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1.
W. Theunis 《国际虫害防治杂志》2013,59(3):139-143
Six strains of entomopathogenic nematodes, Steinernema glaseri (Steiner) (Biosys #326, nc 34, gb), S. feltiae = bibionis (Filipjev) (Biosys #349), S. carpocapsae Weiser (Biosys #25) and Heterorhabditis zealandica Poinar, were evaluated in laboratory tests against taro beetles, Papuana uninodis Prell. Larvae of this species and adult Papuana Arrow spp. were found to be susceptible to entomopathogenic nematodes. The best results were obtained with S. glaseri #326 in larval and adult P. uninodis . The dose causing 50% mortality (LD ) for third instar P. uninodis larvae in Petri dish assays ranged from almost 7000 nematodes/larva for 1 days exposure to less than 250 nematodes/larva for 6 days; in pot assays the concentration causing 50% mortality (LC ) in 2 weeks was 1.4 106 nematodes/m2. For 50 adults in Petri dishes with soil, the LD was ca 20 000 nematodes/ 50 adult for 1 weeks exposure and ca 6000 nematodes/adult for 3 weeks. In pot assays the LC was 2.5 106 nematodes/m2 in 3 weeks. 50 Preliminary tests showed that P. huebneri (Fairmaire) and P. woodlarkiana laevipennis Arrow adults were also most susceptible to S. glaseri #326. A field test on adults Papuana uninodis did not result in damage reduction but served to illustrate the practical difficulties of applying nematodes in remote areas. 50 相似文献
2.
Parwinder S Grewal 《Pest management science》2000,56(5):401-406
Limited shelf‐life is a major obstacle to large‐scale use of entomopathogenic nematodes in biological control. Recently, the development of a water‐dispersible granular formulation (WG) containing entomopathogenic nematodes was described. This paper reports that storage stability of Steinernema carpocapsae Weiser infective juveniles at 25 °C is enhanced from three to six months in this WG. It is also demonstrated that the enhanced stability is achieved through the induction of partial anhydrobiosis that reduces oxygen and lipid reserve utilization by infective juveniles. Nematode infectivity is unaffected during storage under partial anhydrobiosis in the WG formulation. © 2000 Society of Chemical Industry 相似文献
3.
Sayedain Fatemeh Sadat Ahmadzadeh Masoud Fattah-Hosseini Somayeh Bode Helge B. 《植物病害和植物保护杂志》2021,128(1):215-223
Journal of Plant Diseases and Protection - Cucumber (Cucumis sativus) cultivation in commercial greenhouses occupies an important section of vegetable production in Iran. Root-knot nematode... 相似文献
4.
BACKGROUND: Larvae of the crane fly Tipula paludosa (Diptera: Nematocera) are economically important pests of grasslands, nurseries and organically grown crops. This study was conducted to evaluate several entomopathogenic fungal strains, the entomopathogenic nematode Heterorhabditis bacteriophora and the organophosphate insecticide Dursban WG (75% chlorpyrifos) against larval stages of T. paludosa under laboratory and greenhouse conditions. RESULTS: Metarhizium robertsii strain V1005 was the most virulent, causing 100% larval mortality 4 weeks post-inoculation. Eight other M. robertsii strains and M. brunneum (ARSEF 3297) caused mortality ranging between 0 and 60%, whereas strains of Beauveria bassiana, Isaria fumosorosea and Lecanicillium longisporum were non-pathogenic to T. paludosa. In greenhouse tests, medium (2 × 1014 conidia ha−1) and high (2 × 1016 conidia ha−1) concentrations of V1005 gave higher larval mortalities (90 and 100%) than lower (2 × 1013 conidia ha−1) concentrations (52 and 78%) at 4 and 8 weeks after treatment respectively. Dursban WG gave 100% larval mortality 4 weeks after treatment; H. bacteriophora UWS1 caused 28 and 65% mortality 4 and 8 weeks after treatment respectively. CONCLUSIONS: This study shows that M. robertsii V1005 has considerable potential for the control of T. paludosa, thereby reducing the use of chemical insecticides. Copyright © 2012 Society of Chemical Industry 相似文献
5.
We evaluated the potential for using infective juveniles of the entomopathogenic nematode Steinernema feltiae to control the sweetpotato whitefly Bemisia tabaci B biotype on cucumber, hibiscus, and collard, under greenhouse conditions. The effects of four adjuvants (PVA, glycerol, Triton X-100, and horticultural spraying oil) on the efficiency of Steinernema feltiae in B. tabaci control were also assessed because they might increase nematode survival by reducing desiccation. The mortality of B. tabaci nymphs increased by 18, 18, and 20% on collard, hibiscus, and cucumber plants when S. feltiae concentration increased from 5000 to 15,000 infective juveniles/mL. When treated with S. feltiae (10000 infective juveniles/mL), second instar nymphs suffered greater mortality than the other instars of B. tabaci, regardless of host plant species. Mortality of B. tabaci nymphs was higher on hibiscus than on collard and cucumber plants. The use of adjuvants greatly increased infection of B. tabaci by S. feltiae. The combination of S. feltiae (10,000 infective juveniles/mL) and 1% horticultural spraying oil increased the mortality of second instar B. tabaci nymphs to 86% on collard and 90% on hibiscus, while the combination of S. feltiae and 0.1% Triton X-100 caused 83% mortality on collard and 89% on hibiscus. The potential for incorporating S. feltiae and the adjuvants in B. tabaci management is discussed. 相似文献
6.
Little is known regarding non-chemical control measures againstThrips palmi Karny. Since entomopathogenic fungi and nematodes have been found to be active against thrips species such asFrankliniella occidentalis Pergande, comparative bioassays were conducted to determine the extent to which they also show activity againstT. palmi. Significant mortality of the larvae of the species was recorded following treatment withLecanicillium muscarium (Petch) Zare and Gams, and addition of the wetting agent Agral enhanced pathogenicity toT. palmi. T. palmi pupae were not affected byS. feltiae. The potential for use of these agents againstT. palmi in the field is discussed in the light of these results.
http://www.phytoparasitica.org posting Aug. 28, 2005. 相似文献
7.
Virulence and efficacy of five species and strains of the entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae:Steinernema riobravis, Steinernema feltiae strains Ger. and UK, andHeterorhabditis bacteriophora strains HP88 and IS5, against the prepupal and pupal stages of the western flower thrips (WFT),Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), were investigated in the laboratory. Although all these nematodes controlled WFT to some extent, they differed in efficiency. The heterorhabditid nematodeH. bacteriophora strain HP88 was more specific to the soil-inhabiting WFT stages (36–49% thrips mortality). The steinernematid nematodesS. riobravis andS. feltiae strains Ger. and UK had only a slight effect (10% mortality) on prepupal and pupal populations of WFT, andH. bacteriophora strain IS5 had the least effect of all. A possible reason for such species variation is suggested and discussed. 相似文献
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10.
Entomopathogenic nematodes (EPNs) from the genus Steinernema (Steinernematidae) are used for biological control of insect pests. The infective stages of these nematodes are intolerant
of extreme environmental conditions. Genetic improvement has been suggested as an approach for improving their ability to
overcome these limitations. In this study, we bred a heterogeneous population of the EPN Steinernema feltiae Filipjev for desiccation tolerance (both rapid and slow) and enhanced host-seeking ability. We selected for tolerance of
rapid desiccation by exposing infective juveniles (IJs) to ambient conditions (22–25°C; 50–65% r.h.) for 100 min. A survival
rate of 80–90% was reached after ten selection cycles. To select for tolerance of slow desiccation, we exposed IJs to 97%
r.h. for 72 h, followed by further exposure to 85% r.h. for an additional 72 h. A high survival rate (>85%) was obtained after
20 selection cycles. We selected for enhanced downward dispersal by forcing IJs to move through a sand column to reach larvae
of last-instar Galleria mellonella placed at the bottom of the column. After 25 selection cycles, the majority (>75%) of these nematodes were found at the layer
close to the insects. No reduction in fitness was detected in the selected populations. Nevertheless, the nematode population
selected for enhanced downward dispersal displayed significantly higher infectivity than the foundation population. The population
selected for slow desiccation was more tolerant of heat stress than the foundation population. These findings establish the
basis for improvement of this nematode for use as a biological control agent under field conditions. 相似文献
11.
Carla S. Pimentel Jessica McKenney Paulo N. Firmino Teresa Calvão Mathew P. Ayres 《Plant pathology》2020,69(8):1565-1573
Bursaphelenchus xylophilus, the pinewood nematode and causal agent of pine wilt disease (PWD), is a globally destructive pine pest. PWD is favoured by high temperatures and drought, but B. xylophilus can also persist in symptomless hosts in areas not prone to PWD. We compared seedlings of different Pinus species that were inoculated with B. xylophilus when well-watered and under moderate temperatures, conditions that favour sublethal infections. We compared isolates of B. xylophilus in south-west Europe (Portugal) and south-east USA (Louisiana). P. pinea, P. pinaster, and P. radiata were challenged in both areas with inoculations of local B. xylophilus. P. sylvestris in Portugal and P. palustris in Louisiana were also tested. Seedling mortality was low, as expected, but nematode establishment was common. There were higher nematode densities and more damage in seedlings of P. sylvestris and P. radiata, followed by P. pinaster, with P. pinea and P. palustris proving to be more tolerant. Life history of hosts was a better predictor of resistance to B. xylophilus than geographical origin, even under sublethal conditions. Fast-growing species (P. radiata and P. pinaster) appeared most likely to be symptomless carriers in areas not prone to the development of PWD. Cold-adapted species (P. sylvestris) may still be suitable hosts for the pathogen, even at the sublethal conditions of their distribution areas. There were more nematodes per gram of host using nematode isolates from Portugal. Nonetheless, our results opposed the hypothesis that North American pinewood nematodes have such low virulence that they are obligatorily saprophytic. 相似文献
12.
The present study aims at determining the desiccation tolerance of entomopathogenic nematodes from the genusHeterorhabditis recently isolated in Israel. We first verified the most suitable desiccation conditions that lead to induction of the anhydrobiotic
state usingHeterorhabditis bacteriophora HP88. After direct exposure of infective juveniles (IJs) to 97% and 93% r.h. for 96 h, the survival rate was > 70%. By contrast,
exposing HP88 IJs to 88% and 85% r.h. resulted in poor survival (< 10%) or complete mortality. Following exposure to 97% and
93% r.h. for 24, 48, 72 or 96 h, survival ranged from 68% to 79% with no significant differences between the exposure periods.
Stepwise reduction of r.h. conditions (97% > 93% > 88% > 85% r.h.) at a 24-h or 72-h interval resulted in enhanced survival
(30% survival) of IJs at the final r.h. level compared with IJs which were either directly exposed to 85% r.h. (0% survival)
or were preconditioned at the higher r.h. levels prior to exposure to 85% r.h. (15% survival).H. bacteriophora HP88 IJs were able to survive for at least 18 days after preconditioning. At 97% r.h. nematode viability remained stable
at 70–85% and at 93% r.h. survival ranged between 37% and 60%. The data indicate that survival is influenced by rate of water
removal from the nematode’s body and a minimal relative humidity level (>93%). Substantial differences in survival ability
were observed among IJs of 12 new heterorhabditid populations, isolated from different climatic regions in Israel, which were
preconditioned at 97% r.h. for 72 h following by an additional 72 h at 93% r.h. Maximum survival was recorded with HIS-19
(64%), moderate (40–55%) survival was observed with seven isolates, includingH. bacteriophora HP88, and five isolates displayed poor (<25%) desiccation tolerance.
Contribution from the Agricultural Research Organization, Bet Dagan, Israel, No. 502-99, 1999 series. 相似文献
13.
The free-living nematode Panagrellus redivivus was incubated with the organophosphorus pesticide, phorate, and the rates of uptake and metabolism determined by radiochemical methods. Extensive catalysis of phorate hydrolysis and side-chain oxidation was observed, and the location of this activity within the system is discussed. Little accumulation of phorate or its metabolites was found in the nematodes. 相似文献
14.
Pedro Miranda-Fuentes Ana Belén García-Carneros Ana María Montilla-Carmona Leire Molinero-Ruiz 《Plant pathology》2020,69(8):1492-1503
The increasing limitation of agrochemicals for disease control is a major challenge for European agriculture and a spur to developing environmentally friendly approaches such as biological control. Entomopathogenic fungi, which have been used in the control of insect pests for a long time, also have other uses, such as being antagonists of fungi, including plant pathogens. We determined the in vitro effect of three strains of Metarhizium brunneum and two of Beauveria bassiana against Verticillium dahliae and Cadophora helianthi, causal agents of sunflower wilts. Both M. brunneum and B. bassiana were able to inhibit the mycelial growth of the sunflower pathogens and, according to the dual culture and microscopy results, two types of antagonism were observed as being dependent on the strain: competition and/or antibiosis. Greenhouse experiments showed that, after soil treatments with entomopathogens and plant inoculation by root immersion in conidial suspensions of V. dahliae, the entomopathogens were able to efficiently persist in the soil, and three of the four strains even significantly reduced the severity of symptoms in sunflowers. Interestingly, molecular analysis showed that all the strains were able to establish themselves as endophytes in sunflowers in the absence of V. dahliae. When the plants were inoculated with V. dahliae, we detected the pathogen, but not the entomopathogen, in the sunflowers by molecular methods. The results of this work suggest that the protection conferred by M. brunneum and B. bassiana against verticillium wilt might not be plant-located, but is probably the consequence of their competition with V. dahliae in the soil. 相似文献
15.
Proteolytic enzymes secreted by larval stage of the parasitic nematode Trichinella spiralis 总被引:3,自引:0,他引:3
Todorova VK 《Folia parasitologica》2000,47(2):141-145
Excretory/secretory products (ES), collected from in vitro cultures of muscle larvae (L1) of Trichinella spiralis (Owen, 1835) were examined for the presence of proteolytic enzymes. Several discrete proteinases in the size range of 25-55 kDa were identified by substrate gel electrophoresis and were characterised according to pH optima, substrate specificity and inhibitor sensitivity using azocasein assay. Serine, cysteine and metalloproteinases active at pH 5-7 were identified. The serine proteinases were found to predominate and some of them were found to be specific for the larval stage of the parasite. The results from the substrate analysis indicated the presence of collagenolytic and elastolytic activities. The proteinase activity was inhibited by IgG isolated from T. spiralis-infected mice, an observation of relevance to understanding host/parasite interactions and, ultimately, the development of anti-Trichinella vaccine. 相似文献
16.
昆虫病原线虫共生菌在农业及医药领域已成为一种重要的生物活性资源。本研究通过致死的昆虫血腔和侵染期线虫直接分离线虫Heterorhabditis beicherriana的共生细菌,根据形态学特征、生理生化特性及16S rDNA序列初步鉴定为Photorhabdus luminescens,系统发育分析显示为发光杆菌属新亚种菌株。采用共生菌细菌体稀释液注射接种进行致病性测定,结果显示,每头大蜡螟幼虫接种菌量为600 cfu/mL,72 h时死亡率达到100%;24 h时LC50为213.13 cfu/mL,48 h时LC50为46.87 cfu/mL。这为研究该线虫H.beicherriana的致病机制奠定基础,以期发掘新的具有重要价值的活性资源。 相似文献
17.
Molecular identification methods are widely used for the classification of organisms worldwide. Entomopathogenic nematodes
are the most often isolated insect parasitic nematodes in the tropical and subtropical regions. In our investigation, PCR-RFLP
(Polymerase Chain Reaction — Restriction Fragment Length Polymorphism) of the ITS region (Internal Transcribed Spacer) on
the ribosomal (r) DNA of three entomopathogenic nematodes isolated from Ankara, Turkey, was analyzed for identification. The
ITS region of rDNA was amplified by PCR and then digested with the following nine restriction enzymes: Alu I, Dde I, Hae III,
Hha I, Hind III, Hinf I, Hpa II, Rsa I and Sau 3AI. The amplified and restricted sequences of the ITS regions were separated
by agarose gel electrophoresis and the RFLP patterns of these three species were shown in this study. According to our results,
these species were identified asSteinernema feltiae, Steinernema carpocapsae andHeterorhabditis bacteriophora.
http://www.phytoparasitica.org posting Nov. 4, 2005. 相似文献
18.
Accumulation and metabolism of the organophosphate pesticide, phorate by the free-living nematode Panagrellus redivivus was studied under anaerobic conditions and in the presence of carbon monoxide or SKF 525A, and compared with results obtained under normal, aerobic conditions and using heat-killed nematodes. Both phorate hydrolysis and side-chain oxidation were inhibited under anaerobic conditions and with heat-killed nematodes, but only hydrolysis was affected in the presence of carbon monoxide. The much greater phorate accumulation in the nematodes under anaerobic conditions and with carbon monoxide could be explained by this metabolic inhibition. SKF 525A had no significant effect on phorate metabolism or accumulation. The possible mechanisms involved in phorate breakdown by P. redivivus are discussed. 相似文献
19.
南方根结线虫促分裂原活化蛋白激酶(MAPK)基因的RNAi效应分析 总被引:3,自引:0,他引:3
促分裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)在线虫的生长发育等方面具有重要作用,本研究探索利用RNAi技术沉默南方根结线虫mapk-1基因来抑制线虫的生长发育。根据mapk-1基因的cDNA序列设计引物,通过体外转录合成约550bp的dsRNA对南方根结线虫的卵进行RNAi以沉默mapk-1基因。试验结果表明,将南方根结线虫的卵块浸泡在含有2mg/mL dsRNA的M9缓冲溶液中,24h后卵块孵化出的2龄幼虫数量明显多于对照组(无dsRNA),但孵化出的幼虫死亡率高达90%,而对照组的死亡率低于5%,说明mapk-1基因的沉默抑制了卵块的孵化和线虫的生长,同时将孵化的幼虫接种番茄,14d后番茄根部无根结产生,35d后无卵块产生;而浸泡72h后卵块孵化出的2龄幼虫几乎全部死亡,并且孵化的线虫数量明显少于对照。提取导入dsRNA的卵块的RNA进行半定量PCR分析,结果表明mapk-1基因的mRNA被降解。 相似文献
20.
The pine sawyer beetle Monochamus galloprovincialis (Olivier) (Coleoptera Cerambycidae) gained importance as a pest in Europe after the introduction in Portugal of the pine wood nematode Bursaphelenchus xylophilus, the agent of pine wilt disease. As the nematode is transmitted by the adult beetles during both maturation feeding and oviposition, effective methods of monitoring of the longhorn beetle populations are needed for the surveillance of the disease spread in Europe. Although in the last years many studies focused on the efficacy of different trapping methods, the general results are still controversial. In this study, we compared the efficiency of two trap types, cross-vane and multi-funnel, and two attractive blends, a kairomonal lure (??-pinene, ipsenol and methyl-butenol) and a commercial kit specific for M. galloprovincialis (pheromone plus kairomonal lure), in order to identify the trap/blend combination more appropriate for the surveillance of the M. galloprovincialis populations. Moreover, the trap efficiency was tested also in a pine stand colonized by M. galloprovincialis after a hailstorm and in a control stand. The results showed that the multi-funnel traps baited with the specific commercial kit was the most effective combination. Interestingly, trap catch was similar in the two pine stands, despite a different density of the target species. As the trapping method was effective also at low population density of M. galloprovincialis, it may be adopted as a general tool for beetle surveillance in the forest and at ports of entry. 相似文献