Reedbeds as refuges for water voles (Arvicola terrestris) from predation by introduced mink (Mustela vison)

The water vole has recently undergone a catastrophic decline in the UK. This has resulted from loss and fragmentation of suitable habitat leaving water vole populations highly vulnerable to the impact of predation by introduced American mink. However, at some reedbed sites water voles and mink have apparently coexisted for many years. To determine if reedbeds offer a refuge from predation, 70 voles were radio-tagged at three sites in England and overwinter mortality monitored. Water vole perception of predation risk was also assessed. Mortality was high (64%), predation by mustelids, including mink, being the chief cause. Experiments suggested that voles failed to perceive areas of highest predation risk. However, predation rate declined strongly with the distance water voles lived from a main water channel. Thus, reedbeds provide a refuge from predation, even by mink, and calculations suggest that they may support source populations enhancing the viability of water vole metapopulations. Consequently reedbeds are now being used as one focus for the conservation of water voles in England and Wales.     

Natural enemies of the pear psylla<Emphasis Type="Italic">Cacopsylla pyri</Emphasis> in treated<Emphasis Type="Italic">vs</Emphasis> untreated pear orchards in Antalya,Turkey

Populations of pear psylla,Cacopsylla pyri (L.) (Rhynchota: Psyllidae), and its natural enemies were sampled on pears in Antalya province during the years 2000–2002. Thirty-two species of predators and three species of parasitoids were detected to be associated withC. pyri in Antalya province. The heteropterans (especially anthocorid species) were the most abundant predator group. Among the anthocorids,Anthocoris nemoralis (Fabricius) (Heteroptera: Anthocoridae), whose population was closely related to the dynamics of the pear psylla population, was generally the principal antagonist ofC. pyri. Other species recorded during the study were the miridDeraeocoris spp., the chrysopidChrysoperla carnea L., and many coccinellid species. Although these predators are polyphagous, as are theOrius species, their populations were related to the psylla fluctuations. Among the parasitoid complex belonging to the order Hymenoptera, the encyrtidTrechnites psyllae (Ruschka) was the only primary parasitoid. Two hyperparasites,viz., Syrphophagus mamitus (Walker) andPachyneuron aphidis (Bouché) (Encyrtidae and Pteromalidae, respectively), were detected in the surveys. Also, this study revealed new information concerning the pear psylla parasitoid complex in Turkey. WhileT. psyllae andS. mamitus are new records to Turkish parasitoid fauna,C. pyri is a new host record forP. aphidis. The population development and abundance of pear psylla and its natural enemies, as well as the parasitization rates in treated and untreated pear orchards, are presented here. http://www.phytoparasitica.org posting May 6, 2004.     

叶子花组织培养技术研究

通过对叶子花(Bougainvillea glabraChoisy)茎尖组织培养技术的研究,筛选出适宜的增殖培养基为MS+6-BA0.5 mg/L+NAA0.2mg/L,增殖系数达到4.0;最适合的生根培养基为MS+IBA1.0 mg/L,每株平均生根7.2条,根长4.2 cm,侧根数4.5条。以河沙为基质进行试管苗移栽有利于叶子花的成活,25 d后成活率可达78.6%。     

Lotka-Volterra数学模型在草地管理中的应用

介绍了Lotka-Volterra数学模型建立、求解方法,详细讨论了该模型在草地生态系统中的应用特点。通过分析认为可以利用Lotka-Volterra模型调控草地生态系统中载畜量与草地牧草产量间的关系,从而准确指导草地畜牧业生产。     

草莓热处理结合茎尖脱毒技术研究

以草莓品种"红颜"、"章姬"为试材,采用"茎尖培养+热处理"方法获得草莓脱毒组培苗,并建立其组培快繁体系。结果表明:茎尖诱导培养最佳培养基配方为MS+6-BA 0.5mg/L+NAA 0.02mg/L。在继代与增殖培养阶段,初期MS+6-BA 0.5mg/L+NAA 0.05mg/L增殖效果最好,后期培养基MS+6-BA 0.2mg/L+NAA 0.01mg/L有利于壮苗。生根阶段的最佳培养基配方,以1/2MS+IBA 0.1mg/L生根效果最好,生根率为100%。练苗移栽的基质为珍珠岩∶蛭石为1∶1,移栽成活率可达95%以上。     

天敌昆虫对信息化学物质的利用

信息化学物质在天敌昆虫寻找猎物,取食,避敌的过程中起着十分重要的作用。本文从天敌最常用的三种信息化学物质（利他素、互利素和标记信息素）入手,分别阐述了天敌昆虫对各种信息化学物质的利用,总结了国内外对天敌信息化学物研究现状,对将来的研究方向提出了一些建议。     

苦豆子条带对棉田捕食性天敌发生的影响

【目的】 研究田埂边苦豆子(Sophora alopecuroides L.)条带对棉田内捕食性天敌发生及其控蚜作用的影响,为棉花生产中田埂合理保留保育天敌的功能性杂草、促进棉田天敌保育与害虫自然控制提供科学依据。【方法】 系统调查田边苦豆子条带及棉田天敌与害虫种群,罩笼评价天敌控害功能。【结果】 苦豆子与棉花上捕食性天敌种类基本相同、群落结构相似,苦豆子条带上各类主要捕食性天敌的数量均显著高于棉田。处理棉田(棉田边有苦豆子条带)中瓢虫、草蛉、蜘蛛密度分别为对照棉田(棉田边无杂草)的1.3、3.4和4.5倍,发生高峰期较对照棉田提前一周左右。6月上旬和8月,处理棉田的捕食性天敌和蚜虫之间的益害比显著高于对照棉田。处理棉田捕食性天敌对棉蚜控害指数显著高于对照棉田。【结论】 苦豆子杂草带对有益天敌具有明显保育作用,能促进棉田捕食性天敌的发生与生物控害。     

Behavioural response of a trophic specialist, the Iberian lynx, to supplementary food: Patterns of food use and implications for conservation

Prey scarcity compromises population survival, especially for specialist predators. Supplementary feeding is a management tool that can be applied to reverse the decline of food-limited populations. We analyse how a population of Iberian lynx, a threatened food specialist, initially reacted to, and subsequently used, supplementary food. Twenty-seven feeding stations (FS) with domestic rabbits were placed in the Doñana Biological Reserve, SW Spain, between 2002 and 2005. We recorded lynx tracks inside and around stations to analyse spatio-temporal patterns of use, as well as the performance of several station designs. Iberian lynx used 62% of the FS installed, and consumed most of the supplied food. All station designs were used and food provision apparently covered the energetic needs of the lynx inhabiting the reserve. There was spatial aggregation in the use of the FS. Fourteen weeks were needed on average for lynx to become familiar with feeding stations and making a regular use of the supplementary food. Seasonal variations in consumption frequency appeared to be modulated by fluctuations of wild rabbit numbers throughout its annual cycle as well as by variation in energy demand of breeding females. The Iberian lynx responded positively to our supplementary feeding programme. We show that this technique allows the persistence of lynx populations during long periods in areas where wild rabbits are extremely scarce. Supplementary food may be used to sustain lynx whenever rabbit populations need recovery, as well as in the context of lynx restocking or reintroduction programmes.     

甘薯茎尖粉在挂面生产中的应用

为了利用甘薯茎尖丰富的营养成分,该试验通过复因素试验分析测定了添加甘薯茎尖粉和淀粉磷酸酯对挂面弯曲断条率、烹煮时间、烹煮损失、熟断条率和吸水率等品质指标的影响.结果表明:甘薯茎尖粉和淀粉磷酸酯的不同添加量对挂面弯曲断条率的影响较大,且二者存在交互效应;添加甘薯茎尖粉对于挂面烹煮时间、烹煮损失、熟断条率和吸水率均无显著影响,而处理间及添加淀粉磷酸酯对挂面上述4个品质指标均有极显著影响.经综合分析最终确定小麦粉、甘薯茎尖粉、淀粉磷酸酯按100:1.5:7的比例混合为生产挂面的较佳配方,经与市售挂面相比较,发现采用此配方可以生产出营养价值高且质量合格的甘薯茎尖挂面.     

Challenges facing arthropod biological control: identifying traits for genetic improvement of predators in protected crops

Biological control is an efficient pest control method but there are still limitations that are hindering its wider adoption. Genetic improvement of biological control agents (BCAs) can help to overcome these constraints, but the choice of key attributes for better performance that need to be selected is still an open question. Several characteristics have been suggested but the harsh reality is that selective breeding of BCAs has received a lot of attention but resulted in very little progress. Identifying the appropriate traits to be prioritized may be the first step to reverse this situation. In our opinion, the best way is to look at the factors limiting the performance of key BCAs, especially generalist predators (pesticide compatibility, prey‐density dependence, non‐suitable crops, and extreme environmental conditions), and according to these challenges, to choose the attributes that would allow BCAs to overcome those limitations. The benefits of selection for higher resistance to toxins, whether artificially applied (pesticides) or plant produced (plant defenses); increased fitness when feeding on non‐prey food (supplemented or plant‐derived); and better adaptation to extreme temperature and humidity are discussed. In conclusion, genetic improvement of BCAs can bring about new opportunities to biocontrol industry and users to enhance biocontrol resilience. © 2020 Society of Chemical Industry