CONTROL OF SPRUCE BUDMOTH, ZEIRAPHERA CANADENSIS MUT. AND FREE., IN WHITE SPRUCE PLANTATIONS WITH ENTOMOPATHOGENIC NEMATODES, STEINERNEMA SPP.

1991 ◽  
Vol 123 (2) ◽  
pp. 379-385 ◽  
Author(s):  
D.C. Eidt ◽  
Gary B. Dunphy

AbstractA spruce budmoth population reduction of 82%, as measured by moth emergence, was realized after a foliar spray in which Futura®, a commercial Bacillus thuringiensis Berliner (B.t.) formulation, was added to a suspension of Steinernema carpocapsae (Weiser). The nematode suspension, which took advantage of the wetting and spreading agents in the formulation, was applied to runoff at the rate of 9785 viable infective juvenile nematodes per litre. Mortality was attributed to the nematodes; B.t. was not available to the cryptic larvae. Soil drench treatments were encouraging, and suggested that applications of nematodes to the soil may be feasible.

Parasitology ◽  
1996 ◽  
Vol 113 (5) ◽  
pp. 483-489 ◽  
Author(s):  
E. Grenier ◽  
E. Bonifassi ◽  
P. Abad ◽  
C. Laumond

SUMMARYThree satellite DNAs previously isolated from the entomopathogenic nematodes Steinernema carpocapsae, Heterorhabditis bacteriophora and Heterorhabditis indicus give hybridization signals only with the S. carpocapsae, H. bacteriophora and H. indicus populations tested, indicating that these satellite sequences are species-specific. Because of their reiteration and their variabilities, we have shown that these sequences are able to discriminate at the interspecific level between the Steinernema and Heterorhabditis species, but also at the intraspecific level between S. carpocapsae strains. Furthermore, in simple squashed nematode experiments, we are able to unambiguously identify S. carpocapsae, H. bacteriophora and H. indicus populations. This last procedure is effective even on a single infective juvenile, with the main advantage that it avoids time-consuming DNA extractions.


Parasitology ◽  
1995 ◽  
Vol 110 (5) ◽  
pp. 583-590 ◽  
Author(s):  
E. E. Lewis ◽  
S. Selvan ◽  
J. F. Campbell ◽  
R. Gaugler

SUMMARYStudies of foraging strategies are often complicated by competing goals of the forager. In contrast, non-feeding infective juvenile entomopathogenic nematodes forage exclusively for a single host. Two questions were posed: (1) what is the relationship between metabolic rate, energy reserves and foraging strategy and (2) when a foraging strategy fails, will an infective-stage parasite switch strategies? Three species of entomopathogenic nematodes were stored in water and changes in their behaviour, metabolic rate, energy reserves, and infectivity were measured throughout the storage period. Steinernema carpocapsae ambushes insect hosts, whereas S. glaseri and Heterorhabditis bacteriophora cruise forage. Steinernema carpocapsae was least active and had the lowest metabolic rate. Heterorhabditis bacteriophora was more active and had the highest metabolic rate. Steinernema glaseri was most active and had an intermediate metabolic rate. Neither cruising species changed foraging strategy. Steinernema carpocapsae decreased nictation (a behaviour associated with ambushing only) and increased their locomotory rate. Any change in searching strategy occurred without assessment of the profitability or distribution of potential hosts, but the advantage this confers is unknown.


Author(s):  
Mariyono Mariyono ◽  
Eko Yuliarsha Sidhi ◽  
Nugraheni Hadiyanti

The utilization of entomopathogenic nematodes is an example of the uses of an environmentally friendly biological agent. Entomopathogenic nematodes of the family Steinernematidae and Hetrorhabditidae are very potential to control insect pests. The purpose of this study was to study the pathogenicity of the entomopathogenic nematode Steinernema carpocapsae (all strains) as a biological control against Plutella xylostella. This research includes 2 stages, namely the preparation stage and laboratory experiments. The experimental design in this study was a completely randomized design (CRD) consisting of six treatments and three replications. The treatments tested were entomopathogenic nematode concentrations consisting of six levels: 0, 8, 16, 32, 64 and 128 infective juvenile per ml. The LC50 and LT50 values were calculated using Probit analysis. The results of observations of nematodes that enter the insect body and pest mortality were analyzed using analysis of variance (ANOVA), once showing a significant difference, it was then continued to the DMRT test at 5% level. Based on the results of the study, the highest pathogenicity against Plutella xylostella was Steinernema carpocapsae (all strains) when compared to Steinernema glaseri (NC) and Steinernema sp. local isolates. Resistance to Steinernema carpocapsae (all strains) and the LC50 value were determined by the age of Plutella xylostella larvae. The bigger and older the larvae, the more its resistance to Steinernema carpocapsae (All strains) and the LC50 value. The number of entomopathogenic nematodes that enter the body of Plutella xylostella increased with increasing length of contact time.Penggunaan nematoda entomopatogen merupakan salah satu pemanfaatan agensia hayati yang ramah lingkungan. Nematoda entomopatogen dari famili Steinernematidae dan Hetrorhabditidae sangat potensial untuk mengendalikan serangga hama. Tujuan dari penelitian ini adalah mempelajari patogenisitas nematoda entomopatogen Steinernema carpocapsae (all strain) sebagai pengendali hayati terhadap hama Plutella xylostella. Penelitian ini meliputi 2 tahap yaitu tahap persiapan dan percobaan laboratorium. Rancangan percobaan pada penelitian ini adalah Rancangan Acak Lengkap (RAL) yang terdiri enam perlakuan dan tiga ulangan. Perlakuan yang diujikan adalah konsentrasi nematoda entomopatogen yang terdiri enam taraf: 0, 8, 16, 32, 64 dan 128 infektif juvenile/ml. Nilai LC50 dan LT50 dihitung menggunakan analisis probit. Hasil pengamatan nematoda yang masuk dalam tubuh serangga dan mortalitas hama dianalisis menggunakan analisis sidik ragam (ANOVA), apabila menunjukkan beda nyata dilanjutkan uji DMRT taraf 5%. Berdasarkan hasil penelitian, patogenisitas tertinggi terhadap Plutella xylostella adalah Steinernema carpocapsae (all strain) bila dibandingkan dengan Steinernema glaseri (NC) dan Steinernema sp. isolat lokal. Ketahanan terhadap Steinernema carpocapsae (All strain) dan nilai LC50 ditentukan umur larva Plutella xylostella. Semakin besar dan tua umur larva, ketahanan terhadap Steinernema carpocapsae (All strain) dan nilai LC50 juga semakin meningkat. Jumlah nematoda entomopatogen yang masuk kedalam tubuh Plutella xylostella semakin banyak seiring dengan bertambah lamanya waktu kontak.


Author(s):  
Maguintontz Cedney Jean-Baptiste ◽  
Andressa Lima de Brida ◽  
Daniel Bernardi ◽  
Sérgio da Costa Dias ◽  
Juliano de Bastos Pazini ◽  
...  

Abstract The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is among the main pests of fruit crops worldwide. Biological control using entomopathogenic nematodes (EPNs) may be an alternative to suppress populations of this pest. Thus, the aim of this study was to evaluate the pathogenicity and virulence of six EPN isolates (Heterorhabditis bacteriophora HB, H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47, and S. brazilense IBCB-n06) against C. capitata pupae. The compatibility of EPNs with different chemical insecticides that are registered for management of C. capitata was also assessed. Isolates of H. bacteriophora HB and S. brazilense IBCB-n06 at a concentration of 1,000 infective juveniles (IJ)/ml proved to be most pathogenic to C. capitata (70 and 80% mortality, respectively). In contrast, the isolates H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47 provided pupal mortality of less than 60%. Bioassays to determine lethal concentrations indicated that concentrations of 600 IJ/ml (H. bacteriophora HB) and 1,000 IJ/ml (S. brazilense IBCB-n06) showed the highest virulence against C. capitata pupae. In contrast, the highest numbers of IJs emerged at concentrations of 1,200 and 200 IJ/ml. In compatibility bioassays, malathion, spinetoram, phosmet, acetamiprid, and novaluron were considered compatible with and harmless (Class 1) to H. bacteriophora HB and S. brazilense IBCB-n06, according to IOBC/WPRS. This information is important for implementing integrated management programs for C. capitata, using biological control with EPNs, whether alone or in combination with chemical insecticides.


2007 ◽  
Vol 73 (20) ◽  
pp. 6577-6583 ◽  
Author(s):  
Josyanne Lamarche ◽  
Richard C. Hamelin

ABSTRACT Nitrogen fixation is one of the most important roles played by soil bacterial communities, as fixation supplies nitrogen to many ecosystems which are often N limited. As impacts on this functional group of bacteria might harm the ecosystem's health and reduce productivity, monitoring that particular group is important. Recently, a field trial with Bt white spruce, which constitutively expresses the Cry1Ab insecticidal toxin of Bacillus thuringiensis, was established. The Bt white spruce was shown to be resistant to spruce budworm. We investigated the possible impact of these genetically modified trees on soil nitrogen-fixing bacterial communities. The trial consisted of untransformed controls, GUS white spruce (transformed with the β-glucuronidase gene), and Bt/GUS white spruce (which constitutively expresses both the Cry1Ab toxin and β-glucuronidase) in a random design. Four years after planting, soil samples from the control and the two treatments from plantation as well as from two natural stands of white spruce were collected. Diazotroph diversity was assessed by extracting soil genomic DNA and amplifying a region of the nitrogenase reductase (nifH) gene, followed by cloning and sequencing. Analysis revealed that nitrogen-fixing communities did not differ significantly among the untransformed control, GUS white spruce, and Bt/GUS white spruce. Nevertheless, differences in diazotroph diversity were observed between white spruce trees from the plantation site and those from two natural stands, one of which grew only a few meters away from the plantation. We therefore conclude, in the absence of evidence that the presence of the B. thuringiensis cry1Ab gene had an effect on diazotroph communities, that either site and/or field preparation prior to planting seems to be more important in determining diazotroph community structure than the presence of Bt white spruce.


1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.


2008 ◽  
Vol 65 (4) ◽  
pp. 433-437 ◽  
Author(s):  
Juan Carlos Lara ◽  
Cláudia Dolinski ◽  
Elias Fernandes de Sousa ◽  
Rogério Figueiredo Daher

Entomopathogenic nematodes (EPNs) are currently being used as successful biological control agents of soil-dwelling insect pests. Previous field and greenhouse studies demonstrated that application techniques and non-biotic factors (temperature and pressure) have a significant effect on EPNs efficacy. The objective of this study was to evaluate the influence of an irrigation spray application system on the viability, infectivity and host search capability of Heterorhabditis baujardi LPP7 (Nematoda: Heterorhabditidae) infective juveniles (IJ). Two assays were proposed. Their viability was evaluated under the microscope after the IJ passed through the irrigation system. Infectivity on Galleria mellonella larvae, and host search capability, as evidenced by larval mortality, were evaluated in containers (Experiment 1). In the field (Experiment 2), mortality of G. mellonella larvae was evaluated under different nematode concentrations (0, 100,000, 300,000 and 500,000 IJ per tree). No differences were recorded on the viability, infectivity and host search capability of the IJ in Experiment 1. In Experiment 2, differences were recorded among the different concentrations used (p < 0.05), and a higher mortality was observed at the highest nematode concentration (28.3% and 37% in each one of the two experiment repetitions). This irrigation system did not affected adversely the viability, infectivity and host search capability of H. baujardi LPP7.


2004 ◽  
Vol 22 (4) ◽  
pp. 197-201
Author(s):  
Jonathan D. Sammons ◽  
Daniel K. Struve

Abstract Biostimulants are used to reduce the stress associated with non-dormant (summer dug) harvest of field-grown nursery stock; however, the effectiveness of biostimulant treatment is uncertain. This study tested the effects of three application methods of Bioplex™ (a commonly used biostimulant) to container-grown red oak seedlings on whole plant transpirational water use and growth before and after root pruning. Root pruning was used to simulate field harvest; it removed 59% of the seedling's total root surface area. Bioplex™ application by foliar spray, soil drench or a combination of foliar spray and soil drench, significantly reduced whole plant transpirational water use by 15% for three days after application, relative to untreated control seedlings. Root pruning significantly reduced whole plant transpiration, compared to non-root-pruned seedlings, and had a greater effect on transpiration than any Bioplex™ treatment. The previous season's Bioplex treatment had no effect on the spring growth flush following fall root pruning. Root pruning in fall significantly reduced root and total plant dry weights the following spring. Although Bioplex™ applications significantly reduced transpiration for three days after application, there does not seem to be any long-term beneficial effect when used to mediate summer digging transplant stress.


Nematology ◽  
2003 ◽  
Vol 5 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Dammini Premachandra ◽  
Christian Borgemeister ◽  
Oliver Berndt ◽  
Ralf-Udo Ehlers ◽  
Hans-Michael Poehling

Abstract The efficacy of entomopathogenic nematodes (EPN) was evaluated in a laboratory trial against soil-dwelling stages, late second instar larvae and pupal stages of western flower thrips (WFT), Frankliniella occidentalis Pergande. Among the six EPN strains assessed for the first time, Steinernema feltiae (Nemaplus®) and Heterorhabditis bacteriophora (HD01) caused 65 and 59% mortality, respectively. Steinernema carpocapsae (Agriotos) and S. arenarium (Anomali) caused moderate mortality (40-45%) while Steinernema spp. (Morocco) and H. bacteriophora (Nematop®) had little effect. In a dose response study with concentrations of 100, 400 and 800 infective juveniles (IJ) per cm2 soil of H. bacteriophora (HK3), S. feltiae (Nemaplus®) and H. bacteriophora (HD01), mortality increased only up to 400 IJ cm-2. The rate of infectivity of H. bacteriophora (HK3) and S. feltiae (Nemaplus®) indicated that both strains could survive at least 6 days in the soil and infect WFT immature stages.


2012 ◽  
Vol 105 (3) ◽  
pp. 994-1005 ◽  
Author(s):  
Aaron J. Gassmann ◽  
Eugene R. Hannon ◽  
Mark S. Sisterson ◽  
S. Patricia Stock ◽  
Yves Carrière ◽  
...  

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