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1.
Irradiation of Chrysomya bezziana embryos 1 h before hatching with doses less than or equal to 7 kilorad (kr) had a significant effect on percentage egg hatch, weights and survival of larvae. Doses greater than or equal to 1 kr allowed larval development to the end of the 3rd instar stage in vitro, but prevented normal pupal development. Cattle with wounds infested with 1st instar larvae derived from irradiated embryos had 3rd instar larvae present after 3 d but these failed to pupate. Thus it would be feasible to use such larvae for wound infestation for the enhanced detection of screw-worm fly in areas where the release of fertile flies is undesirable.  相似文献   

2.
A number of insecticides used for ectoparasite control in the livestock industry were screened for their efficacy against larvae of the screw-worm fly, Chrysomya bezziana, using in vivo and laboratory tests. Proprietary screw-worm fly treatments (after exposure to outdoor conditions for up to 10 days) were also tested against eggs and adults of C bezziana. Three of these were also evaluated on naturally acquired screw-worm infestations. Residual protection was generally of short duration. Among the organophosphorus compounds, the most effective formulations contained relatively high concentrations (3 to 4% al) of coumaphos, 2.5% fenchlorphos or low concentrations (0.05 to 0.5% al) of diazinon, chlorfenvinphos and fenthion methyl. Two chlorinated hydrocarbon insecticides containing 3% lindane and 5% dieldrin were very effective but are now prohibited for use in Australia. Preparations had serious deficiencies when used under field conditions, especially for treating large, deepseated myiases for which systemic insecticides are recommended. A comparison of methods demonstrated that a laboratory test could supersede live animal experimentation, at least for the initial screening of potential insecticides.  相似文献   

3.
The Old World Screwworm fly (Chrysomya bezziana) has recently been causing aggressive myiasis in pet dogs in Hong Kong, and the Agriculture, Fisheries and Conservation Department of Hong Kong has confirmed the presence of Chrysomya bezziana in the territory. This report describes screwworm infestation in pet dogs presented for treatment at our clinic in the past year. Screwworm fly larvae were found in typically punched out round wounds or embedded in exposed or neglected wounds. Infested wounds had a characteristic strong offensive smell and oozed a sero-sanguineous exudate or frank blood. Removal of the larvae, wound treatment, continuous monitoring for re-infestation, application of insect repellants and protective housing were essential for successful treatment. Because Hong Kong is a source of pet migration or a transit point to Australia, the fly could threaten Australia.  相似文献   

4.
Thirteen acaricides used for control of cattle tick in Queensland were evaluated for their potential in the chemical control of the screw-worm fly, Chrysomya bezziana. Laboratory evaluations and in vivo tests using artificially infested cattle were made in Papua New Guinea. Most of the acaricides caused some mortality of screw-worm larvae in infested cattle and in laboratory tests. Acaricides of the organophosphorous, carbamate and organophosphorous/synthetic pyrethroid groups showed reasonable activity against screw-worm fly, but the amidines were less effective.  相似文献   

5.
OBJECTIVE: To assess the efficacy of four macrocyclic lactones for the control of larvae of the Old World Screw-worm Fly (OWS), Chrysomya bezziana, and to examine the effects of excreted residues on the dung fauna. ANIMALS: 100 heifers were divided into five groups of 20 animals. One group remained untreated, whereas the other groups were treated respectively with pour-on formulations of moxidectin, eprinomectin or doramectin, or a sustained-release bolus of ivermectin. PROCEDURES: At intervals of 1 to 15 weeks after treatment, five cattle from each group were challenged with newly-laid eggs of OWS. The efficacy of each treatment was determined 48 h later by comparing the number of myiases in the treated and untreated groups. Abundance of fly larvae in naturally-voided dung pads and the survival of a species of dung beetle, Onthophagus sagittarius, were used to assess the effects of drug residues on the dung fauna. RESULTS AND CONCLUSIONS: Moxidectin showed no activity against larvae of OWS during the first 14 days after treatment. Eprinomectin provided protection for 3 days after dosing, but failed at days 7 and 14, whereas doramectin was effective at day 7, but not at days 14 or 21. In contrast, no myiases were established on bolus-treated cattle from 14 to 102 days after treatment. Faecal residues of moxidectin had no effect on the survival of larvae of dung-feeding flies, whereas those of eprinomectin and doramectin reduced survival for 1 to 2 weeks. Dung voided by bolus-treated cattle inhibited fly breeding and had adverse effects on the development and survival of O sagittarius for up to 15 weeks after treatment.  相似文献   

6.
Chrysomya megacephala, also known as the Oriental latrine fly, is indigenous to south-east Asia. During the 1970's it successfully invaded Africa and South America, and more recently during the 1980's also established itself in the United States of America. Although the first specimens from South Africa were collected from the south-western Cape Province in 1978, no published data appears to exist on its subsequent spread or status in southern Africa. During May 1991 a specimen of C. megacephala was incidentally captured near Beaufort West, Cape Province, South Africa, which prompted re-examination of blow-flies captured in the Kruger National Park during 1984. In this way it was found that C. megacephala was already well established in the south-eastern Transvaal by mid-1984. Adult C. megacephala can easily be confused with C. bezziana and medical/veterinary entomologists and veterinarians should take note of the existence of this species and the fact that it is probably widespread throughout southern Africa at this state.  相似文献   

7.
Some insecticides to control and prevent screw-worm fly strike by Chrysomya bezziana in calves and adult cattle were tested in field trials on cattle in Sabah, East Malaysia. Ivermectin injected subcutaneously in newborn calves at 200 mu/kg provided 10 days protection from screw-worm fly strike, which allowed navels to dry. Ivermectin, 1% dichlofenthion plus gentian violet and 3% lindane plus pine oil smear were all effective in preventing re-strike of treated wounds in adult cattle. A single subcutaneous injection of ivermectin at 200 mu/kg was effective, whereas it was necessary to re-apply the dichlofenthion and lindane smear preparations every 48h.  相似文献   

8.
Three new insecticide smear preparations for the control of Chrysomya bezziana larvae infesting wounds of cattle have been tested under field and laboratory conditions and compared with an established preparation EQ 335 which is based on 3% lindane. Two preparations based on 3% coumaphos proved comparable to EQ 335 in the field trials and exhibited more prolonged residual effectiveness in laboratory tests. A smear preparation based on 2.5% methoxychlor was only effective in controlling 1 and 2 day-old larvae in wounds and was generally inferior to other smears tested in the laboratory.  相似文献   

9.
An in vitro technique for screening systemic insecticides against larvae of the screw-worm fly, Chrysomya bezziana is described. Susceptibilities of screw-worm larvae of different ages to ivermectin (MK-933) were determined. Based on 24 h larval mortality, the LD50 of 1-,2-,3-,4- and 5-day larvae was 0.01, 0.02, 0.03, 0.2 and 0.4 ppm of ivermectin. LD50 based on adult emergence following treatment of 4- and 5-day larvae was 0.02 and 0.05 ppm. The LD99.9 for 4-day larvae based on 24 h larval mortality and adult emergence was 11.0 and 0.15 ppm respectively and for 5-day larvae, was 44.3 and 0.4 ppm respectively. Pen and field trials with cattle infested with screw-worm fly demonstrated the potential of ivermectin as a systemic insecticide. Dosages of 50, 100 and 200 micrograms/kg, of ivermectin administered subcutaneously to experimentally infested cattle gave complete control for 6, 12 and 14 days respectively. Ivermectin at 200 micrograms/kg caused 100% mortality of screw-worm larvae up to 2 days old at the time of treatment with 70, 64 and 21% mortality of 3-, 4- and 5-day old larvae at the time of treatment. The residual protection from a single dose of 200 micrograms/kg was 16 to 20 days. When bull calves were treated with ivermectin at a dose of 200 micrograms/kg at the time of castration and branding, none of the 77 treated animals sustained a screw-worm strike in the scrotal area compared with 47 strikes (44%) in the 106 control cattle.  相似文献   

10.
OBJECTIVE: To determine application rate and effectiveness of sodium bisulfate to decrease the fly population in a horse barn environment. SAMPLE POPULATION: 12 privately owned farms in southeastern Pennsylvania. PROCEDURE: Application rates of sodium bisulfate were approximately 2.3 kg/stall, 1.1 kg/stall, and 0.5 kg/stall. Two or 3 stalls were treated, and 1 or 2 stalls were not treated (control stalls) at each farm. Farm personnel applied sodium bisulfate in treated stalls daily for 7 days. Fly tapes were hung from the same site in treated and control stalls. After 24 hours, the fly tape was removed, flies adhering to the sticky surface were counted and recorded, and a new fly tape was hung. This procedure was repeated daily during each of the testing periods. RESULTS: Following the application of 2.3 kg of sodium bisulfate/stall, the numbers of flies collected on the fly tape were significantly decreased in treated stalls, compared with control stalls during the same time periods on 9 of the 12 farms evaluated. Following the application of 1.1 kg of sodium bisulfate/stall, fly numbers were significantly decreased in treated stalls on 6 of the 9 farms evaluated. Following the application of 0.5 kg of sodium bisulfate/stall, fly numbers were significantly decreased in the treated stalls on 3 of the 4 farms evaluated. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings suggest that sodium bisulfate would be effective for fly control in horse barns.  相似文献   

11.
A new trap, named the "H trap", was developed at Hellsgate Tsetse Research Station in South Africa for the simultaneous collection of live Glossina brevipalpis Newstead and Glossina austeni Newstead. Its design followed an evaluation of the responses of the two species towards traps that are used elsewhere in Africa for the collection of other tsetse fly species. These traps were found at Hellsgate to be unsuitable for capturing both G. brevipalpis and G. austeni. Some new trap designs and many modifications of these were tested, most of which were unsuccessful.The odour-baited blue and black H trap represents a different approach for trapping tsetse flies as it is fitted with lateral cones of white netting which induce the flies to take a more horizontal flight path once they have entered the trap, instead of the vertical flight paths they assume in existing tsetse fly traps. A number of modifications of the prototype H trap were devised (H1-H5), before the final design was established. Catches of up to 76 G. brevipalpis and 37 G. austeni were obtained per trap on a single day with the H3 modification. Further modifications improved on the trap's efficiency to capture G. brevipalpis and G. austeni. The final modification caught a record number of 180 G. brevipalpis and 57 G. austeni on a single day.  相似文献   

12.
The effects of larvae, nymphs and adults of the brown ear-tick Rhipicephalus appendiculatus on the growth of Bos indicus X B. taurus (Sanga) steers and on B. taurus steers and heifers was measured by exposing groups, maintained in the same pastures, to different levels of tick challenge. Larvae and nymphs had no significant effect on liveweight gains, but adults had a large effect. Each engorging female tick counted was associated with a loss of 4 g. Their effect on the Sanga cattle was minimised by host resistance which severely limited the number of ticks feeding on them. The B. taurus animals were severely affected and suffered extensive ear damage. Both breeds were subjected to screw-worm fly (Chrysomya bezziana) strike in the lesions caused by heavy tick infestations, but the B. taurus animals were much more prone to attack. The results provide a basis for calculating losses in production caused by this species of tick which is widespread in Africa.  相似文献   

13.
The effects of the bont tick Amblyomma hebraeum on the productivity of cattle need to be quantified in order to design economically optimal control programs. Liveweight gains (LWGs) of three groups of Africander steers, maintained in the same pasture and exposed to zero, medium or high numbers of larvae, nymphs and adults of the tick, were measured. Larvae and nymphs had no significant effect on LWG but adults had a large, statistically significant effect (P less than 0.05). The tick-free group had an average LWG of 20 kg more than the heavily infested group after 3.5 months. No mortality was recorded from ticks or tick-borne diseases during the experiment. There was no relationship between the number of engorging adult female ticks counted and loss of LWG of individual animals. The latter suggests that exposure to ticks as well as engorgement by female ticks causes losses. The loss per adult female that completed engorgement was estimated, by relating the LWGs of individual animals to their tick infestations, to be 4 +/- 2 g per adult female tick. An alternative estimate, made by comparing the average LWG and tick infestations of each treatment group, was equal to 10 +/- 4 g. This latter estimate includes the effect of challenge (and rejection) as well as tick feeding and so was accepted as giving the best estimate. Screw-worm fly (Chrysomya bezziana) struck an average of 7.5% of the cattle infested with ticks in any week but the effects on the productivity of the cattle were minimized by immediate treatment. There was a significant, positive correlation between the incidence of screw-worm fly strike and the numbers of adult ticks counted on the experimental animals. The results provide data for calculating losses caused by A. hebraeum in different parts of its geographical range.  相似文献   

14.
通过研究不同天气条件、不同时段果蝇的活动规律,为果蝇成虫诱杀技术的研发与应用提供理论依据。以果蝇为研究对象,设置不同处理,在现场研究果蝇在晴天、阴天、雨天及一天内不同时段的活动规律。在供试的6种成熟水果中,香蕉、蓝莓对果蝇的引诱效果显著高于其他4种水果(P＜0.01),绿如蓝牌果蝇引诱剂的引诱效果显著高于香蕉(P＜0.01)。在晴天,果蝇的活动更为频繁(P＜0.05),晴天诱捕到的雄果蝇数量明显高于阴天和雨天(P＜0.01)。诱捕到的果蝇种类主要是黑腹果蝇、斑翅果蝇、伊米果蝇、海德氏果蝇、筋果蝇等。一天内不同时间段果蝇的活动明显不同,8:00~10:00和16:00~18:00是其活动的两个高峰期。天气条件对果蝇活动有很大影响,一天内果蝇活动存在两个高峰期,分别是8:00~10:00和16:00~18:00,利用绿如蓝牌引诱剂可对果蝇成虫进行有效诱杀。  相似文献   

15.
运用田间罩笼法在明确桔小实蝇释放量与柑桔损失率、释放量与诱捕量之间的关系基础上,推导出诱捕量与损失率之间的关系,并建立了桔小实蝇防治指标模型,以台州市温州蜜橘的最低售价及防治成本等参数得出桔小实蝇在柑桔园相对每棵柑桔的防治指标为2.2头。  相似文献   

16.
We investigated the on-farm potential of common farm invertebrates to transmit porcine circovirus genotype 2 (PCV2) and other non-enveloped viruses. In 2007 (pre-PCV2 vaccination) and 2008 (post-PCV2 vaccination), invertebrate communities were trap-collected (8 trap-dates per year), counted and sorted into genus and species groups on 5 farm study sites within England. Total DNA was extracted from feces of representational cross-sections of pigs on each farm in each year and also from intact samples of Diptera flies (ca. 20 flies per trap) and dissected viscera of any cockroaches (ca. 5 per trap). Each DNA sample was tested for the presence of PCV2 DNA by separate PCRs for ORF1 and ORF2. Positive samples were sub-typed via DNA sequencing of PCR products. The pig-associated Diptera fly community was dominated by Musca domestica (house fly) in both years on all 5 farms; numerous Blatta orientalis cockroaches were only noted on 1 farm throughout. Specific PCV2b DNA elements were routinely detected (25-60% of samples) in weaner/nursery pig feces in 2007, but not in other age groups. Musca collected on 4 of the 5 farms in 2007 was also positive for PCV2b DNA elements. Comparison of ORF2 sequences indicated that ORF2 sequences indicating PCV2b genotype were identical in pigs and flies. Minor changes were noted in ORF1 sequences from different samples. Flies collected in the weaner/nursery area were most likely to be positive (22-50% of fly-trap samples). DNA extracted from all cockroaches (2007 and 2008) and all flies and pig feces in 2008 were also negative throughout. We suggest that Musca flies have the most likely on-farm potential to carry and transmit PCV2b due to their life cycle incorporating stages in close association with pigs and their habitat. Vaccination appeared to reduce environmental load of PCV2b.  相似文献   

17.
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   

18.
In Burkina Faso, we assessed the efficacy of treating cattle with a footbath containing aqueous formulations of pyrethroids to control two tsetse-fly species, Glossina tachinoides Westwood, 1850 (Diptera, Glossinidae) and Glossina palpalis gambiensis Vanderplank 1949. Legs were the most targeted parts of the body for tsetse-fly blood meals: 81% (95% CI: 73, 89) for G. tachinoides and 88% (81, 95) for G. palpalis.

The in-stable efficacy of footbath treatments was compared with manual full spraying with a 0.005% alphacypermethrin (Dominex, FMC, Philadelphia, USA) formulation (250 mL versus 2 L). The proportions of knocked-down flies were the same with footbath and full spray but the latter was more protective against fly bites. In field use, the efficacy of both methods should be similar given the recommended treatment frequency: 3 days for footbath versus 7 days for full spray.

Among 96 cattle drinking at the same water point in Dafinso (Burkina Faso), 68 (71%) were treated with a footbath containing a 0.005% deltamethrin formulation (Vectocid, CEVA SA, Libourne, France). We observed the effect of this live-bait technique on the one hand on released cohorts of reared, irradiated flies, and on the other hand on wild tsetse flies. In both cases, the footbath treatment was associated with a reduction of the apparent fly density probably related to an increased mortality.  相似文献   


19.
通过羽化监测取得大实蝇Bactrocera minax（Enderlein）成虫雌雄性比数据,采用诱蝇球诱集方式,监测弃管园田间成虫数量和性比变化情况,对各时段诱集的雌性成虫进行卵巢解剖分级,发现诱蝇球对雌性成虫的诱集能力略高于雄虫;田间成虫盛期雌性成虫卵巢发育加快,普遍具备产卵能力,田间成虫盛期与产卵为害盛期同步。大实蝇防治实践中,根据成虫发生时间确定诱蝇球的使用时间,不必考虑性别影响。  相似文献   

20.
2021年3月至11月，在杨桃园和莲雾园，经调查发现桔小实蝇在杨桃园和莲雾园均发生3代，杨桃园和莲雾园对桔小实蝇总量、雌蝇、雄蝇的诱捕存在极显著性差异（P=0.001），且杨桃园桔小实蝇总量、雌蝇总量、雄蝇总量均高于莲雾园。在不同诱剂处理下，杨桃园和莲雾园之间均存在极显著性差异（P=0.000），杨桃园和莲雾园桔小实蝇雌蝇的诱虫量和诱捕效果：塞拉诺克联合桶形诱捕器＞塞拉诺克，95%甲基丁香酚＞黄板＞空白桶形诱捕器。对桔小实蝇雄蝇的诱虫量和诱捕效果在杨桃园：95%甲基丁香酚＞塞拉诺克联合桶形诱捕器，塞拉诺克，黄板＞空白桶形诱捕器；莲雾园：95%甲基丁香酚＞塞拉诺克联合桶形诱捕器＞塞拉诺克，黄板＞空白桶形诱捕器。杨桃园和莲雾园雌蝇占比最高为塞拉诺克联合桶形诱捕器处理分别为68.84%、60.84%。  相似文献   

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