Evaluation of Resistance Management for the Oriental Fruit Moth (Lepidoptera: Tortricidae) to Insecticides in Brazilian Apple Orchards

2020 ◽  
Vol 113 (3) ◽  
pp. 1411-1418
Author(s):  
Lino Bittencourt Monteiro ◽  
Luis Gustavo Witt ◽  
Izonete Cristina Guiloski ◽  
Regis Silvori Silva dos Santos ◽  
Helena C Silva de Assis

Abstract The oriental fruit moth, Grapholita molesta (Busk, 1916), is one of the most important pests in apple orchards in southern Brazil. Chemical control is still the most commonly used strategy for pest control. The aim of this study was to determine the resistance evolution of seven South Brazilian populations to four insecticides (chlorantraniliprole, lufenuron, chlorpyrifos, and fenitrothion). Bioassays were paired with metabolic analyses of glutathione-S-transferase (GST), carboxylesterases (α-NA and β-NA), and acetylcholinesterase (AChE) to understand the possible role with phytosanitary strategies in the insects’ susceptibility. Insect populations were collected in the municipalities of Campo do Tenente, Lapa and Porto Amazonas, Fraiburgo, São Joaquim, and Vacaria and multiplied in the laboratory. Two susceptible and two resistant populations were used as references. The bioassays showed that five populations were considered more resistant to organophosphates, six to lufenuron and two to chlorantraniliprole when compared with the sensitive population. None of the field populations had greater resistance than the resistant laboratory population. The enzymatic activity of AChE and GST was elevated in most of the populations that were less susceptible to organophosphates and lufenuron. The populations originating from orchards that used sexual confusion techniques had the greatest susceptibility based on toxicological and biochemical bioassays. Populations under pressure from various compounds had high GST, α and β-NA activity. There is evidence that a diversity of control strategies can provide better resistance management.

2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Lino Bittencourt Monteiro ◽  
Rosangela Teixeira ◽  
Izonete Cristina Guiloski ◽  
Edson Chappuis ◽  
Helena Cristina da Silva de Assis

Abstract Oriental fruit moth (Grapholita molesta) is the most important pest of apple orchards in Brazil. For many years, insecticides have been the only tool used for its control. The aim of this work was to characterize the management of apple orchards by the system for Assessment of Environment Impact of Agricultural Technology Innovations (AMBITEC-AGRO) and to relate it with the resistance status of G. molesta populations. Insecticide resistance was estimated by toxicology and enzymatic activities of glutathione S-transferase (GST), esterases (a-ß EST), and acetylcholinesterase (AChE). The phytosanitary strategies adopted by the four apple production orchards in southern Brazil were analyzed in: Vacaria (RS population), Fraiburgo (SC1 population), São Joaquim (SC2 population), and Porto Amazonas (PR population). Oriental fruit moth field populations were reared in laboratory for bioassays with chlorpyriphos, carbaryl, deltamethrin, and tebufenozide insecticides and were compared with a reference susceptible population. Larval mortality rates were recorded for seven days. GST, a-ß EST, and AChE assays were performed with third- and fourth-instar larvae. Results indicated that oriental fruit moth populations collected in Vacaria, Fraiburgo, and São Joaquim showed tolerance to carbaryl and chlorpyriphos, whereas the population collected in Porto Amazonas was more susceptible. SC2 and PR populations were more tolerant to deltamethrin, while RS and SC1 populations were more susceptible. No population was tolerant to tebufenozide. RS population showed the highest activity for AChE, GST, and a-EST. The findings of this study suggest that the AMBITEC-AGRO system was a suitable method to evaluate the phytosanitary activity of apple orchards and to relate it to the resistance status of G. molesta populations.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 559
Author(s):  
Lambert H. B. Kanga ◽  
Walker Marechal ◽  
Anthony Ananga

The small hive beetle (Aethina tumida Murray) is a serious threat to beekeeping and crops that rely on honeybees for pollination. The small hive beetle not only causes significant damage to honeybees by feeding on pollen and honey, attacking bee brood and causing stored honey to ferment, but also might serve as a vector of diseases. In addition, the small hive beetle has developed resistance to the pyrethroid and organophosphate insecticides registered for control of honeybee pests in the United States. The development of resistance in small hive beetle populations is a great concern to the beekeeping industry; thus, there is an urgent need for strategies to manage that resistance. Therefore, we used synergist probes to determine the mechanisms of resistance in a small hive beetle population to these insecticides. Our studies on the toxicity of insecticides alone or with the synergists piperonyl butoxide (PBO) and S,S,S,-tributyl phosphorotrithionate (DEF) suggested that mixed-function oxidases and esterases were the major resistance factors to these insecticides in a studied population of the small hive beetle. In contrast, there was no synergism with diethyl maleate (DEM), triphenyl phosphate (TPP) and formamidine. Therefore, glutathione-S-transferase, carboxylesterase and target site were not involved in insecticide resistance in the small hive beetle. Rotation of classes of insecticides (with different modes of action) and metabolic synergists were suggested for the development of successful resistance management programs. To the best of our knowledge, this is the first study of the mechanisms of resistance in small hive beetle populations in Florida and suggests an urgent need for alternative control strategies for these serious pests of honeybee colonies.


Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 645 ◽  
Author(s):  
Magellan Tchouakui ◽  
Jacob M. Riveron ◽  
Doumani Djonabaye ◽  
Williams Tchapga ◽  
Helen Irving ◽  
...  

Metabolic resistance to insecticides threatens malaria control. However, little is known about its fitness cost in field populations of malaria vectors, thus limiting the design of suitable resistance management strategies. Here, we assessed the association between the glutathione S-transferase GSTe2-mediated metabolic resistance and life-traits of natural populations of Anopheles funestus. A total of 1200 indoor resting blood-fed female An. funestus (F0) were collected in Mibellon, Cameroon (2016/2017), and allowed to lay eggs individually. Genotyping of F1 mosquitoes for the L119F-GSTE2 mutation revealed that L/L119-homozygote susceptible (SS) mosquitoes significantly laid more eggs than heterozygotes L119F-RS (odds ratio (OR) = 2.06; p < 0.0001) and homozygote resistant 119F/F-RR (OR = 2.93; p < 0.0001). L/L119-SS susceptible mosquitoes also showed the higher ability for oviposition than 119F/F-RR resistant (OR = 2.68; p = 0.0002) indicating a reduced fecundity in resistant mosquitoes. Furthermore, L119F-RS larvae developed faster (nine days) than L119F-RR and L119F-SS (11 days) (X2 = 11.052; degree of freedom (df) = 4; p = 0.02) suggesting a heterozygote advantage effect for larval development. Interestingly, L/L119-SS developed faster than 119F/F-RR (OR = 5.3; p < 0.0001) revealing an increased developmental time in resistant mosquitoes. However, genotyping and sequencing revealed that L119F-RR mosquitoes exhibited a higher adult longevity compared to RS (OR > 2.2; p < 0.05) and SS (OR > 2.1; p < 0.05) with an increased frequency of GSTe2-resistant haplotypes in mosquitoes of D30 after adult emergence. Additionally, comparison of the expression of GSTe2 revealed a significantly increased expression from D1-D30 after emergence of adults (Anova test (F) = 8; df= 3; p = 0.008). The negative association between GSTe2 and some life traits of An. funestus could facilitate new resistance management strategies. However, the increased longevity of GSTe2-resistant mosquitoes suggests that an increase in resistance could exacerbate malaria transmission.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ingvild Loubet ◽  
Laëtitia Caddoux ◽  
Séverine Fontaine ◽  
Séverine Michel ◽  
Fanny Pernin ◽  
...  

AbstractAmbrosia artemisiifolia L. (common ragweed) is a globally invasive, allergenic, troublesome arable weed. ALS-inhibiting herbicides are broadly used in Europe to control ragweed in agricultural fields. Recently, ineffective treatments were reported in France. Target site resistance (TSR), the only resistance mechanism described so far for ragweed, was sought using high-throughput genotyping-by-sequencing in 213 field populations randomly sampled based on ragweed presence. Additionally, non-target site resistance (NTSR) was sought and its prevalence compared with that of TSR in 43 additional field populations where ALS inhibitor failure was reported, using herbicide sensitivity bioassay coupled with ALS gene Sanger sequencing. Resistance was identified in 46 populations and multiple, independent resistance evolution demonstrated across France. We revealed an unsuspected diversity of ALS alleles underlying resistance (9 amino-acid substitutions involved in TSR detected across 24 populations). Remarkably, NTSR was ragweed major type of resistance to ALS inhibitors. NTSR was present in 70.5% of the resistant plants and 74.1% of the fields harbouring resistance. A variety of NTSR mechanisms endowing different resistance patterns evolved across populations. Our study provides novel data on ragweed resistance to herbicides, and emphasises that local resistance management is as important as mitigating gene flow from populations where resistance has arisen.


2014 ◽  
Vol 104 (12) ◽  
pp. 1264-1273 ◽  
Author(s):  
Frank van den Bosch ◽  
Neil Paveley ◽  
Femke van den Berg ◽  
Peter Hobbelen ◽  
Richard Oliver

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.


Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1492
Author(s):  
Nathalie Amvongo-Adjia ◽  
Jacob M. Riveron ◽  
Flobert Njiokou ◽  
Samuel Wanji ◽  
Charles S. Wondji

Increased levels of insecticide resistance in major malaria vectors such as Anopheles funestus threaten the effectiveness of insecticide-based control programmes. Understanding the landscape features impacting the spread of resistance makers is necessary to design suitable resistance management strategies. Here, we examined the influence of the highest mountain in West Africa (Mount Cameroon; 4095 m elevation) on the spread of metabolic and target-site resistance alleles in An. funestus populations. Vector composition varied across the four localities surveyed along the altitudinal cline with major vectors exhibiting high parity rate (80.5%). Plasmodium infection rates ranged from 0.79% (An. melas) to 4.67% (An. funestus). High frequencies of GSTe2R (67–81%) and RdlR (49–90%) resistance alleles were observed in An. funestus throughout the study area, with GSTe2R frequency increasing with altitude, whereas the opposite is observed for RdlR. Patterns of genetic diversity and population structure analyses revealed high levels of polymorphisms with 12 and 16 haplotypes respectively for GSTe2 and Rdl. However, the reduced diversity patterns of resistance allele carriers revealed signatures of positive selection on the two genes across the study area irrespective of the altitude. Despite slight variations associated with the altitude, the spread of resistance alleles suggest that control strategies could be implemented against malaria vectors across mountainous landscapes.


2008 ◽  
Vol 98 (2) ◽  
pp. 145-157 ◽  
Author(s):  
N.M. Endersby ◽  
P.M. Ridland ◽  
A.A. Hoffmann

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.


2002 ◽  
Vol 92 (3) ◽  
pp. 203-212 ◽  
Author(s):  
D.B. Fragoso ◽  
R.N.C. Guedes ◽  
M.C. Picanço ◽  
L. Zambolim

AbstractIncreasing rates of insecticide use against the coffee leaf miner Leucoptera coffeella (Guérin-Méneville) and field reports on insecticide resistance led to an investigation of the possible occurrence of resistance of this species to some of the oldest insecticides used against it in Brazil: chlorpyrifos, disulfoton, ethion and methyl parathion. Insect populations were collected from ten sites in the state of Minas Gerais, Brazil and these populations were subjected to discriminating concentrations established from insecticide LC99s estimated for a susceptible standard population. Eight of the field-collected populations showed resistance to disulfoton, five showed resistance to ethion, four showed resistance to methyl parathion, and one showed resistance to chlorpyrifos. The frequency of resistant individuals in each population ranged from 10 to 93% for disulfoton, 53 to 75% for ethion, 23 to 76% for methyl parathion, and the frequency of resistant individuals in the chlorpyrifos resistant population was 35%. A higher frequency of individuals resistant to chlorpyrifos, disulfoton and ethion was associated with greater use of insecticides, especially other organophosphates. This finding suggests that cross-selection, mainly between organophosphates, played a major role in the evolution of insecticide resistance in Brazilian populations of L. coffeella. Results from insecticide bioassays with synergists (diethyl maleate, piperonyl butoxide and triphenyl phosphate) suggested that cytochrome P450-dependent monooxygenases may play a major role in resistance with minor involvement of esterases and glutathione S-transferases.


2007 ◽  
Vol 97 (2) ◽  
pp. 191-200 ◽  
Author(s):  
A. Khaliq ◽  
M.N.R. Attique ◽  
A.H. Sayyed

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.


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