5种龙眼梢、果害虫的时间、空间、营养生态位研究

研究了为害龙眼梢、果的5种害虫(龙眼亥麦蛾、荔枝尖细蛾、荔枝蒂蛀虫、龙眼角颊木虱、荔枝蝽)的时间、空间、营养上的一维生态位宽度和重叠,在此基础上,建立了5种龙眼梢、果害虫的时间-空间-营养三维生态位,分析了5种龙眼梢、果害虫对资源的利用相似程度.并讨论了生态位在害虫预测预报和防治上的指导作用.     

荔枝蒂蛀虫防治研究进展

荔枝蒂蛀虫[Conopomorpha sinensis Bradley]是为害荔枝和龙眼的重要害虫,在开花结果期为害花穗和果实,致使花穗干枯、果实落果和造成"虫粪果",严重影响产品产量和质量。本文从预测预报、农业防治、物理防治、化学防治和生物防治等方面总结了荔枝蒂蛀虫的防治方法,探讨其综合防治技术。     

龙眼亥麦蛾发生为害特性及综合防治研究

龙眼亥麦蛾Hypitima longanae Yang et Chen在南宁年发生5－6代。其对龙眼石硖品种及春梢、花穗、二次秋梢蛀害较严重。龙眼结果母枝或花梗受蛀害可减产60％以上。此虫蛀害龙眼新梢与龙眼鬼帚症状无因果关系。采用修剪及疏花疏果时结合剪除虫枝，合理施肥，促进新梢抽发整齐；在顶牙萌动期及新梢小叶平展率达80％左右时，各喷一次高效灭百可或巴丹与乐果混合剂等药剂保梢的综合防治措施，防治效果达90．20％。     

大突肩瓢虫生物学特性及越冬保护技术研究

大突肩瓢虫是广西蔗区中甘蔗绵蚜的主要天敌之一,在南宁一年可完成四代发育,以第三、第四代成虫在蔗地及附近竹林越冬。此种瓢虫各虫态历期为:卵期5～6天,幼虫期10～15天,预蛹及蛹期5～8天,完成一世代发育需36～56天。越冬成虫寿命可达7～9个月。在适宜条件下,一头雌虫一生产卵量为400～700粒,最多达1235粒。冬季采集成虫保护饲养过冬,于次年甘蔗绵蚜发生初期补充散放到蔗地,是利用此瓢虫防治甘蔗绵蚜的一种有效途径。12月下旬以前采集的成虫,用适量肝糖代饲料饲养于14～18℃中,越冬存活率可达80％以上。     

黄土高原温室黄瓜斑潜蝇发生规律研究

通过大田调查与室内试验相结合的方法,研究了黄土高原温室黄瓜斑潜蝇发生规律。结果表明,黄土高原温室黄瓜斑潜蝇有4种,美洲斑潜蝇(Liriomyza sativae)为优势种,在温室内年发生8～10代,10月中旬～11月下旬为第一个发生高峰期,3月下旬至5月中旬为第二个发生高峰即防治关键时期。以各种虫态在温室内取食为害度过冬天,不能在田间自然条件下越冬。斑潜蝇幼虫在黄瓜植株上的垂直分布具有明显的层次性,以中下部密度最大,占90％以上。温度超过45℃持续2h或土壤相对湿度达100％超过20h,蛹羽化率均为0。温室种植模式、栽培面积及天敌等是影响斑潜蝇种群数量的主要因素。     

黑水虻生物转化猪粪过程中重金属的迁移变化

利用黑水虻处理猪粪为一种高效的环境友好型的技术,但猪粪中重金属的含量对黑水虻的转化产生影响。该研究在30 ℃环境下猪粪中接种7日龄的黑水虻幼虫,研究黑水虻的生长和对猪粪的转化效率,以及猪粪中的重金属（Cu、Zn、Cr、Cd、As）在黑水虻虫体和虫粪中的变化情况。结果表明：在8 d的生长过程中,0~2 d时,生长速率最慢,4~6 d时生长速率最快,在第8天时虫体干质量最高。黑水虻对猪粪的转化率随着时间的延长而增加,在第6天时达到了最大11.5%,而到第8天时下降。在转化过程中虫体中Cu、Cr、As的浓度随着黑水虻幼虫生长降低,在第8天时,虫体Cu、Cr、As浓度较第2天分别降低了24.5%、21.7%、33.1%。Cd含量随着黑水虻幼虫生长增加,在第8天时,虫体Cd浓度较第2天增加了75.3%。Cu、Cr、As、Cd在虫粪中浓度的变化同虫体变化相反。Zn在虫体和虫粪中含量没有发生显著变化。在第8天时虫粪中的Cd含量显著低于猪粪,而Cu、Cr、As、Zn含量与猪粪比没有显著差异。黑水虻幼虫对猪粪中Cd的富集系数最高,达到了3.8,其余都小于1,各重金属的富集顺序为Cd>Zn>Cu>Cr>As。转化后Cu、Cr、As、Zn有83.6%～92.7%分布于虫粪,而Cd有49.8%～69.7%分布于虫粪,30.3%～50.2%分布于虫体。转化后Cu、As的生物活性提高,Cr、Cd的生物活性降低,Zn的生物活性没有明显的变化。研究结果为畜禽粪便的黑水虻生物转化提供参考。     

牛粪湿法厌氧消化规律及载体影响的研究

在35℃条件下，观察牛粪厌氧消化的沼气产量和生物指标的变化规律及聚丙烯网状空心球、玻璃纤维和碳纤维膜载体对牛粪厌氧消化性能的影响。结果表明：5%牛粪在厌氧发酵过程中，pH值在发酵的第3 d降到最低，在发酵的第7 d升高到7以上；沼气的产量约在发酵的第9 d达到高峰，而后逐渐降低；COD的去除主要发生在发酵的第4～8 d；发酵产物细菌数量在发酵第6 d达到高峰，在第12 d降低到一个基本相对稳定的水平；辅酶F₄₂₀活性与其细菌数量在时间和数量方面有着相同的变化规律。聚丙烯网状球形载体表面附着较多的微生物，由此延长产气高峰期，并显著提高沼气产量(p<0.05)，以及显著降低反应器厌氧微生物的流失(p<0.01)。     

五指山猪不同组织中肌细胞生成素基因Myf4及生肌调节因子Myf6的表达

本文通过运用Real-time PCR技术,检测肌细胞生成素基因Myf4和生肌调节因子Myf6在出生后的第30天、第210天、第360天（出生到体成熟）的五指山猪肌肉组织中的表达变化,以及Myf4、Myf6在体成熟五指山猪肌肉、心、肝、脾、肺、肾、胃、小肠组织中mRNA相对表达情况。结果表明：Myf4及Myf6基因在五指山猪出生后在肌肉组织中的mRNA表达水平随着五指山猪的生长年龄生长而显著增长（p〈0.05）;Myf4及Myf6基因在成年五指山猪以上8种组织中均有表达,其中在肌肉组织中相对表达量最高。本研究结果将为五指山猪肌肉生长发育及矮小性状形成机理提供参考。     

紫色土丘陵侵蚀沟建植物篱自然植被恢复及水土流失特征研究

植物活篱笆恢复紫色土侵蚀沟植被及水土流失特征研究结果：（1）香根草、芦竹栽植半年即可形成植物篱笆，防治水土流失效果显著。据1999年测定，无植物篱处理年径流量为4210．44t／hm^2，泥沙流失量为1726．61t／hm^2，而植物篱处理年径流量只为无植物篱处理的7．2％，泥沙流失量为1％；因而被阻截的泥沙在植物篱笆上方淤积，可增厚土层10～20cm／a，有了土层，植被慢慢恢复，植物篱第1年覆盖度为3％，第2年为10％，第3年为25％，第4年达40％。（2）紫色土坡地水土流失周年变化以5月和6月为高峰期，高峰期径流量占全年径流量总和的45％左右，水土流失为全年流失量的30％左右。由于植物根系改善了土壤物理性状，土壤容重减轻，孔隙增加，因而土壤初始入渗速率、稳定人流速率均显著高于无植物篱处理，降雨量多，径流也多，同时也有较多的水入渗进入农田生态系统，而无植物篱则相反，降雨多，径流多，而进入农田生态系统的水也少。     

基于长期定位试验的变性土养分持续供给能力和作物响应研究

8年定位施肥试验结果表明，不施N肥，淮北变性土N素自然供给能力，第1年降为原来的64％，第2年则降为22％，此后，在20％左右振荡；不施P肥，土壤P素自然供给能力第1年后为95％，8年后逐渐下降为45％左右；不施K肥，土壤K素自然供给能力，第1年后为90％，8年后逐渐下降为60％～70％；而且，土壤P、K素自然供给能力对小麦、玉米有所差异。作物产量响应特点是，CK、N、NP、NK和PK处理区小麦、玉米产量分别为NPK全营养区的26．9％、54．3％、85．2％、53．2％、31．8％和21．4％、68．9％、73．5％、81．6％、28．0％。作物养分浓度响应特点是，施N或P肥提高了籽粒和秸秆的N或P养分浓度，施K肥对籽粒K浓度影响较小，但显著提高了秸秆K浓度。与试验前相比，8年后，土壤全氮含量，不施N处理区降低5％～10％，施N处理区增加12％～16．5％；土壤全磷含量，不施P处理区降低20％左右，施P处理区略有不同程度提高；土壤有效磷含量，不施P处理区降低75％～85％，施P处理提高56．9％～119．3％；土壤全钾含量变化不大；土壤速效钾含量，不施K肥处理区降低35％，NPK处理区降低5．9％，NK和PK处理区增加10％左右；土壤有机质含量，CK和PK处理区降低10％，其他处理基本持平。小麦和玉米对N、P、K肥的表观利用率分别为59．8％、47．3％、50．2％和51．1％、33．2％、49．5％。通过模拟，土壤有效磷消长与P素平衡盈亏的模型为，，（土壤有效磷消长）=0．1138x（P素平衡的盈亏）-0．406l（n=6，r=0．9594），土壤速效钾消长与K素盈亏的模型为y（土壤速效钾消长）=0．1075x（K素平衡的盈亏）-8．787l（n=6，r=0．9021）。     

红外传感器与机器视觉融合的果树害虫识别及计数方法

为了解决果园环境中单一的害虫监测技术存在的缺陷,该研究将红外传感器和机器视觉识别技术进行融合,从两个角度对目标害虫进行识别计数。选取梨小食心虫、苹小卷叶蛾、桃蛀螟、干扰物进行试验,通过实验室人工随机散落试验样本,获得其红外传感器以及机器视觉图像的识别结果,构造融合计数计算公式,通过计算得到害虫计数结果。结果显示:梨小食心虫、苹小卷叶蛾、桃蛀螟、干扰物的红外分类阈值分别为2.25、9.06、17.88、28.38,其红外识别范围分别为(0,5]、(5,13]、(13,23]、(23,32];梨小食心虫、苹小卷叶蛾、桃蛀螟、干扰物的红外识别准确率分别为92%、78%、80%、88%,图像识别准确率分别为92%、88%、92%、90%,融合计数精度分别为98%、92%、94%、96%。可见,将红外传感器和图像识别技术相融合能够提高果树性诱害虫的识别准确率,为果园害虫的合理防治提供参考。     

荔枝瘿螨的为害及其防治方法

荔枝瘿螨在南宁地区每年出现二个虫口高峰,第一个高峰在5～6月;第二个高峰在9～10月。其为害引起落花、落果,着果率降低,被害枝着果率仅为健枝的42.4%,受害果重量减少10%～16%。新梢未萌发之前,螨体大部分集中在被害梢毛瘿内,其中又以鲜褐色毛毡螨量最多,其次为褐色毛毡。过冬瘿螨多群集在被害的夏梢及秋梢毛毡上。当新梢萌发刚露白时,瘿螨即从被害梢毛毡转移至新芽上。基于这一习性,在荔枝树未发新芽前剪除害梢是防治该螨的有效方法,较适合于幼树。药剂防治最好在新梢萌发时进行。     

Fluctuations of diptera larvae in soil from a spruce forest in relation to climatic factors

Summary Diptera larvae were extracted by the wash and flotation method according to Healey and Russell-Smith (1970) as modified by Altmüller (1979). The larvae had been kept in alcohol for at least 2 months. After this time their specific gravity changed, and an additional flotation with MgSO₄-water solution of SG = 1.26 g/cm³ was very effective. This new method is described. The working procedure can be reduced to about 50%–70% of the time Altmüller (1979) and Hövemeyer (1984) needed. Many tests have shown that some small sciarid larvae settle out with the needle and humus particles in solution of SG = 1.26 and cannot be found, so that it is necessary to apply a correction factor. Samples taken each August from 1979 to 1984 were extracted and floated off by the methods described. Larvae from seven families of Diptera nematocera and from six families of Diptera brachycera were found. Numbers of sciarid larvae varied between 2500 (1979) and 100/m² (1981), of the cecidomyid larvae between 6700 (1983) and 400/m² (1980) and of the brachyceran larvae between 650 (1979) and 50/m² (1984). The correlation coefficient (= r) of larval population size with temperature and precipitation, respectively, was calculated and hence the coefficient of determination as a percentage (r ² x 100), which represents the proportion of the fluctuations in population size that is accounted for by weather factors. All families were influenced negatively by the temperature and positively by the precipitation in August, i.e., the higher the precipitation and the lower the temperature in August the higher the larval abundance in August. The development of the larvae begins in the previous year, and the influence of monthly climatic factors during the whole period of development was tested. It was shown that: Precipitation is correlated with the abundance of (1) sciarid larvae in June and August of the previous year (positively); (2) brachyceran larvae in June (August) of the previous year and in (February), March, April and August of the same year (positively); and (3) cecidomyid larvae in July of the same year (negatively). Temperature is correlated with the abundance of (1) sciarid larvae in August of the previous year (negatively); (2) brachyceran larvae in August of the previous year (negatively); and (3) cecidomyid larvae in September of the previous year, in January and July of the same year (positively). Monthly data for precipitation and temperature, taken together, showed maximum positive correlations with abundance as follows: (1) for sciarid larvae, with data for August of the previous year; (2) for brachyceran larvae, with data for August of the previous year; (3) for cecidomyid larvae, with data for July of the same year.     

Natural abundance of 15N in sweet potato, pumpkin, sorghum and castor bean: possible input of N2-derived nitrogen in sweet potato

Two combinations of plant species, sweet potato (three cultivars) and pumpkin, and sweet sorghum (three cultivars) and castor bean were grown separately in three plots of alluvial soil from June to September 1996. The shoots (leaves plus stems) of sweet potato and pumpkin, and the whole tops (leaves plus stems and grains) of sweet sorghum and castor bean were harvested twice, once in August and once in September in order to analyze their natural abundance of ¹⁵N (δ¹⁵N). The δ¹⁵N values of two of the varieties of sweet potato harvested in September were significantly lower than those of pumpkin, while δ¹⁵N values of sweet potato and pumpkin harvested in August, as well as those of sweet sorghum and castor bean harvested in August and September, did not significantly differ. The lower δ¹⁵N values observed in the September-harvested sweet potato may indicate that as much as 40% of the N intake of this species is derived from dinitrogen. This species is known to have a high ability to take up N from undefined sources. Received: 23 February 1997     

金纹细蛾幼虫在陇东苹果树冠层的空间分布研究

为掌握金纹细蛾幼虫在苹果树冠层不同部位的发生规律,为科学防治提供技术支持。以长富2号10年生富士苹果园为研究对象,通过对不同时期金纹细蛾幼虫发生规律、树冠分布特征和集聚性分析,研究了陇东金纹细蛾幼虫在苹果树冠上的空间分布结构。结果发现,金纹细蛾幼虫1 a发生5代。在世代重叠现象和苹果生长期药剂防控的双重影响下,第2代以后各世代之间未出现明显的高峰,在9月上旬之前幼虫数量虽有增长,但增长非常缓慢,而进入9月下旬之后越冬代数量成倍数骤增。从幼虫在树冠上的空间分布看,存在东向和北向＞南向和西向、下部 ＞ 上部、内膛 ＞ 外围的趋势,但是在统计学上却没有显著差异;幼虫在苹果树冠中的分布呈一定的聚集性分布,但聚集度比较小。在前期防控的基础上,加强9月下旬以后的防控,是减少翌年虫源的关键。药剂防控中,在保证树冠全方位防控的同时,树冠下部、内膛、南向和西向为重点防控的空间部位。     

Effects of No. 2 fuel oil water-soluble-fractions on growth and reproduction in Neanthes arenaceodentata (Polychaeta: annelida)

Effects of water-soluble-fractions (WSFs) from No. 2 Fuel Oil on growth and reproduction in a laboratory strain of Neanthes arenaceodentata were studied in experiments simulating conditions of acute and chronic sublethal exposure. Effects were defined relative to concentrations of diaromatic hydrocarbons (naphthalenes) and total dissolved hydrocarbons. Hatching of metatrochophore larvae was inversely related to WSF concentration and to the length of time larvae were exposed prior to hatching. Growth of larvae into juveniles was unaffected by low concentrations. Inhibition of larval growth by higher WSF concentrations was reversible upon return of larvae to hydrocarbon-free sea water. Growth of juveniles into adult polychaetes was inversely related to concentration. Rate of development to the feeding juvenile stage was not affected by WSF in three successive generations of continuously exposed polychaetes. Oocyte maturation rates in the four WSF concentrations (2.5, 5, 10, 2507o) increased with each successive generation. All concentrations suppressed fecundity in each generation. Survival to the 32-segment juvenile stage (brood mortality) was inversely related to concentration in first generation animals. Brood mortality in all WSF concentrations decreased with successive generations thereafter. Levels of naphthalenes in worms declined with each generation. Naphthalenes concentrations in third generation animals was very similar to those of exposure media.     

黑龙江省降雨侵蚀力空间分布规律

利用黑龙江省16个国家级气象站,1960-2000年日降雨量资料,分析黑龙江省侵蚀性降雨和降雨侵蚀力的空间分布规律。在16个气象站中,日降雨量达到侵蚀性标准（≥12mm／d）的降雨时间为9～15d／a,最大值同最小值之间相差近0．7倍;日降雨量达到侵蚀性标准的年降雨量为192～387mm,最大值同最小值之间相差l倍。16个气象站年降雨侵蚀力多年平均值为794～2144MJ·mm／（hm^2·h·a）,最大值同最小值之间相差近2倍。降雨侵蚀力空间分布从西北到中南部逐渐升高,东部低于中部,年降雨侵蚀力空间分布基本与年降雨量空间分布相似。年内降雨侵蚀力分布主要集中在6—9月,7月份下半月或8月份上半月达到最高值,6—9月降雨侵蚀力占全年比率为88％～95％,其中西部比东部略高。     

Assessment of the Crop Water Stress Index and Color Quality of Bur Clover (Medicago polymorpha L.) Under Different Irrigation Regimes

ABSTRACT

Relationship between canopy temperature and soil moisture is important for using the potential of canopy temperature as an indicator of crop water stress. A two-year field experiment was carried out during June to September 2016 and 2017 at the Research Station of College of Agriculture, Darab, Shiraz University, Iran, to determine crop water stress index (CWSI) for bur clover. Irrigation regimes including well-watered [Irrigation according to 100% field capacity (FC)], mild water stress (75% FC), severe water stress (50% FC), and most severe water stress (25% FC) were arranged in a randomized complete block design with four replications. In 2016, CWSI values showed an increasing trend from June (0.066 in well-watered) to August (0.821 in most severe water stress) as a result of higher vapor pressure deficit (VPD) and depression in canopy-air temperature differences (Tc-Ta). A similar trend was observed in the second year. In both years, by increase in mean temperature from June to August, Tc-Ta differential increased and the highest monthly average value of CWSI for all treatments was obtained in August. By enhancing water stress, the color grading score decreased sharply (from 6 to 3) and stayed constant (2) for August and September. Also, a negative relationship was observed between CWSI and dry matter production (R² = 0.88**) and color quality (R² = 0.94**). It was concluded that mild water stress (75% FC) with mean seasonal CWSI being ranged about 0.198 to 0.294, without any loss in visual color quality might be the best irrigation regime for bur clover production.     

稻鸭共作系统中稻纵卷叶螟种群控制的模拟

为研究系统动力学方法在害虫种群的优化管理和预测等研究中的应用,以稻纵卷叶螟第二代种群为研究对象,分析了稻鸭共作系统中捕食性天敌蜘蛛及鸭对稻纵卷叶螟生长发育的影响,构建了相应的系统动力学框架模型,并利用STELLA软件对稻纵卷叶螟种群的数量动态进行了模拟和预测。结果表明,当第二代稻纵卷叶螟初始的百穴卵量为100粒,稻田蜘蛛密度为每百穴12.623头,如果同时考虑鸭对3龄幼虫期稻纵卷叶螟卷苞60%的捕食率,稻纵卷叶螟成虫的密度可降至每百穴9.129头,鸭的捕食可使稻纵卷叶螟第三代卵期末的百穴卵量减少约6.7%