Implementation of a Diagnostic-Concentration Bioassay for Detection of Susceptibility to Pyrethroids in Soybean Aphid (Hemiptera: Aphididae)

Abstract Soybean aphid, Aphis glycines Matsumura, remains the most economically damaging arthropod pest of soybean in the midwestern United States and southern Canada. Foliar applications of a limited number of insecticide modes of action have been the primary management tactic, and pyrethroid resistance was documented recently with full concentration–response leaf-dip and glass-vial bioassays. Full concentration–response bioassays can be cumbersome, and a more efficient assessment tool was needed. In this study, we implemented a diagnostic-concentration glass-vial bioassay using bifenthrin and λ-cyhalothrin. Bioassays were conducted with field-collected soybean aphid populations to assess the geographic extent and severity of resistance to pyrethroids. In 2017, 10 of 18 and 11 of 21 field populations tested with bifenthrin and λ-cyhalothrin, respectively, had mean proportion mortalities less than the susceptible laboratory population. In 2018, 17 of 23 and 13 of 23 field populations tested with bifenthrin and λ-cyhalothrin, respectively, had mean proportion mortalities less than the susceptible laboratory population. Populations collected after reported field failures of a pyrethroid insecticide generally had mean proportion mortalities less than the susceptible laboratory population. In both years, there was a strong correlation between chemistries, which suggests cross-resistance between these insecticides. The diagnostic-concentration glass-vial bioassays reported here will provide the foundation for an insecticide resistance monitoring program with the ability to determine practical levels and geographic extent of insecticide resistance.

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Section 4. Pyrethroid and endosulfan resistance: selection and cross resistance studies

Bulletin of entomological research supplement series ◽

10.1017/s1367426900000102 ◽

1993 ◽

Vol 1 ◽

pp. 28-35 ◽

Cited By ~ 21

Author(s):

Neil W. Forrester ◽

Matthew Cahill ◽

Lisa J. Bird ◽

Jacquelyn K. Layland

Keyword(s):

Insecticide Resistance ◽

Lower Order ◽

Management Strategy ◽

Pyrethroid Resistance ◽

Resistance Management ◽

Resistance Mechanisms ◽

Cross Resistance ◽

Male And Female ◽

Insecticide Resistance Management ◽

Resistance Selection

SummaryResistance to endosulfan and pyrethroids in Helicoverpa armigera in Australia was shown to be due to multiple rather than cross resistance. The independence of the endosulfan and pyrethroid resistance mechanisms vindicates the sequential use of these two groups in Stages I and II of the insecticide resistance management strategy, respectively. Within the cyclodienes, greatest resistance occurred to dieldrin with lower order cross resistance to endosulfan and endrin. Male and female moths expressed cyclodiene resistance equally.

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Functional genetic validation of key genes conferring insecticide resistance in the major African malaria vector, Anopheles gambiae

10.1101/749457 ◽

2019 ◽

Cited By ~ 1

Author(s):

Adriana Adolfi ◽

Beth Poulton ◽

Amalia Anthousi ◽

Stephanie Macilwee ◽

Hilary Ranson ◽

...

Keyword(s):

Public Health ◽

Insecticide Resistance ◽

Anopheles Gambiae ◽

Pyrethroid Resistance ◽

Control Strategies ◽

Resistance Mechanisms ◽

Effective Control ◽

Cross Resistance ◽

Toxic Metabolite ◽

Control Programs

ABSTRACTResistance in Anopheles gambiae to members of all four major classes (pyrethroids, carbamates, organochlorines and organophosphates) of public health insecticides limits effective control of malaria transmission in Africa. Increased expression of detoxifying enzymes has been associated with resistance, but direct functional validation in An. gambiae has been lacking. Here we perform transgenic analysis using the GAL4/UAS system to examine insecticide resistance phenotypes conferred by increased expression of the three genes - Cyp6m2, Cyp6p3 and Gste2 - most often found upregulated in resistant An. gambiae. We report the first evidence in An. gambiae that organophosphate and organochlorine resistance is conferred by overexpression of GSTE2 in a broad tissue profile. Pyrethroid and carbamate resistance is bestowed by similar Cyp6p3 overexpression, and Cyp6m2 confers only pyrethroid resistance when overexpressed in the same tissues. Conversely, such Cyp6m2 overexpression increases susceptibility to the organophosphate malathion, presumably due to conversion to a more toxic metabolite. No resistant phenotypes are conferred when either Cyp6 gene overexpression is restricted to the midgut or oenocytes, answering long standing questions related to the importance of these tissues in resistance to contact insecticides. Validation of genes conferring resistance provides markers to guide control strategies, and the observed negative cross-resistance due to Cyp6m2 gives credence to proposed dual insecticide strategies to overcome pyrethroid resistance. These trasnsgenic An. gambiae resistant lines are being used to test potential liabilities in new active compounds early in development.SIGNIFICANCE STATEMENTInsecticide resistance in Anopheles gambiae mosquitoes can derail malaria control programs, and to overcome it we need to discover the underlying molecular basis. Here, for the first time, we characterise three genes most often associated with insecticide resistance directly by their overproduction in genetically modified An. gambiae. We show that overexpression of each gene confers resistance to representatives of at least one insecticide class and, taken together, the three genes provide cross-resistance to all four major insecticide classes currently used in public health. These data validate the candidate genes as markers to monitor the spread of resistance in mosquito populations. The modified mosquitoes produced are also valuable tools to pre-screen new insecticides for potential liabilities to existing resistance mechanisms.

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First Report of Biochemical Mechanisms of Insecticide Resistance in the Field Population of Culex pipiens (Diptera: Culicidae) From Sari, Mazandaran, North of Iran

Journal of Arthropod-Borne Diseases ◽

10.18502/jad.v13i4.2234 ◽

2020 ◽

Author(s):

Seyed Hassan Nikookar ◽

Mahmoud Fazeli-Dinan ◽

Seyyed Payman Ziapour ◽

Fatemeh Ghorbani ◽

Yaser Salim-Abadi ◽

...

Keyword(s):

Insecticide Resistance ◽

Culex Pipiens ◽

Pyrethroid Resistance ◽

Cytochrome P450s ◽

Field Population ◽

Susceptible Strain ◽

Laboratory Population ◽

Significant Difference ◽

North Of Iran ◽

The Mean

Background: Culex pipiens play an important role in transmission of infectious diseases. Vector control by chemical pesticides, leads inevitably to resistance development. Understanding the underlying resistance mechanisms can help improve the control programmes and insecticide resistance management. Methods: The total contents of cytochrome p450s and the activities of glutathione S-transferases, alpha- and beta-esterases and inhibition rates of acetylcholine esterase (by propoxur) were measured in the field population of Cx. pipiens collected from Sari County, North of Iran, in 2016 and the results were compared with those of the laboratory susceptible strain according to the biochemical assay methods of WHO for adult mosquitoes. Independent sample t-test was used to compare the mean values of enzyme activities/contents between filed and laboratory susceptible popula-tions. Results: The enzyme ratio of cytochrome p450s, alpha- and beta-esterases in the field population was 2.07, 3.72 and 1.36 respectively when compared with the results of the laboratory population. Although not statistically significant, the mean GSTs activities in the field population was marginally less than the laboratory population (ER=0.92). Ace-tylcholinesterase was insensitive to propoxur in 62.82% of the individuals of the tested field population. There was a significant difference (P< 0.05) between all values of the activities/contents of the enzyme in the field population except for GSTs compared with the laboratory susceptible strain. The highest enzyme activity was related to alpha esterase. Conclusion: The present study showed a range of metabolic mechanisms, comprising p450s and esterases combined with target site insensitivity of AChE, contributing to organophosphate, carbamate and pyrethroid resistance in the field population of Cx. pipiens.

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Functional genetic validation of key genes conferring insecticide resistance in the major African malaria vector,Anopheles gambiae

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1914633116 ◽

2019 ◽

Vol 116 (51) ◽

pp. 25764-25772 ◽

Cited By ~ 13

Author(s):

Adriana Adolfi ◽

Beth Poulton ◽

Amalia Anthousi ◽

Stephanie Macilwee ◽

Hilary Ranson ◽

...

Keyword(s):

Insecticide Resistance ◽

Anopheles Gambiae ◽

Pyrethroid Resistance ◽

Control Strategies ◽

Effective Control ◽

Cross Resistance ◽

Toxic Metabolite ◽

Detoxifying Enzymes ◽

Resistant Lines ◽

Key Genes

Resistance inAnopheles gambiaeto members of all 4 major classes (pyrethroids, carbamates, organochlorines, and organophosphates) of public health insecticides limits effective control of malaria transmission in Africa. Increase in expression of detoxifying enzymes has been associated with insecticide resistance, but their direct functional validation inAn. gambiaeis still lacking. Here, we perform transgenic analysis using the GAL4/UAS system to examine insecticide resistance phenotypes conferred by increased expression of the 3 genes—Cyp6m2,Cyp6p3, andGste2—most often found up-regulated in resistantAn. gambiae. We report evidence inAn. gambiaethat organophosphate and organochlorine resistance is conferred by overexpression of GSTE2 in a broad tissue profile. Pyrethroid and carbamate resistance is bestowed by similarCyp6p3overexpression, andCyp6m2confers only pyrethroid resistance when overexpressed in the same tissues. Conversely, suchCyp6m2overexpression increases susceptibility to the organophosphate malathion, presumably due to conversion to the more toxic metabolite, malaoxon. No resistant phenotypes are conferred when eitherCyp6gene overexpression is restricted to the midgut or oenocytes, indicating that neither tissue is involved in insecticide resistance mediated by the candidate P450s examined. Validation of genes conferring resistance provides markers to guide control strategies, and the observed negative cross-resistance due toCyp6m2gives credence to proposed dual-insecticide strategies to overcome pyrethroid resistance. These transgenicAn. gambiae-resistant lines are being used to test the “resistance-breaking” efficacy of active compounds early in their development.

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Evolutionary Genetics of Insecticide Resistance and the Effects of Chemical Rotation

10.1101/072520 ◽

2016 ◽

Author(s):

Dylan J. Siniard ◽

Michael J. Wade ◽

Douglas W. Drury

Keyword(s):

Insecticide Resistance ◽

Resistance Management ◽

Evolutionary Genetics ◽

Stochastic Simulations ◽

Cross Resistance ◽

Laboratory Population ◽

Response Curves ◽

Repeated Use ◽

Insight Into ◽

Quantitative Genetic Parameters

AbstractRepeated use of the same class of pesticides to control a target pest is a form of artificial selection that leads to pesticide resistance. We studied insecticide resistance and cross-resistance to five commercial insecticides in each of six populations of the red flour beetle, Tribolium castaneum. We estimated the dosage response curves for lethality in each parent population for each insecticide and found an 800-fold difference among populations in resistance to insecticides. As expected, a naïve laboratory population was among the most sensitive of populations to most insecticides. We then used inbred lines derived from five of these populations to estimate the heritability (h2) of resistance for each pesticide and the genetic correlation (rG) of resistance among pesticides in each population. These quantitative genetic parameters allow insight into the adaptive potential of populations to further evolve insecticide resistance. Lastly, we use our estimates of the genetic variance and covariance of resistance and stochastic simulations to evaluate the efficacy of “windowing” as an insecticide resistance management strategy, where the application of several insecticides is rotated on a periodic basis.

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A whole transcriptomic approach reveals novel mechanisms of organophosphate and pyrethroid resistance in Anopheles arabiensis from Ethiopia

10.1101/2021.07.09.451871 ◽

2021 ◽

Author(s):

Louisa A Messenger ◽

Lucy Mackenzie Impoinvil ◽

Dieunel Derilus ◽

Delenasaw Yewhalaw ◽

Seth Irish ◽

...

Keyword(s):

Insecticide Resistance ◽

Anopheles Arabiensis ◽

Specific Resistance ◽

Pyrethroid Resistance ◽

Short Form ◽

Expression Patterns ◽

Resistance Mechanisms ◽

Salivary Protein ◽

Malaria Vectors ◽

Cross Resistance

The development of insecticide resistance in malaria vectors is of increasing concern in Ethiopia because of its potential implications for vector control failure. To better elucidate the specificity of resistance mechanisms and to facilitate the design of control strategies that minimize the likelihood of selecting for cross-resistance, a whole transcriptomic approach was used to explore gene expression patterns in a multi-insecticide resistant population of Anopheles arabiensis from Oromia Region, Ethiopia. This field population was resistant to the diagnostic doses of malathion (average mortality of 71.9%) and permethrin (77.4%), with pools of survivors and unexposed individuals analyzed using Illumina RNA-sequencing, alongside insecticide susceptible reference strains. This population also demonstrated deltamethrin resistance but complete susceptibility to alpha-cypermethrin, bendiocarb and propoxur, providing a phenotypic basis for detecting insecticide-specific resistance mechanisms. Transcriptomic data revealed overexpression of genes including cytochrome P450s, glutathione-s-transferases and carboxylesterases (including CYP4C36, CYP6AA1, CYP6M2, CYP6M3, CYP6P4, CYP9K1, CYP9L1, GSTD3, GSTE2, GSTE3, GSTE4, GSTE5, GSTE7 and two carboxylesterases) that were shared between malathion and permethrin survivors. We also identified nineteen highly overexpressed cuticular-associated proteins (including CYP4G16, CYP4G17 and chitinase) and eighteen salivary gland proteins (including D7r4 short form salivary protein), which may be contributing to a non-specific resistance phenotype by either enhancing the cuticular barrier or promoting binding and sequestration of insecticides, respectively. These findings provide novel insights into the molecular basis of insecticide resistance in this lesser well-characterized major malaria vector species.

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Variation in Soybean Aphid (Hemiptera: Aphididae) Biotypes Within Fields

Journal of Economic Entomology ◽

10.1093/jee/toab058 ◽

2021 ◽

Author(s):

S J Bhusal ◽

R L Koch ◽

A J Lorenz

Keyword(s):

Resistance Genes ◽

Environmental Sustainability ◽

Soybean Aphid ◽

Aphis Glycines ◽

Aphid Resistance ◽

Soybean Cultivars ◽

Major Pest ◽

Single Field ◽

Aphis Glycines Matsumura ◽

Multiple Resistance Genes

Abstract Soybean aphid (Aphis glycines Matsumura (Hemiptera: Aphididae)) has been a major pest of soybean in North America since its detection in this continent in 2000 and subsequent spread. Although several aphid resistance genes have been identified, at least four soybean aphid biotypes have been discovered, with three of them being virulent on soybean cultivars with certain soybean aphid resistance genes. These biotypes are known to vary across years and locations, but information on their variation within single fields is limited. An investigation was conducted to study the variation of soybean aphid biotypes within single townships and fields in Minnesota. Screening of 28 soybean aphid isolates collected from seven soybean fields (six soybean fields in Cairo and Wellington Townships of Renville County, MN and one field in Wilmar Township of Kandiyohi County, MN) revealed the existence of multiple known biotypes of soybean aphid within single fields of soybean. We found up to three biotypes of soybean aphid in a single field. Two biotypes were found in five fields while only one field had only a single biotype. Three isolates presented reactions on a panel of resistant and susceptible indicator lines that were different from known biotypes. These results highlight the importance of characterizing soybean aphid biotypes in small geographical areas and utilizing generated knowledge to develop soybean cultivars pyramided with multiple resistance genes. The outcome will be decreased use of insecticides, thereby improving economic and environmental sustainability of soybean production.

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Efficacy of interceptor® G2, a long-lasting insecticide mixture net treated with chlorfenapyr and alpha-cypermethrin against Anopheles funestus: experimental hut trials in north-eastern Tanzania

Malaria Journal ◽

10.1186/s12936-021-03716-z ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Patrick K. Tungu ◽

Elisante Michael ◽

Wema Sudi ◽

William W. Kisinza ◽

Mark Rowland

Keyword(s):

Pyrethroid Resistance ◽

Meta Analysis ◽

Anopheles Funestus ◽

Blood Feeding ◽

Significant Loss ◽

World Health ◽

Cross Resistance ◽

Personal Protection ◽

Experimental Hut ◽

Field Evidence

Abstract Background The effectiveness of long-lasting insecticidal nets (LLIN), the primary method for preventing malaria in Africa, is compromised by evolution and spread of pyrethroid resistance. Further gains require new insecticides with novel modes of action. Chlorfenapyr is a pyrrole insecticide that disrupts mitochrondrial function and confers no cross-resistance to neurotoxic insecticides. Interceptor® G2 LN (IG2) is an insecticide-mixture LLIN, which combines wash-resistant formulations of chlorfenapyr and the pyrethroid alpha-cypermethrin. The objective was to determine IG2 efficacy under controlled household-like conditions for personal protection and control of wild, pyrethroid-resistant Anopheles funestus mosquitoes. Methods Experimental hut trials tested IG2 efficacy against two positive controls—a chlorfenapyr-treated net and a standard alpha-cypermethrin LLIN, Interceptor LN (IG1)—consistent with World Health Organization (WHO) evaluation guidelines. Mosquito mortality, blood-feeding inhibition, personal protection, repellency and insecticide-induced exiting were recorded after zero and 20 washing cycles. The trial was repeated and analysed using multivariate and meta-analysis. Results In the two trials held in NE Tanzania, An. funestus mortality was 2.27 (risk ratio 95% CI 1.13–4.56) times greater with unwashed Interceptor G2 than with unwashed Interceptor LN (p = 0.012). There was no significant loss in mortality with IG2 between 0 and 20 washes (1.04, 95% CI 0.83–1.30, p = 0.73). Comparison with chlorfenapyr treated net indicated that most mortality was induced by the chlorfenapyr component of IG2 (0.96, CI 0.74–1.23), while comparison with Interceptor LN indicated blood-feeding was inhibited by the pyrethroid component of IG2 (IG2: 0.70, CI 0.44–1.11 vs IG1: 0.61, CI 0.39–0.97). Both insecticide components contributed to exiting from the huts but the contributions were heterogeneous between trials (heterogeneity Q = 36, P = 0.02). WHO susceptibility tests with pyrethroid papers recorded 44% survival in An. funestus. Conclusions The high mortality recorded by IG2 against pyrethroid-resistant An. funestus provides first field evidence of high efficacy against this primary, anthropophilic, malaria vector.

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A Linkage Map and QTL Analysis for Pyrethroid Resistance in the Bed Bug Cimex lectularius

G3 Genes|Genome|Genetics ◽

10.1534/g3.116.033092 ◽

2016 ◽

Vol 6 (12) ◽

pp. 4059-4066 ◽

Cited By ~ 5

Author(s):

Toby Fountain ◽

Mark Ravinet ◽

Richard Naylor ◽

Klaus Reinhardt ◽

Roger K Butlin

Keyword(s):

Insecticide Resistance ◽

Candidate Gene ◽

Linkage Map ◽

Pyrethroid Resistance ◽

Cimex Lectularius ◽

Future Research ◽

Potential Candidate ◽

Pest Species ◽

Diverse Range ◽

Bed Bug

Abstract The rapid evolution of insecticide resistance remains one of the biggest challenges in the control of medically and economically important pests. Insects have evolved a diverse range of mechanisms to reduce the efficacy of the commonly used classes of insecticides, and finding the genetic basis of resistance is a major aid to management. In a previously unstudied population, we performed an F2 resistance mapping cross for the common bed bug, Cimex lectularius, for which insecticide resistance is increasingly widespread. Using 334 SNP markers obtained through RAD-sequencing, we constructed the first linkage map for the species, consisting of 14 putative linkage groups (LG), with a length of 407 cM and an average marker spacing of 1.3 cM. The linkage map was used to reassemble the recently published reference genome, facilitating refinement and validation of the current genome assembly. We detected a major QTL on LG12 associated with insecticide resistance, occurring in close proximity (1.2 Mb) to a carboxylesterase encoding candidate gene for pyrethroid resistance. This provides another example of this candidate gene playing a major role in determining survival in a bed bug population following pesticide resistance evolution. The recent availability of the bed bug genome, complete with a full list of potential candidate genes related to insecticide resistance, in addition to the linkage map generated here, provides an excellent resource for future research on the development and spread of insecticide resistance in this resurging pest species.

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