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绵羊痒螨发育分期观察及生物学特性研究 总被引：3，自引：0，他引：3
经动物感染试验,对绵羊痒螨主要虫期的形态特征、发育变化、寄生行为以及生活史进行了观察。绵羊痒螨的发育经过卵、幼螨、若螨、成螨４个发育阶段,每阶段有一静止蜕皮转变期,其若二螨与雄螨在交配前期的徘徊行为,雌痒螨的带卵越冬使痒螨世代发展延续。自然变温与恒温条件下离体痒螨的观察表明,痒螨产卵、孵化、静止脱皮以及各期的发育受温度的影响较大,３０℃是痒螨发育的最适温区,２０￣２６℃发育迟缓呈延长倾向,高于４０ 相似文献
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绵羊毛圆科线虫卵在不同温度下的发育情况观察 总被引：3，自引：0，他引：3
观察了寄生于绵羊体内的优势虫种细颈线虫、奥斯特线虫、捻转血矛线虫、马歇尔线虫等毛圆科线虫卵在不同环境中的发育能力；研究了细颈线虫卵在相对湿度100％，0、3、5、10、15、20、25、30、35℃共9个不同温度梯度的发育率和发育周期；并对毛圆科线虫卵在-17～-25℃自然冷冻环境中的发育情况和幼虫在干燥环境中的抗干旱能力进行了测试。结果表明，细颈线虫卵在20℃、相对湿度100％的条件下发育率最高，发育周期最短；毛圆科线虫卵在-25～0℃环境中不发育，也不死亡；毛圆科线虫的幼虫在无水分的干燥环境中可存活100d左右。 相似文献
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本文报导了实验室内,在相对湿度基本相同(90—94％)、温度不同(14.8—17.4℃、25℃、30℃)的条件下,对采自自然草场上的青海血蜱饥饿成虫,在羊体上吸饱血后,进行了:产卵前期及产卵期、卵期、幼虫吸血期、幼虫蜕变期、若虫吸血期、若虫蜕变期、雌虫吸血期等的试验观察。结果得出其生活史较长,一个世代平均需要525.9—265.9—211.8天。并对性别比例、各期饥饿虫体的寿命和量度,做了观察记载。青海血蜱除邓国藩描述的与日本血蜱在形态上不同外,在生物学特性上也有差异,前者较后者产卵数少而各期虫体的吸血和蜕变时间短。 相似文献
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尚大军 《畜牧兽医科技信息》2011,(10):54-55
绵羊螨病是由疥螨和痒螨寄生在体表而引起的慢性寄生性皮肤病。螨病又叫疥癣、疥虫病、疥疮等,具有高度传染性,往往在短期内可引起羊群严重感染,危害十分严重。1流行特点痒螨具有坚韧的角质表皮,对不利因素的抵抗力较强,如在6￣8℃和85%￣100%空气湿度条件下的畜舍内能存活2个月,在牧场上能存活25d,在 相似文献
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将实验室培育的“洁净”长角血蜱的幼虫、若虫、成虫及微小牛蜱的幼虫,先后分别释放到人工感染卵形巴贝斯虫单一种牛体上不同部位事先粘贴好的布袋中,使其自行叮咬吸血。待饱血脱落后亦分别收集,置28℃、相对湿度约90％的条件下蜕皮或产卵孵化。而后用不同世代和各变态期的蜱,分别叮咬感染除脾和非除脾健康易感牛。结果表明,长角血蜱的当代若虫和成虫对卵形巴贝斯虫没有传播能力,幼虫和若虫吸入的病原亦不能经卵传递;饱血雌虫吸入的病原可经卵传递,次代幼虫、若虫和成虫三个阶段都具有传播能力。次代感染幼虫经兔体后的若虫和成虫也具有感染力。 微小牛蜱不能传播该种病原。 相似文献
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绵羊痒螨病俗称羊疥癣或癞病,是由于痒螨科痒螨属的绵羊痒螨寄生于绵羊体表而引起的慢性寄生性皮肤病。该病是黑龙江省绵羊冬春季常发的一种寄生虫病,有些绵羊常因大面积脱毛、机体消瘦而死亡。现将该病及其综合控制技术介绍如下,供广大养羊户和同行参考。1病原及其发育绵羊痒螨是一种较大的螨虫,呈长圆形,体长0.5￣0.9毫米,肉眼可见。口器为刺吸式,呈圆锥形。成虫有4对较长的足,雄虫的第1、2、4对足和雌虫的前3对足有吸盘。雄虫体末端有尾突,上具有长毛,腹面后端两侧有2个吸盘。雄性生殖器居第4肢之间;雌虫腹面前部正中有产卵孔,后端有纵裂… 相似文献
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The effects of temperature and humidity on the off-host survival of Psoroptes ovis and Psoroptes cuniculi. 总被引：2，自引：0，他引：2
The effects of both temperature and humidity on the survival of the mites Psoroptes ovis and Psoroptes cuniculi were considered in laboratory assays. When P. ovis and P. cuniculi were maintained at 95% humidity, maximum survival decreased linearly with increasing temperature, from approximately 15 days at 9 degrees C to 5 days at 30 degrees C. There was no significant difference between P. ovis and P. cuniculi in the effects of temperature on maximum survival. Adult male P. ovis and P. cuniculi had lower mean maximum survival than any of the other life cycle stages. There was a small but significant effect of humidity on survival for P. cuniculi; LT50 values were greater at 75-85% r.h. than at 55-65% r.h. The influence of off-host survival and the infestation of naive sheep from mites in the environment on the epidemiology of sheep scab are discussed. 相似文献
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Psoroptes ovis of sheep origin, and Psoroptes cuniculi of rabbit origin were used in experimental infestations. In experiment I, groups of four rabbits and four sheep were infested with 50-100 mites of each isolate on the skin of the back (skin infestation, SI) or in the external auditory canal (aural infestation, AI). In rabbits, SI and AI with P. cuniculi and AI with P. ovis induced in all animals typical ear lesions and pronounced antibody reactions to P. cuniculi antigens in ELISA. After SI of rabbits with P. ovis no clinical signs were detected, no mites could be reisolated and no specific antibodies were detected. In sheep, P. ovis SI induced mange whereas AI did not induce typical clinical signs and mites could not be reisolated. In both these animal groups, ELISA revealed pronounced and comparable specific antibody reactions. After SI and AI with P. cuniculi no clinical symptoms were observed and no mites could be reisolated. Nevertheless, low levels of specific antibody were detected. In experiment II, clinical progression and antibody reactions to P. ovis SI in naive sheep were compared with sheep previously exposed to P. ovis or P. cuniculi. In both pre-exposed groups of animals, clinical signs appeared within 2 days after challenge infestation and three days earlier than in primarily infested sheep. Subsequently, no obvious difference in the clinical progression was observed between the three groups of animals. The results of this study document antigenetic crossreactivity of the two morphologically and genetically distinguishable Psoroptes species but differences in their biological behaviour and virulence which both are of epidemiological and taxonomic relevance. 相似文献
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These studies were conducted to investigate the possible role of certain aspects of the on-host ecology and off-host survival of the sheep scab mite, Psoroptes ovis, in the dissemination of infestation. All developmental stages of the mite occurred in the fleece both proximally or distal to the skin of infested Merino and Dorper sheep. A larger proportion of mites was present in the fleece of Dorper sheep distal to the skin in the late afternoon and early morning than at other times during the day. Immature and adult mites readily transferred to tufts of wool or hair placed on infested sheep of both breeds. No mites could be found on wool or hair rubbed off onto tree trunks or branches or other structures in enclosures housing heavily infested sheep, nor could any mites be collected from the soil of these enclosures, whereas more than 80% of mites artificially seeded onto soil samples were recovered. The longest mean off-host survival times for larvae, nymphs, and male and ovigerous female mites were recorded at 10 degrees C, and were 9.25 days (RH = 90%), 15 days (RH = 33% and 75%), 10.5 days (RH = 75% and 90%) and 11.25 days (RH = 90%) respectively. Under natural climatic conditions ovigerous females in glass vials containing Merino wool survived for 17 days compared to 15 days for females in vials without wool; this difference was, however, not significant. The mean off-host pre-hatch period for eggs varied between 5.9 days (T = 25 degrees C and RH = 33%) and 22.1 days (T = 10 degrees C and RH = 75%), while the longest time individual eggs took to hatch at the latter temperature and RH was 31 days. 相似文献
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The response of sheep scab mites to pyrethroid insecticides and organophosphate compounds was studied in vitro with the objective of finding a simple test for detecting insecticide resistance in scab mites. Psoroptes cuniculi from rabbits or P. ovis from sheep were enclosed in small 'tea bags' made from heat sealable paper prior to dipping in insecticide. Mites failed to die 24 h after a 1 min dip in working concentrations of insecticidal sheep dips. With flumethrin a variety of different conditions were tested but most failed to improve the efficacy of flumethrin. It is suggested with freshly collected mites pyrethroids may be taken up by ingestion. 相似文献
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The availability of large numbers of undamaged sheep scab mites, Psoroptes ovis, would be beneficial for discovery screening and development trials. There are several reported procedures for removing scab mites from sheep but they have limitations. To overcome this, a simple but versatile method employing the use of pumped saline was developed to remove all stages of the P. ovis mite from sheep. The method takes no more than 2 min to remove mites from the selected site with relative ease and is not affected by the condition of the fleece or lesion. The number of mites removed with the new method was 5-10 times more than detected by visual examination. These mites were undamaged and survived off-host for up to 16 days. The robust, portable equipment is easy to use under field conditions, making this method suitable for use as a diagnostic tool for early detection and monitoring of scab mites thus providing opportunities for development of novel alternative control strategies. 相似文献
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Abolins S Thind B Jackson V Luke B Moore D Wall R Taylor MA 《Veterinary parasitology》2007,148(3-4):310-317
As part of a research programme designed to identify biological agents for the control of sheep scab, the pathogenicity of the fungus Metarhizium anisopliae to Psoroptes mites in the presence of sheepskin and wool was examined in the laboratory. No inhibitory effects of skin and wool were observed and high levels of infection were recorded. Subsequently the pathogenicity of formulations of both M. anisopliae and Beauveria bassiana to Psoroptes ovis was studied in vivo. For this, 36 batches of 20 adult female Psoroptes mites were confined in 25 mm diameter chambers which were attached to the backs of 6 scab-naive sheep. In some treatments, mites were exposed to the fungal pathogens for 48 h in vitro prior to being placed on the host, while other treatments involved mites with no prior exposure placed directly onto the skin of a host treated with a fungal pathogen. After 48 h on the host, mites were removed, incubated individually and all fungal infections were recorded. Fungal infection was observed in all treatments, except untreated controls. However, B. bassiana infected a significantly greater number of mites than M. anisopliae with all the formulations examined. Infection rates were highest when mites were exposed to dry conidia (>90%) and lowest with M. anisopliae in diatomaceous earth. Overall, the infection rate was not affected by whether or not the mites were given prior exposure to the conidia, before being placed on the sheep. The results demonstrate that Psoroptes mites can become infected by entomopathogenic fungi on the skin of sheep and provides a first demonstration of the potential of this technology for the control of sheep scab. 相似文献
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Diagnosis of psoroptic sheep scab with an improved enzyme-linked immunosorbent assay 总被引：1，自引：0，他引：1
An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of specific antibodies against crude Psoroptes antigen. The diagnostic sensitivity was 93.7% in 191 sheep with clinical signs associated with mange. These animals originated from 29 flocks in which psoroptic mites were detected. All of 59 sheep infested with Psoroptes ovis were seropositive. Additionally, in 49% of 70 clinically unaffected sheep originating from P. ovis-infested flocks, specific antibodies could be detected, suggesting that asymptomatic infestations can be diagnosed by serology. The specificity of the ELISA was 96.5% as determined with 254 sheep originating from 44 flocks without clinical mange. Cross-reactivity in a low range was detected with selected sera of sheep with clinical chorioptic or forage mite infestations. Four sheep seroconverted 2 weeks after experimental P. ovis infestation, i.e. 2 weeks before clinical signs became obvious. After successful doramectin treatment of 14 sheep with naturally acquired P. ovis infestation, the ELISA values declined slowly but remained positive in seven cases beyond 17 weeks. 相似文献
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Skin biopsies from three groups of sheep infested with Psoroptes ovis were cryofixed in liquid nitrogen to preserve outer epidermis with its lipid. From one group of five sheep (Group A), biopsies were taken from relatively healthy skin near the edge of scab lesions where mites had congregated. Frozen vertical sections from these biopsies were stained with Oil Red O and haematoxylin before mounting. Red lipid globules were plentiful within the body cavity of sectioned mites, but ingested lipid could not be distinguished from endogenous mite body stores by this technique. In a second group of five sheep (Group B), enclosed lumbar skin areas were coloured red with the lipophilic stains Oil Red O or Sudan IV. These enclosed coloured skin areas were inoculated with P. ovis and sampled by skin biopsy 1 or 4 days later. Cryofixed biopsies were cut into vertical frozen sections and mounted without staining for examination. Red-coloured lipid within mites, matching red-coloured lipid on outer epidermis, was evidence for the epidermal origin of P. ovis ingesta in the early stages of an infestation. From two other sheep (Group C), cryofixed biopsies were examined by scanning electron microscope and mites were seen with mouthparts embedded in abraded outer epidermis, but the precise depth of epidermal penetration was not determined. A light microscope survey of 3198 frozen vertical skin sections from the first 10 sheep (Groups A and B) showed that inner stratum corneum of the epidermis was the deepest penetration recorded for gnathosomes of P. ovis cryofixed in situ by liquid nitrogen. No structure of P. ovis was identified in dermal tissues. 相似文献
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Psoroptes ovis mites were removed from infected sheep and placed in positions where wool and mites normally accumulate during sheep scab outbreaks. The ambient temperature and humidity were monitored over a 3-week period and the survival and infectivity times were examined. The procedure was carried out during each of the seasons. The hatchability of mite eggs was also examined. It was found that little variation occurred between seasons, with mites regularly retaining viability and infectivity for 15 days during all seasons. Mites that survived for more than 16 days failed to infect sheep. Mite eggs retained hatchability for up to 7 days. 相似文献