Relative Fitness of Three Organophosphate-Resistant Strains of Culex pipiens pattens (Diptera: Culicidae)

1998 ◽  
Vol 35 (5) ◽  
pp. 716-719 ◽  
Author(s):  
Wang Jinfu ◽  
Lu Shaohong ◽  
Chen Rui ◽  
Wang Lingling
Keyword(s):  
Culex Pipiens ◽  
Relative Fitness ◽  
Resistant Strains

Carbamate and organophosphate resistance in Culex pipiens L. (Diptera: Culicidae) in southern France and the significance of Est-3A

1984 ◽  
Vol 74 (4) ◽  
pp. 677-687 ◽  
Author(s):  
R. J. Wood ◽  
N. Pasteur ◽  
G. Sinégre
Keyword(s):  
Culex Pipiens ◽  
Larval Instar ◽  
Piperonyl Butoxide ◽  
Southern France ◽  
Organophosphate Resistance ◽  
Metabolic Component ◽  
Carbamate Insecticides ◽  
Fourth Larval Instar ◽  
Resistant Strains ◽  
Tributyl Phosphorotrithioate

AbstractThree French strains of Culex pipiens L. were compared at the fourth larval instar for tolerance to organophosphate and carbamate insecticides, with and without the addition of synergists (the oxidase inhibitors piperonyl butoxide and CGA 84708) (a propynyl compound) and the carboxylesterase inhibitors triphenyl phosphate (TPP) and S,S,S-tributyl phosphorotrithioate (TBPT). The S54 strain was resistant to all the organophosphates tested (chlorpyrifos, malathion, monocrotophos and profenofos) compared to the susceptible LA VIS strain but only slightly tolerant to the two carbamates (carbaryl and naphthyl phenylcarbamate). The MAURIN strain was resistant to all the insecticides, including the carbamates, at a higher level. The action of chlorpyrifos and malathion on S54 was very strongly synergised by TBPT, less strongly by TPP and not at all by piperonyl butoxide. In fact, resistance was enhanced by piperonyl butoxide, as was resistance to monocrotophos and profenofos by CGA 84708. No synergist had much effect on the MAURIN strain, although TPP slightly increased the toxicity of malathion, and piperonyl butoxide and CGA 84708 slightly increased the toxicity of carbaryl. The toxic effect of carbaryl was also increased by the addition of extra acetone. Electrophoretic studies showed that the carboxylesterase enzyme coded by gene Est-20.64 (which is in linkage disequilibrium withEst-3A and acts as a marker for it) was absent from LA VIS but present in the resistant strains; but, whereas S54 was monomorphic for the gene, MAURIN was polymorphic (frequency 0·5). It is concluded that organophosphate resistance in S54 was due to detoxification by carboxylesterase wherease organophosphate and carbamate resistance in MAURIN had a strong non-metabolic component, possibly an insensitive acetylcholinesterase.

Comparative study of resistance to organophosphate and carbamate insecticides in four strains of the Culex pipiens L. complex (Diptera: Culicidae)

1986 ◽  
Vol 76 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Z. H. Tang ◽  
R. J. Wood
Keyword(s):  
Esterase Activity ◽  
Culex Pipiens ◽  
Larval Instar ◽  
Piperonyl Butoxide ◽  
Lower Sensitivity ◽  
Pyrethroid Insecticides ◽  
Carbamate Insecticides ◽  
High Production ◽  
Resistant Strains ◽  
General Esterase

AbstractFive strains of Culex pipiens L. (four resistant and one susceptible) were compared at the fourth larval instar for tolerance to organophosphate, carbamate and pyrethroid insecticides, with and without the addition of three synergists (piperonyl butoxide, triphenyl phosphate (TPP) and S, S, S-tributyl phosphorotrithiote (TBPT)). The DAR/D strain from Tanzania showed the highest levels and broadest range of resistance (temephos 37 ×, malathion 579×, propoxur 3032× and permethrin 100×). A strain from Rangoon and two from France (S54, BLEUET) showed lower resistance, restricted to organophosphates. Temephos and malathion resistance in the RANGOON strain was strongly inhibited by TBPT but not by TPP or piperonyl butoxide. Temephos and permethrin resistance in the DAR/D strain was slightly inhibited by TBPT and permethrin resistance by piperonyl butoxide. The DAR/D, RANGOON and CfCA (susceptible) strains were also compared for general esterase activity and phosphatase activity, both of which were higher in the resistant strains. It is concluded that resistance in RANGOON is associated with high production of an esterase sensitive to inhibition by TBPT but with little or no sensitivity to TPP, resembling but not identical in properties with the enzyme in strain S54 investigated earlier. Resistance in DAR/D was also associated with some increase in esterase activity, but the basis of resistance was different from that in S54 and RANGOON, having a much lower sensitivity to inhibition by TBPT.

Inheritance and activity of some esterases associated with organophosphate resistance in mosquitoes of the complex of Culex pipiens L. (Diptera: Cnlicidae)

1983 ◽  
Vol 73 (1) ◽  
pp. 153-170 ◽  
Author(s):  
F. Villani ◽  
G. B. White ◽  
C. F. Curtis ◽  
S. J. Miles
Keyword(s):  
Sri Lanka ◽  
High Intensity ◽  
Culex Pipiens ◽  
Resistance Mechanisms ◽  
Enzyme Assays ◽  
Resistance Level ◽  
Organophosphate Resistance ◽  
Esterase Pattern ◽  
Resistant Strains ◽  
Low Activity

AbstractEighteen strains of the complex of Culex pipiens L. from Africa, Asia and Europe were bioassayed for resistance to chlorpyrifos and electro-phoresed and stained for esterases. Susceptible strains showed only low activity esterase bands. The resistant strains of C. quinquefasciatus Say from hot countries (Liberia, Nigeria, Sri Lanka, Tanzania, Thailand) all showed the same two high intensity esterase bands (Rm 0·60 + 0·82). Different patterns of high esterase were found in resistant C. pipiens strains from cooler localities in Nairobi, Kenya (Rm 100), and Mont-pellier, France (Rm 0–50). Selection experiments on strains originally polymorphic for resistance and esterase pattern showed, without exception, that high esterase remained associated with resistance, and it is concluded that the association is almost certainly causal and not merely due to genetic linkage. The high intensity esterase bands were probably due to alleles of the loci Est-l, Est-2 and Est-3, separated by crossover distances of approximately 2·4 and 5·5 units, respectively. Strains monomorphic for what appeared to be the same high esterase pattern varied markedly in resistance level. Enzyme assays showed a direct relationship between levels of enzyme activity and resistance. Bioassays with fenthion and chlorpyrifos revealed differences in the relative resistance of C. quinquefasciatus from Colombo (Sri Lanka) and Dar-es-Salaam (Tanzania). Despite these differential degrees of cross-effectiveness, it is concluded that high intensity esterases are reliable indicators of organophosphate resistance in mosquitoes of the C. pipiens complex, although the possibility of other resistance mechanisms means that the lack of abnormally active esterases does not necessarily indicate the absence of resistance.

scholarly journals Investigation of Relative Development and Reproductivity Fitness Cost in Three Insecticide-Resistant Strains of Aedes aegypti from Thailand

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 265 ◽  
Author(s):  
Jassada Saingamsook ◽  
Jintana Yanola ◽  
Nongkran Lumjuan ◽  
Catherine Walton ◽  
Pradya Somboon
Keyword(s):  
Aedes Aegypti ◽  
Egg Production ◽  
Natural Populations ◽  
Blood Feeding ◽  
Developmental Time ◽  
Resistance Mechanisms ◽  
Fitness Cost ◽  
Detoxification Enzymes ◽  
Relative Fitness ◽  
Resistant Strains

Knockdown resistance (kdr) and detoxification enzymes are major resistance mechanisms in insecticide-resistant Aedes aegypti throughout the world. Persistence of the resistance phenotype is associated with high fitness of resistance alleles in the absence of insecticide pressure. This study determined the relative fitness cost of three insecticide-resistant strains of Aedes aegypti—PMD, PMD-R, and UPK-R—and a hybrid under similar laboratory conditions in the absence of insecticide. The PMD strain is resistant to DDT with no kdr alleles; the PMD-R is resistant to DDT and permethrin with 1534C homozygous kdr alleles; and UPK-R is resistant to DDT, permethrin, and deltamethrin with 989P + 1016G homozygous alleles. The DDT-resistant PMD strain had the highest fitness compared with the two DDT/pyrethroid-resistant strains (PMD-R and UPK-R) and hybrid. Consistent fitness costs were observed in the DDT/pyrethroid-resistant strains and hybrid, including shorter wing length, reduced egg hatchability, shorter female lifespan, and shorter viability of eggs after storage, whereas no effect was observed on blood feeding rate. In addition, reduced egg production was observed in the PMD-R strain and prolonged developmental time was seen in the UPK-R strain. The corresponding hybrid that is heterozygous for kdr alleles was fitter than either of the homozygous mutant genotypes. This is in accordance with the high frequency of heterozygous genotypes observed in natural populations of Ae. aegypti in Chiang Mai city.

ANALYSIS ON LIFE TABLE OF ORGANOPHOSPHATE-RESISTANT STRAINS OF CULEX PIPIENS PALLENS

1998 ◽  
Vol 5 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Jinfu Wang ◽  
Shaohong Lu ◽  
Rui Chen ◽  
Lingling Wang
Keyword(s):  
Life Table ◽  
Culex Pipiens ◽  
Culex Pipiens Pallens ◽  
Resistant Strains ◽  
Pipiens Pallens

Cross-resistance in DDT-resistant strains of various mosquitoes (Diptera, Culicidae)

1975 ◽  
Vol 65 (3) ◽  
pp. 459-471 ◽  
Author(s):  
Y. Rongsriyam ◽  
J. R. Busvine
Keyword(s):  
Culex Pipiens ◽  
Large Degree ◽  
Resistance Mechanisms ◽  
Cross Resistance ◽  
Normal Strain ◽  
Anopheles Quadrimaculatus ◽  
Culex Pipiens Fatigans ◽  
Resistant Strains ◽  
Ddt Resistance ◽  
Oxidation System

AbstractLarvicide tests were conducted on five species of mosquitoes, each of which had one or more DDT-resistant strains. The high potencies of DDT and, to a large degree, of DDD were completely lost by resistance. Other compounds were affected in different degrees according to the resistance mechanisms present, as indicated by resistance spectra and the effects of synergists. DDT-resistant strains of Culex pipiens fatigans Wied., Anopheles quadrimaculatus Say and A. stephensi List, showed highly specific resistance to DDT, probably dependent on a dehydrochlorination mechanism. DDT-resistance in Aedes aegypti (L.) and A. gambiae was also high, but there was definite evidence of cross-resistance to biodegradable DDT-analogues (about ×4 and ×10, respectively). This low-level, but definite, cross-resistance extended to a number of other compounds, notably pyrethroids, insect development inhibitors, amines, etc. The presence of synergistic action by piperonyl butoxide suggested that this depended on a microsomal oxidation system.Isotopically labelled (14C) DDT and malathion were used to study pick-up and penetration of these insecticides by larvae of normal and resistant Ae. aegypti. Both the actual and the percentage penetration of DDT were greater in the resistant than in the normal strain. Whatever the reason for this, it disposes of the possibility of reduced pick-up and penetration as a factor in DDT-resistance. With malathion, the percentage penetration was always higher in the susceptible strain than in the resistant one, though in some cases the actual amount was less.

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