Domestica Strains Research Articles

Monitoring of Thiamethoxam Resistance in Turkish House Fly Strains, Musca domestica (Diptera: Muscidae).

The house fly, Musca domestica, is vector for pathogens and parasites and causes economic damage to livestock by reducing forage conversion efficiency, negatively impacting weight gain and milk production. It has shown resistance to multiple insecticide classes. The aim of this research was to determine the susceptibility levels of seventeen field M. domestica strains to thiamethoxam, a neonicotinoid insecticide, in Türkiye. Insecticide susceptibility of the house flies to thiamethoxam was determined using the WHO glass jar method. A probit analysis program was used to determine LD50 values, and then the resistance ratios were compared with insecticide-susceptible strain. All strains were ≥18.5-fold resistant to thiamethoxam. The data showed that 10 out of 17 strains had either high or very high resistance levels. Our findings revealed that house flies from solid waste landfills in Samsun, Ankara, and Kocaeli exhibited higher resistance ratios compared to those found in animal shelters. Conversely, in Gaziantep, Antalya, İzmir and Erzurum, the exact opposite trend was observed. Regarding the LD50 values among solid waste storage areas, the lowest rate was obtained from Gaziantep (0.72 gr ai/m2), and the highest rate was obtained from Ankara (9.35 gr ai/m2). Furthermore, regarding the LD50 values among animal shelters, the lowest was obtained from Samsun (0.37 gr ai/m2), and the highest was obtained from Denizli (21800 gr ai/m2). The use of integrated control systems is recommended for controlling house fly populations, including insecticide class rotations for preventing, or at least, delaying the onset of resistance.

Monitoring resistance to methomyl and synergism in the non-target Musca domestica from cotton fields of Punjab and Sindh provinces, Pakistan

Insecticides are an integral part of most of the cropping systems worldwide; however, these usually exert negative impact on the environment and non-target insects as well. Non-target insects are prone to develop resistance to insecticides due to prolonged and repeated lethal and sublethal exposures. Musca domestica is a common non-target, pollinator and nectar feeder species in cotton ecosystem, besides its status as a public health pest in human habitations. In the present work, resistance to methomyl, one of the major insecticides used for cotton pest management, was assessed in 20 M. domestica strains from the major cotton producing areas of the Punjab and Sindh provinces of Pakistan. The results revealed that toxicity values of methomyl for Punjabi and Sindhi strains ranged from 28.07 to 136.16 µg fly−1 and 29.32 to 136.87 µg fly−1, respectively. Among Punjabi strains, D.G. Khan, Lodhran, Bahawalpur, Toba Tek Singh, Bahawalnagar, Rajanpur and Jhang strains exhibited very high levels of resistance (RR > 100) to methomyl; Bhakkar, Kasur, Vehari, Layyah, Muzaffargarh and R.Y. Khan showed high resistance (RR = 51–100 fold), while the Mianwali strain showed a moderate level of resistance to methomyl (RR = 36.45 fold). In case of Sindhi strains, very high levels of resistance (> 100 fold) were reported for Sukkar and Sanghar strains, high levels of resistance (RR 51–100 fold) for Khairpur, Jamshoro and Ghotki, and moderate resistance to methomyl (38.08 fold) in the Dadu strain. There was a significant synergism of methomyl toxicity in all field strains when methomyl bioassayed along with piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) providing clues of metabolic-based mechanisms of resistance to methomyl. In conclusion, insecticides used in crop farming can cause resistance development in non-target M. domestica. It is necessary to adopt the pest management activities that are safe for the environment and non-target insect species.

Alpha-Cypermethrin Resistance in Musca domestica: Resistance Instability, Realized Heritability, Risk Assessment, and Insecticide Cross-Resistance.

Musca domestica L., the common house fly, is a cosmopolitan carrier of human and livestock disease pathogens. The species exhibits resistance to many insecticides; therefore, effective M. domestica insecticide resistance management programs are required worldwide. In the present study, the development of alpha-cypermethrin resistance, realized heritability (h2), instability of resistance trait (DR), and cross-resistance (CR) was investigated in an alpha-cypermethrin-selected M. domestica strain (Alpha-Sel) across 24 generations (Gs). Compared with an alpha-cypermethrin-unselected strain (Alpha-Unsel), resistance to alpha-cypermethrin increased from 46.4-fold (G5) to 474.2-fold (G24) in Alpha-Sel females and 41.0-fold (G5) to 253.2-fold (G24) in Alpha-Sel males. Alpha-cypermethrin resistance declined by between -0.10 (G5) and -0.05 (G24) in both M. domestica sexes without insecticide exposure for 24 generations. The h2 of alpha-cypermethrin resistance was 0.17 and 0.18 for males and females, respectively, in G1-G24. With selection intensities of 10-90%, the G values required for a tenfold increase in the LC50 of alpha-cypermethrin were 6.3-53.7, 4.1-33.8, and 3.0-24.7, given h2 values of 0.17, 0.27, and 0.37, respectively, and a constant slope of 2.1 for males and h2 values of 0.18, 0.28, and 0.38, respectively, and a constant slope of 2.0 for females. Compared with Alpha-Unsel, Alpha-Sel M. domestica exhibited moderate CR to bifenthrin (15.5-fold), deltamethrin (28.4-fold), and cyfluthrin (16.8-fold), low CR to two pyrethroids and five organophosphates, and no CR to insect growth regulators. The instability of resistance trait, low h2, and absent or low CR associated with alpha-cypermethrin resistance in M. domestica indicate resistance could be managed with rotational use of the insecticide.

Transcriptome changes associated with apple (Malus domestica) root defense response after Fusarium proliferatum f. sp. malus domestica infection

BackgroundApple replant disease is a soilborne disease caused by Fusarium proliferatum f. sp. malus domestica strain MR5 (abbreviated hereafter as Fpmd MR5) in China. This pathogen causes root tissue rot and wilting leaves in apple seedlings, leading to plant death. A comparative transcriptome analysis was conducted using the Illumina Novaseq platform to identify the molecular defense mechanisms of the susceptible M.26 and the resistant M9T337 apple rootstocks to Fpmd MR5 infection.ResultsApproximately 518.1 million high-quality reads were generated using RNA sequencing (RNA-seq). Comparative analysis between the mock-inoculated and Fpmd MR5 infected apple rootstocks revealed 28,196 significantly differentially expressed genes (DEGs), including 14,572 up-regulated and 13,624 down-regulated genes. Among them, the transcriptomes in the roots of the susceptible genotype M.26 were reflected by overrepresented DEGs. MapMan analysis indicated that a large number of DEGs were involved in the response of apple plants to Fpmd MR5 stress. The important functional groups identified via gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were responsible for fundamental biological regulation, secondary metabolism, plant-pathogen recognition, and plant hormone signal transduction (ethylene and jasmonate). Furthermore, the expression of 33 up-regulated candidate genes (12 related to WRKY DNA-binding proteins, one encoding endochitinase, two encoding beta-glucosidases, ten related to pathogenesis-related proteins, and eight encoding ethylene-responsive transcription factors) were validated by quantitative real-time PCR.ConclusionRNA-seq profiling was performed for the first time to analyze response of apple root to Fpmd MR5 infection. We found that the production of antimicrobial compounds and antioxidants enhanced plant resistance to pathogens, and pathogenesis-related protein (PR10 homologs, chitinase, and beta-glucosidase) may play unique roles in the defense response. These results provide new insights into the mechanisms of the apple root response to Fpmd MR5 infection.

The role of Musca domestica and milk in transmitting pathogenic multidrug-resistant Escherichia coli and associated phylogroups to neonatal calves.

Escherichia coli, as a global source of antimicrobial resistance, is a serious veterinary and public health concern. The transmission of pathogenic multidrug-resistant (MDR) E. coli within diarrheic calves and its correlation with Musca domestica and milk strains have been investigated. In total, 110, 80, and 26 E. coli strains were obtained from 70 rectal swabs from diarrheic calves, 60 milk samples and 20M. domestica, respectively. Molecular pathotyping of E. coli revealed the presence of pathogenic E. coli with a higher percentage of shigatoxigenic strains within diarrheic calves and M. domestica at 46.4% and 34.6%, respectively. Phenotypic antimicrobial resistance revealed higher β-lactams resistance except for cefquinome that exhibited low resistance in M.domestica and milk strains at 30.8% and 30%, respectively. The extended-spectrum cephalosporin (ESC) resistant strains were detected within fecal, M. domestica, and milk strains at 69.1%, 73.1%, and 71.3%, respectively. All E. coli strains isolated from M. domestica exhibited MDR, while fecal and milk strains were harboring MDR at 99.1% and 85%, respectively. Molecular detection of resistant genes revealed the predominance of the blaTEM gene, while none of these strains harbored the blaOXA gene. The highest percentages for blaCTXM and blaCMYII genes were detected in M. domestica strains at 53.8% and 61.5%, respectively. Regarding colistin resistance, the mcr-1 gene was detected only in fecal and milk strains at 35.5% and 15%, respectively. A high frequency of phylogroup B2 was detected within fecal and M. domestica strains, while milk strains were mainly assigned to the B1 phylogroup. Pathogenic E. coli strains with the same phenotypic and genotypic antimicrobial resistance and phylogroups were identified for both diarrheic calves and M. domestica, suggesting that the possible role of M. domestica in disseminating pathogenic strains and antimicrobial resistance in dairy farms.

Biological responses in Musca domestica to fipronil and chlorfenapyr exposures

Insect populations exist under acute and chronic exposures to lethal and sublethal insecticide concentrations. Among the sublethal effects of insecticides on insects are reductions in life span, development rates, population growth, fertility, fecundity, changes in sex ratio, deformities, changes in behaviour, feeding, searching, and oviposition. These effects may differ depending on the modes of action of insecticides, their doses, and developmental stage of application. This study evaluated the life-history parameters in Musca domestica Linnaeus, 1758 (Diptera:Muscidae) strains that were exposed to two insecticides (fipronil and chlorfenapyr) with different modes of action at sublethal concentrations in each generation up to tenth. Two approaches to each insecticide’s exposure were used in this study, particularly in one approach, only adults M. domestica were exposed to fipronil or chlorfenapyr and in another approach, only larvae were exposed to each insecticide. The susceptibility of adult flies to these insecticides was assessed by resistance ratio based on results of non-choice feeding bioassays. Fipronil exposure at the sublethal concentration in each generation did not affect the susceptibility of adult M. domestica (in the tenth generation) to fipronil. The resistance ratio values revealed tolerance to chlorfenapyr in adults of M. domestica strains that were exposed to this insecticide, independent of the approach used to insecticide exposure. Most of the life-history parameters (such as durations of separate developmental stages, the emergence duration, the adult emergence ratio, the female ratio, and the number of eggs per female per day) of the second, fourth, sixth, eighth, and tenth generations of the insecticide-exposed strains were similar to those of the control strain. At the same time, the sublethal effects of both insecticides fipronil and chlorfenapyr prolonged the larval duration (1.63–2.22 times) and the number of days from egg to adult (1.18–1.39 times) compared to the control strain. Further studies are needed to investigate a possible genetic variability in M. domestica in response to exposure of parental generation to sublethal doses of fipronil and chlorfenapyr.

Inheritance, stability, cross-resistance, and life history parameters of a clothianidin-selected strain of house fly, Musca domestica Linnaeus.

The house fly, Musca domestica L., is a cosmopolitan insect pest of public and animal health importance that serves as a mechanical vector of pathogens. Aimed at prospective resistance management to reduce environmental pollution, we characterized the inheritance pattern, realized heritability, fitness cost, cross resistance, stability and mechanism of clothianidin resistance in M. domestica that were collected from the poultry farm. By continuous selection with clothianidin for 11 generations, the clothianidin selected M. domestica strain (Clotha-SEL) developed a 3827-fold resistance compared to a susceptible strain. However, resistance to clothianidin was proved to be unstable when selection with clothianidin was removed for five generations (G7 to G12). Inheritance pattern analysis at G8 of Clotha-SEL (RR=897) revealed that resistance to clothianidin was polygenic, autosomal and incompletely dominant. Realized heritability (h2) for resistance value was 0.38 (at G11) in the tested strain. Synergist bioassays showed that microsomal oxidases and esterases might not contribute significantly in resistance evolution. Fitness costs of clothianidin resistance were present, for example, reduction in growth potential of the Clotha-SEL strain in comparison to the untreated counterpart strain (UNSEL) was observed. No cross resistance to bifenthrin and fipronil and a very low cross-resistance to spinosad were observed. These insecticides could be alternated with clothianidin as an insecticide resistance management tool to sustain its efficacy for a longer time period. These results shall be utilized to devise a proactive resistance management strategy for use of clothianidin against M. domestica that will be helpful to alleviate the allied threats to environmental and human health.

Comparative morphological, histological, and RAPD analysis of Columba livia domestica strains

Comparative morphological, histological, and RAPD analysis of Columba livia domestica strains

Realized heritability of resistance to deltamethrin in a field strain of Musca domestica Linnaeus (Diptera: Muscidae)

A deltamethrin selected field strain of the house fly, Musca domestica, was used to assess realized heritability (h2) and risk for resistance development to deltamethrin. The estimated value of h2 was 0.27 with phenotypic standard deviation σp = 0.56 and selection differential S = 0.64. The intensity of deltamethrin selection had a direct effect on the rate of resistance development in the selected strain. Assuming the h2 value = 0.27 for six generations under selection pressure, a tenfold increase in the LC50 values has been expected in only 8-4 generations at the selection intensity 50–90%, respectively. In conclusion, the estimated values of h2 and the projected rate of deltamethrin resistance revealed a strong and rapid potential of the M. domestica strain to develop resistance against deltamethrin. Therefore, this insecticide should be used cautiously in the field.

Biological trait analysis and stability of lambda-cyhalothrin resistance in the house fly, Musca domestica L. (Diptera: Muscidae).

House flies, Musca domestica L., (Diptera: Muscidae), are pests of poultry and have the ability to develop resistance to insecticides. To design a strategy for resistance management, life history traits based on laboratory observations were established for lambda-cyhalothrin-resistant, susceptible and reciprocal crosses of M. domestica strains. Bioassay results showed that the lambda-cyhalothrin-selected strain developed a resistance ratio of 98.34 compared to its susceptible strain. The lambda-cyhalothrin-selected strain had a relative fitness of 0.26 and lower fecundity, hatchability, lower number of next generation larvae, and net reproductive rate compared with its susceptible strain. Mean population growth rates, such as intrinsic rate of population increase, and biotic potential were lower for the lambda-cyhalothrin-selected strain compared to its susceptible strain. Resistance to lambda-cyhalothrin, indoxacarb, and abamectin was unstable while resistance to bifenthrin and methomyl was stable in the lambda-cyhalothrin-selected strain of M. domestica. Development of resistance can cost considerable fitness for the lambda-cyhalothrin-selected strain. The present study provided useful information for making potential management strategies to delay resistance development in M. domestica.

Mechanism, stability and fitness cost of resistance to pyriproxyfen in the house fly, Musca domestica L. (Diptera: Muscidae)

Pyriproxyfen, a bio-rational insecticide, used worldwide for the management of many insect pests including the house fly, Musca domestica. To devise a retrospective resistance management strategy, biological parameters of pyriproxyfen resistant (Pyri-SEL), unselected (UNSEL), Cross1 and Cross2M. domestica strains were studied in the laboratory. Additionally, the stability and mechanism of resistance was also investigated. After 30 generations of pyriproxyfen selection, a field-collected strain developed 206-fold resistance compared with susceptible strain. Synergists such as piperonyl butoxide and S,S,S-tributylphosphorotrithioate did not alter the LC50 values, suggesting another cause of target site resistance to pyriproxyfen in the Pyri-SEL strain. The resistance to all tested insecticides was unstable in Pyri-SEL strain. The relative fitness of 0.51 with lower fecundity, hatchability, lower number of next generation larvae, reduced mean population growth rate and net reproductive rate were observed in the Pyri-SEL strain compared with the UNSEL strain. The cost of fitness associated with pyriproxyfen resistance was evident in Pyri-SEL strain. The present study provides useful information for making pro-active resistance management strategies to delay resistance development.

Cross-resistance, stability, and fitness cost of resistance to imidacloprid in Musca domestica L., (Diptera: Muscidae).

Imidacloprid, a neonicotinoid insecticide, has been used frequently for the management of Musca domestica L., (Diptera: Muscidae) worldwide. To design the strategy for resistance management, life history traits were established for imidacloprid-resistant, susceptible counterpart, and reciprocal crosses M. domestica strains based on laboratory observations. Bioassay results showed that the imidacloprid-selected strain developed a resistance ratio of 106-fold to imidacloprid, 19-fold to nitenpyram, 29-fold to chlorpyrifos, and 3.8-fold to cypermethrin compared to that of the susceptible counterpart strain. The imidacloprid-selected strain showed very low cross-resistance against nitenpyram and cypermethrin and a lack of cross-resistance to chlorpyrifos. Resistance to imidacloprid, nitenpyram, and chlorpyrifos was unstable, while resistance to cypermethrin was stable in Imida-SEL strain of M. domestica. The imidacloprid-selected strain had a relative fitness of 0.61 and lower fecundity, hatchability, number of next-generation larvae, and net reproductive rate compared with the susceptible counterpart strain. Mean population growth rates, such as intrinsic rate of population increase and biotic potential, were lower for the imidacloprid-selected strain compared with the susceptible counterpart strain. Development of resistance can cost considerable fitness for the imidacloprid-selected strain. The present study provided useful information for making potential management strategies to overcome development of resistance.

Laboratory and field assessment of cyantraniliprole relative to existing fly baits.

Toxic fly baits are commonly used for fly control in California animal operations. However, resistance development has been a problem. Comprehensive laboratory and field studies were conducted to test commercial baits (imidacloprid, methomyl, dinotefuran, spinosad) and one novel cyantraniliprole bait. A susceptible Musca domestica strain was compared with wild-type M. domestica and Fannia canicularis strains in the laboratory using choice/no-choice tests. Field visitation to baits and both short- and longer-term mortality were documented. Susceptible Musca suffered high mortality with all baits after 3 days of choice and no-choice tests. Wild-type Musca mortality was more variable and higher in no-choice relative to choice tests. Fannia were most susceptible to spinosad > dinotefuran = cyantraniliprole > methomyl = imidacloprid. Field Musca were most attracted to spinosad > cyantraniliprole > dinotefuran > sugar > methomyl > imidacloprid. Delayed mortality from bait-fed field flies (captured and held with untreated food and water for 3 days) was ranked spinosad = cyantraniliprole > dinotefuran = methomyl > imidacloprid > sugar. Behavioral resistance of M. domestica to imidacloprid and methomyl persists. Spinosad and cyantraniliprole baits (delayed mortality) performed best. Speed of action may be a factor in use and misuse of baits.

Preliminary evaluation of insecticide resistance in a strain of Musca domestica (Diptera: Muscidae) from an intensive chicken farm of Northern Italy

The house fly, Musca domestica L., a relevant sanitary pest, is mainly controlled by insecticides. However, an inappropriate use of chemicals may induce resistance, treatment efficacy decline and environmental damages. We evaluated toxicity of some organophosphates, pyrethroids, spinosad and neonicotinoids by topical applications on adults of a M. domestica strain (OcRo) collected from an intensive chicken farm in Northern Italy, in comparison to a susceptible strain (s-DBF). The OcRo strain exhibited higher levels of resistance (RR50) to four pesticides in comparison to s-DBF. Spinosad and imidacloprid had very low RR50, thus were still efficient in OcRo control. We also tested resistance to pesticides in OcRo after topical applications of synergistic compounds. Hydrolases were involved in phosphorganic detoxification and cytochrome P450 monoxygenases in that of pyrethroids. These results indicate that OcRo strain is now multiresistant to organophosphates and pyrethroids, and this should be considered for an environmentally safe pest management.

Determination of Malathion and Diazinon Resistance by Sequencing the Md E7 Gene from Guatemala, Colombia, Manhattan, and Thailand Housefly (Musca domestica L.) Strains

Organophosphate (OP) insecticides (parathion/diazinon) resistance in housefly (Musca domestica L.) is associated with the change in carboxylesterase activity. The product of alpha E7 gene, which is a member of alpha-esterase gene cluster, is probably playing a role in detoxification of the xenobiotic esters. In parathion/diazinon resistant M. domestica species Gly137 to Asp substitution was found in the active center of the product of alpha E7 gene. In malathion (an OP) resistant M. domestica strains Trp251 to Ser substitution was identified in the active center of the Md alpha E7. In our research, to understand the allelic diversity of the Md alpha E7, the gene was partially sequenced from four different housefly strains from different localities (Guatemala, Manhattan (USA), Colombia (USA) and Thailand). It was found out that; in Thailand strain one allele has Cys residue at the position of 251, the other allele contains a Trp for the same site. In Colombia strain, one allele has Asp137, the other allele contains a Gly residue at this point. The Manhattan and Guatemala strains have Asp137 and Trp251 residues on their both alleles at these two different positions.

Multiple Resistance in the Larger House FlyMusca domesticain Germany

Populations of the housefly Musca domestica isolated from farms in different German districts with strong resistance problems were compared to laboratory strains with varying resistance spectra. Resistance against pyrethroids, organophosphates and carbamates was tested using impregnated filter papers, and by topical application using a susceptible housefly strain (origin WHO) for comparison. The multi-resistant fly strains tested had a strong resistance against these insecticide groups, ranging from 37- to >10 000-fold for organophosphates and 150- to >6600-fold for pyrethroids. The constituent enantiomer pairs of the α-cyano-pyrethroid cyfluthrin were tested, as was beta-cyfluthrin. With respect to multi-resistant fly strains, the isomers II and IV had the best activity, with LD 50 values of 0.012 and 0.014 μg per fly, respectively. In addition, different groups of insect growth regulators (juvenile hormone analogues, chitin synthesis inhibitors and one triazine derivative) were tested in a special larvicidal test. The chitin synthesis inhibitors were quite effective against multi-resistant M. domestica strains except for one strain with strong resistance against chitin synthesis inhibitors, developed after extensive treatments with benzoylphenylureas for several years. The fly strains tested were not resistant against cyromazine. Additionally, the insecticides were combined with the synergists piperonyl butoxide, tributylphosphorotrithioate (DEF) and Cibacron blue and tested against the fly strain with the strongest resistance spectrum ('Grimm') in comparison to the susceptible strain ('WHO-N'). Piperonyl butoxide had the greatest effect on the efficacy of cyfluthrin followed by Cibacron blue and DEF. In a parallel investigation with susceptible and resistant house fly strains, different enzyme activities related with resistance mechanisms were tested, e.g. glutathione S-transferase (3.5-fold) and mixed-function oxidase (2.3-fold). Implications of these results for management of insecticide resistance in M. domestica are discussed.

6-Phosphogluconate dehydrogenase activity variants in Musca domestica L.: A further allele at the Pgd locus as proved by densitometric assay.

A new electrophoretic variant of 6-phosphogluconate dehydrogenase (6PGD) has been detected in flies of a laboratory Musca domestica strain. This variant is to be added to the two already described, PGD-A and PGD-B, identified by a fast-weak and a slow-thick electrophoretic band, respectively. The new variant, PGD-C, has the same mobility as PGD-A but provides a more intensely stained band; therefore it can be described as a fast-thick phenotype. The staining intensity of PGD-C is slightly lower than that of PGD-B. Genetic and densitometric tests have shown that the different levels of enzymatic activity of the two fast variants A and C are inherited as alternative genetic units, and they have been interpreted as one aspect of the phenotypic expression of two Pgd alleles, namely, PgdA and PgdC. These alleles determine both the rates of electrophoretic mobility (fast in both cases) and the levels of activity (low for A, strong for C; shown by weak or thick stained electrophoretic bands). Similarly, the two distinctive features of PGD-B, namely, slow mobility and high activity level, are always jointly inherited and appear as two pleiotropic aspects of the phenotype coded for by the PgdB allele. The PgdB/PgdC heterozygous flies provide a slightly asymmetrical three-banded zymogram, while the PgdA/PgdC combination leads to a single-banded pattern, showing the same mobility as the parents and an intermediate staining intensity. The quantitative analysis of enzyme activity of 6PGD zymograms, performed through densitometric methods, has led to the recognition of three different activity levels coded for by Pgd alleles, one of which, namely, PgdC, would not have been detected using electrophoretic methods alone.