scholarly journals Reduced response of insecticide-resistant aphids and attraction of parasitoids to aphid alarm pheromone; a potential fitness trade-off

2005 ◽  
Vol 95 (1) ◽  
pp. 37-46 ◽  
Author(s):  
S.P. Foster ◽  
I. Denholm ◽  
R. Thompson ◽  
G.M. Poppy ◽  
W. Powell
Keyword(s):  
Insecticide Resistance ◽  
Alarm Pheromone ◽  
Virgin Female ◽  
Pleiotropic Effect ◽  
Resistance Mechanisms ◽  
Diaeretiella Rapae ◽  
Resistance Development ◽  
Trade Off ◽  
Aphid Alarm Pheromone ◽  
Laboratory Bioassays

AbstractResponse to the alarm pheromone, (E)-β-farnesene, produced by many species of aphids, was assessed in laboratory bioassays using an aphid pest, Myzus persicae (Sulzer), and its primary endoparasitoid, Diaeretiella rapae (McIntosh). This was done in three separate studies, the first investigating responses of a large number of M. persicae clones carrying different combinations of metabolic (carboxylesterase) and target site (kdr) insecticide resistance mechanisms, and the other two investigating the responses of young virgin female adult parasitoids. In M. persicae, both insecticide resistance mechanisms were associated with reduced repellence suggesting that each has a pleiotropic effect on aphid behaviour. In contrast, D. rapae females were attracted to the alarm pheromone source. The implications of this apparent fitness trade-off for the evolution and dynamics of insecticide resistance, and the potential for using beneficial insects to combat resistance development are discussed.

Fitness trade-off in peach-potato aphids (Myzus persicae) between insecticide resistance and vulnerability to parasitoid attack at several spatial scales

2010 ◽  
Vol 101 (6) ◽  
pp. 659-666 ◽  
Author(s):  
S.P. Foster ◽  
I. Denholm ◽  
G.M. Poppy ◽  
R. Thompson ◽  
W. Powell
Keyword(s):  
Insecticide Resistance ◽  
Myzus Persicae ◽  
Alarm Pheromone ◽  
Spatial Scales ◽  
Diaeretiella Rapae ◽  
Potato Aphid ◽  
Aphid Movement ◽  
Whole Plants ◽  
Peach Potato Aphid ◽  
Aphid Alarm Pheromone

AbstractInsecticide-resistant clones of the peach-potato aphid, Myzus persicae (Sulzer), have previously been shown to have a reduced response to aphid alarm pheromone compared to susceptible ones. The resulting vulnerability of susceptible and resistant aphids to attack by the primary endoparasitoid, Diaeretiella rapae (McIntosh), was investigated across three spatial scales. These scales ranged from aphids confined on individual leaves exposed to single female parasitoids, to aphids on groups of whole plants exposed to several parasitoids. In all experiments, significantly fewer aphids from insecticide-susceptible clones became parasitised compared to insecticide-resistant aphids. Investigations of aphid movement showed at the largest spatial scale that more susceptible aphids than resistant aphids moved from their inoculation leaves to other leaves on the same plant after exposure to parasitoids. The findings imply that parasitoids, and possibly other natural enemies, can influence the evolution and dynamics of insecticide resistance through pleiotropic effects of resistance genes on important behavioural traits.

scholarly journals Indiscriminate use of agro-veterinary pesticides in plague endemic foci in Tanzania: potential risk for development of insecticide resistance in flea vectors

2020 ◽  
Author(s):  
Grace Rugalema ◽  
Ladslaus Mnyone
Keyword(s):  
Insecticide Resistance ◽  
Resistance Mechanisms ◽  
Resistance Development ◽  
Agricultural Pesticides ◽  
Development Of Resistance ◽  
Direct Observations ◽  
Cropping Season ◽  
Lambda Cyhalothrin ◽  
Safety Procedures ◽  
Structured Questionnaire

Abstract Background: Agro-veterinary pesticides are increasingly associated with the development of resistance in arthropod disease vectors. However, no has been conducted so far to assess such risk in flea vectors despite the indiscriminate use of pesticides in plague endemic foci in Tanzania.Methods: We identified risk factors associated with the use of agro-veterinary pesticides, which could enhance development of resistance in flea vectors in two plague endemic districts, using structured questionnaire and direct observations.Results: Excessive and injudicious use of agricultural and veterinary pesticides was common in both Lushoto and Mbulu district. Most farmers (80%, n=73) were applying agricultural pesticides over three times per cropping season, did not adhere to manufacturers recommended doses, and had limited or no knowledge on safety procedures and adverse effects associated with pesticides. Up to 49% were applying pesticides more than twice the recommended doses. About 91% of respondents in Lushoto and 93% respondents in Mbulu reported using agricultural pesticides. The three (3) out of fourteen (14) most commonly used agricultural pesticides in Lushoto were master kinga72WP (mancozeb 640g/kg+cymoxanil 80g/kg) (44%), suracron720EC (profenos 500g/l EC) (25.3%) and Sumo 5EC (lambda-cyhalothrin) (18.7%). The three (3) out of seventeen (17) most commonly used agricultural pesticides in Mbulu were Dursban50W (Chlorpyrifos) (29%), Duduban 450EC (Cypermethrin 10g/lt+chloropyrifos 35g/lt) (18%) and Dursban+farmerzeb (Chlorpyrifos 48%, Mancozeb 80%WP). Cybadip (Cypermethrin) (≥45%) and paranex (alphacypermethrin) (≥13%) were the most commonly used livestock pesticides.Conclusion: This study identified injudicious uses and/or other malpractices, which enhance contamination of environments/surfaces with pesticides and consequently the exposure of flea vectors. Therefore, the flea vector populations in Lushoto and Mbulu districts are putatively under high risk of resistance development. Further studies are underway to confirm the insecticide resistance status, unravel distribution of the resistance, and involved resistance mechanisms.

scholarly journals The influence of the molecular basis of resistance on insecticide discovery

1998 ◽  
Vol 353 (1376) ◽  
pp. 1723-1728 ◽  
Author(s):  
M. D. Broadjurst
Keyword(s):  
Insecticide Resistance ◽  
Molecular Basis ◽  
Resistance Mechanisms ◽  
Insect Control ◽  
Control Technology ◽  
Main Section ◽  
High Quality ◽  
Resistance Development ◽  
Other Information ◽  
The Impact

This paper focuses on the process of invention and development of new insecticides and the impact of current research in resistance mechanisms on that process. The topic is introduced in the context of (i) the critical need to develop new insect–control agents to ensure a continued supply of high–quality food and fibre; (ii) how resistance development will continue to influence the potential to ensure the supply of these essentials; and (iii) why new insect–control technology is welcomed by growers. The main section of the paper describes a generic agrochemical invention process and discusses the impact that an understanding of the molecular basis of resistance will have on the various stages of this process, using specific examples to illustrate these points. By focusing on insecticide invention, this paper provides a context in which other information more specific to insecticide resistance from this issue can be understood.

scholarly journals Multiple insecticide resistance mechanisms in Anopheles gambiae s.l. populations from Cameroon, Central Africa

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Philippe Nwane ◽  
Josiane Etang ◽  
Mouhamadou Chouaїbou ◽  
Jean Claude Toto ◽  
Alphonsine Koffi ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Gambiae ◽  
Central Africa ◽  
Resistance Mechanisms ◽  
Anopheles Gambiae S.L

scholarly journals Development of Resistance in Wild-Type and Hypermutable Pseudomonas aeruginosa Strains Exposed to Clinical Pharmacokinetic Profiles of Meropenem and Ceftazidime Simulated In Vitro

2007 ◽  
Vol 51 (10) ◽  
pp. 3642-3649 ◽  
Author(s):  
Beate Henrichfreise ◽  
Irith Wiegand ◽  
Ingeborg Luhmer-Becker ◽  
Bernd Wiedemann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Parent Strain ◽  
Resistance Mechanisms ◽  
In Vitro Models ◽  
Wild Type ◽  
Resistance Development ◽  
Development Of Resistance ◽  
Pharmacokinetic Profiles ◽  
Mutant Prevention Concentration

ABSTRACT In this study we investigated the interplay of antibiotic pharmacokinetic profiles and the development of mutation-mediated resistance in wild-type and hypermutable Pseudomonas aeruginosa strains. We used in vitro models simulating profiles of the commonly used therapeutic drugs meropenem and ceftazidime, two agents with high levels of antipseudomonal activity said to have different potentials for stimulating resistance development. During ceftazidime treatment of the wild-type strain (PAO1), fully resistant mutants overproducing AmpC were selected rapidly and they completely replaced wild-type cells in the population. During treatment with meropenem, mutants of PAO1 were not selected as rapidly and showed only intermediate resistance due to the loss of OprD. These mutants also replaced the parent strain in the population. During the treatment of the mutator P. aeruginosa strain with meropenem, the slowly selected mutants did not accumulate several resistance mechanisms but only lost OprD and did not completely replace the parent strain in the population. Our results indicate that the commonly used dosing regimens for meropenem and ceftazidime cannot avoid the selection of mutants of wild-type and hypermutable P. aeruginosa strains. For the treatment outcome, including the prevention of resistance development, it would be beneficial for the antibiotic concentration to remain above the mutant prevention concentration for a longer period of time than it does in present regimens.

scholarly journals Comparative Study of the Effect of Solvents on the Efficacy of Neonicotinoid Insecticides Against Malaria Vector Populations Across Africa

2022 ◽  
Author(s):  
Magellan Tchouakui ◽  
Tatiane Assatse ◽  
Leon M. J. Mugenzi ◽  
Benjamin D. Menze ◽  
Daniel Nguiffo-Nguete ◽  
...  
Keyword(s):  
Democratic Republic Of Congo ◽  
Natural Populations ◽  
Resistance Mechanisms ◽  
Lower Mortality ◽  
Malaria Vectors ◽  
Cross Resistance ◽  
Metabolic Resistance ◽  
Resistance Development ◽  
Development Of Resistance ◽  
Bottle Test

Abstract Background New insecticides with a novel mode of action such as neonicotinoids have recently been recommended for public health by WHO. Resistance monitoring of such novel insecticides requires a robust protocol to monitor the development of resistance in natural populations. In this study, we comparatively used three different solvents to assess the susceptibility of malaria vectors to neonicotinoids across Africa.MethodsMosquitoes were collected from May to July 2021 from three agricultural settings in Cameroon (Njombe-Penja, Nkolondom, and Mangoum), the Democratic Republic of Congo (Ndjili-Brasserie), Ghana (Obuasi), and Uganda (Mayuge). Using the CDC bottle test, we compared the effect of three different solvents (ethanol, acetone, MERO) on the efficacy of neonicotinoids against Anopheles gambiae s.l. In addition, TaqMan assays were used to genotype key pyrethroid-resistant markers in An. gambiae and to evaluate potential cross-resistance between pyrethroids and clothianidin.ResultsLower mortality were observed when using absolute ethanol or acetone alone as solvent (11.4- 51.9% mortality in Nkolondom, 31.7- 48.2% in Mangoum, 34.6- 56.1% in Mayµge, 39.4- 45.6% in Obuasi, 83.7- 89.3% in Congo and 71.05- 95.9% in Njombe pendja) compared to acetone + MERO for which 100% mortality were observed for all the populations. Synergist assays (PBO, DEM and DEF) revealed a significant increase of mortality suggesting that metabolic resistance mechanisms are contributing to the reduced susceptibility. A negative association was observed between the L1014F-kdr mutation and clothianidin resistance with a greater frequency of homozygote resistant mosquitoes among the dead than among survivors (OR=0.5; P=0.02). However, the I114T-GSTe2 was in contrast significantly associated with a greater ability to survive clothianidin with a higher frequency of homozygote resistant among survivors than other genotypes (OR=2.10; P=0.013). ConclusionsThis study revealed a contrasted susceptibility pattern depending on the solvents with ethanol/acetone resulting to lower mortality, thus possibly overestimating resistance, whereas the MERO consistently showed a greater efficacy of neonicotinoids but it could prevent to detect early resistance development. Therefore, we recommend monitoring the susceptibility using both acetone alone and acetone+MERO (8-10µg/ml for clothianidin) to capture the accurate resistance profile of the mosquito populations.

scholarly journals Insecticide resistance in Anopheles stephensi in Somali Region, eastern Ethiopia

2020 ◽  
Author(s):  
Solomon Yared ◽  
Araya Gebressielasie ◽  
Lambodhar Damodaran ◽  
Victoria Bonnell ◽  
Karen Lopez ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Stephensi ◽  
Mortality Rates ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vectors ◽  
Resistance Locus ◽  
Eastern Ethiopia ◽  
Pyrethroid Insecticides ◽  
Pirimiphos Methyl

Abstract Background The movement of malaria vectors into new areas is a growing concern in the efforts to control malaria. The recent report of Anopheles stephensi in eastern Ethiopia has raised the necessity to understand the insecticide resistance status of the vector in the region to better inform vector-based interventions. The aim of this study was to evaluate insecticide resistance in An. stephensi in eastern Ethiopia using two approaches: 1) World Health Organization (WHO) bioassay tests in An. stephensi; and 2) genetic analysis of insecticide resistance genes in An. stephensi in eastern Ethiopia. Methods Mosquito larvae and pupae were collected from Kebri Dehar. Insecticide susceptibility of An. stephensi was tested withmalathion 5%, bendiocarb 0.1%, propoxur 0.1%, deltamethrin 0.05%, permethrin 0.75%, Pirimiphos-methyl 0.25% and DDT 4%, according to WHO standard protocols. In this study, the knockdown resistance locus (kdr) in the voltage gated sodium channel (vgsc) and ace1R locus in the acetylcholinesterase gene (ace-1) were analysed in An. stephensi. Results All An. stephensi samples were resistant to carbamates, with mortality rates of 23% and 21% for bendiocarb and propoxur, respectively. Adult An. stephensi was also resistant to pyrethroid insecticides with mortality rates 67% for deltamethrin and 53% for permethrin. Resistance to DDT and malathion was detected in An. stephensi with mortality rates of 32% as well as An. stephensi was resistance to pirimiphos-methyl with mortality rates 14%. Analysis of the insecticide resistance loci revealed the absence of kdr L1014F and L1014S mutations and the ace1R G119S mutation. Conclusion Overall, these findings support that An. stephensi is resistant to several classes of insecticides, most notably pyrethroids. However, the absence of the kdr L1014 gene may suggest non-target site resistance mechanisms. Continuous insecticide resistance monitoring should be carried out in the region to confirm the documented resistance and exploring mechanisms conferring resistance in An. stephensi in Ethiopia.

scholarly journals Insecticide Resistance in Anopheles Albitarsis S.S. From a Rice Production Field, With the First Record of Kdr Mutation in This Species 

2021 ◽  
Author(s):  
Taiza Andrade Braga ◽  
Aline Cordeiro Loureiro ◽  
José Bento Pereira Lima ◽  
Ademir J Martins
Keyword(s):  
Insecticide Resistance ◽  
Taxonomic Status ◽  
First Record ◽  
Blood Feeding ◽  
Resistance Mechanisms ◽  
Field Population ◽  
Low Frequencies ◽  
Laboratory Colony ◽  
Field Samples ◽  
Rice Plantation

Abstract Background: Although there is a vast literature concerning insecticide resistance (IR) in Plasmodium vectors from African and Asian continents, similar studies with Neotropical anophelines are scares. Herein we evaluated the IR profile of Anopheles albitarsis s.s. of a laboratory colony and a natural population collected around a rice plantation field. The laboratory colony is original from a collection performed in this same region more than two decades ago. Methods: We collected An. albitarsis females while resting after blood feeding, around rice field plantations in Massaranduba, SC, Brazil. These females laid their eggs in the laboratory, and the larvae were raised in parallel with our lab colony. To be sure about the field samples’ taxonomic status, we amplified and sequenced the mitochondrial COI gene of a sampling of field captured mosquitoes. We performed a simplified knockdown test with larvae exposed to permethrin and deltamethrin and submitted adult females to a WHO like tube test with the pyrethroids permethrin, deltamethrin, and etofenprox, in addition to the organophosphate malathion. A segment of the voltage-gated sodium channel gene (NaV) was amplified and cloned. Based on the observed sequences, we developed a TaqMan genotyping assay for the variation L1014F and calculated the genotypic and allelic frequencies concerning this SNP in the field population.Results: The COI analyses confirmed the taxonomic status of An. albitarsis s.s in laboratory and field samples. The field population was resistant to pyrethroids but not to malathion. We observed the substitutions L1019R, F1020S, and the classical kdr L1014F in the NaV gene. This classical kdr allele was present under low frequencies in the overall field population (2%), although more frequent in pyrethroid-resistant insects.Conclusions: The An. albitarsis s.s. population from Massaranduba was resistant to pyrethroids, likely due to selection pressure exerted by agrochemical pesticides. We registered the classical kdr mutation in a Brazilian Anopheles species for the first time. Further investigations are necessary to disclose additional resistance mechanisms.

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