scholarly journals Susceptibility of field populations of Haematobia irritans to fipronil in Uruguay

2021 ◽  
Vol 41 ◽  
Author(s):  
Cecilia Miraballes ◽  
Antonio Thadeu M. Barros ◽  
Martin Lucas ◽  
Guilherme M. Klafke ◽  
Luísa N. Domingues ◽  
...  

ABSTRACT: Fipronil was registered in Uruguay in 1997, and, since then, it has been used for the control of Haematobia irritans irritans and Rhipicephalus microplus. The susceptibility of H. irritants to this drug has not been evaluated. Therefore, the goal of the present study was to evaluate the resistance of H. irritans to fipronil. Additionally, a survey was carried out with the farmers to evaluate the use of fipronil for H. irritans control in the ranches where the flies came from. For the bioassays, 31 field populations of H. irritans were exposed to 10 concentrations of fipronil (3.2-16.0μg.cm2), and their LC50 values were calculated using probit analysis. A bioassay was performed with horn flies from the susceptible colony maintained at the USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory for comparison and calculation of resistance ratios (RRs). All 31 field populations surveyed in the study were susceptible to fipronil, with resistance ratios ranging from <0.5 to 2.2. Four populations with RRs >1 did not differ significantly from the susceptible strain. A single population showed an RR >2.2. Overall, the survey shows that fipronil was mostly used for R. microplus control, and in only three ranches, which were free of R. microplus, was fipronil used for horn fly control. Seventeen farmers did not use fipronil at all in the last three years. It is concluded that, in Uruguay, field populations of horn flies remain susceptible to fipronil.

1993 ◽  
Vol 125 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Felix S. Mwangala ◽  
Terry D. Galloway

AbstractResistance of horn fly, Haematobia irritans (L.), to fenvalerate and permethrin was evaluated in Manitoba from 1987 to 1989. The number of resistant populations and the intensity of resistance increased during the period. In 1987, resistant flies were observed on three of 18 herds sampled. Resistance, determined by comparison with a susceptible strain at the LC50, was less than 6-fold for fenvalerate and 3-fold for permethrin except for one population whose resistance was 14-fold for permethrin. In 1988, resistant flies were observed on six of 26 herds sampled. Resistance ranged from 0.03- to 38-fold for fenvalerate and 0.1- to over 100-fold for permethrin. In 1989, resistant flies were found on 10 of 22 herds sampled. Resistance ranged from 1- to 62-fold for fenvalerate and 0.8- to over 100-fold for permethrin. Resistant populations were interspersed among susceptible ones.


1965 ◽  
Vol 45 (1) ◽  
pp. 43-50 ◽  
Author(s):  
M. A. Khan ◽  
J. E. Lawson

Spraying yearlings with 2% Co-Ral in July was 100% effective for systemic control of cattle grubs (Hypoderma spp.). Spraying spring calves with 1% Co-Ral in August was equally effective, and gave better control (P < 0.01) than spraying with 1 or 2% Co-Ral in June or 0.5% Co-Ral in July. Co-Ral sprays were not suitable for horn fly (Haematobia irritans L.) control.Two per cent Sevin sprayed on calves in June or July did not control cattle grubs, and only partially controlled horn flies.Compared with the control group, the average daily gain was higher (P < 0.05) to weaning but lower (P < 0.05) in the feedlot in calves sprayed with 2% Sevin in June. Similarly, it was higher (P < 0.05) from birth to the end of the feedlot period in calves sprayed with 2% Co-Ral in June, but lower (P < 0.05) in calves sprayed with 0.5% Co-Ral in July.Mild toxicosis occurred in five calves sprayed with 2% Co-Ral in June, and subclinical toxicosis in calves sprayed with 1% Co-Ral in August.


2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Mukund Madhav ◽  
Rhys Parry ◽  
Jess A. T. Morgan ◽  
Peter James ◽  
Sassan Asgari

ABSTRACT The horn fly, Haematobia irritans irritans, is a hematophagous parasite of livestock distributed throughout Europe, Africa, Asia, and the Americas. Welfare losses on livestock due to horn fly infestation are estimated to cost between $1 billion and $2.5 billion (U.S. dollars) annually in North America and Brazil. The endosymbiotic bacterium Wolbachia pipientis is a maternally inherited manipulator of reproductive biology in arthropods and naturally infects laboratory colonies of horn flies from Kerrville, TX, and Alberta, Canada, but it has also been identified in wild-caught samples from Canada, the United States, Mexico, and Hungary. Reassembly of PacBio long-read and Illumina genomic DNA libraries from the Kerrville H. i. irritans genome project allowed for a complete and circularized 1.3-Mb Wolbachia genome (wIrr). Annotation of wIrr yielded 1,249 coding genes, 34 tRNAs, 3 rRNAs, and 5 prophage regions. Comparative genomics and whole-genome Bayesian evolutionary analysis of wIrr compared to published Wolbachia genomes suggested that wIrr is most closely related to and diverged from Wolbachia supergroup A strains known to infect Drosophila spp. Whole-genome synteny analyses between wIrr and closely related genomes indicated that wIrr has undergone significant genome rearrangements while maintaining high nucleotide identity. Comparative analysis of the cytoplasmic incompatibility (CI) genes of wIrr suggested two phylogenetically distinct CI loci and acquisition of another cifB homolog from phylogenetically distant supergroup A Wolbachia strains, suggesting horizontal acquisition of these loci. The wIrr genome provides a resource for future examination of the impact Wolbachia may have in both biocontrol and potential insecticide resistance of horn flies. IMPORTANCE Horn flies, Haematobia irritans irritans, are obligate hematophagous parasites of cattle having significant effects on production and animal welfare. Control of horn flies mainly relies on the use of insecticides, but issues with resistance have increased interest in development of alternative means of control. Wolbachia pipientis is an endosymbiont bacterium known to have a range of effects on host reproduction, such as induction of cytoplasmic incompatibility, feminization, male killing, and also impacts vector transmission. These characteristics of Wolbachia have been exploited in biological control approaches for a range of insect pests. Here we report the assembly and annotation of the circular genome of the Wolbachia strain of the Kerrville, TX, horn fly (wIrr). Annotation of wIrr suggests its unique features, including the horizontal acquisition of additional transcriptionally active cytoplasmic incompatibility loci. This study provides the foundation for future studies of Wolbachia-induced biological effects for control of horn flies.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6936
Author(s):  
Javier Espinoza ◽  
Cristian Medina ◽  
Washington Aniñir ◽  
Paul Escobar-Bahamondes ◽  
Emilio Ungerfeld ◽  
...  

Haematobia irritans is a cosmopolitan obligate blood-feeding ectoparasite of cattle and is the major global pest of livestock production. Currently, H. irritans management is largely dependent on broad-spectrum pesticides, which has led to the development of insecticide resistance. Thus, alternative control methods are needed. Essential oils have been studied as an alternative due to their wide spectrum of biological activities against insects. Thus, the main aim of this study was to evaluate the insecticidal, repellent and antifeedant activity of the essential oils from Blepharocalyx cruckshanksii leaves and Pilgerodendron uviferum heartwood against horn flies in laboratory conditions. The composition of the essential oils was analyzed using gas chromatography coupled to mass spectrometry. Accordingly, α-pinene (36.50%) and limonene (20.50%) were the principal components of the B. cruckchanksii essential oil, and δ-cadinol (24.16%), cubenol (22.64%), 15-copaenol (15.46%) and δ-cadinene (10.81%) were the most abundant compounds in the P. uviferum essential oil. Mortality of flies and feeding behavior were evaluated by non-choice tests, and olfactory response was evaluated using a Y-tube olfactometer. Both essential oils were toxic to horn flies, with LC50 values for B. cruckchanksii essential oil of 3.58 µL L−1 air at 4 h, and for P. uviferum essential oil of 9.41 µL L−1 air and 1.02 µL L−1 air at 1 and 4 h, respectively. Moreover, the essential oils exhibited spatial repellency in the olfactometer using only 10 µg of each oil, and these significantly reduced the horn fly feeding at all doses evaluated. Although further laboratory and field studies related to the insectistatic and insecticide properties of these essential oils against H. irritans are necessary, B. cruckshanksii leaves and P. uviferum heartwood essential oils are promising candidates for horn fly management.


2019 ◽  
Vol 28 (3) ◽  
pp. 465-472
Author(s):  
Márcia Alves de Medeiros ◽  
Antonio Thadeu Medeiros de Barros ◽  
Franklin Riet-Correa ◽  
Ana Rita Marques ◽  
José Radmácyo Gomes Lopes ◽  
...  

Abstract To identify susceptible and resistant Haematobia irritans cows, horn flies were counted biweekly for 3 years in a herd of 25 Sindhi cows. Repeated measures linear mixed models were created including cow as a random factor. The results were analyzed by: 1) observing horn fly counts, considering fly-susceptible cows with infestations appearing in the upper quartile more than 50% of the weeks and in the lower quartile less than 20% of the weeks, and fly-resistant cows those that the number of flies was in the lower quartile more than 50% of the weeks and in the upper quartile less than 20%; 2) by the best linear unbiased predictions (BLUPs), to evaluate the cow effect on fly counts. Fly-susceptible cows were those in which the infestation appeared in the 90th percentile of the BLUPs, whereas fly-resistant cows appeared in the 10th percentile. For the observational method the individuals identified as resistant varied between 8% and 20% and 8% to 12% were susceptible. For the BLUP method, the rates of susceptible and resistant cows were 12%. The agreement among methods suggests that susceptible cows can be identified by observations of fly counts, allowing for selective breeding, culling or treatment.


1994 ◽  
Vol 19 (1) ◽  
pp. 363-363
Author(s):  
D. J. Boxler ◽  
J. B. Campbell

Abstract Ivomec® pour-on was evaluated in two studies at two different locations in West Central Nebraska. In study No. 1, Ivomec was applied to 72 yearling steers located at the Gudmundsen Sandhills Laboratory, Whitman, NE. The steers were weighed and the Ivomec was applied at the recommended rate. A second application was made 28 d later, 7 Jul. A group of 44 cows served as an untreated control. In study No. 2, Ivomec pour-on was compared to 1% Co-Ral dust bags (force-use, to obtain water) for horn fly control. This study was located near North Platte, NE, in native range. Ivomec was first applied to 41 heifers 27 May at the recommended rate and subsequent applications were made about every 28 d until the end of the study. Treatment dates were 27 May, 30 June, and 4 Aug. Eighty heifers utilized the 1% Co-Ral dust bags and a group of 10 cows served as an untreated control. Horn fly counts for both studies were recorded at weekly intervals by counting the total number of horn flies on both sides on an animal.


1986 ◽  
Vol 66 (3) ◽  
pp. 575-589 ◽  
Author(s):  
W. O. HAUFE

Experiments conducted on a ranch in southern Alberta evaluated the productivity of the cow-calf unit in breeding herds in response to treatment with pesticidal (8% fenvalerate wt/wt) ear tags to control infestations of horn flies, Haematobia irritans (L.). Optimum economic productivity was found to depend on the effectiveness of tags in establishing fly-free grazing (FFG) conditions and maintaining them without interruption during the complete summer grazing period. This was achieved when animals were tagged before the first overwintering horn flies emerged in spring. Present formulations of pesticide in tags will support the required FFG conditions for 85–90 d. Management of herds for maximum gains throughout the summer in southern Alberta requires fly control that will maintain FFG conditions for at least 115 d. Rates of gain in weight of animals under FFG conditions on dry range conformed with the 16% improvement in efficiency of production projected from controlled experiments on irrigated pastures. Key words: Cattle, cow-calf unit, flies, Haematobia irritans, ear tags, fenvalerate


1992 ◽  
Vol 124 (5) ◽  
pp. 841-851 ◽  
Author(s):  
T.J. Lysyk

AbstractDevelopmental times were determined at constant temperatures for an Alberta population of horn flies, Haematobia irritans irritans (L.). Prepupal (egg and larval) developmental time was determined at seven constant temperatures and ranged from 8.9 days at 20.1°C to 3.5 days at 34.5°C. Prepupal development averaged 44.8% of the preadult (egg, larval, and pupal) developmental time. Preadiilt developmental time was determined at 43 constant temperatures and ranged from 41.6 days at 15°C to 8.4 days at 35°C. The relationship between preadult developmental rate and constant temperature was used in a model to simulate developmental times of horn fly immatures exposed to fluctuating temperatures. The model simulated adult eclosion times well. Deviations of simulated from observed (observed – simulated) mean developmental times averaged 0.4 (SD = 1.3) days, and were less than those found when previously published developmental rate equations were used.


1993 ◽  
Vol 125 (5) ◽  
pp. 839-845 ◽  
Author(s):  
Felix S. Mwangala ◽  
Terry D. Galloway

AbstractInitially, fenvalerate and permethrin tags at two tags per animal and one tag for every other animal nearly eliminated horn flies [Haematobia irritons (L.)] at Glenlea Research Station, Manitoba. However, fly numbers increased 8 weeks post-treatment in 1987 and 6 weeks post-treatment in 1988. LC50 values of the flies to fenvalerate and permethrin increased toward the end of each season but the slope of regression lines decreased in 1987. In 1988, initial LC50 values were lower compared with those observed at the end of the 1987 season. When tags were applied in 1988, LC50 values increased from 0.42 to 3.14 μg per cm2 for fenvalerate and from 2.06 to 10.76 μg per cm2 for permethrin. Mortality observed at discriminating concentrations of fenvalerate (0.625 μg per cm2) and permethrin (5 μg per cm2) during the season decreased from 67.9 to 2.8% and from 66.8 to 5.7%, respectively. Cattle at Glenlea and in a second herd at Libau were not treated in 1989; susceptibility of flies resistant to pyrethroids did not change significantly during the season in these herds. Discontinuing use of pyrethroid-impregnated ear tags for one season was not long enough for substantial reduction in resistance to occur.


2019 ◽  
Author(s):  
Mukund Madhav ◽  
Rhys Parry ◽  
Jess A.T. Morgan ◽  
Peter James ◽  
Sassan Asgari

AbstractThe horn fly, Haematobia irritans irritans, is a hematophagous parasite of livestock distributed throughout Europe, Africa, Asia, and the Americas. Welfare losses on livestock due to horn fly infestation are estimated to cost between USD 1-2.5 billion annually in North America and Brazil. The endosymbiotic bacterium Wolbachia pipientis is a maternally inherited manipulator of reproductive biology in arthropods and naturally infects laboratory colonies of horn flies from Kerrville, USA and Alberta, Canada, but has also been identified in wild-caught samples from Canada, USA, Mexico and Hungary. Reassembly of PacBio long-read and Illumina genomic DNA libraries from the Kerrville H. i. irritans genome project allowed for a complete and circularised 1.3 Mb Wolbachia genome (wHae). Annotation of wHae yielded 1249 coding genes, 34 tRNAs, three rRNAs, and five prophage regions. Comparative genomics and whole genome Bayesian evolutionary analysis of wHae compared to published Wolbachia genomes suggests that wHae is most closely related to and diverged from Wolbachia supergroup A strains known to infect Drosophila spp. Whole-genome synteny analyses between wHae and closely related genomes indicates that wHae has undergone convoluted genome rearrangements while maintaining high nucleotide identity. Comparative analysis of the cytoplasmic incompatibility (CI) genes of wHae suggests two phylogenetically distinct CI loci and acquisition of another CifB homolog from phylogenetically distant supergroup A Wolbachia strains suggesting horizontal acquisition of these loci. The wHae genome provides a resource for future examination of the impact Wolbachia may have in both biocontrol and potential insecticide resistance of horn flies.ImportanceHorn flies, Haematobia irritans, are obligate hematophagous parasites of cattle having significant effects on production and animal welfare. Control of horn flies mainly relies on the use of insecticides, but issues with resistance have increased interest in development of alternative means of control. Wolbachia pipientis is an endosymbiont bacterium known to have a range of effects on host reproduction such as induction of cytoplasmic incompatibility, feminization, male killing, and also impacts on vector transmission. These characteristics of Wolbachia have been exploited in biological control approaches for a range of insect pests. Here we report the assembly and annotation of the circular genome of the Wolbachia strain of the Kerrickville, USA horn fly (wHae). Annotation of wHae suggests its unique features including the horizontal acquisition of additional transcriptionally active cytoplasmic incompatibility loci. This study will provide the foundation for future Wolbachia-induced biological effect studies for control of horn flies.


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