Susceptible Strains Of House Flies Research Articles

Topical Toxicity and Repellency Profiles of 17 Essential Oil Components against Insecticide-Resistant and Susceptible Strains of Adult Musca domestica (Diptera: Muscidae).

The house fly is a significant pest in agriculture and human health that is increasingly difficult to manage due to multiple limitations including resistance development. To explore alternative pesticides, the topical toxicity and repellency profiles of 17 essential oil components (EOCs) were evaluated against a resistant and a susceptible strain of house fly, Musca domestica L., using topical application and Y-tube olfactometers, respectively. Six of the most toxic EOCs based on the LD50 were further investigated against a susceptible strain of house fly. Thymol, (+)-pulegone, eugenol, and carvacrol were always the top four most toxic chemicals tested against the resistant house fly strain. Little to no resistance was observed to the top six EOCs based on the comparison of the results between resistant and susceptible house fly strains. P-Cymene, citronellic acid, R-(+)-limonene, linalool, γ-terpinene, estragole, and eugenol were repellent to adult house flies at certain concentrations while (-)-carvone and thymol were attractive to adult house flies. This screening of a wide variety of individual EOCs provides a stronger foundation of information for further research. This should encourage further investigation into the topical toxicity and repellency in field studies, which will provide more insight into the performance of biopesticides for house fly management and potential commercialization.

Перспективы применения приманок на основе современных действующих веществ для борьбы с комнатными мухами

Topical application revealed the high resistance of field populations of houseflies to pyrethroids (500–900?), neonicotinoids (345–500?), phenylpyrazoles (46–75?), susceptibility to FOS (0.6–1.4?) and oxadiazines (0.2?). With intestinal exposure, resistance rates are somewhat lower, but resistance remains at a high level to fipronil (33–76?), thiamethoxam (80–105?) and clothianidin (80–98?). Susceptibility to indoxacarb (0.2–1.4?) was revealed. The comparative efficacy of two modern baits based on indoxacarb and dinotefuran for resistant and susceptible strains of house flies was studied. Both insecticides are highly toxic to house flies in the form of commercially available baits. Indoxacarb and dinotefuran can be recommended for introduction into rotation schemes of insecticides in the form of food baits to control adult flies. Keywords: dinotefuran, indoxacarb, house flies, insecticide resistance, baits.

Efficacy of insecticide mixtures against a resistant strain of house fly (Diptera: Muscidae) collected from a poultry farm

House flies (Musca domestica L.) are key pests of poultry and are managed worldwide with a variety of insecticides. However, extensive and injudicious use of insecticides has led to the development of resistance in many insect pests. Insecticide mixtures can increase the efficacy of the product and/or delay the development of resistance, thus making them a useful tool for pest control. In addition to their efficacy when used alone, mixtures of emamectin benzoate, spinosad or nitenpyram with either lambda-cyhalothrin or profenofos were assessed against a susceptible strain of house flies collected from poultry farms. The analysis revealed that combination indices for lambda-cyhalothrin/emamectin benzoate and lambda-cyhalothrin/spinosad mixtures were significantly >1, indicating an antagonistic effect. In contrast, the indices for all the tested ratios of lambda-cyhalothrin/nitenpyram were significantly < 1, suggesting a synergistic effect. For mixtures containing profenofos, combination indices varied significantly. For example, synergism was observed in a 1:1 mixture containing lambda-cyhalothrin and emamectin benzoate, but antagonism occurred when a higher proportion of the latter insecticide was used. Conversely, synergism in a mixture containing profenofos and nitenpyram was observed only when a lower proportion of the second insecticide was used. The present results suggest that ideal insecticide mixtures must be empirically determined and alternative strategies such as mosaics, rotations and cultural control should be considered for the management of the house fly.

Differential expression of CYP6A5 and CYP6A5v2 in pyrethroid‐resistant house flies, Musca domestica

Two cytochrome P450 alleles, CYP6A5 and CYP6A5v2, were isolated from a pyrethroid-resistant house fly stain, ALHF. The two alleles shared 98% similarity in amino acid sequence. To understand the importance of these two alleles in resistance and examine the expression profile of the two alleles between resistant and susceptible strains, quantitative real-time PCR (qRT-PCR) was performed and compared with the Northern blot analysis. We found that qRT-PCR was an efficient method to characterize the expression profiles between these two sequence-closely-related P450 genes between resistant and susceptible houses flies. One of them, CYP6A5v2, was constitutively overexpressed in ALHF house flies compared with susceptible house fly strains. Moreover, this gene was predominantly expressed in the abdominal tissues of ALHF, in which the primary detoxification organs of insects are located. However, there was no significant difference in the expression of CYP6A5 between ALHF and susceptible house flies. The genetic linkage analysis was conducted to determine the possible link between the constitutively overexpressed CYP6A5v2 and insecticide resistance. CYP6A5v2 was mapped on autosome 5, which is correlated with the linkage of resistance in ALHF. Taken together, the study suggests the importance of CYP6A5v2 in increasing metabolic detoxification of insecticides in ALHF. The distinct expression of CYP6A5 and CYP6A5v2 in resistant and susceptible house flies implies the functional difference of theses two genes in house flies and suggests that they are two recently diverged P450 genes presented in a single organism.

Effect of synergists on the oral and topical toxicity of azamethiphos to organophosphate-resistant houseflies (Diptera: Muscidae).

Dermal and oral toxicities of azamethiphos were determined in two organophosphate-resistant and one susceptible strain of houseflies, Musca domestica L. The 594vb strain was 1,967-fold more resistant to azamethiphos when compared with the susceptible Chemical Specialties Manufacturers Association (CSMA) strain by dermal application. When the compound was administered orally to the 594vb strain, we observed only a 15-fold resistance. In contrast, the Yachiyo strain, which show 1,500-fold resistance to diazinon and which has known multiple mechanisms for organophosphate resistance, showed only 6-fold resistance to azamethiphos by topical application and 4-fold resistance by oral administration. Azamethiphos administered dermally and orally was equally toxic to the CSMA and Yachiyo strains. However, when azamethiphos was administered to the 594vb strain, the insecticide was 71 times more toxic orally than by the dermal route. This result indicated involvement of a cuticular penetration factor in the resistance mechanism. The effect on azamethiphos toxicity of piperonyl butoxide (PB), an inhibitor of the monooxygenases, and tributylphosphorotrithioate (DEF), an esterase inhibitor, was investigated in the three strains. Pretreatment of the flies with PB, DEF, or PB+DEF before topical application of azamethiphos resulted in a significant decrease in LD50s in all the strains. The degree of synergism, however, varied depending upon the strains and the synergists. Similar results were obtained when azamethiphos was administered orally following pretreatment of the flies with PB+DEF. We attribute the high level of azamethiphos resistance in the 594vb strain partly to increased degradation by oxidative and hydrolytic enzymes. The hydrolytic enzymes are more important, but other factors including reduced cuticular penetration and insensitive acetylcholinesterase may be involved.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of cytochrome P450 lpr in deltamethrin metabolism by pyrethroid-resistant and susceptible strains of house flies

The LPR strain of house fly is highly resistant to pyrethroid insecticides and this resistance is associated with high levels of monooxygenase activity and total cytochromes P450. To evaluate the role of P450 lpr (the major P450 in LPR house flies) in pyrethroid resistance, an antiserum specific for house fly cytochrome P450 lpr was tested for its ability to inhibit cytochrome P450 monooxygenase-dependent metabolism of the pyrethroid insecticide deltamethrin. Treatment of microsomes from pyrethroid resistant LPR house flies with anti-P450 lpr antiserum resulted in 97% of the radiolabel being recovered as deltamethrin compared to 76% in the normal serum control. There was no significant difference in the amount of deltamethrin recovered from microsomes of susceptible (S+) flies treated with normal serum or anti-P450 lpr antiserum compared to the carbon monoxide-inhibited control. However, there was statistically significant inhibition of specific metabolite production in both strains. Using LPR microsomes, seven NADPH-dependent products of [ 14C]deltamethrin metabolism could be identified by thin-layer chromatography, designated as B, C, D, E, F, G, and H (origin). Metabolites B, C, D, and H were the major metabolites. Formation of metabolites B, C, and H was inhibited by anti-P450 lpr while D was increased. In S+ microsomes, only metabolites C, D, and E were consistently detected and anti-P450 lpr inhibited formation of C and D while E was unchanged. The primary metabolites inhibited by the antiserum in LPR appear to be modifications of the acid portion of the deltamethrin molecule, and the major metabolites increased by antiserum treatment were oxidations on the alcohol portion of the molecule, suggesting that P450 lpr preferentially attacks the gem-dimethyl group of deltamethrin. Pyrethroid-resistant LPR flies, topically dosed with a sublethal dose of deltamethrin, rapidly metabolized and excreted polar metabolic products. Similarly, microsomes from LPR house flies exhibited rapid cytochrome P450-dependent metabolism of deltamethrin. This study indicates that P450 lpr contributes to monooxygenase-dependent deltamethrin resistance in LPR house flies.

Studies on the metabolism of vamidothion and its thioanalog in insecticide-resistant and susceptible house fly strains

The in vivo and in vitro metabolism of vamidothion [ O,O-dimethyl S-[2-(1-methylcarbamoyl)-ethylthio] ethylphosphorothiolate] as well as the in vitro metabolism of thiovamidothion [ O,O-dimethyl S-[2-(1-methylcarbamoyl)ethylthio] ethylphosphorodithioate] was investigated in insecticide-resistant and susceptible house fly strains. Vamidothion was converted in vivo to the sulfoxide, the principle metabolite, and subsequently to the sulfone at a slower rate. Vamidothion and vamidothion sulfoxide were hydrolyzed at the PS and SC bond. The resulting primary alcohol metabolite was further oxidized to a carboxylic acid followed by decarboxylation. No metabolism of vamidothion or thiovamidothion occurred in vitro without the addition of NADPH. The addition of NADPH resulted in rapid conversion of vamidothion to the sulfoxide, and thiovamidothion was oxidatively metabolized to six metabolic products. No qualitative differences were found between resistant and susceptible strains, but there were signficant quantitative differences. The metabolism was highest in the Rutgers strain followed by Cornell-R, Hirokawa, and then CSMA strain. The route of vamidothion and thiovamidothion metabolism was via the cytochrome P-450-dependent monooxygenase system, and none of the resistant strains showed glutathione S-transferase activity toward vamidothion or thiovamidothion. No further oxidation of vamidothion sulfoxide to the sulfone was observed and also no hydrolysis products were formed, in vitro.

Resistance stability and coadaptation in diazinon-resistant house flies (Diptera: Muscidae).

The mean frequency (±SD) of the diazinon resistance allele in Musca domestica L. recently collected from the field in Mississippi was 0.265 ± 0.051. Estimates of reproductive potential (fecundity and developmental time) indicated no differences between resistant and susceptible strains of house flies isolated directly from the field. A backcrossing scheme was used to isolate the resistance allele in a susceptible genetic background. The RR genotype was not at a significant disadvantage compared to the SS genotype, even in the apparent absence of fitness modifiers. Therefore, coadaptation of resistance and fitness does not appear to be important in these populations.

Characterization of antibodies to house fly NADPH-cytochrome [formula omitted] reductase

Antibodies to solubilized and purified NADPH-cytochrome P-450 reductase from house fly microsomes were obtained in rabbits. Evolution of antibody titre was determined by the increasing inhibition of house fly microsomal NADPH-cytochrome c reductase activity by serum samples. An IgG fraction was obtained from the serum by ammonium sulphate precipitation. These antibodies inhibited microsomal NADPH-cytochrome c reductase from insecticide-resistant and susceptible house fly strains as well as from phenobarbital-treated insects. The antibodies were specific for NADPH-cytochrome P-450 reductase because they did not inhibit the NADH-dependent reduction of cytochrome c, dichlorophenolindophenol or ferricyanide. The antibodies distinguished the native NADPH-cytochrome P-450 reductase from the proteolytically processed NADPH-cytochrome c reductase as shown by differential inhibition of solubilized, purified enzymes. The antibodies inhibited microsomal cytochrome P-450 monooxygenase activities such as epoxidation and O- dealkylation , thus confirming the role of NADPH-cytochrome P-450 reductase in these reactions. Cross-reactivity towards the microsomal enzyme of 15 animal species was shown by inhibition of NADPH-cytochrome c reductase activity. Cross-reactivity was high for the enzyme of other Diptera such as a Drosophila melanogaster and Culex pipiens, but was very low for NADPH-cytochrome c reductase from vertebrate sources.

Cuticular lipids of two resistant and a susceptible strain of houseflies

AbstractA study was made of the composition of the cuticular lipids of two resistant strains of houseflies (Rutgers and Fc), both of which show a reduced rate of absorption of insecticides as a partial mechanism of resistance and a susceptible strain (CSMA). Total lipids, monoglycerides, diglycerides and sterol esters (except in the Fc strain), sterols, fatty acids and phospholipid phosphorus were higher in resistant strains than in the susceptible strain. Phosphatidyl‐ethanolamine and phosphatidyl‐choline were major constituents of the phospholipid fractions and were appreciably higher in the resistant strains. Cuticular wax contents did not differ among strains. Incorporation of lipid precursors, [U‐14]acetate and [32P]orthophosphate, was greater in the cuticle of one or both resistant strains, depending on the lipid component examined.

Effect of anomalous cuticular phospholipids on penetration of insecticides in susceptible and resistant house flies

The cuticular lipid composition of resistant and susceptible strains of house flies ( Musca domestica L.) was altered by incorporation of dl-carnitine and 2-dimethylaminoethanol into the artificial diet under axenic conditions. β-Methyl-choline or 2-dimethylaminoethanol partially replaced the naturally occurring phospholipids (phosphatidyl choline and phosphatidyl ethanolamine) in the cuticular lipids of the adult of all strains. Effects of altered cuticular lipid composition on absorption of DDT, dieldrin, diazinon, parathion, and carbaryl in susceptible and resistant strains of house flies were studied. Upon incorporation of β-methyl-choline, the absorption pattern in the susceptible strain was decreased slightly, but this qualitative change caused increased absorption of DDT, dieldrin, diazinon, and parathion in one or more resistant strains. Incorporation of 2-dimethylaminoethanol changed the absorption pattern of insecticides in both susceptible and resistant strains of house flies to a slightly greater extent than did β-methyl-choline.

&lt;i&gt;In vitro&lt;/i&gt; Metabolism of Malathion by Malathion Resistant and Susceptible Strains of Houseflies, &lt;i&gt;Musca domestica&lt;/i&gt; L.

由来のことなるマラチオン抵抗性 (札幌, 藻岩, 15-D) および感受性 (高槻, 八雲, 鉾田) イエバエをもちい, in vitro でのマラチオンの代謝をしらべた. 感受性の高槻系に対する抵抗性の札幌, 藻岩, 15-D系のマラチオンの抵抗性比はそれぞれ57.4, 83.6, 113.3であった. 一方, マラチオンを分解する carboxylesterase の活性は, 抵抗性系統では高槻系に比べ30～39倍であり, マラオクソン分解活性も10～12倍であった. マラチオンを分解する carboxylesterase 活性は, 札幌, 藻岩系ではミトコンドリア分画で, 15-D系では上清分画で最も高かった. また in vitro でのマラチオンの主要な代謝物は malathion monocarboxylic acid および malathion dicarboxylic acid であった. 以上のことから, マラチオンを分解する carboxylesterase 活性の高揚およびマラオクソン分解活性の高揚がマラチオン抵抗性機構の主要因と考えられた. さらに15-D系では抵抗性機構に GSH S-transferase が関与していると考えられた.

Purification and properties of housefly glutathione [formula omitted

Glutathione S- transferases were partially purified from an insecticide resistant and a susceptible strain of houseflies and characterized using 3,4-dichloronitrobenzene (DCNB) as the substrate. The molecular weight of the enzyme was estimated to be 50,000 and SDS gel electrophoresis revealed that the enzyme consisted of two equal subunits of 23,000. An Arrhenius plot of temperature versus DCNB conjugation showed a discontinuity at about 35°C. The optimum pH for enzyme activity was 9.5 to 10. A difference in the equilibrium constants between the enzymes from the resistant and susceptible strains did not explain the higher overall reactions in the resistant strain. The same enzyme was active for methyl iodide conjugation, degradation of organophosphorus insecticides and γ-BHC, but was inactive for DDT-dehydrochlorination. The degradation of organophosphorus insecticides was via alkyl conjugation and/or “leaving group” conjugation.

LOW-VOLUME AND CONVENTIONAL NON-THERMAL AEROSOLS AGAINST INSECTICIDE SUSCEPTIBLE AND RESISTANT HOUSE FLIES (DIPTERA: MUSCIDAE)

AbstractSeven of 17 insecticides tested as conventional aerosols were effective against a susceptible strain of house flies, Musca domeslica L., producing 90% or more mortality at a distance of 150 ft from the generator. Of the seven, three were equally effective as low-volume aerosols. Diazinon was the most effective of the conventional aerosols, and Dursban® (0,0-diethyl 0-(3,5,6-trichloro-2-pyridyl) phosphorothioate) was the most effective low-volume aerosol. However, none of the compounds was effective as a conventional or low-volume aerosol against an insecticide resistant strain of flies.

In vitro metabolism of azinphosmethyl in susceptible and resistant houseflies

The in vitro metabolism of [ 14C-methoxy] or [ 32P]azinphosmethyl by subcellular fractions of abdomens from a resistant and a susceptible strain of houseflies was studied. The degradative activity in both strains was associated with the microsomal and soluble fractions and required NADPH and glutathione, respectively. The resistant strain possessed higher activity for both the mixed-function oxidases and the glutathione transferase than the susceptible strain, and both systems appear to be important in the resistance mechanism. The mixed-function oxidases were involved in the oxidative desulfuration as well as the dearylation of azinphosmethyl. A glutathione transferase located in the soluble fraction catalyzed the formation of desmethyl azinphosmethyl and methyl glutathione. This enzyme also demethylated azinphosmethyl oxygen analog. Although the soluble fraction exhibited both glutathione S-alkyltransferase and S-aryltransferase activity against noninsecticidal substrates, no evidence of the transfer of the benzazimide moiety from azinphosmethyl to glutathione was obtained. Sephadex G-100 chromatography of the soluble enzymes revealed a common eluting fraction responsible for both types of transferase activity.

Screening tests of contact sprays for control of adult house flies.

Wind-tunnel tests were made to evaluate the effectiveness of 119 promising insecticides as contact sprays against a susceptible strain of house flies, Musca domestica L., and a strain resistant to insecticide. Forty of the compounds were more effective against both strains, based on the LC50 levels, than the malathion or ronnel standards.

Quantitative aspects of the detoxication of naphthalene by resistant and susceptible house flies.

The rate of metabolism and excretion of naphthalene-l-C14 and 1-naphthol-1-C14 by resistant and susceptible strains of house flies, Musca domestica L., has been studied by means of injection and feeding experiments. Combustion of insects given single doses of the radioactive drugs has shown that both are rapidly eliminated; approximately 80% of an injected dose is excreted within 7 hours and 90% in 24 hours. When fed up to 0.4% 1-naphthol in sugar, the flies excrete naphthol metabolites at the rate of approximately 3 to 5 µg per day per insect. Males of both strains excrete the metabolized drug about 50% more rapidly than females. About 23 to 68% of the excreted drug is in the form of 1-naphthyl glucoside and about 8 to 17% as 1-naphthyl sulfate. Relatively more glucoside is produced by young females but the absolute amount produced by the sexes is approximately the same. Although R and S insects were compared both quantitatively and qualitatively for naphthol metabolism, no differences either in rate of metabolite production or in relative levels of metabolites could be seen.

Resistance of the house fly to Bacillus thuringiensis Berliner

Resistance to Bacillus thuringiensis Berliner was induced in house flies (Musca domestica Linnaeus) by selecting survivors from treated larval medium during 50 generations of rearing. The degree of resistance, based on the ratios of LD50 values, varied from 8- to 14-fold between the 27th and 50th generation, inclusive. Resistance, developed during 30 generations of selection, appeared to decline slightly during 20 generations without selection pressure. A wild strain subjected to 10 generations of selection did not become more resistant than a laboratory strain with comparable selection. Early and late pupating strains of house flies, with larval periods of 5 and 8 days, respectively, were equally susceptible. As the age of larvae increased from 1 to 4 days, the LD50 values increased from four- to sixfold with each additional day larvae were reared in the absence of spore powder. Mortality occurred primarily in the larval stage when tests were initiated with eggs, and it occurred mainly in the pupal stage when tests were initiated with 2-day-old larvae. The relative increase in LD50 values was the same for both resistant and susceptible strains of house flies when spore powder was autoclaved.

A dipping technique for selecting house-flies, Musca domestica L., for resistance to insecticides

A dipping technique for exposing large numbers of house-flies (Musca domestica L.) to measured doses of insecticide is described. It is suitable for selecting resistant populations and, while giving consistent results, is more rapid than other techniques used for this purpose.Up to 2,000 flies of both sexes, less than 24 hr. old, are immersed for three minutes in 100 ml. of a 70 per cent, mixture of acetone and water containing the required concentration of insecticide, using a 9-cm. sintered glass Büchner funnel as the immersion chamber. The liquid is then removed by suction, the sides of the funnel are wiped with filter paper, and the flies are allowed to drain for three minutes; they are then transferred in small batches to plastic recovery chambers containing food. Mortality is recorded next day, and the survivors are released into breeding cages.Experiments showed that immersion for three minutes in 70 per cent, acetone was virtually harmless to the flies and that the amount of insecticide deposited on individual flies was reasonably uniform (coefficient of variation about 20%). Batches of 2,000 flies, but not more, could be treated at one time.When the dipping technique was compared with topical application of measured drops of insecticide, using a susceptible strain of house-flies and two other strains that were resistant to DDT and diazinon, dipping gave steeper log-probit regression lines than topical application, and the LD50's and resistance factors of the resistant strains were smaller. With flies resistant to DDT, dipping gave straight regression lines whereas topical application gave compound lines.

Inhibition of the Succinoxidase System of Susceptible and Resistant House Flies by DDT and Related Compounds1

The dehydrochlorination of DDT [2, 2- bis ( p -chlorophenyl)-1, 1, 1-trichloroethane] to DDE [2, 2- bis ( p -chlorophenyl)-1, 1-dichloroethylene] has been shown to occur at a considerably more rapid rate and to a greater extent in resistant than in susceptible strains of house flies (Sternburg et al., 1950a, 1950b; Perry and Hoskins, 1950, 1951a, 1951b; Winteringham et al., 1951). The enzyme system which catalyzes this reaction has been isolated from resistant flies and examined in vitro by Sternburg et al., (1953), and the rate of conversion of DDT to DDE in vivo has been proposed as a critical yardstick for assessing resistance by Perry et al., (1953). DDT-dehydrochlorinase activity is undoubtedly an important factor in the development of resistance to DDT. However, unchanged DDT in amounts greater than the LD50 for susceptible flies can be recovered from living, resistant flies more than 24 hours after topical application of the insecticide. Bradbury et al., (1954) have recently shown that adult flies of a lindaneresistant strain are able to carry over from the larval stage larger amounts of intact lindane ( gamma -isomer of hexachlorocyclohexane) than are necessary to kill susceptible individuals. The presence of these large amounts of intact insecticides in living, resistant insects indicates that other factors in addition to a detoxication mechanism may be involved in the biochemical mechanisms of resistance. Babers and Pratt (1953) have recently reviewed the evidence in this regard. On the basis of this evidence and their own studies they have concluded that the ability to metabolize DDT is not sufficient explanation for the resistance phenomenon.