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1.
The occurrence of blowfly strike between 1993 and 1999, derived from the reported use of pesticides for flystrike control, was investigated in 247 sheep flocks in Queensland, Australia using autoregressive techniques. Although there was a small increase (0. 0016 per year) in flystrike incidence during the study period, this long-term linear trend was not significant (p=0.53). The occurrence of flystrike was best described by an autoregressive model that included flystrike in the previous 2 months: flystrike(t)=0.0170+0. 0392 flystrike(t-1)+0.3589 flystrike(t-2). Flystrike was associated with the southern oscillation index (SOI). The SOI is based on barometric pressure readings and is associated with periods of below- (negative SOI) and above-average (positive SOI) rainfall in northern Australia. Flystrike incidence was significantly (p=0.03) greater in months in which the SOI was positive. The strongest correlation (r=0.33) was found between flystrike incidence and the SOI 2 months previously. Using the SOI, the best-fitting autoregressive model describing flystrike was flystrike(t)=0.0238+0. 3033 flystrike(t-2)+0.0009 SOI(t-2). The incidence of flystrike was significantly (p<0.05) correlated with average monthly radiation (r=0.26), but not with average monthly maximum and minimum temperature, total rainfall, evaporation and vapour pressure. The best-fitting autoregressive model describing flystrike occurrence based on these variables was flystrike(t)=-0.0259+0.3610 flystrike(t-2)+0.0022 radiation(t). Results suggest that a useful early-warning system could be developed based on the correlation between flystrike incidence and the SOI up to 2 months previously. Such attempts to forecast flystrike may assist decision-making by wool producers with respect to flystrike control options, leading to more efficient control of blowfly strike in their industry.  相似文献   

2.
The effectiveness of a synthetic lure system (Lucitrap) to reduce blowfly strike incidence was assessed in a field trial conducted on two properties located in southern Queensland, Australia. Nine hundred and fifty sheep were randomised to treatment (one or more Lucitrap per 100 sheep) and control paddocks. Sheep were physically inspected for flystrike each month between August 1999 and May 2000. On one property, the risk of flystrike in the control group was 1.86 times (95% confidence interval, 1.19-2.90) greater than that in the treatment group. On the other property, two cases of flystrike were detected in the control group, but no cases were detected in the treatment group. These preliminary observations suggest that the use of Lucitrap can reduce the incidence of blowfly strike by up to about one-half. Blowfly traps have a role in controlling flystrike in circumstances in which sheep are susceptible to flystrike and the likelihood of flystrike occurring is at least moderate. The use of fly traps could assist the Australian wool industry to meet targets of reduced pesticide use.  相似文献   

3.
The intervals between the jetting of sheep with dieldrin or BHC, and the inducement of flystrike by implants of hybrid and homozygous BHC/dieldrin resistant larvae of Lucilia cuprina, were compared. Flystrikes soon established with homozygous resistant larvae, but considerable protection was afforded against hybrid larvae, the interval being longer with BHC than with dieldrin. Dieldrin was shown to have a residual effect on rr larvae in a mixed population 9 weeks after jetting. It is suggested that wide adoption of mulesing and mid-season's crutching would favour reversion to susceptibility in the blowfly and thus extend the field life of insecticides to which resistance has emerged.  相似文献   

4.
SUMMARY Resistance to organophosphorus (OP) insecticides in the Australian sheep blowfly has decreased the larvicidal effectiveness of several popular products used as dressings for flystrike. Laboratory bioassays in which near full-size Australian sheep blowfly larvae were immersed in flystrike dressings at registered concentrations for times ranging from 5 to 180 s indicated that none of the products was completely effective in killing highly OP-resistant larvae. Several products performed poorly, even against a susceptible population. Effectiveness did not always reflect the concentration of active ingredient. For example, the products considered to be the most, and least effective overall, contained 0.036% propetamphos but were formulated very differently. Larvicidal efficacy is important in terms of minimising injury to stock but also in the management of insecticide resistance. In situations when the degree of resistance is known, it will be possible to make recommendations for the most cost-effective treatment of flystrike. In the meantime, there appears to be a clear advantage for woolgrowers to use a propetam-phos-based flystrike jetting product to dress flystrike lesions.  相似文献   

5.
Trapping sheep blowflies using bait-bins   总被引：2，自引：0，他引：2  
A bait-bin designed to attract and kill sheep blowflies is described. It is composed of a garbage bin plus lid, attractant and insecticide-treated offal. Fly entry holes are covered with differentiator wire to increase selectivity of kill. Placing bait-bins in preferred habitats of blowflies to optimise kill is outlined and temporal insecticide strategies to increase effectiveness of kill and reduce blowfly resistance are suggested. Preliminary data supporting the effectiveness of bait-bins in reducing blowfly numbers and flystrike in combination with good management practices to reduce sheep susceptibility to flystrike in the arid zone of New South Wales are presented and cost-effectiveness of bait-bins is analysed.  相似文献   

6.
OBJECTIVE: To describe the occurrence of blowfly strike in sheep flocks in two shires located in south-eastern Queensland. DESIGN: Postal survey of woolgrowers within Stanthorpe and Inglewood shires. PROCEDURE: Questionnaire posted to woolgrowers in June 1999 seeking information on the monthly occurrence of flystrike and number of sheep at risk. RESULTS: Incidence of body strike and breech strike between August 1998 and May 1999 was 1.1 and 0.5%, respectively. The highest incidence of body strike and breech strike was reported in lambs (6.1%) and weaner sheep (1.5%), respectively. The seasonality of the incidence of body strike was bimodal (November and February), whereas the seasonality of the incidence of breech strike was unimodal (April). Occurrence of body strike within a 3-month period in flocks located within 40 to 50 km of each other was significantly (P < 0.05) clustered. CONCLUSION: Body strike appears to be more common than breech strike in the study area, mainly affects lambs and weaners and high-risk periods occur during late spring and autumn. Study results provide valuable information for planning blowfly strike control programs in the area such as timing of management procedures, use of fly traps), and enable the economic impact of flystrike on the industry in this area to be assessed.  相似文献   

7.
Blowfly strike and the methods used to combat blowfly strike were recorded on 33 properties in the R?ens area of South Africa during 2003/2004. Data were recorded on Merino and Dohne Merino hoggets (n = 4951) with at least 3 months' wool growth. The following data were captured: presence or absence of strike, site of the strike (body or breech), presence or absence of dermatophilosis as well as subjective scores for wool quality and wool colour. Control measures recorded include: chemical treatment (preventative and spot treatment), crutching, mulesing and the use of the Lucitrap system. Blowfly strike was not significantly influenced by gender or breed. Hoggets suffering from dermatophilosis were more likely to be struck, compared with contemporaries not suffering from the skin disorder (0.057 vs 0.027; P < 0.05). Merino hoggets generally had higher scores than their Dohne Merino contemporaries for wool quality (32.6 vs 27.4; P < 0.05) and wool colour (29.0 vs 27.2; P < 0.05). There was an indication that the Lucitrap system may have reduced flystrike, but the effect was not statistically significant (P = 0.19 for overall strikes and P = 0.12 for body strike). The Mules operation benefited overall flystrike (0.013 vs 0.110; P < 0.05); mainly through an effect on breech strike (0.010 vs 0.109; P < 0.05). The proportion of fly strikes increased with wool length, and declined with an increase in farm size in wool colour score. None of the ethically acceptable control measures assessed could substantially reduce blowfly strike on their own, and an integrated pest management programme was proposed.  相似文献   

8.
Summary. 1,1-Bis(4-ethoxyphenyl)-2-nitropropane (GH74) was evaluated as an oviposition deterrent for the sheep blowlly Lucilia cuprina. In several test situations, flies laid only very few egg masses on fleece to which 0.5% GH74 had been applied, and which had been exposed in the field for up to 6 months. However, a significant number of egg masses were laid on the breech of severely scouring sheep when tested several weeks after application of GH74 at the same concentration. Procedures for evaluating oviposition deterrents against sheep blowfly are discussed.  相似文献   

9.
The reported occurrence of blowfly strike in 57 sheep flocks in Queensland, Australia, was investigated for time-space clustering in an exploratory study using Knox's method. Flystrike occurrence peaked in late spring and early summer, with an additional late-autumn peak in southern-Queensland flocks. A total of 1596 case-pairs was examined. Significant clustering (P = 0.07) was only detected for case-pairs occurring within 3 months and 150 km of each other; 164 case-pairs were declared close compared to an expectation of 151. We suggest that factors common to a district (such as rainfall and temperature) are responsible for clustering of flystrike in Queensland.  相似文献   

10.
Females of the Australian sheep blowfly, Lucilia cuprina, exploit sheep dung as a source of protein for egg development. Flies fed on dung collected from sheep 1 to 6 days after being drenched with the broad-spectrum antiparasitic drug ivermectin showed delayed reproductive development and reduced fecundity. Male and female survival was also reduced. Despite these effects, except where the recommended frequency of drenching (1 to 4 times per annum) is greatly exceeded, it is unlikely that ivermectin residues will affect any useful reduction in blowfly populations.  相似文献   

11.
In three multicentered field trials run during 1995 to 1997, involving a total of 12,928 lambs, the preventive effects on blowfly strike of a ready-to-use 5 per cent dicyclanil pour-on formulation and of a ready-to-use 6 per cent cyromazine pour-on formulation were compared with untreated controls for periods of up to 22 weeks. Their efficacy was assessed by calculating the consolidated cumulative strike rate for each treatment group and the consolidated percentage reduction of flystrike achieved by the two formulations. The consolidated cumulative strike rate for all three years together reached 29.2 per cent for the untreated control lambs at week 22, 2.8 per cent for the dicyclanil-treated lambs at week 22, and 6.9 per cent for the cyromazine-treated lambs at week 20. The consolidated cumulative percentage reduction of blowfly strike remained above 89 per cent for the dicyclanil-treated lambs. For the cyromazine-treated lambs the consolidated cumulative percentage reduction of blowfly strike reached 90 per cent during weeks 9 to 10, and 80 per cent during weeks 11 to 12.  相似文献   

12.
Four groups of five Romney lambs were treated by plunge dipping with one of four registered organophosphorus flystrike preventatives. Untreated lambs acted as controls. The sheep were challenged at weekly intervals with larval implants of organophosphate-susceptible and -resistant strains of Lucilia cuprina. All four treatments provided 19-21 weeks protection against susceptible larvae but chlorfenvinphos provided the longest protection (16-17 weeks), followed by propetamphos (15-16 weeks), dichlofenthion (10-13 weeks) and diazinon (9-13 weeks), against the resistant strain.  相似文献   

13.
OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on Merino sheep under Australian conditions. DESIGN: Randomised clinical trials conducted in an environment house and in the field. PROCEDURE: Two environment house trials were used to measure the protection against flystrike provide by a jetting or a ready-to-use 5% spray-on formulation of dicyclanil over 22 and 31 weeks respectively. Oviposition and strikes were recorded weekly for each sheep. In two field trials the occurrence of strike in Merino sheep treated off-shears or in long wool with dicyclanil or with cyromazine was compared for up to 38 weeks after treatment. Efficacy was assessed by calculating the cumulative percentage of sheep struck. RESULTS: Under environment house conditions, sheep jetted with dicyclanil at 1.50, 0.75 and 0.30 g per sheep developed 0, 8 and 9 strikes respectively during the 22 weeks of the trial, whereas there were 358 strikes present in the placebo group. Sheep sprayed with dicyclanil at 2.25, 1.50 and 0.75 g per sheep developed 5, 11 and 29 strikes respectively between weeks 15 and 31 after treatment, whereas there were 185 strikes present in the untreated controls. In field trials the cumulative percentage of sheep struck reached 1% between weeks 12 to 13 after sheep had been treated with cyromazine. Sheep treated with dicyclanil reached the 1% limit at week 21 after treatment. CONCLUSION: Under Australian field conditions, a ready-to-use 5% spray-on formulation of dicyclanil applied off-shears or to long wool protected Merino sheep from blowfly strike for a period of at least 20 weeks.  相似文献   

14.
Sheep which have been bred for resistance (R) or susceptibility (S) to fleece rot and blowfly strike, were tested for intradermal inflammatory responses to excretory and secretory products of Lucilia cuprina larvae. R rams and lambs gave significantly larger skin weals than S animals. In addition, R and S rams were infected with L cuprina first instar larvae and wound exudates were collected. In the first 12 hours of infection R rams released significantly more exudate protein at the wound site than S rams. Correlations suggested that exudate production was stimulated by both larval burden and inflammatory responses, however, in the R group the inflammatory correlation was positive while in the S group it was negative. The results imply that inflammatory responses may play a role in innate resistance to L cuprina. The difference in inflammatory responses suggests genetic differences between the flocks and therefore could show some potential as a trait for indirect selection for resistance to fleece rot and body strike.  相似文献   

15.
The effect of three commonly used anthelmintics, levamisole hydrochloride, ivermectin and closantel, on the development of the sheep blowfly, Lucilia cuprina, was determined. Sheep were treated with each anthelmintic using the manufacturers' recommended dose for helminth control. Both ivermectin and closantel significantly (p < 0.05) reduced the growth rate of larvae of L cuprina cultured in vitro on serum from these sheep. Levamisole hydrochloride had no effect. Ivermectin was effective for less than 6 days after treatment, whereas closantel significantly reduced larval growth 21 days after treatment. Dose-response experiments showed that lower concentrations of both ivermectin and closantel were not as effective in reducing larval growth.  相似文献   

16.
A proprietary insecticidal mulesing powder containing diazinon and an experimental liquid dressing based on eucalyptus oil, naphthalene, cresylic acid and chlorfenvinphos in a carrier of liquid hydrocarbons and petroleum oil were compared for their ability to promote wound healing and reduce the incidence of fly strike in freshly mulesed lambs. Throughout the trial period of 4 weeks, fly trapping confirmed the presence of Lucilia cuprina in the paddock where the ewes and lambs were grazing At inspection one month after mulesing, no deaths had occurred since mulesing and no lambs showed evidence of cutaneous myiasis, although a number of their dams (with 8 months wool) were struck. At 4 weeks after mulesing, the wounds of the lambs treated with the experimental liquid dressing showed better healing than those treated with the powder dressing. It was concluded that both mulesing preparations were effective in inhibiting flystrike, but the liquid dressing promoted faster wound healing than did the powder.  相似文献   

17.
Cellular immune responses were observed in the skin of sheep after primary and secondary infection with sheep blowfly (Lucilia cuprina) larvae. Both primary and secondary infections resulted in a massive cellular infiltration within 48 h of wound initiation, with the majority of cells having the CD45 phenotype. Neutrophils comprised the major cell type at the skin surface. In the dermis, the number of CD4+ T helper, gamma delta-TCR+ cells and T19+ (CD4-, CD8-) T cells also increased significantly in skin during both primary and secondary infections compared with control sites. However, there was no significant difference in the numbers of these cells between primary and secondary infections. An increase in the expression of the CD1 antigen on Langerhans/dendritic cells was observed, along with an apparent increase in the number of these cells in secondary lesions, with the majority of the cells being concentrated in the upper dermis and epidermis. While there was no increase in mast cells, eosinophils increased significantly during infection compared with control sites. The cellular infiltration observed following primary and secondary infections suggests polyclonal activation of T cells and their selective recruitment to the lesion site.  相似文献   

18.
Laboratory studies were conducted to assess the effect of tea tree oil (TTO) from Melaleuca alternifolia (terpinen-4-ol chemotype) against different stages of the Australian sheep blowfly Lucilia cuprina. When applied to wool, 3% TTO formulation repelled gravid female L. cuprina and prevented oviposition for six weeks. Formulations containing 1% TTO caused 100% mortality of L. cuprina eggs and 1st instar larvae and 2.5% TTO caused mortality of most second and third instar larvae in agar feeding assays. In experiments where third instar larvae were dipped in TTO formulations for 60s, concentrations of up to 50% TTO gave less than 50% kill. TTO at concentrations of 0.5%, 2% and 5% was strongly repellent to third instar larvae and caused them to evacuate treated areas. Inclusion of TTO in formulations with diazinon, ivermectin and boric acid reduced mortality in comparison with the larvicides used alone, at least partially because of avoidance behaviour stimulated by the TTO. Addition of TTO to wound treatments may aid in wound protection and myiasis resolution by preventing oviposition by L. cuprina adults, insecticidal action against L. cuprina eggs and larvae, stimulating larvae to leave the wound and through antimicrobial and anti-inflammatory properties that aid in wound healing.  相似文献   

19.
The effectiveness of a synthetic lure system to reduce the incidence of blowfly strike in sheep flocks was assessed, using randomised field trials. Four field trials used eight total groups of sheep randomised to treatment (flytrap) or control on two properties in southern Queensland between 1999 and 2001. Treatment consisted of the operation of flytraps in paddocks as per manufacturer's recommendations. All sheep were inspected physically each month for flystrikes. Flytraps were associated with a reduction in flystrike incidence of 38-55%, compared to control sheep. Results confirm that traps are a useful component of a flystrike-control program. The use of fly traps by a substantial proportion of woolgrowers could assist the Australian wool industry to meet targets of reduced pesticides on shorn wool.  相似文献   

20.
A multi-centered field trial was carried out in the Netherlands to evaluate the efficacy of a ready-to-use 5% dicyclanil formulation as a preventative of natural flystrike on lambs. In four different sites a total of 1215 lambs treated with dicyclanil were compared with 431 untreated lambs during periods of 15 to 16 weeks. Efficacy was assessed by calculating the weekly cumulative strike rate for each site and treatment group and the percentage reduction achieved by dicyclanil. In two of the four sites untreated controls did not receive enough fly challenge and were not considered for efficacy assessment. At the other two sites untreated controls reached cumulative strike rates of 10.5 and 19.5% 15 and 16 weeks after treatment, respectively. None of the 549 lambs treated with dicyclanil at these two sites were struck, resulting in a 100% reduction of flystrike during the whole length of the trial.  相似文献   

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