Biological control of Tipula paludosa (Diptera: Nematocera) using entomopathogenic nematodes (Steinernema spp.) and Bacillus thuringiensis subsp. israelensis

Oestergaard, Jesko; Belau, Christian; Strauch, Olaf; Ester, A.; Rozen, K. van; Ehlers, Ralf‐Udo

doi:10.1016/j.biocontrol.2006.07.003

Cited by 29 publications

(22 citation statements)

References 11 publications

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“…An alternative approach could be the use of biological control agents based on Bacillus thuringiensis serovar israelensis (B. thuringiensis subsp. israelensis), which is toxic to T. paludosa larvae (29,37,40).…”

mentioning

confidence: 99%

Binding of Cyt1Aa and Cry11Aa Toxins of Bacillus thuringiensis Serovar israelensis to Brush Border Membrane Vesicles of Tipula paludosa (Diptera: Nematocera) and Subsequent Pore Formation

Oestergaard

Ehlers

Martínez‐Ramírez

et al. 2007

Appl Environ Microbiol

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Bacillus thuringiensis serovar israelensis (B. thuringiensis subsp. israelensis) produces four insecticidal crystal proteins (ICPs) (Cry4A, Cry4B, Cry11A, and Cyt1A). Toxicity of recombinant B. thuringiensis subsp. israelensis strains expressing only one of the toxins was determined with first instars of Tipula paludosa (Diptera: Nematocera). Cyt1A was the most toxic protein, whereas Cry4A, Cry4B, and Cry11A were virtually nontoxic. Synergistic effects were recorded when Cry4A and/or Cry4B was combined with Cyt1A but not with Cry11A. The binding and pore formation are key steps in the mode of action of B. thuringiensis subsp. israelensis ICPs. Binding and pore-forming activity of Cry11Aa, which is the most toxic protein against mosquitoes, and Cyt1Aa to brush border membrane vesicles (BBMVs) of T. paludosa were analyzed. Solubilization of Cry11Aa resulted in two fragments, with apparent molecular masses of 32 and 36 kDa. No binding of the 36-kDa fragment to T. paludosa BBMVs was detected, whereas the 32-kDa fragment bound to T. paludosa BBMVs. Only a partial reduction of binding of this fragment was observed in competition experiments, indicating a low specificity of the binding. In contrast to results for mosquitoes, the Cyt1Aa protein bound specifically to the BBMVs of T. paludosa, suggesting an insecticidal mechanism based on a receptor-mediated action, as described for Cry proteins. Cry11Aa and Cyt1Aa toxins were both able to produce pores in T. paludosa BBMVs. Protease treatment with trypsin and proteinase K, previously reported to activate Cry11Aa and Cyt1Aa toxins, respectively, had the opposite effect. A higher efficiency in pore formation was observed when Cyt1A was proteinase K treated, while the activity of trypsin-treated Cry11Aa was reduced. Results on binding and pore formation are consistent with results on ICP toxicity and synergistic effect with Cyt1Aa in T. paludosa.

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confidence: 99%

Binding of Cyt1Aa and Cry11Aa Toxins of Bacillus thuringiensis Serovar israelensis to Brush Border Membrane Vesicles of Tipula paludosa (Diptera: Nematocera) and Subsequent Pore Formation

Oestergaard

Ehlers

Martínez‐Ramírez

et al. 2007

Appl Environ Microbiol

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“…In previous studies, applications of S. carpocapsae or H. indica have performed well against various insect pests (Yang et al 2003;Dillon et al 2006;Lacey et al 2006;Oestergaard et al 2006;Ansari et al 2008). Both S. carpocapsae and H. indica were also deemed to be promising biocontrol agents against P. striolata in laboratory screening experiments (Xu et al 2010).…”

Section: Discussionmentioning

confidence: 97%

Field evaluation of entomopathogenic nematodes for biological control of striped flea beetle, Phyllotreta striolata (Coleoptera: Chrysomelidae)

Yan

Han²,

Moens

et al. 2012

BioControl

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The striped flea beetle, Phyllotreta striolata (F.) (Coleoptera: Chrysomelidae) is a key pest of crucifer vegetables in Southern China. The use of entomopathogenic nematodes (EPNs) within an integrated pest management approach may offer an effective and environmentally safe strategy to suppress outbreaks of this pest. In the present study, the efficacy of Steinernema carpocapsae All and Heterorhabditis indica LN2 for the control of P. striolata in the field was evaluated, as well as the combined application of EPNs and azadirachtin against the pest. Both nematode species were capable of reducing populations of the soil-dwelling stages of P. striolata, thus leading to a reduction of the adult populations and the associated shot-hole damage on the leaves. Nematode treatments also increased cabbage yields as compared to the control and azadirachtin treatments alone. Azadirachtin alone was not effective to prevent damage by P. striolata, but it could enhance the control effect of S. carpocapsae shortly after application. Osmotically treated infective juveniles (IJs) of S. carpocapsae All performed as well as untreated IJs.

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“…However, the choice of prophylaxis for an autumn treatment was pragmatic on two counts. First, the October treatments used by Oestergaard et al (2006) were at a larval stage when detection and enumeration is difficult, even for experts. There is also evidence from modelling of management options for leatherjackets using conventional insecticides that the difference in economic returns for rational versus prophylactic early autumn treatments is slight, leaving little margin to pay for monitoring ( Blackshaw, 1985 ).…”

Section: Discussionmentioning

confidence: 99%

“…The maximum mortalities achieved in recent field trials were 80% in the autumn and 40% in the spring irrespective of the agent ( Oestergaard et al , 2006 ). These values are used in the simulations.…”

Section: Model Assumptionsmentioning

confidence: 99%

“…Given that the effects of seed-bed preparation on population levels are known ( Blackshaw, 1988 ), together with the mortality from biological control agents ( Oestergaard et al , 2006 ), it is possible to calculate a set of break-even values (where cost of control equals the benefits derived from control) for different leatherjacket populations (62 500, 125 000, 250 000, 500 000, 1 000 000, and 2 000 000 ha -1 ) in grass before cultivation over a range of values for application costs and barley. This was performed for additional cultivation in the spring before crop establishment, and biological control applications in the autumn and spring.…”

Section: Economic Thresholds For Biological Control and Additional Cumentioning

confidence: 99%

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A comparison of management options for leatherjacket populations in organic crop rotations using mathematical models

Blackshaw

2009

Agri and Forest Entomology

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1 Pest management in organic systems is challenged by the paucity of options for direct interventions to control damaging populations compared with conventional agriculture. Consequently, a greater emphasis has to be placed on managing pest numbers through a rotation. In the present study, simulation modelling is used to evaluate the effects of different management options on populations of Tipula paludosa (leatherjackets) in organic rotations. 2 The growth of leatherjacket populations in grass was simulated over 5 years for different starting numbers. A significant risk of leatherjacket attack to subsequent crops can be avoided by limiting the fertility building phase of a rotation to a maximum of 2 years. 3 The effect of cultural control through additional cultivation interventions was compared in rotations comprising a grass/clover fertility building phase with host and/or nonhost crops. It is concluded that the effects are marginal and that prophylactic use cannot be recommended. 4 The prophylactic use of biological control agents in permanent grass and grass/ arable rotations was investigated. Maximum population reductions in grass were achieved through annual autumn applications but the optimal economic strategy was less frequent than this. Application in the autumn preceding a spring-sown arable crop provided the best risk reduction. 5 A model decision support system for the control of pests in organic systems using data for leatherjacket damage to spring barley is presented. Economic threshold concepts are used to define when cultural control (as additional cultivation) and biocontrol applications should be used. 6 The present study shows the potential benefits of simulation modelling for the rapid evaluation of a wide range of pest management options. Any conclusions drawn from such simulations, however, are provisional until they can be tested experimentally.

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Biological control of Tipula paludosa (Diptera: Nematocera) using entomopathogenic nematodes (Steinernema spp.) and Bacillus thuringiensis subsp. israelensis

Cited by 29 publications

References 11 publications

Binding of Cyt1Aa and Cry11Aa Toxins of Bacillus thuringiensis Serovar israelensis to Brush Border Membrane Vesicles of Tipula paludosa (Diptera: Nematocera) and Subsequent Pore Formation

Binding of Cyt1Aa and Cry11Aa Toxins of Bacillus thuringiensis Serovar israelensis to Brush Border Membrane Vesicles of Tipula paludosa (Diptera: Nematocera) and Subsequent Pore Formation

Field evaluation of entomopathogenic nematodes for biological control of striped flea beetle, Phyllotreta striolata (Coleoptera: Chrysomelidae)

A comparison of management options for leatherjacket populations in organic crop rotations using mathematical models

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