蜜蜂白垩病综合防治初探

蜜蜂白垩病多年来对蜂群的危害相当严重 ,威胁着养蜂业的发展 ,因此 ,对该病的防治非常重要。1　白垩病的病原蜜蜂白垩病原主要是蜂球囊菌 (Ａｓ ｃｏｓｐｈａｅｒａａｐｉｓ)所引起。蜂球囊菌的实体里面有许多孢囊 ,孢囊内充满大小的孢囊孢子 ,孢子的抗逆性很强 ,在适宜条件下孢囊萌发雌、雄菌丝。雌菌丝形成藏卵器并与雄菌丝生长形成藏精器结合 ,再形成膨大球形的子囊 ,子囊具有很强的生命力 ,在干燥状态下 ,存活时间很长。蜜蜂白垩病主要是通过孢囊孢子和子囊孢子传播。患病幼虫、病死幼虫的尸体 ,以及被污染的饲料 ,蜂具等都是该病的传…     

白垩病流行病学

<正>白垩病是蜂球囊菌侵染蜜蜂幼虫(工蜂、蜂王和雄蜂幼虫)导致其死亡的真菌性传染病。尽管该病导致蜜蜂幼虫个体死亡,但是通常不会摧毁整个蜂群,不过会引起群势下降。工蜂能有效识别并清理发病幼虫,因此大部分蜂群可自愈。蜂群间甚至同一蜂群内来自不同父系的工蜂在感病性和清理行为方面有差异。白垩病在全球范围内发生,并有逐渐上升的趋势。蜂球囊菌是异菌体形,只有在两种不同株菌丝相互接触的地方才能形成孢子。     

科学管理蜂群预防白垩病

科学管理蜂群预防白垩病［美国］德拉普兰．Ｋ．Ｓ白垩病是一种蜜蜂幼虫病，由真菌（蜂球囊菌）引发致病。成年蜂不生此病，但会在箱内和箱外（采集飞行时）传播真菌孢子。成年蜂因接触污染的水源、花朵、花粉或盗蜂而沾染上孢子。带回到箱里后，幼虫一吞进孢子，便得病。...     

蜜蜂白垩病的防治

我地位于河北省西北部山区的出入口 ,洋槐多 ,蜜源充足 ,是省内外蜂友的首选放蜂之地。每年春季 ,由于大量转地蜂群的涌入 ,我地蜂群不同程度地受到白垩病的侵染 ,当地蜂农因此而造成的经济损失不小。因此 ,白垩病的防治工作显得尤为重要。白垩病是由蜂球囊菌引起的 ,能使大幼虫及封盖的幼虫死亡。死虫表面布满白色的丝状菌 ,慢慢变成疏松的石灰状硬块 ,颜色由灰逐渐变黑。白垩病的发生有如下特点：１ .蜂群发病的箱外条件是：低温、潮湿、蜜源不足或蜜蜂被蜜蜂球囊菌感染。２ .蜂群染病的箱内条件是：蜂种抗病能力差 ,巢内缺粉蜜 ,蜂数稀疏…     

蜜蜂白垩病的诊断与防治

意蜂白垩病又名石灰质病,是蜜蜂幼虫的一种顽固性传染性病害,多发生于春季或夏初,特别是阴雨潮湿的环境条件下,更容易发生。一、病源:此病是由能侵染蜜蜂的真菌——子囊菌所引起的。每个子囊内部含有大量的子囊孢子,这些孢子具有很强的生命力,在干燥条件下,可存活10到15年。二、症状:主要使大幼虫、     

蜜蜂对接种球囊菌孢子幼虫清除行为的研究

为研究不同白垩病抗性蜜蜂蜂群对接种蜜蜂球囊菌孢子幼虫的清除行为。利用微量移液器对未患白垩病的意大利蜜蜂、患白垩病的意大利蜜蜂以及从未报道患病的中华蜜蜂的二日龄幼虫接种蜜蜂球囊菌孢子的水溶液,观察计算患病与否蜂群对接种幼虫的清除能力的差异。结果显示,未患病的意大利蜜蜂和中华蜜蜂对接种蜜蜂幼虫分别有65%和60%的清除率,而患病意大利蜜蜂则只有约22%的清除率。抗性蜂群对接种幼虫的清除主要发生在接种后的2～3天内和化蛹后,而患病蜂群在幼虫期则基本没有清除,只在蛹期有少量的清除。该结果说明,对染病幼虫的及时清除行为是蜜蜂抗白垩病的重要机制。     

防治蜜蜂白垩病的微生物筛选

蜜蜂白垩病是由蜜蜂球囊菌(Ascosphaera apis)感染西方蜜蜂(Apis mellifera)幼虫引起的一种真菌性传染病.防治白垩病微生物筛选,是从土壤、腐烂果蔬、发酵蜂蜜、小曲和固体酵母中分离出28株酵母茵,用平板抑菌圈法筛选到5株酵母茵对蜂球囊菌有抑制作用.     

中、意蜂抗白垩病能力的检测与分析

蜜蜂白垩病(chalkbrood disease)是由蜜蜂球囊菌(Ascosphaeraapis)引起的蜜蜂幼虫死亡的真菌性疾病,该病已蔓延至世界各地并对养蜂业造成严重危害。本研究采用20个患白垩病蜜蜂黑色干尸混合50 g花粉粉碎,用蜂蜜混和制成条状花粉饼对意蜂蜂群进行人工接种感染,发现意蜂蜂群在接种前后患病个数差异显著(P=0.0227);自然情况下发病率差异显著不同组的蜂群之间在接种感染前后患病个数差异均显著(P=0.0238和P=0.0211),证实了不同蜂群抗白垩病能力确实存在显著差异。采用封盖子脾冷冻法检测了5群意蜂蜂群的清理能力,发现蜂群内幼虫的患病个数与清理率呈显著负相关(P=0.01 87),说明蜂群清理能力越强患白垩病的个数越少。采用蜂群白垩病人工接种方法对3个中蜂蜂群进行接种感染,结果均没有发现中蜂幼虫患白垩病。采用封盖子脾冷冻法检测蜂群的清理能力,发现中蜂和意蜂蜂群的清理能力无显著差异(P=0.2638),提示中蜂蜂群的抗白垩病能力可能由其他因素决定。     

蜜蜂白垩病发病特点及其防治

蜜蜂白垩病是真菌蜜蜂球囊菌(Ascophaera apis)引起的,容易感染西方蜜蜂的幼虫,成年蜂虽不易感染,但是病原的携带者和传播者。1991年我     

中蜂的自然王台与交替王台的区别

引起蜜蜂白垩病的蜂球囊菌繁殖快、传播快、不易消灭,因而危害大.患此病蜂群幼虫死亡率高,新老蜂接代脱节,群势快速下降,甚至全群覆灭,短时间内可弄跨一个蜂场.因此蜂农必须高度重视蜜蜂白垩病防治工作.     

患白垩病蜂群的温湿度研究

以蜜蜂白垩病致病菌蜜蜂球囊菌(Ascosphaera apis)感染西方蜜蜂(Apis mellifera).通过记录染病蜂群的温湿度和发病幼虫数,研究了养蜂生产中,温湿度变化对感染该病的西方蜜蜂蜂群(中等群势)的影响.结果显示:当蜂群内的温度降低到某个阈值范围时,不论是试验组还是对照组都会出现不同程度地增加发病幼虫数.     

蜜蜂白垩病PCR快速检测方法的建立及初步应用

根据Genebank网站公布的蜜蜂球囊菌ITSl.5.8s,ITS2 rDNA保守序列(U68313)设计出一对特异性引物ASCU和ASCD,可特异性的扩增蜜蜂球囊菌ITSI,5.8srRNA,ITS2序列上大小为471 bp的片段.优化了PCR最佳反应条件和体系;特异性试验结果表明与蜜蜂幼虫芽孢杆菌、蜂房蜜蜂球菌、蜜蜂败血杆菌无交叉反应,具有良好的特异性.敏感性试验结果表明敏感性可达7CFU/mL的蜜蜂球囊菌.通过将定量的蜜蜂球囊菌添加到蜂蜜、花粉、蜂胶和蜂王浆等蜂产品中进行模拟检疫,结果显示所建立的PCR检测方法适用于上述蜂产品中蜜蜂球囊菌的检疫.该方法与病原菌分离培养等传统检疫方法相比较,具有快速、灵敏、特异等优点,可用于蜜蜂及蜂产品中白垩病的进出口检疫及快速诊断.     

分子技术在蜜蜂白垩病病原鉴定和诊断上的应用

蜜蜂白垩病是一种由球囊菌属（Ascosphaera）的真菌寄生而引起蜜蜂幼虫死亡的传染性疾病，对蜂群的群势发展影响极大，近几年又呈现出大面积爆发的趋势。但目前对于该病的诊断和病原鉴定多依赖于典型症状，方法极不可靠。本文介绍了可用于分子鉴定和诊断的的研究基础，探讨利用球囊菌属的各病原rDNA的ITS1—5．8S-ITS2序列资料，分别设计出高特异性引物，用PCR技术扩增出可用于鉴定病原物种的分子标记，从而构建一套快速、准确诊断该病的分子技术。     

Temperature dependent virulence of obligate and facultative fungal pathogens of honeybee brood

Chalkbrood (Ascosphaera apis) and stonebrood (Aspergillus flavus) are well known fungal brood diseases of honeybees (Apis mellifera), but they have hardly been systematically studied because the difficulty of rearing larvae in vitro has precluded controlled experimentation. Chalkbrood is a chronic honeybee-specific disease that can persist in colonies for years, reducing both brood and honey production, whereas stonebrood is a rare facultative pathogen that also affects hosts other than honeybees and can likely survive outside insect hosts. Hive infection trials have indicated that accidental drops in comb temperature increase the prevalence of chalkbrood, but it has remained unclear whether virulence is directly temperature-dependent. We used a newly established in vitro rearing technique for honeybee larvae to test whether there are systematic temperature effects on mortality induced by controlled infections, and whether such effects differed between the two fungal pathogens. We found that increasing spore dosage at infection had a more dramatic effect on mortality from stonebrood compared to chalkbrood. In addition, a 24h cooling period after inoculation increased larval mortality from chalkbrood infection, whereas such a cooling period decreased mortality after stonebrood infection. These results raise interesting questions about honeybee defenses against obligate and facultative pathogens and about the extent to which stress factors in the host (dis)favor pathogens with lesser degrees of specialization.     

Top Dressing of Feed with Desiccated Chlamydospores of Duddingtonia flagrans for Biological Control of the Pre-Parasitic Stages of Ovine Haemonchus contortus

Feeding trials were conducted with stall-fed sheep parasitized with Haemonchus contortus. For 10 days they were offered 250 g of a concentrate feed that had been top-dressed with desiccated chlamydospores of Duddingtonia flagrans at 1×10⁵, 5×10⁵, 1×10⁶ or 2×10⁶ chlamydospores/kg body weight. Pooled faeces from each group on day 7 of spore feeding were spread on different pasture plots. On day 28 after the start of spore feeding, further pooled faeces from each group were spread on the same plots. The larval burdens on the plots were monitored for 2 months and the larval harvest from in vitro faecal cultures were monitored regularly. The application of 1×10⁶ or more spores/kg body weight virtually eliminated larvae from both the pasture and the faecal cultures. The application of as few as 1×10⁵ spores/kg body weight had a profound impact on larval recovery. The effect persisted while the spores were being fed but not for more than 4 days following discontinuation of spore feeding. Top dressing supplementary feed with dried chlamydospores offers a potential way of using D. flagrans for biological control of the pre-parasitic stages of H. contortus.     

Anthelminthic activity of acetone extract and fractions of Vernonia amygdalina against Haemonchus contortus eggs and larvae

The current control of parasitic nematodes in small ruminants relies on the use of chemical anthelminthics, but the development of resistance and the problem of drug residues require research into alternatives. Acetone extract and solvent–solvent fractions of Vernonia amygdalina Del. (Compositae) were evaluated in vitro for potential anti-parasitic effects against the eggs and larvae of Haemonchus contortus. Significant effects were obtained with the extract and fractions but differences were observed depending on the parasitic stage. The acetone extract and fractions inhibited egg hatching and inhibited larval development and killed larvae of H. contortus in a concentration-dependent manner. Best-fit 50% lethal concentration (LC₅₀) values were 957.0, 76.0, 524.0, 309.0 and 224.0 μg/ml for the acetone extract, and the butanol, hexane, chloroform and 35% water in methanol fractions, respectively, when tested against nematode eggs. Best-fit LC₅₀ values for the larval viability test were 508.2, 485.5, 569.3, 348.9 and 196.6 μg/ml for the acetone extract, and the butanol, hexane, chloroform and 35% water in methanol fractions, respectively. The butanol fraction was most active against nematode eggs while the 35% water in methanol fraction was the most active on nematode larvae, although differences in activity between fractions were not significant (p > 0.05). Overall, these in vitro results suggest that V. amygdalina, traditionally used by small farmers in Western Africa, does possess anti-parasitic properties.     

Consumption of bee pollen affects rat ovarian functions

The aim of this study was to examine possible effects of bee pollen added to the feed mixture (FM) on rat ovarian functions (secretion activity and apoptosis). We evaluated the bee pollen effect on the release of insulin‐like growth factor I (IGF‐I) and steroid hormones (progesterone and estradiol), as well as on the expression of markers of apoptosis (Bcl‐2, Bax and caspase‐3) in rat ovarian fragments. Female rats (n = 15) were fed during 90 days by FM without or with rape seed bee pollen in dose either 3 kg/1000 kg FM or 5 kg/1000 kg FM. Fragments of ovaries isolated from rats of each group (totally 72 pieces) were incubated for 24 h. Hormonal secretion into the culture medium was detected by RIA. The markers of apoptosis were evaluated by Western blotting. It was observed that IGF‐I release by rat ovarian fragments was significantly (p < 0.05) decreased; on the other hand, progesterone and estradiol secretion was increased after bee pollen treatment at dose 5 kg/1000 kg FM but not at 3 kg/1000 FM. Accumulation of Bcl‐2 was increased by bee pollen added at 3 kg/1000 kg FM, but not at higher dose. Accumulation of Bax was increased in ovaries of rats fed by bee pollen at doses either 3 or 5 kg/1000 kg FM, whilst accumulation of caspase‐3 increased after feeding with bee pollen at dose 5 kg/1000 kg FM, but not at 3 kg/1000 kg FM. Our results contribute to new insights regarding the effect of bee pollen on both secretion activity (release of growth factor IGF‐I and steroid hormones progesterone and estradiol) and apoptosis (anti‐ and pro‐apoptotic markers Bcl‐2, Bax and caspase‐3). Bee pollen is shown to be a potent regulator of rat ovarian functions.     

The in vitro response of field strains of sheep blowflies Lucilia sericata and L. cuprina (Calliphoridae) in New Zealand to dicyclanil and triflumuron

AIM: To evaluate the in vitro efficacy of triflumuron and dicyclanil against field strains of Lucilia sericata and L. cuprina in New Zealand to establish whether anecdotal reports of declining protection periods afforded by dips containing these active ingredients had validity.

METHODS: Strains of field-derived blowflies (Lucilia cuprina and L. sericata) were obtained from adult flies from flytraps or larvae from sheep with flystrike submitted from seven regions of the North and two regions of the South Islands of New Zealand. A total of 27 strains of L. sericata and 19 of L. cuprina were established in culture and first instar larvae obtained were exposed in vitro to dilution series of technical-grade dicyclanil (a pyrimidine carbonitrile) and triflumuron (a benzoyl urea). Concentrations lethal to 50% (LC₅₀) and 95% (LC₉₅) of each strain were calculated and tested by probit analysis, with the ratio of LC₅₀ of each strain divided by LC₅₀ of the most susceptible strain (resistance factor) derived in order to facilitate between-strain comparisons of susceptibility.

RESULTS: There was considerable variation between strains of L. sericata larvae in their susceptibility to triflumuron, with those least susceptible originating from the Waikato region. Strains from both Tararua and Manawatu regions were most susceptible and East Coast strains intermediate. All strains of the species tested showed a narrow band of susceptibility to dicyclanil with no regional trends apparent.

CONCLUSIONS: Representative field-strains of sheep blowflies exhibited a range of susceptibilities to both triflumuron and dicyclanil, suggestive of both genetic heterogeneity among fly populations and the spectrum of dip use in their source areas. This means there should be concerns for the long-term benefits of benzoyl urea insecticides for sheep farmers in New Zealand, but not yet for dicyclanil-based formulations.

CLINICAL RELEVANCE: Flystrike is a debilitating and occasionally lethal disease in sheep such that efficacious sheep dips have prophylactic value in reducing the prevalence of the condition.     

Nosema spp. infection and its negative effects on honey bees (Apis mellifera iberiensis) at the colony level

Nosemosis caused by the microsporidia Nosema apis and Nosema ceranae are among the most common pathologies affecting adult honey bees. N. apis infection has been associated with a reduced lifespan of infected bees and increased winter mortality, and its negative impact on colony strength and productivity has been described in several studies. By contrast, when the effects of nosemosis type C, caused by N. ceranae infection, have been analysed at the colony level, these studies have largely focused on collapse as a response to infection without addressing the potential sub-clinical effects on colony strength and productivity. Given the spread and prevalence of N. ceranae worldwide, we set out here to characterize the sub-clinical and clinical signs of N. ceranae infection on colony strength and productivity. We evaluated the evolution of 50 honey bee colonies naturally infected by Nosema (mainly N. ceranae) over a one year period. Under our experimental conditions, N. ceranae infection was highly pathogenic for honey bee colonies, producing significant reductions in colony size, brood rearing and honey production. These deleterious effects at the colony level may affect beekeeping profitability and have serious consequences on pollination. Further research is necessary to identify possible treatments or beekeeping techniques that will limit the rapid spread of this dangerous emerging disease.     

In vitro antiviral activity of chestnut and quebracho woods extracts against avian reovirus and metapneumovirus

Field evidences have suggested that a natural extract, containing tannins, could be effective against poultry enteric viral infections. Moreover previous studies have shown that vegetable tannins can have antiviral activity against human viruses. Based on this knowledge three different Chestnut (Castanea spp.) wood extracts and one Quebracho (Schinopsis spp.) wood extract, all containing tannins and currently used in the animal feed industry, were tested for in vitro antiviral activity against avian reovirus (ARV) and avian metapneumovirus (AMPV). The MTT assay was used to evaluate the 50% cytotoxic compounds concentration (CC₅₀) on Vero cells. The antiviral properties were tested before and after the adsorption of the viruses to Vero cells. Antiviral activities were expressed as IC₅₀ (concentration required to inhibit 50% of viral cytopathic effect). CC₅₀s of tested compounds were >200 μg/ml. All compounds had an extracellular antiviral effect against both ARV and AMPV with IC₅₀ values ranging from 25 to 66 μg/ml. Quebracho extract had also evident intracellular anti-ARV activity (IC₅₀ 24 μg/ml). These preliminary results suggest that the examined vegetable extracts might be good candidates in the control of some avian virus infections. Nevertheless further in vivo experiments are required to confirm these findings.