马尾松毛虫质型多角体病毒替代宿主的研究

马尾松毛虫(D? p? Walker)质型多角体病毒(DpCPV)能交叉感染粉纹夜蛾(Trichoph?)、斜纹夜蛾(Spadop?)、亚洲玉米螟(O?)、大蜡螟(Go?riamallonella)、菜青虫(P?)等鳞翅目幼虫,致病程度随昆虫种的不同而有较大差异,米蛾(Corc?)幼虫则对DpCPV不敏感.DpCPV对粉纹夜蛾幼虫的致死率可达100％.从粉纹夜蛾幼虫中复制出来的病毒(Tn-DpCPV)对松毛虫3～4龄和4～5龄幼虫的LC_?分别为1.73×10~5和3.06×10~?.在粉纹夜蛾幼虫中肠细胞中,多角体的形成是以小块状结晶开始,边包埋病毒粒子边相互聚合而成.     

2,4-D丁酯·异丙甲草胺与扑草净不同配比对杂草的防除效果

[目的]探索2,4-D丁酯、异丙甲草胺与扑草净的增效作用.[方法]通过盆栽马唐、马齿苋等杂草,喷施混配制剂,筛选最佳配比.[结果]当2,4-D丁酯、异丙甲草胺、扑草净三者配比为20∶ 37∶8时增效作用最强.[结论]确认了混配的最佳比例,为田间试验提供理论依据.     

Resistance monitoring for eight insecticides in Plutella xylostella in central China

The diamondback moth, Plutella xylostella L., is one of the most important pests of cruciferous vegetables in the world. Assessment of changing insecticide resistance is essential for maintaining control efficiency and resistance management. In this study, four field populations of P. xylostella were collected from cabbage (Brassica oleracea, var. capitata L.) fields in central China from 2010 to 2012 to monitor their resistance to abamectin, Bacillus thuringiensis (BT) subsp. kurstaki (WG-001), spinosad, chlorfluazuron, chlorfenapyr, diafenthiuron, indoxacarb and beta-cypermethrin by using a leaf-dipping bioassay method. The results indicated that chlorfenapyr and diafenthiuron showed high toxicity to P. xylostella in central China, with no obvious toxicity change during the three years. The resistance of P. xylostella to spinosad was at low to moderate levels of resistance in all three years. Resistance of P. xylostella to abamectin, chlorfluazuron and indoxacarb varied greatly among the four regions. P. xylostella exhibited moderate and high levels of resistance to abamectin, chlorfluazuron and indoxacarb. The resistance of this pest to BT (WG-001) and beta-cypermethrin was severe in the four regions. Our study was conducive for developing a more effective resistance management program for P. xylostella.     

超临界CO2萃取杉木根化感物质对杉木的化感效应

采用正交试验及超临界CO_2流体萃取技术萃取杉木根化感物质,并通过杉木种子发芽试验进行杉木根化感物质对杉木的化感作用进行评价。结果表明:就化感物质萃取得率而言,在众多萃取因素当中,萃取压力和萃取温度是两个最主要的因素;经纯CO2及乙醇和CO2混和萃取的杉木根化感物质对杉木存在不同的化感效应,其中经乙醇和CO2混和萃取的杉木根化感物质对杉木种子发芽的抑制效应强于纯CO2萃取的化感物质。表3参20。     

用亚洲玉米螟测定苏芸金杆菌制剂毒力效价的研究

利用亚洲玉米螟对苏芸金杆菌的毒力效价进行了测定.供试虫以玉米螟二龄幼虫为佳.用候选苏芸金杆菌制剂与半人工混合饲料混合接虫感染的方法作毒力效价测定,结果准确,操作方便,完成一次测定需时三天,标准差为15.49%.     

青海草原毛虫核型多角体病毒的初步研究

1987年从青海省海北州草地上罹病死亡青海草原毛虫(Gynaephora qing haien sis Chouet Ying)幼虫分离获得草原毛虫核型多角体病毒(GqNPV)。多角体(PIB)近圆形、菱形、三角形或六角形,大小约0.26—0.294βm。试验结果显示 GqNPV 对草原毛虫有较强的毒力。其杀虫效果达85%,并有后效作用。     

Study on Cytoplasmic polyhedrosis virus onDendrolimus superans

A strain of Cytoplasmic polyhedrosis virus (CPV) was separated from the infected larva during the research of integrated pest management ofDendrolimus superans. The morphology, bioassay, histopathology and field-test for this CPV were studied. The size of CPV is 0.16 μm×1.57 μm and the virion is 16.0 nm×58.1 nm. The L_C50 to the 3rd and 5th instar larva ofDendrolimus superans were 2.81×10⁴ PIB/mL and 7.17×10⁴ PIB/mL respectively. The polyhedrosis were formed after midgut of larva were infected for 72 h. A large amount of polyhedrosis was formed after 144 h. The mortality was more than 82% and average mortality was 84.62% when using 1.17×10⁸ PIB/mL virus suspension to control the pest in field test. The project was supported by the Natural Sciences Foundation of Heilongjiang Province. (Responsible Editor: Chai Ruihai)     

Biologic and molecular characterization of Toxoplasma gondii isolates from pigs from Portugal

Little is known of Toxoplasma gondii infections in animals in Portugal. In the present paper, we report the first isolation of viable T. gondii from pigs in Portugal. Antibodies to T. gondii were found in 52 (15.6%) of 333 pigs prior to slaughter using the modified agglutination test (MAT) at a serum dilution of 1:20. Attempts were made to isolate T. gondii from 37 seropositive pigs. Samples of brain and/or heart from each pig were digested in acid pepsin, and bioassayed into mice. Viable T. gondii was isolated from 15 pigs. Restriction fragment length polymorphism on products of SAG2 locus amplified by PCR and microsatellite analysis revealed that 11 isolates were Type II and four were Type III. The results indicate that phenotypically and genetically T. gondii are similar to isolates from pigs from the U.S.     

番茄煤霉病菌致病毒素提取及其活性测定

采用3种方法提取毒素,结果表明:活性碳法、有机溶剂法、硫酸铵分级沉淀法均提取到毒素,硫酸铵分级沉淀法是比较简便而有效的方法。生物测定结果表明:该毒素对番茄幼苗及叶片具有致萎作用。针刺叶片可产生褪绿斑。滤液透析及热稳定性测试结果表明:该毒素为大分子化合物,这与用有机溶剂提取毒素所得结果一致,同时测得它具有很强的热稳定性。     

Crude Bacillus thuringiensis pellets efficiently combats Eutetranychus orientalis,the spider mite

This study demonstrates the efficacy of the crude pellet of Bacillus thuringiensis subs. kurstaki (Btk) obtained by SmF or SSF to combat Eutetranychus orientalis Klein. For bioassay, the mites were collected from infested leaves of Vigna unguiculata and Moringa oleifera, and reared by leaf-disc method employing artificial feeding system. In terms of LC₅₀ values, the crude Btk-toxin (probit: 9.51 mg/mL) obtained by SSF was 2.2-fold more efficient in killing E. orientalis than that of SmF (probit: 22 mg/mL). For the efficacy trial with potted plants, 10 mg crude Btk-toxin obtained by SSF was directly sprayed on the infested plants (V. unguiculata), which completely eliminated the mites from the infested plants within 12 days of treatment. In comparison, the survival rate of mites which received Btk-toxin from SSF was significantly (P < 0.0001) lesser than those received Btk-toxin from SmF. In this first report, apart from the efficiency of Btk-toxin in solid-fermented matter to deter the mites without supplementing any adhesive or surfactant in the diet, a feeding system for its rearing in the laboratory coupled with bioassay was also demonstrated.