Fumigant activity of plant essential oils and components from horseradish (Armoracia rusticana), anise (Pimpinella anisum) and garlic (Allium sativum) oils against Lycoriella ingenua (Diptera: Sciaridae)

Plant essential oils from 40 plant species were tested for their insecticidal activities against larvae of Lycoriella ingénue (Dufour) using a fumigation bioassay. Good insecticidal activity against larvae of L. ingenua was achieved with essential oils of Chenopodium ambrosioides L., Eucalyptus globulus Labill, Eucalyptus smithii RT Baker, horseradish, anise and garlic at 10 and 5 microL L(-1) air. Horseradish, anise and garlic oils showed the most potent insecticidal activities among the plant essential oils. At 1.25 microL L(-1), horseradish, anise and garlic oils caused 100, 93.3 and 13.3% mortality, but at 0.625 microL L(-1) air this decreased to 3.3, 0 and 0% respectively. Analysis by gas chromatography-mass spectrometry led to the identification of one major compound from horseradish, and three each from anise and garlic oils. These seven compounds and m-anisaldehyde and o-anisaldehyde, two positional isomers of p-anisaldehyde, were tested individually for their insecticidal activities against larvae of L. ingenua. Allyl isothiocyanate was the most toxic, followed by trans-anethole, diallyl disulfide and p-anisaldehyde with LC(50) values of 0.15, 0.20, 0.87 and 1.47 microL L(-1) respectively.     

水菖蒲超临界CO_2流体萃取物对储粮害虫的活性

研究了水菖蒲超临界CO2流体萃取物对储粮害虫玉米象、谷蠢、赤拟谷盗、杂拟谷盗、长角扁谷盗和锯谷盗的触杀、驱避和熏蒸活性.结果表明,水菖蒲萃取物时长角扁谷盗触杀活性强,处理24 h后的校正死亡率达100%;对杂拟谷盗和赤拟谷盗的触杀活性最弱,处理96 h后的校正死亡率分别为48.31%和24.44%;对谷蠹、赤拟谷盗、杂拟谷盗、长角扁谷盗和锯谷盗的驱避效果较好,驱避率均在90%以上;对玉米象的驱避效果较差,驱避率为76.09%;对谷蠹、长角扁谷盗、锯谷盗的熏蒸作用最明显,处理120 h后的校正死亡率均达100.00%,显著高于其他试虫,对赤拟谷盗和杂拟谷盗的熏蒸作用最差,校正死亡率分别为33.33%和32.22%.试验表明水菖蒲根茎萃取物对6种主要储粮害虫均具有较高的活性,有望开发成为储粮害虫的防护剂或熏蒸剂.     

不同土壤消毒剂防除烟草苗床杂草试验

对不同土壤消毒剂防除烟草苗床杂草的效果进行了试验研究。结果表明,4种土壤消毒剂对苗床杂草均具有极强的防除效果,明显优于对照药剂溴甲烷。综合防除效果及安全性等因素,以32.7%斯美地水剂和35%线克水剂效果理想,可在安徽省烟区推广使用。     

农药的混用及其在储粮害虫害螨防治中的应用

文章对储粮杀虫剂的混配基本原则，单剂的选用方法以及国内有对机农药与其它杀虫剂的混配，熏蒸剂的混用进行了介绍，并提出需对农药混剂在作用对象，效果，作用机理及毒理学方面作进一步的研究。     

储粮熏蒸剂的发展动态与前景

本文扼要介绍了当前主要储粮熏蒸剂的发展动态与前景，包括溴甲烷的淘汰问题、磷化氢的现状与前景、熏蒸能力有限的敌敌畏、面临淘汰的氯化苦、对环境友好但应用成本较高的二氧化碳和氮气、研究中的氧硫化碳和甲基磷、重新评价的甲酸乙酸、二硫化碳、环氧乙烷等的情况，并对新熏蒸剂研究开发前景进行了简单分析。     

硫酰氟对梳角窃蠹幼虫的毒力测定

用新型熏蒸剂硫酰氟(SO_2F_2)对梳角窃蠹幼虫进行了毒力测定,建立了毒力回归方程y=5.5078 2.0853x,根据该方程求得致死中量LD_(50)=0.57g/m~3.毒力测定表明:用3g/m~3、5g/m~3和8g/m~3的剂量,死亡率分别为78%、95%和100%.经新复全距检验表明,以上三种剂量的死亡率与0.3g/m~3的死亡率差异显著,而它们三者之间的死亡率差异不显著.     

Effects of propylene oxide doses on Cyperus and Belonolaimus control and nutrient absorption in tomato

Among the current methyl bromide alternatives under study, propylene oxide has shown potential to control soilborne diseases, nematodes, and weeds in polyethylene-mulched tomato (Lycopersicon esculentum Mill.). Therefore, field trials were conducted to determine the most effective propylene oxide doses against populations for the nematode Belonolaimus spp. and the weed Cyperus spp. and their effect on nutrient uptake. Propylene oxide doses were 0, 190, 380, 570, 760, and 950 L/ha. Data indicated that populations of Belonolaimus and Cyperus rapidly decreased with 570 L/ha of propylene oxide. Propylene oxide doses also affected foliar concentrations of phosphorus and potassium. There was a linear increase of phosphorus concentration as dose increased, whereas potassium concentration increased rapidly after 190 L/ha of propylene oxide. The highest tomato yields were obtained with application of 760 and 950 L/ha of propylene oxide.     

Methyl bromide alternatives for strawberry and tomato pre-plant uses: A meta-analysis

This paper reports the results of a meta-analytic synthesis of information from a large number of horticultural experiments that evaluated the technical feasibility of methyl bromide alternatives as soil fumigants in strawberry (Fragaria ananassa) cultivation in California, Florida, and Spain, and in tomato (Solanum lycopersicum) cultivation in Florida. A technically feasible alternative is defined as a treatment that provides pest control and crop yields similar to methyl bromide standard fumigation. We selected papers using five criteria, which jointly ensured inclusion of field experiments that contained usable information on at least three treatments—(1) an untreated control, (2) a methyl bromide treatment, and (3) a treatment that is an alternative to methyl bromide treatment. Because of the differences in regional cropping environments, we performed separate meta-analyses for four crop/region combinations. To explore the potential effects of missing information on past fumigation history and pest pressure on the results, we performed two sensitivity analyses, in which the set of usable field experiments included only those experiments in which the improvement of the methyl bromide treatment yield over the control yield was either 15% or 50%. Finally, the definition of several potential alternative chemical treatments took into account differences in formulations and application rates. The results we obtained do not support the technical superiority of methyl bromide over its alternatives. We found several potential alternatives for which we could not reject the hypothesis of technical feasibility, based on the experimental data for strawberries in California and Spain. In particular, the results on strawberry field experiments in California indicate that the estimated effect size of the treatment using 1,3-dichloropropene/chloropicrin 65:35 formulation (applied at the standard rate) was close to the estimated effect size for methyl bromide. The results from strawberry and tomato field experiments in Florida were inconclusive. However, this does not establish that methyl bromide is technically superior to its alternatives. Given the data-related limitations of the analysis, standard protocols are necessary for conducting and reporting the experiments to allow for more meaningful synthesis of the experimental data.     

甲酸乙酯对锯谷盗的熏蒸活性研究

采用密闭熏蒸法,在实验室条件下研究甲酸乙酯(EtF)对储藏物害虫锯谷盗Oryzaephilus surinamensis成虫的熏蒸活性。结果表明,熏蒸时间和温度显著影响甲酸乙酯对锯谷盗的熏蒸致死效果。甲酸乙酯在24 h内就能发挥很好的熏蒸活性,在低温条件下处理比在高温下熏蒸效果更好。在20℃、25℃和30℃条件下,熏蒸处理锯谷盗成虫24 h,其LC50分别为14.78、16.77和17.65μL/L。     

氰在禾谷类粮食中的吸附与降解

利用静态法研究了氰(C_2N_2)在禾谷类粮食中的吸附与降解过程,采用气相色谱法分析了C_2N_2在粮食中的吸附、残留和挥发行为,采用流动注射分析仪(FIA)测定了C_2N_2在粮食中可能的降解产物。结果表明:粮食对C_2N_2有较强的吸附能力,熏蒸1h,90%以上的C_2N_2被粮食吸附,其吸附能力为稻谷高梁玉米大麦小麦,同时C_2N_2在粮食中可降解为氰化氢(HCN)。通风后,C_2N_2及其降解产物HCN从粮食中缓慢挥发,其中C_2N_2从小麦和大麦中挥发的速率高于玉米、高梁和稻谷,HCN从小麦、大麦、玉米和高梁中挥发的速率高于稻谷。C_2N_2及其降解产物HCN在粮食中的消解动态符合一级动力学指数模型,通风后在小麦、大麦、玉米、高梁和稻谷中的半衰期(t_(1/2)),C_2N_2分别为1.82、2.57、2.81、1.97和2.98 d,HCN分别为4.46、4.30、4.01、3.94和5.26d。C_2N_2在粮食中可降解为NH_4~+和HCN,同时产生少量的NO_3~-和NO_2~-。C_2N_2在不同粮食中的降解产物存在差异,在小麦和玉米中检测到HCN、NH_4~+、NO_3~-和NO_2~-4种降解产物,在稻谷中检测到HCN、NH_4~+和NO_3~-3种降解产物,而在大麦和高梁中仅检测到HCN和NH_4~+两种降解产物。