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1.
The soil, being rich in microbes, should be an ideal environment in which to practise microbial control of insect pests, but relatively few organisms have been developed into successful microbial control agents for soil pests. Difficulty arises in implementation of microbial control, as the soil is a highly complex, competitive environment where survival of applied microbes is by no means assured. In addition, soil dwelling pests appear to show a high level of resistance to broad spectrum pathogens and microbial toxins. However, some significant successes have been achieved with bacteria, fungi and nematodes for control of a range of soil inhabiting pest species. The successful microbial controls are based on highly specific microbial/insect interactions where co-evolved pathogens can overcome the host's defences. These agents also have the ability to persist in the soil, either through the inherent stability of the organism or from recycling through the host population. While strain selection for high levels of pathogenicity and environmental competence is the essential first step in microbial control of soil dwelling pests, it must be followed by development of efficient production systems and quality control measures to ensure application of standardised, high quality products. Success in microbial control of soil dwelling pests depends on an appropriate combination of these factors, with failure likely to occur if any one of these essential components is overlooked.  相似文献   

2.
A search for patterns in the success and failure of microbial insecticides in vegetable crops was conducted through review of four case studies: the use of Bacillus thuringiensis (B.t.) var. tenebrionis for control of the Colorado potato beetle, the use of B.t. var. kurstaki for control of the diamondback moth, the use of various B.t.s for control of lepidopterous pests in tomatoes and celery, and the use of a granulosis virus for control of potato tuber moth. With success defined in terms of achievement of technical goals (efficacy), commercial goals (end-user and insecticide manufacturer satisfaction) and social, or public goals (environmental and health safety), only certain of the case studies could be judged a success. These successes shared a variety of features including: (1) use of the microbial insecticide as a component, rather than as the sole agent, in an integrated crop management program; (2) unavailability of conventional insecticides, due to insecticide resistance, lack of registered products or mandatory IPM programs, provided incentive for the use of microbial insecticides; (3) modification of the expectation that microbial insecticides will perform within the chemical paradigm – fast, lethal and on contact; (4) exploitation of all possible benefits of the microbial insecticide, including safety to natural enemies, as well as efficacy against the target insect, and (5) support from large private and public institutions in the form of research, grower education, scouting programs, subsidized production, and economic and legal incentives to the use of microbial insecticides.  相似文献   

3.
Factors in the Success and Failure of Microbial Control in Turfgrass   总被引:2,自引:0,他引:2  
Turfgrass is an important component of urban landscapes and turf associated products and services are valued at about $45 billion in the US alone. Turf insecticide market is about $500 million per year of which microbial insecticides constitute less than 0.1%. Major factors in the poor market penetration of microbial insecticides include low damage thresholds, narrow spectrum of activity, a definite pest monitoring requirement, shortage of quality products, and competition with the newly registered less-toxic chemical insecticides. Enhancement of market share of microbial insecticides in turf will depend upon successful development of more appropriate application strategies, an increase in the availability of quality products, and the development of a systems approach in which microbial insecticides are used together with chemical insecticides in a more compatible manner. The long-term benefits derived from the use of microbial insecticides must be documented to enhance acceptance of microbial control.  相似文献   

4.
Development of Clonostachys rosea in rose leaves and petals and control of Botrytis cinerea by the agent were investigated. C. rosea germinated, established endophytic growth, and sporulated abundantly whether the tissues were mature, senescent or dead when inoculated. Germination incidence was moderate on mature and senescent leaves (47% and 35%) and petals (31% and 43%), and high (>98%) on dead tissues. Sporulation of C. rosea in tissues inoculated when mature, senescent or dead averaged 41%, 61%, and 75% in leaves, and 48%, 87% and 53% in petals. When leaves were wounded with needles before inoculation, germination of C. rosea increased from 45–56% to 90–92%, but sporulation became high (>75%) regardless of wounds. When leaves were inoculated with C. rosea at 0–24h after wounding and subsequently with B. cinerea, germination of the pathogen was reduced by 25–41% and sporulation by 99%. A humid period prior to inoculation of senescent or dead leaves promoted communities of indigenous fungi, reduced sporulation of C. rosea and B. cinerea, and, in dead leaves, increased control of the pathogen associated with C. rosea. Applied at high density, isolates of indigenous Penicillium sp. and Alternaria alternata from rose interacted with C. rosea and reduced control of the pathogen by 16% and 21%, respectively. In conclusion, C. rosea markedly suppressed sporulation of B. cinerea in rose leaves and petals regardless of developmental stage, minor wounds, and natural densities of microflora. This versatility should allow C. rosea to effectively control inoculum production of B. cinerea in rose production systems.  相似文献   

5.
This paper describes a factorial trial designed to investigate the delivery systems of fungal biological agents (Clonostachys rosea), applied as single strain or as strain mixture, in comparison with copper hydroxide as a chemical standard against Moniliophthora roreri in cocoa. Application techniques compared were motorised mistblowers fitted with rotary atomisers and hydraulic sprayers fitted with cone nozzles giving a narrow angle of spray. The third factor was the presence or absence of an emulsifiable rape-seed adjuvant oil in the tank mixture. Copper fungicide was the best agent for moniliasis control and resulted in the highest yield. Both the mycofungicides reduced sporulation of the pathogen. Net reduction of inoculum was best for the hydraulic sprayer-applied copper fungicide and the motorised mistblower-applied single-strain biocontrol agent. Overall, directional hydraulic sprays were found to be somewhat superior to the motorised mistblower technique, with its dissipated cone of spray. Addition of the adjuvant oil was the least important of the factors, but efficacy depended on the agent used, with a significant enhancement in the efficacy of copper with oil but a detrimental effect on C. rosea.  相似文献   

6.
The minor position of microbial insecticides within the global pesticide market can be attributed to a number of causes, including high cost of production, high specificity, poor application technology, poor persistence and slow speed of kill. These aspects are discussed in relation to the potential for use of microbial insecticides against forest pests. Many of the constraints are not limiting in forestry and some of the ways in which they can be overcome are discussed, including the concept of a better appreciation of the ecological context. This approach encompasses knowledge of the behaviour of the target host species, both for improved targeting and for maximum exploitation of secondary inoculum. These, and other aspects are brought together in discussing the future for microbial insecticides in forest pest management.  相似文献   

7.
8.

Discussion

Panel Discussion: Factors in the Success and Failure of Microbial Insecticides  相似文献   

9.
微生物制剂对草莓重要真菌病害的作用研究   总被引:1,自引:0,他引:1       下载免费PDF全文
为筛选防治草莓几种重要真菌病害的高效微生物制剂,本研究测定了以植物免疫蛋白、淡紫拟青霉、枯草芽胞杆菌和粉红黏帚霉等为活性成分的3种微生物制剂对草莓炭疽病、灰霉病和白粉病的防治作用及对草莓生长的影响。结果表明,3种微生物制剂对草莓炭疽病的防效均在65%以上,对灰霉病的防效在30%~55%。对于草莓白粉病害,沃丰康-克线散防治效果较好,达到64.1%,而普绿通粉剂和沃丰康-复合微生物菌剂防效不明显(<40%)。此外,3种微生物菌剂均表现出明显的促生、增产作用,其中沃丰康-复合微生物菌剂效果最为显著,植株干重增加57.3%,草莓干重增加83.1%;施用沃丰康-克线散粉剂植株和果实增幅分别为47.5%和76.1%,普绿通粉剂分别增加17.9%和66.2%。本研究表明,生防制剂可以替代化学农药用于草莓病害防治和有机生产。  相似文献   

10.
黄曲条跳甲是为害十字花科蔬菜的世界性害虫。本文研究了昆虫病原菌苏云金杆菌工程菌G033A和金龟子绿僵菌CQMa421防治萝卜黄曲条跳甲田间应用技术。结果表明,采用昆虫病原微生物苏云金杆菌G033A和金龟子绿僵菌CQMa421土壤处理防治黄曲条跳甲均具有较好的防效,其中32000 IU/mg苏云金杆菌工程菌G033A可湿性粉剂300 g/667 m2土壤处理防治效果显著优于对照化学药剂,且持效期较长,具有明显的减药、省力、降成本作用。针对萝卜主要病虫害开展了全程生物防控技术示范,结果表明全程生物防控技术不仅防治效果好,且较常规化学防治技术增产达到14.8%,品质得到提升,商品优良率提高12%,可进一步大面积示范推广。  相似文献   

11.
为解决微生物生防制剂在实际应用过程中防效不稳定的问题,本研究通过在不同微生物生防产品中添加有机物料,分析了添加有机物料对草莓灰霉病防治和土壤微生物数目的影响。本试验共设15个处理。微生物生防制剂(BCA)包括枯草芽胞杆菌Bacillus subtilis(Bs),木霉菌Trichoderma(Tr),EM菌(effective microorganisms,EM),半量枯草芽胞杆菌+木霉菌(1/2BT),以及无菌剂对照(CK);有机物料用量(米糠+豆粕粉,RB)设3个水平,分别为不添加,1/2RB(15 g/m2米糠+60 g/m2豆粕粉)和RB(30 g/m2米糠+120 g/m2豆粕粉)。移栽55 d后将各处理组分均匀撒施至根周,随后覆盖地膜并滴灌保湿。结果表明,木霉菌和EM菌能够有效降低灰霉病发病率,有机物添加量一致时,微生物生防制剂的防效规律为EM > Tr > Bs > 1/2BT。木霉菌和EM菌单剂在发病较轻的试验地1中防效为60.00%~68.00%,发病严重的试验地2中防效为16.39%~29.01%。各处理中EM+RB防效最高,最高可达90.00%。添加全量米糠和豆粕粉能够显著提高生防制剂的防效。生防制剂添加有机物料的防效规律为BCA+RB > BCA+1/2RB > BCA,Tr+RB防效比Tr单剂施用提高0.17~1.1倍,EM+RB防效比EM单剂提高0.32~1.84倍。同时土壤微生物的数目随有机物料的增加而增加,1/2RB和RB可使数目分别增长0.43~8.86倍和0.93~32.72倍。以上结果表明,实际生产中施用木霉菌或EM菌能够有效防治草莓灰霉病,添加足量的有机物料可以增加土壤微生物丰度从而提高防治效果。  相似文献   

12.
为探究复合微生物菌剂对苹果再植病害的生防效果,以苹果砧木实生海棠幼苗为试材,通过盆栽试验测试了木美土里复合微生物菌剂对苹果再植病害的防治效果及对再植海棠的促生作用,然后对该菌剂的可分离微生物进行了分离纯化,并以尖孢镰刀菌Fusarium oxysporum菌株HS2为靶标菌,测试分离获得的10株菌株的拮抗效果,并对拮抗效果显著的1株真菌菌株和2株细菌菌株进行种类鉴定。结果表明,木美土里复合微生物菌剂对苹果再植病害的防治效果达87.78%;经该菌剂处理后,再植海棠苗的株高、茎粗、鲜重、干重及叶面积分别是对照处理的1.51、2.00、5.74、5.21和2.83倍,表明该菌剂有显著的促生作用。木美土里复合微生物菌剂对菌株HS2的抑制率达到68.59%,并从中分离到7株真菌菌株,3株细菌菌株。其中,拮抗效果高于80.00%的真菌菌株有1株,细菌菌株有2株。经鉴定,真菌菌株MMTL-1为哈茨木霉Trichoderma harzianum;细菌菌株BM-01和BM-03均为解淀粉芽胞杆菌Bacillus amyloliquefaciens。  相似文献   

13.
国内外杀虫绿僵菌制剂的登记现状与剂型技术进展   总被引:1,自引:0,他引:1  
生物农药在植物保护工作中日益受到重视。绿僵菌是重要的昆虫病原真菌,作为真菌杀虫剂已被成功应用于蝗虫、金龟子、象甲等多种害虫的田间防治。近40年来,已有83个绿僵菌产品在13个国家或地区获得注册,制剂研究与加工技术方面取得了新进展,可湿性粉剂、悬浮剂等传统剂型质量得到改善,超低容量剂、浸渍剂等新剂型可适应特殊应用环境,产品的防治对象涵盖范围更广。本文就国内外绿僵菌产品注册登记情况、制剂类型特性及制剂技术的载体、助剂和加工过程等主要因素进行综述,以期为我国真菌生物农药的科研、应用及产业发展提供基础依据。  相似文献   

14.
A field study is described which explored the possibility of controlling Stagonospora nodorum and Septoria tritici on wheat using a barley pathogen, Drechslera teres. Pre-treatment of wheat cv. Hussar flag leaves with D. teres resulted in a significant reduction in disease caused by S. nodorum and S. tritici, resulting in a significant increase in grain yield. When cv. Brigadier leaves were treated with D. teres prior to inoculation with S. nodorum there was an initial increase in disease expression whilst D. teres had no effect on symptoms produced by S. tritici on cv. Brigadier. There was significantly less disease on leaves of cvs. Hussar and Brigadier pre-treated with D. teres prior to inoculation with an equal mixture of S. nodorum and S. tritici compared to plants pre-treated with water. It is concluded that D. teres and other non-host pathogens show potential as biological control agents for S. nodorum and S. tritici.  相似文献   

15.
为明确樟树枝叶提取物对葡萄霜霉病的防治效果,采用混合液滴显微镜观察法研究了樟树枝叶提取物及其活性成分对病原菌孢子囊萌发的抑制作用,利用高效液相色谱法鉴定了枝叶乙酸乙酯萃取物的化学成分,测定了其活性成分对葡萄霜霉病的室内和田间防治效果。结果表明,浓度为0.1 g/mL以上的樟树枝叶提取物对孢子囊萌发均有很好的抑制效果,抑制率达100.0%;樟树枝叶提取物经不同极性有机溶剂萃取后,分别获得正己烷、乙酸乙酯、正丁醇和水相分离物,浓度为1.0%时各分离物对孢子囊萌发的抑制率分别为58.4%、92.4%、32.5%和58.7%,乙酸乙酯相富集了主要抑菌活性成分,经液相色谱分析并与色谱库数据比对,确定其活性成分中含有芦丁和槲皮素;浓度为1.0%的芦丁和槲皮素对孢子囊具有抑制作用;田间试验显示,浓度为0.3 g/mL以上的枝叶提取物对葡萄霜霉病预防效果显著,治疗效果在60.0%以上。研究表明,樟树枝叶提取物可以有效控制葡萄霜霉病,提取物的活性成分芦丁和槲皮素可以作为植物源药剂。  相似文献   

16.
The biological control of pest tephritid flies using parasitoids has been successful in relatively few subtropical and tropical regions. The best documented successes were in Hawaii and Florida, USA, Fiji and southern Europe. There were relatively limited successes in Australia, Costa Rica and Mexico. With the accidental establishment of new pest tephritids, such as Bactrocera latifrons (Hendel) in Hawaii or Bactrocera papayae Drew and Hancock in Australia, foreign exploration for new parasitoids is essential. A renewal of interest in classical biological control has recently occurred, although not at the same level as in the 1940s and 1950s. New parasitoid species are currently being obtained for several tephritids, such as Ceratitis capitata (Weidemann), B. latifrons and Anastrepha suspensa (Loew). The advances in mass rearing and quality control technology for parasitoids has enabled researchers to perform large-scale field testing of these parasitoids to determine the potential of augmentative releases. Numerous studies on the augmentative release of parasitoids have been done. Historically, the larval—pupal parasitoid Diachasmimorpha longicaudata (Ashmead) has been the most frequently studied parasitoid, due to the ease of rearing this species. However, recent successes in rearing other species with different biologies, e.g. the egg—pupal parasitoid Biosteres arisanus (Sonan), the gregarious eulophid, Tetrastichus giffardianus (Silvestri) and the pupal parasitoid, Coptera sp., will enable researchers to broaden the repertoire of parasitoid species for the future. Both successes and failures in augmentative releases have occurred. Without knowledge of the behavioural ecology of parasitoids, the reasons for success or failure can only be surmised. Recent research on the dispersal and host habitat finding of tephritid parasitoids will provide insights into improving augmentation and conservation strategies. The integrated pest management (IPM) of tephritid flies in the tropics has been less well-developed than research and programmes for tephritids in temperate zones. Significant emphasis is now being placed on the development of quarantine treatment methods that are environmentally sound; thus IPM will take a larger role. Several existing pest management strategies are reviewed which show the potential for compatibility with the activities of tephritid parasitoids. These include trap cropping, insecticides with selective toxicity to the target pests, mass trapping with parapheromones, the sterile insect technique and field sanitation.  相似文献   

17.
A number of the members of the Noctuidae (subfamily Plusiinae) are polyphagous insects that infest a variety of economically important crops world-wide. These hosts include but are not limited to cotton, vegetable and field crops and also such specialty crops as mint. Many of these crops require multiple applications of chemical pesticides to protect them from various loopers and other economic pests. One proposed alternative to the use of chemical pesticides to protect these crops is the development of insect-specific viruses of the family Baculoviridae. Hundreds of these viruses of the genus Nucleopolyhedrovirus have been isolated, many from economically important Lepidoptera. The advent of the discovery that some of these viruses may have a broad host range increased the interest in the development of them as microbial agents throughout the world. The broad host range (over 30 species in some cases) provided the possibility to control not only one species, but a complex of lepidopterous pests infesting specific or multiple crops. From the 1960s to the present, extensive basic and applied research has been conducted on the multi-nucleocapsid (MNPV) forms within which a broad host range appears to be characteristic. Of these, the virus isolated from the alfalfa looper, Autographa californica (Speyer) (AcMNPV) has been the most studied, particularly as related to microbial control. Two of the viruses isolated from loopers have been registered in the USA. Although efficacy has been demonstrated for loopers, there is a paucity of data on the other important species that may simultaneously infest looper hosts. Because of their relatively slow action, the viruses will probably be used in integrated programs with chemical pesticides applied during critical periods of high population pressure. Further research needs to be conducted to establish efficacy for other hosts, improved production methods either in vivo or in vitro, increased field persistence as related to timing and frequency of applications, and finally the utility of genetically engineered MNPVs as microbial pesticides. The potential of these organisms has been demonstrated and new developments are being made to increase the overall efficiency and economics of their use. These improvements can only increase interest in use of the baculoviruses in pest management systems for loopers and other pests.  相似文献   

18.
生物防治是草地植保学科的重要范畴。进入21世纪以来,随着生命科学和生物技术的发展,使该分支学科在我国得到了快速发展。本文概述了“十二·五”期间草地有害生物生防技术在我国的发展现状,在分析我国本领域学科发展水平与国际差距的基础上,指出了我国草地有害生物生防领域存在的主要问题及未来优先发展方向。  相似文献   

19.
The hibiscus mealybug, Maconellicoccus hirsutus Green, was first reported in the Caribbean in 1994 in Grenada. This was the first record of the insect as a major pest in the New World. By the beginning of 2001, the pest had spread to over 25 territories from Guyana and Venezuela in the South to Bahamas in the North. The pest has also extended its distribution to Central America (Belize) and North America (California, USA). Early attempts to control the pest using pesticides resulted in failure and a classical biological control approach was adopted. Several exotic natural enemies were introduced but control was attributed to Anagyrus kamali Moursi and Cryptolaemus montrouzieri Mulsant. In all countries where biological control was implemented, this resulted in success. This paper reviews the remarkable success story. Information is provided on the distribution and factors leading to rapid spread of the pest, its pest status and resultant economic losses, and implementation of the biological control effort.  相似文献   

20.
Verticillium dahliae antagonistic endorhizosphere bacteria were selected from root tips of tomato plants grown in solarized soils. Fifty-three out of the 435 selected bacterial isolates were found to be antagonistic against V. dahliae and several other soilborne pathogens in dual cultures. Significant biocontrol activity against V. dahliae in glasshouse trials was demonstrated in three of 18 evaluated antagonistic isolates, provisionally identified as Bacillus sp. Although fluorescent pseudomonads were also isolated from root tips of tomato plants, none of the tested isolates exercised any significant antagonistic activity against V. dahliae in dual cultures. So these isolates were not tested in glasshouse trials in this study. Finally, two of the most effective bacterial isolates, designated as K-165 and 5-127, were shown to be rhizosphere colonizers, very efficient in inhibiting mycelial growth of V. dahliae in dual cultures and successfully controlling Verticillium wilt of solanaceous hosts. In glasshouse experiments, root dipping or soil drenching of eggplants with bacterial suspension of 107cfu ml–1 resulted in reduced disease severity expressed as percentage of diseased leaves (40–70%) compared to the untreated controls under high V. dahliae inoculum level (40 microsclerotia g–1 soil). In heavily Verticillium infested potato fields, experiments with potato seeds dusted with a bacterial talc formulation (108cfu g–1 formulation), showed a significant reduction in symptom development expressed as percentage of diseased potato plants and a 25% increase in yield over the untreated controls. As for their effectiveness in increasing plant height, both bacterial isolates K-165 and 5-127 produced indolebutyric, indolepyruvic and indole propionic acids. Both antagonists are considered as plant growth promoting rhizobacteria bacteria since significantly increased the height of treated plants compared with the untreated controls. Chitinolytic activity test showed that both isolates were able to produce chitinase. Testing rhizospheric and endophytic activity of the antagonists it was shown that although the bacteria are rhizosphere inhabitants they also preferentially colonize the endorhizosphere of tomatoes and eggplants. Fatty acid analysis showed that isolate K-165 could belong to Paenibacillus alvei while 5-127 to Bacillus amiloliquefaciens.  相似文献   

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