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1.
Nobutaka Someya Shinichi Numata Masami Nakajima Akira Hasebe Katsumi Akutsu 《Journal of General Plant Pathology》2004,70(6):371-375
Chitinolytic activity of the biocontrol bacterium Serratia marcescens strain B2 was inhibited by bacteria isolated from rice, even though its growth was not affected. Antifungal activity of the strain against Pyricularia oryzae was also reduced under the influence of these bacteria. In contrast, the rice-epiphytic bacterium Erwinia ananas NR1, transformed with chitinase gene chiA derived from strain B2, had high chitinolytic activity regardless of the presence of the bacteria isolated from rice. Therefore, the introduction of an antagonistic factor gene with a promoter from the recipient into the epiphytic bacteria may prove useful in the development of effective biocontrol agents. 相似文献
2.
为探讨昆虫生长调节剂氟铃脲和虱螨脲对黑腹果蝇Drosophila melanogaster和斑翅果蝇D.suzukii的毒性机制,采用室内生测法测定氟铃脲、虱螨脲对2种果蝇2龄幼虫的毒力,以及其在亚致死浓度LC_(10)、LC_(20)下对2种果蝇体内几丁质酶活性的影响。结果显示,经不同浓度的氟铃脲和虱螨脲处理后,随着时间的延长和浓度的增加,2种果蝇的死亡率均明显增加,氟铃脲处理可使2种果蝇的死亡率最高达到83.33%,明显高于虱螨脲处理后黑腹果蝇(65.00%)和斑翅果蝇(66.66%)的死亡率。亚致死浓度LC_(10)和LC_(20)的虱螨脲处理果蝇2龄幼虫24 h后,黑腹果蝇2龄幼虫体内的几丁质酶活性呈下降趋势,而斑翅果蝇2龄幼虫体内的几丁质酶活性则呈上升趋势。另外,亚致死浓度的氟铃脲可明显抑制黑腹果蝇体内几丁质酶的活性。表明昆虫生长调节剂氟铃脲和虱螨脲对果蝇有较强的毒力,氟铃脲的毒力高于虱螨脲,且果蝇体内几丁质酶的活性与氟铃脲和虱螨脲密切相关。 相似文献
3.
Hailong Kong Yunxia Cheng Lizhi Luo Thomas W. Sappington Xingfu Jiang Lei Zhang 《国际虫害防治杂志》2013,59(3):174-179
Transmission of parasites and pathogens is generally positively density-dependent: as an insect population's density increases, the risk of an individual becoming attacked or infected also increases. In some insect species, individuals experiencing crowded conditions are more resistant to natural enemies than those experiencing low density conditions, and they are predicted to divert resources to increase resistance. This phenomenon is called density-dependent prophylaxis. Here, possible expression of prophylaxis in fifth-instar larvae of Beet Webworm, Loxostege sticticalis, to biocontrol agents was investigated under rearing densities of 1, 10, and 30 larvae per jar (650 mL). Larvae reared at the moderate density and those reared in isolation displayed the greatest and lowest resistance, respectively, to an entomopathogenic fungus and a parasitoid. Moreover, larvae from the moderate density treatment exhibited elevated phenoloxidase, total haemocyte count and antibacterial activity in the haemolymph, whereas phenoloxidase levels in the midgut were not affected. The results suggest that larval rearing density significantly affects the immune system, and they provide evidence for density-dependent prophylaxis of larval L. sticticalis against its biocontrol agents. These results have implications for understanding the population dynamics and biocontrol of beet webworm. 相似文献
4.
Regine Blattner Philippa J. Gerard Margarethe Spindler-Barth 《Pest management science》1997,50(4):312-318
The chitinase inhibitor/insect ecdysis inhibitor allosamidin and eight allosamidin analogues have been synthesised from simple carbohydrate starting materials. Allosamidin was assayed against Tineola bisselliella (Hummel) larvae and all nine compounds were examined for their effects on the development of larvae of Lucilia cuprina (Wiedemann). High larval mortality compared to controls resulted when T. bisselliella and L. cuprina larva were exposed to allosami-din. The (1→3) linked regioisomer, the dimeric analogue and the gluco-configurated dimeric analogue of allosamidin all showed high activity against L. cuprina larvae. The regioisomer, the (1→3) linked isomer and its dimeric analogue, as well as the monomer allosamizoline and its regioisomer, were inactive. These new in-vivo results are consistent with known in-vitro insect chitinase inhibition data, in that greatest larval mortality was exhibited by the best inhibitors. © 1997 SCI 相似文献
5.
Laboratory evaluation of the insect growth regulator lufenuron againstHelicoverpa armigera on cotton
An insect growth regulator (IGR), lufenuron (Match 5EC), was tested for its toxicity toHelicoverpa armigera on cotton. Potency of the IGR against the larval stage of the pest was demonstrated with respect to larval instars; the LC90 values of 1st, 2nd, 3rd, 4th and 5th instar larvae were 5.63, 7.89, 8.03, 11.39 and 14.76 mg a.i.l
−1, respectively. However, different larval instars did not differ significantly with respect to LC50 and LC10. IGR-treated larvae had swollen heads and were significantly smaller (1.5–2.3 mm) than the untreated control (2.9 mm). Larval
weight was significantly reduced from 190 mg in the control to 50–70 mg in the lufenuron treatment. IGR treatment in the larval
stage significantly affected both pupal length and pupal weight. Pupal duration of the test insect was significantly extended
by IGR treatment. Pupal deformities, including an inability to shed the last larval skin and formation of larval-pupal intermediates,
occurred following treatment. A significant reduction in adult emergence was recorded. In addition, abnormalities in the form
of development of cavities in the forewings of adult were evident. A significant decline in fecundity was noted in the studies.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
6.
为寻找有效防控外来入侵物种草地贪夜蛾Spodoptera frugiperda的技术,以烟芽夜蛾囊泡病毒3h株(Heliothis virescens ascovirus 3h,HvAV-3h)为研究对象,通过测定不同龄期草地贪夜蛾幼虫口服或针刺感染HvAV-3h后的死亡率、存活时间、取食量及体重,分析该毒株对草地贪夜蛾幼虫的感染特性及对其生长发育的影响。结果显示,草地贪夜蛾1、2龄幼虫口服HvAV-3h后的校正死亡率分别为9.22%和0,3～6龄幼虫针刺感染HvAV-3h后的校正死亡率则高达100.00%,感染HvAV-3h的幼虫均在幼虫期或蛹期死亡。3～5龄幼虫针刺感染HvAV-3h后的存活时间明显长于健康幼虫;3～6龄幼虫针刺感染HvAV-3h后其体重和取食量均受到不同程度的抑制作用,体重抑制率分别为67.79%、41.68%、16.31%和10.30%,总取食量抑制率分别为57.80%、33.90%、17.42%和41.82%;其中3龄幼虫针刺感染HvAV-3h后的体重和取食量被显著抑制,且蜕皮困难,最终在幼虫期死亡;部分4～6龄感染HvAV-3h幼虫能够完成化蛹,但是均无法羽化。表明HvAV-3h感染能够有效控制草地贪夜蛾幼虫,有望开发为草地贪夜蛾的生防制剂。 相似文献
7.
Spoiled and diffuse knapweed, Centaurea maculosa Lam. and C. diffusa Lam., both of European origin, are two of the most important rangeland weeds in North America. Surveys for potential biological control agents started in 1961, and agents were first introduced in 1970. So far, 11 phytophagous insect species of European origin have been released in North America. Despite legislation (restricted transport), large-scale application of herbicides and reductions in seed production of up to 95% by the existing seed-feeding biocontrol agents established, knapweed infestation has further increased during the last decade, covering nearly 2-8 and 13 million ha for spotted and diffuse knapweed, respectively. In this paper, the biocontrol programme is reviewed critically and the present status analysed. To reach a break-through in knapweed control, a cumulative stress approach is now envisaged, by extending the stress imposed by the biocontrol agents to increasing competition by the other vegetation through grazing regimes and reseeding programmes. Four steps to optimize the biocontrol effect and which lead to the integration of biocontrol into range management are described and suggestions, both scientific and political, are presented to render biological control more efficient and predictive. 相似文献
8.
BACKGROUND: The triazole-based antiviral nucleoside ribavirin exhibited significant in vitro insecticidal effects against Spodoptera litura, a finding that has prompted further investigations into its in vivo insecticidal properties and mode of action against this insect pest. RESULTS: Ribavirin showed delayed insecticidal effects on third-instar larvae of S. litura at a concentration of 1 mg mL−1. When incorporated into an artificial diet, ribavirin caused various effects, depending on the concentration used. Compared with controls, food intake was lower, larval growth was reduced and larval development prolonged. Pupae weight was reduced, and adult morphology was also affected. Relative to the untreated group, treated groups showed higher mortality at larval and pupal stages, which was generally caused by moult disruption. Results of this study with ribavirin resemble those found in treatment with insect growth regulators. CONCLUSION: This work shows that ribavirin merits further study as a lead compound in a novel class of potential insect control agents or for managing field populations of Lepidoptera pests on cruciferous crops. Copyright © 2012 Society of Chemical Industry 相似文献
9.
P. Gamard S. H. De Boer 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(5):519-525
Bacterial strains with potential for biological control of bacterial ring rot of potato caused byClavibacter michiganensis subsp.sepedonicus were isolated from the surface of potato tubers. Eighty-eight potential biocontrol candidates, selected on the basis ofin vitro antibiosis toC. m. sepedonicus, produced inhibition zones with radii ranging from 0.5 to 16 mm on test plates. All antagonistic isolates were screened in the greenhouse for biocontrol activity on micropropagated potato plantlets root-inoculated withC. m. sepedonicus. Eight strains consistently prevented infection of plantlets but there was no significant correlation between the width of the inhibition zone in thein vitro assay and ring rot suppression in the plant bioassay. Three strains that showed a high level of biological control potential were identified as a saprophytic enteric bacterium (strain 7G), anArthrobacter sp. (strain 16C), and a soil coryneform bacterium (strain 18A). These were tested in a field plot by co-inoculating cut seed potato tubers withC. m. sepedonicus and antagonists. Strains 7G and 18A significantly increased plant stand whereas 16C decreased disease incidence. The relative number of ostensibly ring rot-free progeny tubers was generally greater when antagonists were present. 相似文献
10.
Ricardo Petersen-Silva Lurdes Inácio Joana Henriques Pedro Naves Edmundo Sousa Juli Pujade-Villar 《国际虫害防治杂志》2013,59(2):106-112
Six entomopathogenic fungal isolates were tested under controlled conditions, as biological control agents against Monochamus galloprovincialis (Coleoptera: Cerambycidae) (Olivier), the vector of the pine wood nematode Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) (Steiner and Buhrer). The fungi Beauveria bassiana (Bals.-Criv.) Vuill, Metarhizium anisopliae (Metchnikoff) Sorokin, Metarhizium sp. and Fusarium sp. were tested against larvae and adults of the insect, by comparing two exposure techniques: continuous contact and spraying. Regarding the larvae, only Fusarium sp. and Metarhizium sp. killed more than 40% of the individuals, while B. bassiana and M. anisopliae were found to kill 50% of the adults (LT50) within five days. Exposure to B. bassiana reduced adult longevity by 19 days, when compared to untreated beetles, and had a direct efficacy of 46%. Continuous contact with the fungi proved to be more effective than spraying. A larval disinfection protocol was developed to eliminate other fungal isolates from the wood-collected tested individuals. The implications of the results and possible applications of selected strains as bio-control agents against M. galloprovincialis are discussed. 相似文献
11.
Recognizing the potential significance of using nuclear techniques in biological control, investigations were conducted on the rearing of parasitoids of the peach fruit-fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) to lead to a greater flexibility in the use of irradiated hosts. For improving mass production of the biological control agents, the use of irradiated fruit-fly larvae at the dose of 15 Gy proved useful for enhancing the parasitism and adult emergence of the larval parasitoid, Trybliographa daci (Weld) (Hymenoptera: Eucoilidae) due to no negative repercussions on parasitoid development. Overall, parasitism by the parasitoid increased with age of the host larvae; however, significantly higher parasitism occurred on 4 d-old irradiated larvae of B. zonata compared to those aged 5 d. The female parasitoids preferred the irradiated larvae, and significantly higher numbers of larvae were parasitized compared with non-irradiated larvae. There was no significant difference in adult parasitoid emergence with respect to the sex of the host. A radiation level of 80 Gy was the best dose for rearing of the pupal parasitoid, Dirhinus giffardii (Silvestri) (Hymenoptera: Chalcididae) owing to broad tolerances in the use of irradiation for the rearing of fruit-fly's parasitoids. Percentage parasitism by D. giffardii varied with host pupal age, and the preference of the female parasitoid was lower on 48 h old host pharate pupae due to optimum size and mass of host. Present findings further revealed that the 24 h old host pupae of B. zonata were relatively more suitable for the maximum parasitism and progeny production of D. giffardii. Parasitisms by D. giffardii and T. daci were significantly higher on B. zonata host when parasitoids were released at a density of 3000 individuals per acre (7500 per hectares) than the other release rates of parasitoids for the management of fruit-flies in mango orchards. The implementation of these findings ought to help improve the mass production of parasitoids and the effectiveness of releases of biocontrol agents for control of B. zonata in mango plantations. 相似文献
12.
暗黑链霉菌PY-1活性产物分析及其对葡萄霜霉病田间防效评价 总被引：2，自引：0，他引：2
为探究暗黑链霉菌Streptomyces atratus PY-1对葡萄霜霉病菌Plasomopara viticola的抑制作用,通过扫描电镜观察PY-1发酵滤液对葡萄霜霉病菌孢子囊的影响,检测PY-1的活性物质种类,并测定其对葡萄霜霉病的田间防效。结果表明,PY-1发酵滤液能够导致葡萄霜霉病菌孢子囊和孢子囊梗出现褶皱、破裂和畸形,进而使其丧失侵染功能。PY-1菌株代谢产物中包含几丁质酶、蛋白酶、嗜铁素、1-氨基环丙烷-1-羧酸脱氨酶、氰化氢、吲哚乙酸,不含纤维素酶。PY-1菌株对葡萄霜霉病具有较好的田间防效,发酵原液对葡萄霜霉病的田间中期防效可达到89.17%以上,末期防效达86.28%以上,比52.5%噁唑菌酮·霜脲氰2 000倍液的防效略低,但显著高于58%甲霜·锰锌1 000倍液的防效;PY-1菌株发酵液稀释700倍后对葡萄霜霉病的末期防效与甲霜锰锌1 000倍液防效相当。表明PY-1菌株具有研制防治葡萄霜霉病生防制剂的潜力。 相似文献
13.
为有效防控十字花科蔬菜生产中的毁灭性病害——根肿病,以尖孢镰孢菌Fusarium oxysporum和辣椒疫霉Phytophthora capsici为指示菌,利用平板对峙法对分离自土壤的1 198株细菌进行筛选,进通过盆栽试验筛选对十字花科根肿病具有良好防效的生防菌株,并基于形态学特征、生理生化特性及16S rDNA、gyrB和atpD多基因系统发育分析对生防菌株进行鉴定,同时测定其抑菌谱和田间防效。结果表明,通过对峙培养筛选获得115株有抑菌效果的生防菌株,采用盆栽试验获得1株对根肿病菌具有拮抗效果的菌株,命名为ZF480。结合形态学特征和系统发育分析结果将该菌株鉴定为副地衣芽胞杆菌Bacillus paralicheniformis。菌株ZF480对野油菜黄单胞野油菜变种Xanthomonas campestris pv. campestris等10种病原菌具有拮抗效果,抑菌谱较宽,对白菜根肿病的盆栽防效和田间防效分别达到72.82%和64.08%。表明副地衣芽胞杆菌菌株ZF480对十字花科根肿病具有显著的防效,可作为生防菌进一步开发利用。 相似文献
14.
为评估转cry1Ab/cry2Aj、cry1Ab/vip3DA玉米对棉铃虫Helicoverpa armigera(Hübner)、甜菜夜蛾Spodoptera exigua(Hübner)和斜纹夜蛾Prodenia litura(Fabricius)的抗虫性,在室内测定了3个转cry1Ab/cry2Aj玉米品系和1个转cry1Ab/vip3DA玉米品系对3种害虫幼虫存活和生长发育的影响,研究了该系列Bt玉米不同组织器官对害虫的杀虫活性和控制效果。结果显示,棉铃虫初孵幼虫取食各品系Bt玉米叶片96h后死亡率为87.50%~90.00%,取食花丝和雌穗的幼虫96h后几乎全部死亡;甜菜夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗168h后死亡率为22.50%~68.33%,幼虫的生长发育受到明显抑制,体重抑制率达85.00%~95.00%;斜纹夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗96 h后死亡率显著高于非转基因亲本对照,168h后幼虫死亡率达90.00%以上。研究表明,转cry1Ab/cry2Aj和cry1Ab/vip3DA玉米品系对棉铃虫和斜纹夜蛾的初孵幼虫表现出较好的抗性,可以作为转多基因抗虫玉米育种的备选材料。 相似文献
15.
A multitude of bacteria have been isolated from the guts of several insect species. Some of these have been modified to interfere
with the development of the host insect or with the development and transmission of plant and animal pathogens transmitted
by the host insect. We surveyed the gut flora of the Pacific Coast wireworm,Limonius canus LeConte, a serious pest of potato, at two sites in Oregon and Washington. Isolates were obtained from surface-sterilized
triturated larvae by dilution plating on standard media. A rich diversity of species was found in 86 isolates, including spore-formers,
non-spore-formers and aerobic and facultatively anaerobic species collected on four sampling dates at each location. Twenty-one
of the isolates were identified to species based on rDNA sequence (nine distinct species). An additional 34 isolates were
identified to genus from the sequence data while six isolates could be assigned only to family based on sequence comparisons.
Twenty-seven additional isolates were identified to species (9), genus (17) or family (1) based on side-by-side morphological
comparisons with isolates identified from rDNA sequence. The most frequently isolated bacterium wasBacillus megaterium, followed byRahnella aquatilis. A naturally occurring bacterium found in the gut and/or environment of a targeted insect that is modified to express toxins
or other detrimental substances could provide certain advantages (such as persistence and recycling) over inundatively applied
microbial control agents, particularly within soil habitats. The hypothesis that these species or others from the survey represent
candidates for genetic modification to provide control options forL. canus is discussed. 相似文献
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The present study assessed the insecticidal potential of purified Bowman-Birk proteinase inhibitors from red gram (RgPI) and black gram (BgPI) towards lepidopteran insect pests. Both RgPI and BgPI showed remarkable inhibitory activity against midgut trypsin-like proteinases of Achaea janata. While, BgPI showed moderate to low inhibitory activity towards the midgut trypsin-like proteinases of Helicoverpa armigera, Spodoptera litura, Papilio demoleus, Amsacta albistriga, Corcyra cephalonica, Bombyx mori and Daphnis nerii, RgPI showed low to negligible inhibitory activity. The isoinhibitors of RgPI and BgPI were stable in presence of trypsin and chymotrypsin of bovine pancreatic origin, as well as larval midgut proteinases of A. janata, H. armigera and S. litura. The midgut trypsin-like proteinases of A. janata and H. armigera as well as midgut trypsin- and chymotrypsin-like proteinases of S. litura were susceptible to inhibition by RgPI and BgPI. Feeding assays displayed a dose-dependent decrease in body weight and survival rate of these larvae with increasing concentration of inhibitors supplemented in the diet. RgPI displayed significant reduction in body weight and survival rate of A. janata larvae compared with BgPI. Conversely, BgPI showed significant reduction in body weight of S. litura larvae compared with RgPI. 相似文献
19.
为明确田间使用多杀霉素亚致死浓度对棉铃虫Helicoverpa armigera幼虫的影响,用含多杀霉素亚致死浓度LC25的人工饲料持续饲喂棉铃虫3龄幼虫,并对饲喂后其体重、取食量、累计蛹化率、蛹发育历期和蛹重等生长发育及脂肪体内甘油三脂（triglyceride,TG）含量和相关基因SREBP、FAS和HSL表达情况进行测定。结果表明,多杀霉素对棉铃虫的亚致死浓度LC25为0.21 mg/kg;多杀霉素亚致死浓度处理4~6 d后,棉铃虫3龄幼虫体重分别为0.065、0.263和0.329 g,较对照显著降低;处理6 d后,其取食量为0.082 g,较对照显著降低;处理4~7 d后,其累计化蛹率分别为60.90%、63.20%、65.50%和65.50%,较对照显著降低。多杀霉素亚致死浓度处理后,棉铃虫蛹发育历期由对照9.89 d显著延长至10.74 d,单头蛹重为0.274 g,显著低于对照的0.324 g;其脂肪体TG含量较对照显著降低。多杀霉素亚致死浓度处理24~72 h后,参与脂肪酸合成信号通路中重要基因SREBP和FAS的相对表达量较对照均显著下调,而参与脂肪代谢的重要基因HSL则较对照显著上调。 相似文献
20.
昆虫病原线虫泰山Ⅰ号是小杆目异杆线虫科异杆线虫属(Heterorhabditis)线虫。1984年5月,自山东泰安苹果园土壤及桃小食心虫(简称桃小)(Carposina niponensis Walsingham)圆茧分离获得。在长江以北地区分离到这种昆虫寄生性线虫还未见有报道。其生活史包括两个世代,即卵生世代(短世代)和卵胎生世代。25℃温度下完成整个生活史需9天时间。它与一种无色杆菌(Xencrhabdus)互惠共生,线虫进入昆虫体腔便释放出其共生菌,引起昆虫败血病,48小时内导致寄主死亡。尸体变红并发出较强的生物光。本文主要报道其生活史、形态、共生菌、人工繁殖方法及对桃小的致死效果。 相似文献