Attraction ofTrichogramma platneri to eggs of some lepidopterous pests of avocado

The attraction ofTrichogramma platneri Nagarkatti (Hymenoptera: Trichogrammatidae) to eggs of two lepidopterous avocado pests,Boarmia sel-enaria (Schiffermüller) (Geometridae) andCryptoblabes gnidiella (Millière) (Phycitidae), was evaluated in olfactometer tests. The mobility of the wasp as measured by a mobility index was 0.6 for males and 1.8 for females; the males had a lower mobility and a lower search capacity index than the females. Frozen and fresh youngB. selenaria eggs had the greatest attraction forT. platneri, which diminished with increasing age of the eggs. The eggs ofC. gnidiella were also attractive to the parasitoid. Contribution from the Agricultural Research Organization. No. 2704-E, 1989 series.     

昆虫病原线虫生物防控草地贪夜蛾的室内及田间效果和影响因素

联合国粮食及农业组织2018年向全球发布草地贪夜蛾Spodoptera frugiperda是重要的预警害虫。据报道,2019年我国已有26个省（区、市）的作物受到草地贪夜蛾为害。目前已经发现草地贪夜蛾幼虫对某些化学农药产生抗性的现象,为缓解其抗药性产生,具有主动寻找寄主害虫的昆虫病原线虫为草地贪夜蛾的生物防治提供了应用潜能。该文从昆虫病原线虫高效侵染种（品系）及其浓度、共生菌、草地贪夜蛾幼虫易感龄期、田间致死力及影响防控效果的因素等方面进行综述,以期为田间有效利用昆虫病原线虫防治草地贪夜蛾提供参考。     

高校实验室安全及规范操作慕课建设思路

我国《教育信息化十年发展规划(2011-2020年)》提出推进信息技术与高等教育的深度融合,目前部分高校已开始采用慕课形式开展实验室安全及规范操作教育.在分析慕课优势以及当前高校实验室安全及规范操作慕课建设不足的基础上,提出了慕课建设应以教师结合学生的需求为核心,并对课程的内容和评价体系给出了思路.     

离心式撒肥机撒肥部件研究设计

通过分析推肥板在撒肥圆盘上的布置对肥料颗粒在撒肥圆盘上运动的影响,得出推肥板在撒肥圆盘上的布置形式,计算了肥料颗粒的抛撒半径。据此设计了一种离心式撒肥机用的撒肥部件,并简介了撒肥部件的结构及参数的确定。试验及大面积生产考核证明,该离心式撒肥部件效率高,肥料撒施均匀,能够满足新疆兵团农场对全耕层施肥的要求。     

The use of sewage sludge as soil amendment. The need for an ecotoxicological evaluation

Background, aim, and scope  Sewage sludge use in agriculture should be limited by the presence of metals and other persistent environmental pollutants. The present study aims to contribute for the definition of a test battery of ecotoxicological assays that allows a proper ecotoxicological characterization of sludges, providing information on their potential hazard and identified “safe” application levels. Materials and methods  Three sludges from distinct sources (urban, olive-processing, and electroplating industries) were tested using avoidance and reproduction tests with earthworms (Eisenia andrei) and springtails (Folsomia candida) and plant growth tests with turnips (Brassica rapa) and oats (Avena sativa). Different soil–sludge mixture concentrations mimicking recommended/realistic field dosages were tested. Results  Only the sludge from the electroplating industry induced an avoidance response from the earthworms (EC₅₀ = 0.4 t/ha) and collembolans (no observed effect concentration (NOEC) = 15 t/ha). This sludge was the only sludge responsible for any effect on the reproductive output of the earthworms (EC₅₀ = 7.74 t/ha). Regarding collembolans, none of the sludges tested caused any significant decrease in reproduction. In higher plant tests, the two industrial sludges were toxic, causing a decrease growth in both species. The EC₂₀ values determined for B. rapa were 20.3 and 24.2 t/ha and for A. sativa 14.7 and 16.2 t/ha for sludges from olive-processing and electroplating industries, respectively. Discussion  The metal loadings of the different test sludges could partially explain the results obtained. The toxicity of the test sludge from electroplating industry observed on the tested invertebrates and plants could be explained by the high amount of total chromium from which 22.3% was in the most toxic oxidation state—Cr(VI). However, the toxicity caused by the sludge from the olive-processing industry in the test plants could be attributed to the presence of other compounds (not measured in this study) since the metal content was not high enough to induce such an effect. The absence of toxicity showed by the urban test sludge was in agreement with its low levels of metals. Conclusions  The response of the different test organisms and end points varied according to the sludge type. The urban sludge was non-toxic whereas the sludge from the electroplating industry caused a toxic effect on almost all parameters measured (avoidance behavior of both test organisms, reproduction of earthworms, and growth of both plant species). Sludge from the olive-processing industry only caused a toxic effect on growth of both plant species. By analyzing the sensitivity of the different parameters for the most toxic sludge, it was found that avoidance and reproduction were more sensitive than plant growth, whereas plant seed germination was not sensitive at all. Recommendations and perspectives  The ecotoxicological evaluation of wastes can be used as an environmental safety control of sludge use in agriculture. A tiered approach could be adopted for this purpose, incorporating avoidance tests in the first tier (screening level) and reproduction and plant growth tests in a second tier. But more evidence aiming to define the most suitable ecotoxicological test battery for specific sludges with a different contamination profile is still needed.     

土体构型对花岗岩红壤细沟发育形态的影响

为探究花岗岩红壤细沟形态特殊变化的原因,解释土体构型影响细沟形态发育的机理。设计单一红土层(H)、单一砂土层(S)、上红下砂层状土层(HS)3种土体构型、不同径流量(低径流量3 L/min、高径流量6 L/min)和不同坡度(中坡20°、陡坡40°)的室内模拟细沟冲刷试验。结果表明：H处理下,细沟形态更多向“V”形和“U”形发育;S处理下,细沟沟道发育过程中短暂形成上窄下宽的深宽梯形断面后,完全崩塌;HS处理下,细沟形态能发育为梯形断面,且能继续扩大发育。与H和S相比,HS陡坡(40°)处理下沟岸崩塌更加频繁且单次大质量崩塌更多。HS陡坡(40°)处理下沟岸崩塌发生21次,其中,单次崩塌量>1 kg的占比为63%。HS与H和S相比,雷诺数(Re)和弗罗德数(Fr)的波动更剧烈,更有利于梯形断面形成。与H、S相比,HS沟壁崩塌发生时,上层红土层含水量最低为0.31 cm³/cm³,抗剪强度最高为178 kPa;而下层砂土层含水量较高(0.33 cm³/cm³),抗剪强度最小为54 kPa。上红下...     

改进实验室管理培养大学生创新能力

本文研究了实验室管理对大学生创新能力培养的重要作用,从丰富实验室资源、拓宽实验范围、增加设计型和综合型实验项目比重,加大实验室开放的时间和范围,规范实验室仪器设备管理并加强实验教学队伍建设等3个方面探讨了推进实验室管理、提高人才培养质量的措施。     

生长青山羊能量需要的研究

选用5月龄青山羊30只,按体重分成5组,每组6只,分别饲予由花生秧,地瓜秧、青干草、玉米面、豆饼和地瓜面组成的五种不同日粮。含有相同水平的粗蛋白质(13%,DM),各日粮的ME含量分别为2047、2127、2175、2243、2254kcal/kg DM,进行100天的饲养试验和6天的消化代谢试验,研究生长青山羊对不同日粮能量的消化、代谢和能值对羔羊生长发育的影响。试验结果表明:(1)青山羊生长阶段对日粮能量的消化率和代谢率分别为63.5%和82.3%;(2)日增重(g)和MEI(x)呈明显的直线相关:y=0.0358x+0.81;(3)日增重(g)和日粮ME值(x)呈现对数关系:y=111.4LnX-836.5;(4)在自由采食和正常饲养的条件下,日粮ME值以2250kcal/kg DM比较有利于羔羊的生长发育。试验结果还证明:青山羊对日粮中主要成分具有较高的消化率。生长青山羊每日每头需要的ME量可按下式计算: MEI=93W~(0.75)+(1.65W-2.68)△W     

通用电工实验台的设计与试制

主要叙述了所研制的一种通用电工实验台的设计与试制,该实验台采用双重保护线路,安全可靠,仪表布置合理,显示直观,操作简便,可完成电路、电机和电器控制等多项电工类实验教学,经专家和实际实验实习检验,表明其电器及安全性能良好,使用方便,具有一定的推广应用价值。