释放花绒寄甲卵对光肩星天牛幼虫的防治效果

采用木块法饲养花绒寄甲成虫,然后将其所产的卵块保存在5℃恒温条件下,以确定低温保存后花绒寄甲卵的生活力、初孵幼虫的行为学和对光肩星天牛幼虫的寄生率,并比较林间释放花绒寄甲卵与树干打孔注药(氧化乐果)防治光肩星天牛幼虫的防治效果.结果表明:低温保存49天与花绒寄甲新产卵的孵化率没有差异,花绒寄甲1龄幼虫在室内可存活1～8天、平均2.26天,爬行速度为6.5～100 cm·h-1,平均25.23 cm·h-1,室内及林间释放花绒寄甲卵后其初孵幼虫均能找到光肩星天牛幼虫并进行寄生;如果温度和湿度适宜,按照每头光肩星天牛幼虫释放15～25粒花绒寄甲卵时其寄生率可达90%;树干打孔注药与林间释放花绒寄甲卵后光肩星天牛幼虫的虫口减退率均在85%以上,两者的控制效果基本无差别.     

日本食蚧蚜小蜂的寄生行为观察

日本食蚧蚜小蜂Coccophagus japonicus Compere是橡副珠蜡蚧Parasaissetia nigra Nietner的重要天敌之一。为了明确该蜂的寄生行为及雌蜂体型大小对其产卵的影响,在室内观察其寄生行为及雌蜂不同体型大小条件下的产卵情况。结果表明：日本食蚧蚜小蜂的寄生过程包括搜寻寄主、识别寄主、产卵器刺探、产卵、产卵后处理5个阶段。日本食蚧蚜小蜂的寄生时间、寄生率、平均着卵量随寄生次数增多而增加,寄生次数与卵量吻合率随寄生次数增加而降低;第1次寄生时,寄生所需时间为19.75 s,寄生率为73.12%,寄生次数与卵量吻合率为69.89%,平均着卵量为0.76粒;第3次寄生时,寄生所需时间为24.37 s,寄生率为83.33%,寄生次数与卵量吻合率仅为8.33%,平均着卵量为1.67粒。雌蜂体型大小与其产卵量呈正相关,体长小于等于1.20 mm时,产卵量及寄生率最小,分别为16.83粒和49.4%;1.40 mm<体长≤1.50 mm时产卵量为33.06粒,寄生率72.3%;而体长大于1.50 mm时产卵量达37.5粒,寄生率为72.2%;雌蜂后足胫节长对其产卵及寄生率也有类似影响,说明该蜂扩繁时应选用体型较大的雌蜂。     

Residue Analysis of Five Kinds of Penicillins in Eggs by High Performance Liquid Chromatography-Ultraviolet Detection

This study was aimed to develop a method for simultaneous determination of five kinds of penicillins in eggs by high performance liquid chromatography-ultraviolet detection (HPLC-UVD). The eggs samples were extracted by acetonitrile,degreased by n-hexane,concentrated by rotary evaporation,derivatization,and then was separated by HPLC. The results showed that the calibration curves of five kinds of penicillins were linear correlated in the concentration ranges of 10 to 1 000 μg/kg with the correlation coefficients >0.999,which the limits of detection and quantification were 1.5 μg/kg (S/N=3) and 5.0 μg/kg (S/N=10),respectively. The average recoveries were 62.04% to 93.13%,the relative standard deviations were 3.91% to 13.69%.And the intra-day and inter-day RSDs were 3.98% to 14.71% and 4.26% to 12.71%,respectively. The developed method was suitable for detecting five kinds of penicillins residues in eggs with high repeatability and sensitivity.     

番茄青枯病病原菌拮抗菌株的筛选及其田间防控作用研究

从番茄青枯病发病严重田块的健康植株根际土壤中分离筛选得到2株高效拮抗菌株,命名为W12和W118,经16SrDNA基因鉴定均属芽胞杆菌属;用PCR扩增的方法扩增脂肽类抗生素合成基因,结果表明W12和W118含有合成bacillomycin、iturin和fengycin三种抗生素的基因;将2株拮抗菌用于田间试验,结果表明混合菌株防控效果最好,3次灌菌后防控效果达到62.3%,单独施用菌株W118较单独施用W12防控效果好,3次灌菌后防控效果达到56.7%。     

禽蛋基本特性参数分析与试验

为了探讨与禽蛋大小头自动定向排列机理相关的基本特征参数分布和估算模型,测定了禽蛋的几何尺寸、质心位置、体积和质量,研究了禽蛋几何尺寸与体积、质量的关系。结果表明,禽蛋的几何尺寸和质量都呈正态分布;禽蛋质心位于禽蛋长径中点处,相对于长径与短径交点向小头侧偏移3～5 mm,质心位置称重法优于支撑法;用标准椭球体体积计算方法估算的3种禽蛋体积与实测体积相关性均在0.94以上;禽蛋质量与禽蛋估算体积的相关性优于与长径、短径、蛋形指数、禽蛋长径处椭圆面积的三元和一元线性回归,3种禽蛋质量模型的相关系数均在0.95以上。     

枝角类适种探索和休眠卵的利用

实验表明多刺裸腹蚤是最易培养的淡水枝角类。适宜条件下接种后６ｄ可达５０００个／Ｌ的生一,人为改变饵 料及水温条件可获得大量休眠卵。休眠卵无休眠期,适宜条件下可卵化。孵化时数与水温的为Ｈ＝４７４．３２５９－２９．４５１５Ｔ＋０．４７８３Ｔ＾２。干燥低温保存休眠卵效果较好。１年后的孵化率可达６０％。     

Nonlocal wind-driven fjord–coast advection and its potential effect on plankton and fish recruitment

The Bergen Ocean Model (BOM), a three-dimensional physical coastal ocean model, was used for a numerical simulation experiment to investigate short-term effects of wind-generated coastal upwelling and downwelling on the dynamics of adjacent large outer and smaller inner fjords. The effect of the real alongshore wind regime on advection for an idealized fjord topography, resembling Masfjorden, western Norway, is used as an example. This modelling exercise is a supplement to, and its predictions support, the various hypotheses investigated in ecosystem simulation studies of the Masfjorden. The model predicts that coastal winds from the north cause upwelling and transport the upper water layer out from the fjords. Winds from the south cause downwelling and transport the upper water layer into the fjords. The transport is rapid and ≈50% of the upper water layer may be replaced within 1–2 days. Implications of these physical processes for the dispersal and retention of planktonic organisms and the early life stages of fish are discussed. If strong southerly winds occur frequently, this will transport planktonic organisms into the fjord and may increase the carrying capacity for planktivorous fish. In contrast, frequent strong northerly winds may reduce the abundance of planktonic organisms, including the early life stages of marine fish, and thus possibly reduce recruitment to fjord fish populations. Frequent shifts between southerly and northerly winds would cause an exchange of early life stages between neighbouring fjords and thus enhance genetic exchange.     

Recovery threshold of Toxocara canis eggs from soil

The purpose of this study was to evaluate the threshold of Toxocara canis eggs form soil samples through utilisation of a centrifuge-flotation technique (CFT). Aliquots of soil (1 g each) were artificially contaminated with known numbers of T. canis eggs (1, 10, 25, 50, 100, and 200 eggs). The threshold was evaluated based on a CFT using zinc sulphate (Zn₂SO₄) and sodium nitrate (Na₂NO₃) solutions at a specific gravity of 1.20. The number of eggs recovered was directly proportional to the number of eggs employed to seed the soil. Both solutions enabled full recovery of samples containing merely three eggs; only Zn₂SO₄ demonstrated efficiency in soil contaminated with a single egg. A recovery rate of 100% was obtained for all tests with samples containing 10 and 25 eggs for Zn₂SO₄ and Na₂NO₃, respectively_. There was no difference in the mean number of recovered eggs regarding either the efficacy of the solutions or the repetition of evaluations in the same trial (p > 0.05). Therefore, the CFT is efficient for the detection of Toxocara eggs, even in samples containing low egg numbers.     

斜纹夜蛾化学不育研究初报

选用塞替派注射液做雄性不育剂,氟脲嘧啶注射液作雌性不育剂;采用成虫饲喂法致不育;利用2种不育剂单独饲喂或混合饲喂,然后合笼配合交配的办法;以校正不育卵率作为评价指标,进行了2种不育剂对斜纹夜蛾的不育作用研究。结果表明:在室内条件下0.01%塞替派饲喂雄蛾,0.02%塞替派饲喂雄蛾,0.01%塞替派、0.025%氟脲嘧啶分别饲喂雄雌蛾,及0.01%塞替派和0.025%氟脲嘧啶混合饲喂雌雄蛾,平均校正不育卵率均在96%以上;0.025%氟脲嘧啶饲喂雌蛾平均校正不育卵率为86.59%;雌蛾第一次能否与不育雄蛾交配,是影响雄性不育效果的关键因素;0.01%塞替派饲喂雄蛾交配竞争力略低于正常雄蛾。     

黄脊竹蝗产卵地与其生态因素关系的调查研究

黄脊竹蝗是楠竹的严重食叶害虫,防治黄脊竹蝗的关键在于顺利地找到产卵地,以便在产卵地内治理孵化出土跳蝻或已上竹尚未分散危害的1～2龄跳蝻。本文报道成虫产卵规律以及与9种生态因素的关系。其产卵地必须具备综合多生态因素,而光照是最重要的因素。只有竹林和植被稀疏,地面透光度大,光照强的地方才是成虫产卵的首选之地。