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1.
Fenvalerate and permethrin insecticide tags were tested for horn fly (Haemotobia irritans) control. Three fenvalerate-impregnated ear tags attached to a chain and used as a backrubber controlled horn flies on steers for 8 weeks, and six tags provided 18 weeks control. Ten tags impregnated with permethrin failed to control horn flies. The choice of insecticide in tags attached to chains and used as backrubbers for horn fly control may be important, as fenvalerate and permethrin (both pyrethroids) varied in effectiveness. 相似文献
2.
Pyrethroid-resistant horn flies, Haematobia irritans (L.), were controlled (92–100%) by fenvalerate, permethrin, coumaphos, dioxathion, crotoxyphos, malathion and chlorpyrifos applied by dust bags or backrubbers. Only methoxychlor and stirofos were not effective, indicating possible cross resistance to these insecticides.
Pyrethroids, which were not effective when applied from ear tags, were effective in dust bags or oil-type backrubbers, indicating that resistance may be overcome by high doses of insecticides.
Except for methoxychlor and stirofos, it appears that insecticides being recommended for horn fly control in dust bags and backrubbers are effective against pyrethoid-resistant horn flies. 相似文献
3.
Guglielmone AA Castelli ME Volpogni MM Medus PD Martins JR Suárez VH Anziani OS Mangold AJ 《Veterinary parasitology》2001,101(1):67-73
Synthetic pyrethroids are considered currently less effective than organophosphate insecticides for controlling Haematobia irritans on cattle in its American southern range. To test the validity of this hypothesis, horn fly populations from 95 cattle herds in central-northern Argentina and southern Brazil were evaluated to determine 50% lethal concentrations (LC(50)) to cypermethrin and diazinon, respectively. Horn flies were exposed to filter papers and glass vials treated with cypermethrin and diazinon, respectively, and LC(50) values were determined using probit analysis. Two and 78 fly populations showed LC(50) values indicating susceptibility and resistance to cypermethrin, respectively, in comparison to historical LC(50) values obtained when the horn fly populations were susceptible to cypermethrin. Five fly populations had an undetermined resistance status to cypermethrin. The diazinon tests showed no obvious indications of H. irritans resistance. Thirty nine percent of farmers still rely on pyrethroids to control horn fly populations on cattle which represents a decreasing proportion from a few years ago when horn fly control was carried out using pyrethroids almost exclusively. Organophosphates could provide control for horn flies resistant to pyrethroids; however, the reliance on chemicals alone to control H. irritans is not considered a proper approach for the future. 相似文献
4.
Oremus G Guerrero FD Alison MW Kimball MM Kim JH Foil LD 《Veterinary parasitology》2006,141(1-2):156-164
Between 1999 and 2002, the effect of mid-season doramectin treatments on the level of resistance in pyrethroid-resistant horn fly populations was examined at three separate Louisiana State University Agricultural Center research stations. The cattle were treated with pyrethroid ear tags in all years at all farms, and each farm received a mid-season doramectin treatment in 1 year. The number of weeks of control at Red River was 11 weeks higher in the year following the mid-season treatment of doramectin. At Macon Ridge, the number of weeks of control was 2 weeks higher in the year following the doramectin treatment. No change was observed at St. Joseph. The LC50s for fly populations tested at Macon Ridge and St. Joseph were found to increase for pyrethroids from the spring populations to the fall populations between 2000 and 2002. The LC50s for fly populations at Red River followed the same trends except in 2000, the year when the doramectin treatment was administered. Flies collected pre and post-treatment each year from St. Joseph and Red River were assayed for two alleles (kdr and skdr) associated with target site resistance to pyrethroids. Flies collected pretreatment at Macon Ridge in 1999 also were assayed for the kdr and skdr, and this population of flies had a frequency of 85.6% R-kdr alleles. At St. Joseph and Red River there was a general decline in the frequency of homozygous susceptible skdr (SS-skdr) and homozygous susceptible kdr (SS-kdr) individuals, as well as a general increase in homozygous resistant skdr (RR-skdr) and homozygous resistant kdr (RR-kdr) individuals, during the 4-year study. At both sites, the frequency of R-kdr alleles increased significantly in flies collected in the fall compared to flies collected in the spring with the exception of Red River in 2000, when dormacetin was applied. The frequency of the R-kdr alleles was significantly higher in flies collected in the fall compared to flies collected in the spring in the following year at both sites in two out of three comparisons. The frequency of R-skdr alleles was significantly lower in fly populations tested in the spring compared to fly populations tested in the fall at both farms in years when doramectin was not applied but there were no differences in the years when doramectin was applied. The frequency of R-skdr alleles was significantly higher in fly populations tested in the fall compared to in the spring the following year during all three comparisons at Red River and in one of three comparisons at St. Joseph. 相似文献
5.
In 1998, three groups of cattle at three locations in Lousiana were treated with Dectomax® (0.5% doramectin) Pour-On and horn fly populations were monitored. Acceptable levels (less than 50 flies per side) of horn fly control were observed from 4 to 8 weeks. Differences in the length of control among the three sites were most likely affected by immigration of adult flies from untreated groups. In 1999, acceptable horn fly control was obtained for 13 weeks by the use of two treatments of doramectin Pour-On. 相似文献
6.
Mercier P Jasmin P Sanquer A 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(3):309-316
Dogs are the primary domestic reservoir of Leishmania infantum, the parasite responsible for most cases of human visceral leishmaniasis. A strategy for the control of leishmaniasis would be to inhibit the sand fly bite. A study was designed to measure the prevention of the sand fly attack by spraying a combination of permethrin and pyriproxyfen on dogs artificially exposed to the vector of leishmaniasis. Eight dogs were individually challenged with 100 female sand flies for 1 hour on Days -7, 0, 7, 14, 21, and 28. Four dogs were randomly assigned to a control group and four dogs were treated with topically applied permethrin/pyriproxyfen on Day 0. After each exposure, sand flies were collected, counted, and scored as fed or unfed. Efficacy of the combination for prevention of feeding was based on the number of unfed sand flies (dead or alive). The combination of permethrin/pyriproxyfen demonstrated a significant (P <.05) repellent effect against Phlebotomus perniciosus bites as soon as it was sprayed on the dogs, and its repellent efficacy lasted at least for 28 days. The combination product provided significant (P <.05) knockdown activity against challenge with sand flies for 21 days in adult dogs and 14 days in puppies. These findings indicate that adult animals in endemic areas should be sprayed with the permethrin/pyriproxyfen product at 3- to 4-week intervals, and young dogs should be sprayed at approximately 2-week intervals, to prevent sand fly attack. 相似文献
7.
Pyrethroid resistance in three horn fly populations in Louisiana was monitored by weekly fly counts, filter paper bioassays, and diagnostic PCR assays for the presence of pyrethroid resistance-associated mutations in the sodium channel gene coding region. The PCR assay for the knockdown resistance (kdr) and superkdr sodium channel mutations was used to determine the frequency of the target site insensitivity mechanism in the populations of horn flies, which possessed varying degrees of insecticide resistance. The bioassays and frequency of homozygous-resistant (RR) kdr genotypes were relative predictors of the fly control subsequently observed. Flies exposed to filter paper impregnated with a discriminating concentration of one of four different insecticides were collected when 50% mortality was estimated. Genotypes for the dead flies and the survivors were determined by the PCR assay. The results of the PCR assays indicated that the genotype at the kdr locus of the flies exposed to the two pyrethroids had an effect upon whether the flies were considered to be alive or dead at the time of collection. The kdr genotype of flies exposed to either diazinon or doramectin was unrelated to whether the flies were considered to be alive or dead, except for a single comparison of flies exposed to diazinon. When possible interactions of the kdr and superkdr mutations were compared, we found that there were no associations with the response to diazinon and doramectin. For one location, there were no survivors of the 75 flies with the SS-SS (superkdr-kdr) homozygous susceptible wild type genotype exposed to pyrethroids, while there were survivors in all of the other five genotypes. The SS-RR genotype flies were more susceptible to the pyrethroids than the SR-RR flies, but that was not the case for exposure to diazinon or doramectin. In the St. Joseph population, there were an adequate number of flies to demonstrate that the SS-SR genotype was more susceptible to pyrethroids than the SS-RR and that flies with the SR-SR genotype were more susceptible to pyrethroids than the flies with the SR-RR genotype. 相似文献
8.
Chamorro MF Passler T Givens MD Edmondson MA Wolfe DF Walz PH 《Veterinary research communications》2011,35(2):123-129
Identifying reservoirs and transmission routes for bovine viral diarrhea virus (BVDV) are important in developing biosecurity programs. The aim of this study was to evaluate BVDV transmission by the hematophagous horn fly (Haematobia irritans). Flies collected from four persistently infected cattle were placed in fly cages attached to principal (n?=?4) and control (n?=?4) BVDV-naïve calves housed individually in isolation rooms. Flies were able to feed on principal calves, but a barrier prevented fly feeding from control calves. Flies were tested for BVDV by RT-PCR and virus isolation at time of collection from PI cattle and after 48 h of exposure on BVDV-naïve calves. Blood samples were collected from calves and tested for BVDV infection. Virus was isolated from fly homogenates at collection from PI animals and at removal from control and principal calves. All calves remained negative for BVDV by virus isolation and serology throughout the study. Bovine viral diarrhea virus may be detected in horn flies collected from PI cattle, but horn flies do not appear to be an important vector for BVDV transmission. 相似文献
9.
A A Guglielmone M E Castelli M M Volpogni O S Anziani S G Flores 《Veterinary parasitology》1999,83(1):65-72
Development of pyrethroid resistance in Haematobia irritans in Santa Fe province, Argentina, resulted in an increased use of pyrethroid insecticides, probably due to lack of suitable alternative treatments. We explored the efficacy of mixtures of cypermethrin and piperonyl butoxide (PBO) against pyrethroid-resistant H. irritans. Groups of 25 Holstein cows each, naturally infested with cypermethrin resistant H. irritans were assigned to treated or control groups in April, September, October and December 1997. Cattle in treated groups were medicated with pour-on oil formulations of 5% cypermethrin (dose = 4 mg per kg of body weight) with 5% or 10% PBO in April, and with a mixture containing 5% of both components thereafter. Efficacy was tested for 21 days after treatment. A treatment of 5% cypermethrin pour-on without PBO was evaluated in October 1997. Samples of horn flies were obtained before September, October and December treatments and exposed for 2 h to filter papers impregnated with different cypermethrin concentrations to determine the 50% lethal concentration (LC50). No difference in efficacy was found between cypermethrin pour-on formulations with 5% or 10% of PBO (more than 94% efficacy on day 21 after treatment). Efficacy of 5 % cypermethrin-5% PBO mixture decreased rapidly in the successive treatments (less than 40% efficacy was observed on day 21 after the December treatment), and the period after treatment with an efficacy higher than 95% was 14 days for the treatment carried out in April, 10 days in September; 7 days for the treatment performed in October and 4 days for the December treatment. The LC50 of cypermethrin was 36.6 microg per cm2 in September and increased to 116.6 and 226.1 microg per cm2 in October and December, respectively. It is concluded that the addition of PBO to cypermethrin did not provide a treatment that would give a long term control of pyrethroid resistant-horn flies. 相似文献
10.
Twenty-three mixed-breed herd cows were phenotyped for their ability to serve as a suitable host for Haematobia irritans, the horn fly. Based upon consistent observations within the lower quartile or upper quartile of individual fly counts, four cows were phenotyped as low carriers and five cows were phenotyped as high carriers of horn flies. The cows designated as low carriers consistently carried levels of flies below the economic threshold. However, during a period of fly population explosion, low carriers harbored flies well above the economic threshold. Although the number of flies counted on these low carrying cattle increased as the population increased, the relative percentage of the population that they carried changed very little. A hypothesis is proposed to explain this observation, and future studies are suggested. 相似文献
11.
Insecticidal ear tags impregnated with organophosphate (OP) insecticides were used each year from 1989 to 1998 at Rosepine, LA. Weekly fly counts were conducted to evaluate control efficacy of the treatments, and bioassays were conducted at least twice per year to measure fly susceptibility to OP and pyrethroid insecticides. Between 1989 and 1992, the efficacy of 20% diazinon-impregnated ear tags was reduced from >20 to just 1 week of control. A high risk of control failure was observed when a resistance frequency of approximately 5% was measured in pre-season bioassays. Resistance to diazinon, fenthion, ethion, pirimiphos-methyl, and tetrachlorvinphos was observed. Esterase activity toward alpha-naphthyl acetate was significantly higher in flies collected at Rosepine in 1997 than in flies from a laboratory colony and from a susceptible field population. 相似文献
12.
The ability of stable flies (Stomoxys calcitrans), horn flies (Haematobia irritans), and tabanids (Diptera: Tabanidae) to transmit bovine leukosis virus (BLV) was investigated. Stable flies and horn flies were fed on blood collected from an infected cow, and the flies' mouthparts were immediately removed, placed in RPMI-1640 medium, ground, and inoculated into sheep and calves. Infection of sheep occurred with mouthparts from as few as 25 stable flies or 25 horn flies. However, sheep were not infected when removal of stable fly mouthparts was delayed greater than or equal to 1 hour after blood feeding. Infection of calves occurred after inoculation of mouthparts removed immediately after feeding from as few as 50 stable flies or 100 horn flies. Infected blood, applied by capillary action to the mouthparts (labella) of 15 deer flies (Chrysops sp) and a single horse fly (Tabanus atratus) caused infection in each of 2 sheep. Infection did not occur in 2 calves inoculated daily for 5 days with mouthparts from 50 horn flies collected after feeding on a BLV-infected steer. Four calves receiving bites from 75 stable flies interrupted from feeding on a BLV-positive cow also were not infected. Seronegative cattle held for 1 to 4 months in a screened enclosure with positive cattle in the presence of biting flies were not infected with BLV. The feeding behavior of each insect is discussed to assess their potential as vectors of BLV. 相似文献
13.
Thrombostasin is an anti-thrombin factor that plays a role in successful feeding of the horn fly, Haematobia irritans. It has been isolated and characterized from saliva, and polymorphisms in the gene coding sequence have been previously reported. In the present study, the thrombostasin gene was analyzed from 60, field-collected flies from Camp Stanley, Texas and the allele and genotype frequencies were compared with previously published data for an Alabama field collection and a Texas in vitro colony-reared collection. Significant differences in genotype frequency and extent of genotypic diversity observed between the Alabama and Camp Stanley field collections may be attributable to host genetic differences. In addition, bull calves that were phenotyped as either high- or low-carriers were parasitized by horn flies that displayed a significantly different genotype distribution, supporting a possible explanation for horn fly host selection behavior, as evidenced by thrombostasin sequence analysis of 95 additional horn flies collected from respective hosts. 相似文献
14.
Y Uzuka T Yoshioka S Tanabe G Kinoshita T Nagata K Yagi H Funaki H Hanyu T Sarashina 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(3):287-289
A field trial was conducted to evaluate the efficacy of a topical formulation of ivermectin administered at the dose of 500 micrograms/kg against horn flies (Haematobia irritans) in cattle. Eighty-eight cattle in four herds naturally exposed to horn flies were used in the trial. Replicates were formed of two herds. Within replicates, one herd was randomly allocated to the untreated control and the other to the ivermectin treatment group. Horn fly counts were taken on the treatment day (Day 0) and on Days 7, 14, 21, 28, and 35 post-treatment. There were no horn flies on any cattle in the treatment group, whereas all the control cattle were continuously infested by horn flies on each examination day. 相似文献
15.
Miró G Gálvez R Mateo M Montoya A Descalzo MA Molina R 《Veterinary parasitology》2007,143(3-4):375-379
The phlebotomine sand fly Phlebotomus perniciosus is one of the main vectors of Leishmania infantum, responsible for human and canine leishmaniasis in the Mediterranean Basin. The objective of this study was to evaluate the repellent and insecticidal efficacy of imidacloprid 10% (w/v)/permethrin 50% (w/v) spot-on against sand flies (P. perniciosus) on dogs. The dogs used in this trial were laboratory-bred beagles: eight were impregnated with the solution (treated group), while the other eight were left untreated (control group). On day 0 the animals in the treatment group received 0.1 ml/kg body weight of the combination imidacloprid/permethrin spot-on. Dogs were exposed for 1h to about 100 female sand flies at weekly intervals for a period of 4 weeks, on day 1, 7, 14, 21, and 28 after applying the product. The repellency criterion was based on the feeding rate of sand flies in the treated compared to the untreated group. The insecticidal efficacy criterion was based on comparison of the survival rate of sand flies between the two groups. The product had an insecticidal efficacy on female sand flies of 53.2% (day 1), 49.4% (day 7), 15.1% (day 14), 13.2% (day 22), and 2.9% (day 29). The product showed a repellent effect of 97.7% (day 1), 96.3% (day 7), 96.5% (day 14), 92.7% (day 22), and 74.0% (day 29). Within the first week of application the insecticidal effect was significant; however it did not surpass 50%. On the other hand, the product showed a potent anti-feeding effect of over 90% during the first 3 weeks of this trial. Therefore, the application of this product every 3 weeks would be a good tool to significantly reduce sand fly bites over the period of transmission of vectorial diseases such as leishmaniasis and several arbovirosis such as Toscana virus. 相似文献
16.
Molina R Espinosa-Góngora C Gálvez R Montoya A Descalzo MA Jiménez MI Dado D Miró G 《Veterinary parasitology》2012,187(3-4):529-533
Leishmania infantum is a protozoan parasite causing leishmaniosis, a visceral disease transmitted by the bites of sand flies. As the main reservoir of the parasite, dogs are the principal targets of control measures against this disease, which affects both humans and dogs. Several studies have revealed the usefulness of topical insecticide treatment (collars, spot-ons and sprays) in reducing the incidence and prevalence of L. infantum. The present study was designed to test the efficacy of 65% permethrin applied to dogs as a spot-on against the sand fly vector Phlebotomus perniciosus. The duration of the desired effects was also estimated to help design an optimal treatment regimen. Twelve dogs assigned to treatment (n=6) and control (n=6) groups were exposed to sand flies once a week over a seven-week period. Repellent and insecticidal efficacies were estimated and compared amongst the groups. Our findings indicate satisfactory repellent, or anti-feeding, effects lasting 3 weeks and short-term insecticidal effects lasting 2 weeks after initial application. Accordingly, we recommend the use of this product every 2-3 weeks during the active phlebotomine sand fly period to protect dogs against the bites of P. perniciosus. 相似文献
17.
Magona JW Walubengo J Olaho-Mukani W 《Journal of the South African Veterinary Association》2004,75(4):173-176
A pilot survey using a structured questionnaire was conducted in Tororo and Busia districts of Uganda on the knowledge and attitudes of cattle owners regarding tsetse fly and trypanosomosis control, in order to understand factors that hindered their full participation. A total of 81 cattle owners was randomly selected and interviewed, of which 92.5% were aware of tsetse flies and trypanosomosis and 87.6% recognised animal trypanosomosis as a problem in the area. Most cattle owners were aware of tsetse fly trapping (76.5%), isometamidium chloride use (55.5%), diminazene aceturate use (48%) and pour-on applications (18.5%). However, knowledge did not coincide with the application of control measures. Despite the widespread awareness, tsetse fly trapping and pour-on applications were used by only a small percentage of cattle owners (7.5% applied tsetse fly trapping while 76.5% were aware of it; 1.2% applied pour-on insecticides while 18.5% were aware of them). Differences between awareness and application were highly significant for tsetse fly trapping (chi2 = 67.8, d.f. = 1, P < 0.001) and pour-on applications (chi2 = 10.8, d.f. = 1, P < 0.05), but not for isometamidium chloride use (chi2 = 0.08, d.f. = 1, P = 0.77) and diminazene aceturate use (chi2 = 0.00, d.f. = 1, P = 1.00). Most cattle owners (97.5%) were willing to participate in future control programmes, but preferred participating on a group basis (85.2%) rather than individually (14.8%). The 4 most favoured control options in order of importance were: fly traps supplied by the government and maintained by cattle owners; contribution of labour by cattle owners for trap deployment; self-financing of trypanocidal drugs and self-financing of pour-on insecticide. The control options that should be selected in order to elicit full participation by cattle owners are discussed. 相似文献
18.
Temeyer KB Li AY Lohmeyer KH Chen AC Olafson PU Sanson DW Foil LD 《Veterinary parasitology》2008,154(3-4):300-310
Acetylcholinesterase (AChE) cDNA from individual field-collected diazinon-resistant horn flies was amplified by RT-PCR. Sequencing of the amplification products revealed that 8/12 of the diazinon-resistant horn flies contained a point mutation previously associated with resistance to organophosphates in house flies and Drosophila, strongly suggesting that this cDNA encodes the AChE that is the target site for organophosphate (OP) pesticide. The point mutation (G262A) resulted in a shift from glycine to alanine in the mature HiAChE amino acid sequence at position 262. Allele-specific PCR and RLFP assays were developed to diagnose the presence or absence of the G262A mutation in individual flies. Use of the allele-specific assays each demonstrated the presence of the G262A mutation in 10 of 12 individual field-collected flies, demonstrating higher sensitivity than direct sequencing of RT-PCR amplification products. The G262A mutation was found in additional fly populations previously characterized as OP-resistant, further supporting that this AChE is the target site for OP pesticide. The allele-specific assay is a useful tool for quantitative assay of the resistance allele in horn fly populations. 相似文献
19.
During the 2004 and 2005 sand fly seasons, we evaluated the efficacy of a 65% spot-on solution of permethrin (Exspot, Schering & Plough) and deltamethrin-impregnated collar (Scalibor, Intervet) in reducing Leishmania infantum infection, in a canine leishmaniasis (CanL) endemic region (Liguria) in Italy. Immunofluorescent assay (IFA) revealed that three of 120 dogs (2.5%) treated with a 65% spot-on solution of permethrin, as three of 119 dogs (2.5%) treated with deltamethrin-impregnated collar have shown seroconversion after sand fly season. On the contrary, seroconversion was 15% in 188 untreated control dogs. Treatment reduced the risk of infection by 84%. The difference in treated dogs and control ones is highly significant (chi2 = 12.4; P = 0.0004). Our results show that treatment with 65% spot-on solution of permethrin and the deltamethrin-impregnated collar are effective in reducing the risk of acquiring L. infantum infection. 相似文献
20.
A trained observer direct count method to measure horn fly population was evaluated to determine the reliability (inter-observer agreement) and its validity when compared with a "gold standard" method (video film). All the counts were performed with the animals restrained in a chute in a single herd. A direct count of horn flies by each of two observers on opposite sides of the animal was made. In addition a videotape recording of the counting surface on each animal was made. Horn flies were counted on 80 cows in the morning twice monthly from 22 October 1999 to 24 March 2000. The correlation between observer counts was high as was the correlation between observer counts and counts made from a videotape recording. Direct counts by trained observers were highly reliable and had good validity. However, videotape recording can be useful when the horn fly population is high, because it is faster in the field than the direct count method. The results of this study suggest that the direct count method can be used with confidence under field conditions. 相似文献