRE, and POST residual herbicides. The most effective strategy included four glyphosate applications with a preplant fomesafen application, and POST tank mixtures of glyphosate plusS-metolachlor followed by glyphosate plus flumioxazin. This strategy reduced the resistance risk to 12% of populations. A second series of simulations compared strategies where glyphosate-resistant cotton was grown in one-to-one rotations with corn or cotton with other herbicide resistance traits. In general, crop rotation reduced risks of resistance by approximately 50% and delayed the evolution of resistance by 2 to 3 yr. These analyses demonstrate that risks of glyphosate resistance evolution in Palmer amaranth can be reduced by reducing glyphosate use within and among years, controlling populations with diverse herbicide modes of action, and ensuring that population size is kept low. However, no strategy completely eliminated the risk of glyphosate resistance.

scholarly journals Within-host dynamics explain patterns of antibiotic resistance in commensal bacteria

2017 ◽  
Author(s):  
Nicholas G. Davies ◽  
Stefan Flasche ◽  
Mark Jit ◽  
Katherine E. Atkins
Keyword(s):  
Antibiotic Resistance ◽  
Management Strategies ◽  
Resistance Management ◽  
Population Level ◽  
Antibiotic Consumption ◽  
Mathematical Framework ◽  
Host Immune Responses ◽  
Resistance Evolution ◽  
Resistant Strains ◽  
The Impact

The spread of antibiotic resistance, a major threat to human health, is poorly understood. Empirically, resistant strains gradually increase in prevalence as antibiotic consumption increases, but current mathematical models predict a sharp transition between full sensitivity and full resistance. In other words, we do not understand what drives persistent coexistence between resistant and sensitive strains of disease-causing bacteria in host populations. Without knowing what drives patterns of resistance, we cannot accurately predict the impact of potential strategies for managing resistance. Here, we show that within-host dynamics—bacterial growth, strain competition, and host immune responses—promote frequency-dependent selection for resistant strains, explaining patterns of resistance at the population level. By capturing these processes in a parsimonious mathematical framework, we resolve a long-standing conflict between theory and observation. Our models capture widespread coexistence for multiple bacteria-drug combinations across 30 European countries and explain associations between carriage prevalence and resistance prevalence among bacterial subtypes. A mechanistic understanding of resistance evolution is needed to accurately forecast the impact and effectiveness of resistance-management strategies.

scholarly journals Widespread Report of Multiple Insecticide Resistance in Anopheles gambiae s.l. Mos-quitoes in Eight Communities in Southern Gombe, North-Eastern Nigeria

2019 ◽  
Author(s):  
Adedayo Olatunbosun-Oduola ◽  
Ezra Abba ◽  
Olukayode Adelaja ◽  
Adeolu Taiwo-Ande ◽  
Kennedy Poloma-Yoriyo ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Gambiae ◽  
Management Strategies ◽  
Resistance Management ◽  
Current Control ◽  
Control Programs ◽  
Anopheles Mosquitoes ◽  
Exposed Population ◽  
Pirimiphos Methyl ◽  
Anopheles Gambiae S.L

Background: Timely entomological and insecticide resistance monitoring is a key to generating relevant data for vector management. We investigated the insecticide susceptibility status of Anopheles gambiae s.l. in eight rural farming communities in Southern Gombe, Nigeria. Methods: Overall, 3–5 days-old adult female Anopheles mosquitoes reared from field-collected immature stages between September and November, 2014 were exposed to the diagnostic doses of pyrethroids, organophosphate and carbamate insecticides using the Center for Disease Control Bottle bioassay. The observatory knockdown time from exposure to each insecticide was recorded up to two hours. The dead mosquitoes were then identified morphological­ly and by molecular assays. Results: Mortality results showed resistance in An. gambiae s.l. populations to bendiocarb (2.3–100%), deltamethrin (39–70%), pirimiphos-methyl (65–95%), dichloro-diphenyl-trichloroethane (0–38.1%), permethrin (0–46.3%) and lambda-cyhalothrin (42.5–86.4%). The few cases of full susceptibility were observed from lamdacyhalothrin exposed population of An. gambiae s.l. in Banbam and Pantami respectively. An. gambiae 177 (45%) was significantly higher (P< 0.05) than An. arabiensis 64 (16.3%), An. coluzzii 34 (8.7%) and An. gambiae/An. coluzzii hybrid 78 (19.8%). Conclusion: A strong evidence of widespread resistance in the major malaria vector species in Southern Gombe to all common classes of insecticides is a justification for the State Malaria Elimination Programme to consciously con­sider incorporating insecticide resistance management strategies into control programs in order to sustain the future of current control interventions

Genetic Aspects of Herbicide-Resistant Weed Management

1999 ◽  
Vol 13 (3) ◽  
pp. 647-652 ◽  
Author(s):  
Michael J. Christoffers
Keyword(s):  
Herbicide Resistance ◽  
Weed Management ◽  
Selection Pressure ◽  
Management Strategies ◽  
Resistance Management ◽  
Wild Type ◽  
Frequency Increase ◽  
Specific Nature ◽  
Herbicide Resistant ◽  
Case Basis

Weed populations develop herbicide resistance when they evolve due to selection pressure. Mutations and gene flow contribute to genetic variability and provide resistant alleles. The speed of resistance gene frequency increase is determined by the inheritance of resistance alleles relative to wild-type susceptibility and is influenced by the interaction between gene expression and selection. The goal of herbicide resistance management is to minimize selection pressure while maintaining adequate weed control. However, the specific nature of each herbicide, weed, and resistance combination determines the practices that optimize undesirable selection pressure. Therefore, generalized management strategies should be recommended with caution and must not be mandated without thorough evaluation on a case-by-case basis.

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