Temephos resistance and the associated cross-resistance spectrum in a strain of Culex quinquefasciatus Say (Diptera: Culicidae) from Peliyagoda, Sri Lanka

1990 ◽  
Vol 80 (1) ◽  
pp. 49-55 ◽  
Author(s):  
H.T.R Peiris ◽  
J Hemingway
Keyword(s):  
Culex Quinquefasciatus ◽  
Cross Resistance ◽  
Single Family ◽  
Parental Population ◽  
Pirimiphos Methyl ◽  
Bendiocarb Resistance ◽  
Low Levels ◽  
Resistance Spectrum ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

AbstractA heterogeneous population (Pel) of Culex quinquefasciatus Say was selected, by single family rearing, to give a strain, Pel SS, which had low levels of hydrolysis of the esterase substrates α and β-naphthyl acetate. The level of temephos resistance was three-fold lower in this strain than the original parental population, and the levels of resistance to malathion, fenitrothion, pirimiphos-methyl, chlorpyrifos and permethrin were also reduced. In contrast, temephos selection increased the temephos-resistance in the Pel-RR strain ten-fold compared to the original parental population and 29-fold compared to Pel SS. The level of temephos-resistance in Pel RR compared to Pel SS at the LC50 level was 37-fold. Larval cross-resistance, at different levels, was observed to the organophosphorus insecticides, malathion, fenitrothion, parathion, pirimiphos-methyl, chlorpyrifos, fenthion and phoxim, and to the carbamates, propoxur and bendiocarb, but the level of fenthion, propoxur and bendiocarb resistance was less than three-fold. Adults showed cross-resistance to malathion and fenitrothion, but not to propoxur. There was negative cross-resistance to permethrin in both the larvae and adults of Pel RR compared to the Pel and Pel SS strains.

The mechanisms of organophosphate and carbamate resistance in Culex quinquefasciatus (Diptera: Culicidae) from Cuba

1990 ◽  
Vol 80 (3) ◽  
pp. 245-250 ◽  
Author(s):  
J.A. Bisset ◽  
M.M. Rodriguez ◽  
C. Diaz ◽  
E. Ortiz ◽  
M.C. Marquetti ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
Cross Resistance ◽  
Standard Laboratory ◽  
Biochemical Tests ◽  
Low Level ◽  
Laboratory Selection ◽  
Resistance Spectrum ◽  
Havana City ◽  
Level Resistance ◽  
Selection Of

AbstractTwo field-collected strains of Culex quinquefasciatus Say, collected 50 km apart in Havana City, Cuba, were both resistant to malathion and propoxur, while one population also showed low level resistance to temephos. Laboratory selection of the latter population with malathion for 22 generations increased the malathion resistance 1050-fold, temephos resistance 24-fold and propoxur resistance 453-fold compared to the standard laboratory susceptible strain. Synergist studies and biochemical tests indicated that two mechanisms, an elevated esterase and an insensitive acetylcholinesterase, were operative in these strains. The esterase mechanism conferred resistance to malathion, but not to temephos or propoxur. The acetylcholinesterase mechanism increased the level of malathion resistance and extended the cross-resistance spectrum to temephos and propoxur.

Characterization and inheritance of elevated esterases in organophosphorus and carbamate insecticide resistant Culex quinquefasciatus (Diptera: Culicidae) from Sri Lanka

1993 ◽  
Vol 83 (1) ◽  
pp. 127-132 ◽  
Author(s):  
H.T.R. Peiris ◽  
J. Hemingway
Keyword(s):  
Sri Lanka ◽  
Culex Quinquefasciatus ◽  
Sri Lankan ◽  
Relative Importance ◽  
Glutathione S Transferase ◽  
Carbamate Insecticide ◽  
A Minor ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

AbstractCulex quinquefasciatus Say from Peliyagoda, Sri Lanka, has elevated esterases A2 and B2. In vitro insecticide metabolism studies on the temephos-selected Sri Lankan Cutex quinquefasciatus strain, Pel RR, showed that fenitrothion was hydrolysed more rapidly than malathion. A significantly larger amount of fenitrothion was metabolized in Pel RR compared to the insecticide susceptible Pel SS strain, but the amount of malathion metabolized in the two strains was not significantly different. There was more esterase hydrolysis of fenitrothion than oxidase or glutathione S-transferase metabolism in Pel RR, which suggests that the elevated esterases in this strain have both metabolic and sequestering functions and that the relative importance of the two roles depends on the insecticide used. Genetic crosses of the temephos resistant and susceptible strains, showed that both resistance and elevated esterase activity were inherited as semi-dominant multi-genic characters. Hydrolysis of 2-naphthyl acetate was highest in the Pel RR strain, lowest in the Pel SS and intermediate in the F1 cross of the two strains. A minor maternal effect on resistance occurred with backcrosses involving resistant (F1) females, which gave consistently and significantly lower mortalities than those involving resistant (F1) males.

Cross Resistance in S-Methoprene-Resistant Culex quinquefasciatus (Diptera: Culicidae)

2020 ◽  
Author(s):  
Tianyun Su ◽  
Jennifer Thieme ◽  
Robert Cummings ◽  
Min-Lee Cheng ◽  
Michelle Q Brown
Keyword(s):  
Culex Quinquefasciatus ◽  
Environmental Protection Agency ◽  
The United States ◽  
Cross Resistance ◽  
Lysinibacillus Sphaericus ◽  
Lack Of Information ◽  
Hormone Analog ◽  
Laboratory Reference ◽  
Unselected Population ◽  
Low Levels

Abstract The juvenile hormone analog S-methoprene is the only synthetic biopesticide that is registered with the United States Environmental Protection Agency to control arthropods of economic importance in public health, livestock, pets, urban, and stored products. The high activity, relative target specificity, and benign environmental profile of S-methoprene have been well documented. While the risk of resistance in mosquitoes to S-methoprene is generally low, there is a lack of information regarding cross resistance in S-methoprene-resistant mosquitoes to other pesticides. In this paper, a population of the southern house mosquito Culex quinquefasciatus Say from southern California acquired low levels of resistance to S-methoprene in the field, where the resistance ratios ranged 7.0- to 8.8-fold as compared with a laboratory reference colony. After 30 generations of laboratory selections by S-methoprene when resistance was elevated to 57.4- to 168.3-fold relative to an unselected population, various levels of cross resistance to other commonly used pesticides were revealed in the selected population. Cross resistance to the microbial mosquito larvicide Lysinibacillus sphaericus (Meyer & Neide) (Bacillales: Bacillaceae) was the most profound, amounting to 77.50- to 220.50-fold. The mechanism and potential management tactics toward cross resistance are discussed to preserve the unique value of this synthetic biopesticide.

scholarly journals Efficacy of broflanilide (VECTRON T500), a new meta-diamide insecticide, for indoor residual spraying against pyrethroid-resistant malaria vectors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Corine Ngufor ◽  
Renaud Govoetchan ◽  
Augustin Fongnikin ◽  
Estelle Vigninou ◽  
Thomas Syme ◽  
...  
Keyword(s):  
Indoor Residual Spraying ◽  
Malaria Vectors ◽  
Cross Resistance ◽  
Malaria Vector Control ◽  
Mosquito Vectors ◽  
Experimental Huts ◽  
Application Rates ◽  
Wettable Powder ◽  
Cone Bioassay ◽  
Pirimiphos Methyl

AbstractThe rotational use of insecticides with different modes of action for indoor residual spraying (IRS) is recommended for improving malaria vector control and managing insecticide resistance. Insecticides with new chemistries are urgently needed. Broflanilide is a newly discovered insecticide under consideration. We investigated the efficacy of a wettable powder (WP) formulation of broflanilide (VECTRON T500) for IRS on mud and cement wall substrates in laboratory and experimental hut studies against pyrethroid-resistant malaria vectors in Benin, in comparison with pirimiphos-methyl CS (Actellic 300CS). There was no evidence of cross-resistance to pyrethroids and broflanilide in CDC bottle bioassays. In laboratory cone bioassays, broflanilide WP-treated substrates killed > 80% of susceptible and pyrethroid-resistant An. gambiae sl for 6–14 months. At application rates of 100 mg/m2 and 150 mg/m2, mortality of wild pyrethroid-resistant An. gambiae sl entering experimental huts in Covè, Benin treated with VECTRON T500 was similar to pirimiphos-methyl CS (57–66% vs. 56%, P > 0.05). Throughout the 6-month hut trial, monthly wall cone bioassay mortality on VECTRON T500 treated hut walls remained > 80%. IRS with broflanilide shows potential to significantly improve the control of malaria transmitted by pyrethroid-resistant mosquito vectors and could thus be a crucial addition to the current portfolio of IRS insecticides.

A Potential Systematic Error in Using Lysivane as Inhibitor in the Measurement of Amniotic Fluid Acetylcholinesterase by the Ellman Method

1983 ◽  
Vol 20 (3) ◽  
pp. 159-162 ◽  
Author(s):  
B A Webb ◽  
S J Richardson ◽  
R Garry ◽  
J Atkins
Keyword(s):  
Enzymatic Hydrolysis ◽  
Amniotic Fluid ◽  
Systematic Error ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Acidic Solution ◽  
Rate Of Increase ◽  
Background Absorption ◽  
Low Levels ◽  
Hydrolysis Of

The measurement of low levels of cholinesterase or acetylcholinesterase by the Ellman method requires correction for a non-enzymatic increase in absorption at 412 mμ that is due both to non-enzymatic hydrolysis of the acetylthiocholine substrate and to modification of the colour reagent. The rate of increase in absorption is dependent on temperature and pH. Addition of an acidic solution of lysivane to the assay solution for selective measurement of amniotic fluid acetylcholinesterase gives rise to a shift in pH; the use of methanol is suggested as an easier method of dissolving the inhibitor and does not affect the pH of the assay, obviating any need to redetermine the background absorption. There is, however, no improvement in ability of the method to predict pregnancies associated with neural-tube defects.

Colorimetric Screening Device for Pesticide Analysis Based on the Liposome

2013 ◽  
Vol 726-731 ◽  
pp. 850-853
Author(s):  
Hua Nan Guan
Keyword(s):  
Enzymatic Activity ◽  
Organophosphorus Pesticides ◽  
Ph Sensitive ◽  
Pesticide Analysis ◽  
Ph Indicator ◽  
Fluorescent Indicator ◽  
Fluorescent Signal ◽  
Low Levels ◽  
Screening Device ◽  
Hydrolysis Of

Monitoring of the organophosphorus pesticides dichlorvos at very low levels has been achieved with liposome-based nanobiosensors. The enzyme acetylcholinesterase was effectively stabilized within the internal nanoenvironment of the liposomes. Within the liposomes, the pH sensitive fluorescent indicator pyranine was also immobilized for the optical transduction of the enzymatic activity. Increasing amounts of pesticides lead to the decrease of the enzymatic activity for the hydrolysis of the acetylcholine and thus to a decrease in the fluorescent signal of the pH indicator. The decrease of the liposome biosensors signal is relative to the concentration of dichlorvos down to 10-12 M levels. Also a colorimetric screening device for pesticide analysis has been evaluated.

Dieldrin-resistance in a strain of Aedes aegypti (L.) from Puerto Rico

1964 ◽  
Vol 55 (3) ◽  
pp. 519-526 ◽  
Author(s):  
A. M. Guneidy
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Cross Resistance ◽  
Autosomal Gene ◽  
Normal Strain ◽  
Susceptible Parent ◽  
Resistant Parent ◽  
Back Cross ◽  
Direct Cross ◽  
Resistance Spectrum

The cross-resistance characteristics of a dieldrin-resistant strain of Aedes aegypti (L.) from Puerto Rico were investigated by comparative tests on the adults of this and of a normal strain, using various insecticides. A resistance spectrum typical of that associated with resistance to BHC/dieldrin in other insects was revealed, characterised by slight or negligible cross-resistance to DDT, malathion and diazinon.The mode of inheritance of dieldrin-resistance was studied by determining resistance levels in the progeny of direct crosses of the resistant and normal strains and of back-crosses. The F1 generation of the direct cross was of intermediate resistance, and the F1 generation showed 1:2:1 segregation into normal, intermediate and resistant individuals. Both back-crosses showed 1:1 segregation into susceptible and intermediate individuals when the back-cross was to the susceptible parent, or into intermediate and resistant individuals when it was to the resistant parent, and these results were confirmed when one genotype was eliminated and the back-cross was repeated. These results indicate monofactorial inheritance of an autosomal gene with intermediate dominance, which is typical of the BHC/dieldrin type of resistance.

Mechanisms of insecticide resistance in a temephos selected Culex quinquefasciatus (Diptera: Culicidae) strain from Sri Lanka

1990 ◽  
Vol 80 (4) ◽  
pp. 453-457 ◽  
Author(s):  
H.T.R. Peiris ◽  
J. Hemingway
Keyword(s):  
Cytochrome P450 ◽  
Sri Lanka ◽  
Culex Quinquefasciatus ◽  
Resistant Strain ◽  
Resistance Mechanism ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Biochemical Assays ◽  
Significant Difference ◽  
Naphthyl Acetate

AbstractCulex quinquefasciatus Say from Peliyagoda, Sri Lanka, has larval resistance to temephos, malathion, fenitrothion and chlorpyrifos. Biochemical assays on individual resistant and susceptible mosquitoes of this strain showed that there was a good correlation between this resistance and increased esterase activity with both 1-and 2-naphthyl acetate, which appears to be the major resistance mechanism in this multiple organophosphate resistant strain. There was no significant difference in malaoxon, bendiocarb or propoxur sensitivity of the acetylcholinesterase from the resistant and susceptible strains, indicating that the sensitivity of the target site has not been altered. Biochemical assays on mass homogenates of the resistant and susceptible strains showed no correlation between resistance and the level of glutathione s-transferase activity, or the amount of cytochrome P450 present.

Detection of esterase activity in susceptible and organophosphate resistant strains of the cattle tick Boophilus microplus (Acari: Ixodidae)

1997 ◽  
Vol 87 (2) ◽  
pp. 197-202 ◽  
Author(s):  
R. Rosario-Cruz ◽  
E. Miranda-Miranda ◽  
Z. Garcia-Vasquez ◽  
M. Ortiz-Estrada
Keyword(s):  
Esterase Activity ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Molecular Weights ◽  
Sds Page ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Hydrolysis Of ◽  
Coomassie Brilliant ◽  
Naphthyl Acetate

AbstractTwo organophosphate (OP) resistant strains of the cattle tick Boophilus microplus (Canestrini) from Mexico and Costa Rica were used to analyse the presence of esterase activity associated with resistance. The concentrations of six major proteins in both resistant strains were increased compared to the susceptible Morelos strain, both when stained with Coomassie Brilliant Blue after SDS-PAGE, and when analysed for esterase activity by the hydrolysis of naphthyl acetate esters. Esterases were named A or B in relation to the substrate preference for alpha or beta naphthyl acetate and numbered according to their position on the SDS—PAGE. The molecular weights of these proteins were: 125, 115, 108, 77, 43 and 67 Kd for Est-Bl, Est-B2, Est-B3, Est-B4, Est-B5 and Est-A respectively. Est-B3 showed cholinesterase (ChE) activity. This study strengthens the hypothesis that the mechanism associated with OP resistance found in many other insects includes an increase of esterase activity, probably as a result of gene amplification. The genes encoding these enzymes could be potentially used as molecular markers to detect resistance in the cattle tick B. microplus using a DNA probe.

A Kinetic Study of the Aminolysis and Hydrolysis of α-Naphthyl Acetate

1955 ◽  
Vol 77 (10) ◽  
pp. 2771-2773 ◽  
Author(s):  
Peter J. Hawkins ◽  
Ivan Piscalnikow
Keyword(s):  
Kinetic Study ◽  
Hydrolysis Of ◽  
Naphthyl Acetate
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