Effects of chlorantraniliprole on development and reproduction of beet armyworm, <Emphasis Type="Italic">Spodoptera exigua</Emphasis> (Hübner)

The lethal and sublethal effects of chlorantraniliprole against Spodoptera exigua (Hübner) were evaluated under laboratory conditions by oral exposure of neonate larvae to the compound. The 72 h LC₅₀ value of this insecticide to S. exigua was found to be 12.747 μg l⁻¹. A progressive larval mortality of 24.32% for LC₃₀ treatment and 42.61% for LC₅₀ treatment was observed from 4th to 6th day after exposure, which resulted in the reduced pupation rates in exposure groups. The sublethal effects of this chemical were indicated by prolongation of larval period, the increase of pupal weight and decrease in hatch rate of egg. Chlorantraniliprole at LC₃₀ and LC₅₀ rate significantly delayed larval development; the developmental duration of surviving larvae was extended for 22.5 and 28.6%, respectively, compared with that of control group. LC₃₀ treatment increased the mean weight of pupa and induced to the production of heavier pupa (>150 mg). In LC₅₀ treatment, heavier pupa also showed up but the mean weight of pupa was not influenced. The egg hatch rate in LC₅₀ group was significant lower than that in control and LC₃₀ groups. No significant differences in pupal duration, emergence rate, sex ratio, egg number per female, and longevity of adults were observed among treatments. Chlorantraniliprole had exceptional activity against S. exigua according to concentration–response bioassay in laboratory, and the toxicities were primarily resulted from immediate lethality.     

沉水植物化感作用抑制藻类生长的研究进展

根据国内外相关报道,重点对9科15种沉水植物化感作用物质的构成及抑制15种藻类的生长,沉水植物化感作用抑制藻类生长的机理等方面的研究进展进行综合评述。     

隧道窑用于焖烧法生产活性炭初试

用隧道式活化炉取代焖烧炉生产活性炭的试验结果表明：按照活化工艺温度８５０℃,时间３６～６０ｈ,粉状活性炭产品质量可达到部颁标准,颗粒活性炭延长活化时间,产品质量可达到载体炭的质量,隧道窑焖烧法用以生产颗粒炭是可行的。     

基于正交试验设计的绿竹容器苗影响因素研究

采用L₉（3⁴）正交试验设计结合主成分分析法研究了影响绿竹容器苗质量的因素,试验设置的4个因素为容器类型、容器规格、基质种类和肥料类型,每个因素设置3个水平。试验结果表明：影响绿竹生长和发笋量的各因素主次顺序为：肥料类型>基质种类>容器规格>容器类型,其中肥料类型与基质种类为主导因子,对育苗质量起决定性作用;各因素的最优水平组合为：施用有机肥,采用泥炭与珍珠岩（7∶3）为基质,容器规格为25 cm×23 cm×23 cm（上口直径×下口直径×盆高）,容器采用无纺布容器。     

改革助推兵团走上生态与民生林业可持续发展之路——新疆生产建设兵团63团、71团林业改革调研报告

通过对新疆生产建设兵团63团、71团林业改革的调研,分析了兵团林业改革面临的新形势和历史背景,总结了其主要做法和成效,并得出了3个方面的启示,即:生态林业民生林业共同发展是林业改革成功与否的标准,改革是重新调整生产要素的重要举措,改革应该是全方位系统性的。     

Essential oil from the leaves of Cryptomeria japonica acts as a silverfish (Lepisma saccharina) repellent and insecticide

This is the first article to report the evaluation of a natural product used as an antisilverfish agent. Silverfish (Lepisma saccharina), primitive wingless insects, feed on a variety of materials, including paper, cotton, starch, and cereals. They can be a problem in libraries and other places where books, documents, and papers are stored. In this pilot study, the essential oil from leaves of Cryptomeria japonica was investigated to test its properties as a silverfish repellent and insecticide. The results from a repellency bioassay show that the essential oil significantly repelled silverfish. The repellent activity was 80% at a dosage of 0.01 mg/cm³. When silverfish were exposed to a concentration of 0.16 mg/cm³ of essential oil, they were killed within 10h. The chemical composition of essential oil, the emissions from a test chamber, and the residue left on filter papers previously soaked with the essential oil in a chamber were analyzed by gas chromatography-mass spectrometry. The components of the essential oil were found to be: elemol (18.22%), 16-kaurene (11.63%), 3-carene (9.66%), sabinene (9.37%), 4-terpineol (9.06%), β-eudesmol (5.70%), α-pinene (5.62%), and limonene (5.26%). Only some constituents of the essential oil compounds collected by solid-phase microextraction were found to be emitted in the test chamber. The main constituents were: 3-carene (21.03%), p-cymene (10.95%), limonene (9.49%), β-myrcene (9.39%), γ-terpinene (9.10%), α-terpinene (8.57%), and 4-terpineol (7.97%).     

乡土树种石笔木播种育苗技术研究

通过对赣南优良乡土树种石笔木的种子预处理、种子主要参数测定、以及对苗木物候、苗木根系生长、苗木生长节律进行研究,从而得出石笔木实用的、较为系统的播种育苗技术。     

银川市几种针叶绿化树种的春季滞尘能力比较

对银川市西夏区的四个针叶树种在三个不同粉尘污染区的春季滞尘能力进行测定与分析,结果表明:各树种在不同的粉尘污染区均表现出明显的滞尘效应;不同树种的滞尘能力存在明显差异;树种的滞尘能力与降尘环境、滞尘时间等因素有关;随着时间的延长,四树种在不同的粉尘污染区的滞尘能力呈增大趋势;几种针叶树种的滞尘能力由强到弱的顺序为:侧柏>白皮松>桧柏>云杉。