东西方蜜蜂越冬期过冷却点的测试及过冷却点与越冬性能的关系

针对越冬期东西方蜜蜂的过冷却点进行了测试并对其与越冬性能的关系进行了分析。结果发现:在越冬期,东西方蜜蜂存在过冷却点且二者差异显著,东方蜜蜂过冷却点明显低于西方蜜蜂,蜜蜂的过冷却点与其越冬性能密切相关。     

柞蚕综合利用（Ⅳ）——柞蚕蛹繁殖白蛾周氏啮小蜂防治美国白蛾

长期以来在农林害虫防治过程中,由于化学农药长期无节制地使用,不少害虫已产生了明显的抗药性,大量天敌被杀伤,致使一些害虫的危害十分猖獗.而且,许多化学农药严重污染水体、大气和土壤,并通过食物链进入人体,严重地危害人类健康.多年来的实践证明,利用天敌生物防治农林业害虫,既能有效地避免上述缺点,又能达到增产增收、节省能源和降低生产成本的明显效果.由于它具有良好的经济、生态和社会效益,越来越受到社会各界的重视.利用柞蚕蛹繁殖白蛾周氏啮小蜂防治美国白蛾的研究成功,既是柞蚕应用于生物防治方面又一典型事例,也是我国生物防治领域的又一重大突破,这为我国的生物防治工作开辟了新的途径.     

利用柞蚕蛹繁育白蛾周氏啮小蜂的几项关键技术措施

柞蚕(antheraea pernyipupa)蛹是白蛾周氏啮小蜂的最佳中间寄主。近几年利用白蛾周氏啮小蜂(Chouioia cunea)防治美国白蛾(Hyphantria cunea Drury)已取得了很大的成效。本文简要总结了利用柞蚕蛹繁殖白蛾周氏啮小蜂的技术。     

桑螟幼虫的越冬死亡率及过冷却点的研究

本文运用NTC-TD热敏电阻法测定了桑螟越冬幼虫的过冷却点、冰点。统计了桑螟幼虫的越冬死亡率。结果表明：前年9月到翌年4月间，过冷却点和冰点随温度降低而降低，随温度的升高而升高，并且均呈现一定的滞后性，但两者变化幅度不同，过冷却点的变化幅度显著大于冰点的变化幅度。4个处理中，越冬幼虫死亡率以枯枝落叶中为最高，室内最低。外界温度和过冷却点的变化，可能是引起桑螟死亡的重要原因。     

美国白蛾的发生规律与综合治理

美国白蛾为外来入侵种,现已扩散蔓延到辽宁、河北、天津、山东、陕西、上海等省市.美国白蛾是食叶性害虫,桑树是其喜食树种,对桑树生长和桑叶产量的影响很大.本文介绍了美国白蛾的发生规律、成灾原因及其相关的综合治理措施.     

桑尺蠖越冬幼虫的耐寒性研究

研究了桑尺蠖越冬幼虫的耐寒能力 ,测定了虫体内抗寒物质的组成成分 ,并对其耐寒机理作了初步探讨。结果表明 :越冬幼虫从越冬初期至越冬滞育期 ,4龄幼虫的平均过冷却点从初期的-1 7 2℃下降至滞育期的 -2 4 4℃ ;5龄幼虫的平均过冷却点从 -1 3 4℃下降至 -2 4 8℃。越冬幼虫体内水分、糖元、脂肪含量下降 ,其中以糖元含量下降明显 ;越冬幼虫以“小分子糖—氨基酸—糖蛋白”物质系统形成抗寒基质 ,增强耐寒性。     

浅谈美国白蛾的危害与防治

美国白蛾是世界性检疫病虫害,在各地均有分布,危害植物种类广泛,给林业生产造成了严重的危害。本文介绍了通过实施人工剪除网幕、围草诱蛹等防治美国白蛾,美国白蛾一年可发生两代,主要危害糖槭、沙果、杨树、柳树等树木,积极采取有效的综合防治措施,把美国白蛾的危害控制在损失最小的范围。     

美国白蛾在桑园的危害及防控措施

介绍了美国白蛾在盐城地区的发生情况、危害特点和防控措施,并就如何提高桑园美国白蛾的防控效果和保障蚕作安全提出了建议。     

美国白蛾在睢宁地区桑园的发生情况与防控措施

介绍了美国白蛾在江苏睢宁地区的发生情况和防控措施,在对美国白蛾幼虫的罩养过程发现了美国白蛾幼虫新的寄生蜂,经鉴定为茧蜂科、盘绒茧蜂(Cotesia sp.)     

Oxygen saturation measurements in canine blood containing hemoglobin glutamer-200 (Bovine): in vitro validation of the NOVA CO-Oximeter

Abstract: This study was designed to validate in vitro oxygen saturation (SO₂) measurements with the NOVA CO-Oximeter (Nova Biomedical Corp, Waltham, Mass, USA) in canine blood containing hemoglobin (Hb) glutamer-200 bovine (Hb-200; Oxyglobin, Biopure, Cambridge, Mass, USA) as a Hb-based oxygen carrier recently introduced into clinical practice. In the first set of experiments, stored blood from 6 mixed-breed canine blood donors was used. Target PO₂ levels were reached in aliquots of blood samples by tonometry. Oxygen saturation was then measured with the test device and calculated based on known PO₂ values. In the second set of experiments, total oxygen content was directly measured by means of an oxygen-specific electrode in aliquots of fresh whole arterial, venous, and mixed (arterial-venous) blood withdrawn from the same canine blood donors. Hb-200 was added to those blood samples to yield plasma Hb concentrations of 1.62, 3.25, 6.50, and 9.75 g/dL. Based on Hb content and SO₂ measured by the NOVA CO-Oximeter in these samples, total oxygen content was also calculated for each sample and compared with measured values. A strong correlation was found between SO₂ values measured with the co-oximeter in samples after tonometry, and calculated SO₂ based on known PO₂. Directly measured total blood O₂ content varied by ≤ 5% from values computed based on co-oximeter measurements of Hb content and SO₂. These results did not change with different levels of oxygenation of the samples or different plasma Hb-200 concentrations. In conclusion, the NOVA CO-Oximeter is an accurate analyzer for measurement of SO₂ after Hb-200 administration to canine blood.     

Changes in the risk management of Salmonella enterica subspecies diarizonae serovar 61:(k):1, 5, (7) in Swedish sheep herds and sheep meat due to the results of a prevalence study 2012

Background

The prevalence of Salmonella in food producing animals is very low in Sweden due to rigorous control programmes. However, no active surveillance is in place in sheep. The authorities decided to perform a prevalence study in sheep herds because findings at slaughter indicated that sheep associated S. diarizonae (S. enterica subspecies diarizonae serovar 61:(k):1, 5, (7)) might be common in sheep. Sampling was stratified by herd size in two groups, small herds with ≤ 30 animals and large herds with > 30 animals. In each stratum, 237 herds were selected at random. Faecal samples received from 244 out of the 474 randomly selected herds were analysed.

Results

A total of 40 of 100 (40%) of large herds and 17 of 144 (12%) of small herds were positive. The overall adjusted prevalence was 17.6% (95% CI, 12.9-22.2). Sheep associated S. diarizonae was detected in all counties (n = 21). Scientific opinions and an evaluation of on-farm control measures performed concluded that the impact of sheep associated S. diarizonae on human health is very low, and that risk management measures applied in response to findings of sheep associated S. diarizonae in sheep or sheep meat can be expected to have very little impact on reducing risks to human health. As a result, Swedish authorities decided to make an exemption for sheep associated Salmonella diarizonae in sheep and sheep meat in the current Salmonella control measures.

Conclusions

Sheep associated S. diarizonae is endemic in Swedish sheep herds. It is more common in large herds and not limited to certain parts of the country. The responsible authorities concluded that current risk management actions regarding sheep associated S. diarizonae in sheep and sheep meat are not proportional to the risk. This is the first time in the history of the Swedish Salmonella control programme that an exemption from the legislation has been made for a specific serovar. If there is any future indication of an increasing risk, due to e.g. change in the pathogenicity or development of antimicrobial resistance, the risk assessment will be re-evaluated and control measures reinforced if needed.