Effects of natural pyrethrum and synthetic pyrethroids on the tiger mosquito,Aedes albopictus (skuse) and non-target flower-visiting insects in urban green areas of Padua,Italy

Abstract

The tiger mosquito is a key vector of several human diseases and is considered a public health concern worldwide. The implementation of strategies aimed at maximizing mosquito control without affecting non-target insect groups is of major importance. In a field trial, we tested the efficiency of a natural pyrethrum-based vs. a synthetic pyrethroid-based insecticide in reducing tiger mosquito population and how they affect the diversity of non-target flower-visiting insects in green urban areas. Only the pyrethroid insecticide was effective in reducing mosquito abundance, although its effects disappeared nine days after application. The two adulticides did not significantly affect the diversity of flower-visiting insects, probably because of their large body size and the difference in flying and foraging activity. To effectively control mosquito populations while preventing intoxication of non-target flower-visiting insects, adulticide applications should be applied early in the morning and only on bushes and trees. Results from our small-scale applications cannot be extrapolate when larger areas are treated.     

森林主产利用计划系统编制工作初探

森林经营方案的编制与实施是提高森林经营水平的重要步骤。在编案中森林主产利用计划系统的编制是关键的工作。本文针对森林主产利用系统在编制过程中存在的问题，提出解决问题的途径、方法及其前景。     

柳杉花粉的散发规律

柳杉花粉囊为纵向开裂，雄球花在雨季对花粉具有保护功能；雌雄球花和花粉都对风媒传播发生了适庆性变化；花粉的散发，传播，沉降和空间分布，出现规律性变化，并受降水，气温，风力和大气湿度的综合影响。针对花粉散发特性，提出了经营种子园的有关建议。     

落叶松红腹叶蜂的防治技术

本文描述了落叶松红腹叶蜂的管理和防治技术．管理技术包括：（１）提高测报水平；（２）制定和应用防治指标；（３）制定防治计划和开展防治措施。防治技术包括：（１）采取营林措施，使郁闭度保持０．７；（２）用壮苗造林，并适地适树；（３）利用天敌开展生物防治，还可以采用化学药物防治措施。     

Studies on Tomato Seedling Quality Indices Under Simulated Shipping and Storage Conditions

Indices of the tomato seedling quality maintenance level after production before field planting were studied through simulated experiments, small--scale operation, indoor analyses and measurements, and field observation. The results showed that under simulated shipping and storage conditions, seedling quality change following different durations (days) of shipping and storage was correlated significantly or even very significantly with certain physiological and morphological indices. With various measured indices following different periods of shipping and storage treatment subjected to multinomial successive regressive correlation analysis, the principal factors influencing seedling quality maintenance level are identified to be chlorophyll content→dry short weight→ leaf freshness index in order of their importance. Significance analysis with multinomial fitted equation indicated that correlations between any one of above three factors and the growth index after field planting reached very significant difference level.     

城镇化水平计算方法比较分析

城镇化是社会经济发展的必然趋势，与小城镇人口、经济实力、社会发展和环境保护等方面密切相关。城镇化判别指标归纳起来分两大类：一类是单一指标法或称主要指标法；另一类是多项指标法、复合指标法或称综合指标法。在常用的、单一指标法的城镇化水平计算方法中，城镇人口比重指标法和带眷系数法两种方法能够比较准确地反映小城镇的城镇化水平，尤其以城镇人口比重指标法计算结果最符合实际。     

An evaluation of the Olsen test as a measure of plant-available phosphorus in grassland soils derived from basalt parent material

Abstract. Anecdotal and circumstantial evidence have suggested that the Olsen test underestimates plant-available phosphorus (P) in basaltic soils in Northern Ireland. Therefore, the ability of this test to predict plant-available P in basaltic (and non-basaltic) soils was investigated by regressing Olsen-P data against herbage P indices calculated from plant tissue test data using the diagnosis and recommendation integrated system. The average Olsen-P concentration for a range of fields situated on basaltic soils was considerably lower than the average Olsen-P concentration for a range of fields situated on non-basaltic soils, and yet mean sward P status, as given by the herbage P indices, was similar for both groups of fields. Herbage P indices were also much better correlated with Olsen-P measurements in non-basaltic soils than in basaltic soils. Furthermore, at low Olsen-P values (≶9mgPL⁻¹) some swards on basaltic soils were genuinely deficient in P, while others were sufficient or even in surplus for this nutrient. The results confirm that Olsen-P is inadequate as a predictor of plant-available P in basaltic soils. It is concluded that an alternative soil test is needed to provide a reliable assessment of plant-available P in basaltic soils, to prevent overuse of fertilizer and manure P and to minimize the amounts of P entering local watercourses.     

Social, economic and cultural perspectives of European inland fisheries: review of the EIFAC symposium on fisheries and society

The contributions presented at the EIFAC Symposium on Fisheries and Society in 2000 are reviewed. There have been considerable advances in many sectors of inland fisheries over the past decade. Nowadays the value of inland fisheries to society is generally better understood and increasingly recognized. However, it was recognized that the allocation of fishery resources and their management could still be made more effective through more extensive application of the recent approaches and techniques discussed during the Symposium and reviewed in the paper.     

治疗图书馆顽症:流程重组

本文将流程重组理论引入图书馆管理，分析了图书馆流程重组的必要性，同时具体阐述了图书馆流程重组的三种方式。     

高校公寓文化建设的几点思考

从校园文化、学风建设、素质教育、思想教育等方面，阐述公寓文化的作用和意义，提出理顺管理机制、发挥学生主体作用、加强制度建设，开展公寓文化活动等几点建议。