BioControl (2000) 45, 483-500

O. Strauch, I. Niemann, A. Neumann, A.J. Schmidt, A. Peters and R.-U. Ehlers (2000)
Storage and formulation of the entomopathogenic nematodes Heterorhabditis indica and H. bacteriophora
BioControl 45 (4), 483-500
Abstract: Successful control of insect pests through the application of entomopathogenic nematode dauerjuveniles of H. bacteriophora and H. indica can only be achieved when the nematode material reaches the end user in good condition. Storage and formulation techniques must provide optimum conditions to guarantee a maximum survival and infectivity of the nematodes. Nematode survival was tested at temperatures ranging between 5-25 °C. A maximum survival of H. indica was achieved at 15 °C and the highest mortality at 5 °C. H. bacteriophora survived best at 7.5 °Cand least at 25 °C. An increase of the salt concentration had positive effects on dauer juvenile survival in aqueous suspensions. Low pH between 6 and 4 reduced the bacterial growth and prolonged survival of stored dauer juveniles. Of the organic acids ascorbic, benzoic, citric and sorbic acid, onlyascorbic acid had a positive effect on H. indica survival. Extracts of the dried spice plants cinnamon,c loves, rosemary and oregano were tested. Enhancementof H. indica survival was recorded for cinnamon and cloves. Survival and infectivity of nematodes stored in attapulgite and bentonite clays and sponge were recorded over several weeks at different storage temperatures. Infectivity was not influenced by the different formulation materials. When stored in sponge at 25 °C nematodes survived less than 1 week and the formulation in clay could only prolong this period for another week. At 5 °C the survival of H. bacteriophora in sponge was superior to that in clay, whereas H. indica survived less well in sponge than in clay at 15 °C. Storage in aerated water at 5 °C for H. bacteriophora and at 15 °C for H. indica resulted in the lowest mortality. For storage at controlled conditions (temperature, pH and osmolarity), aerated water is superior to all other methods tested and the addition of preservatives will increase survival.
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Link to article at publishers website
Database assignments for author(s): Arne Peters, Ralf-Udo Ehlers

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
formulation/storage of bioagents

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Heterorhabditis indica/Photorhabdus (entomopathogen)
Heterorhabditis bacteriophora/Photorhabdus (entomopathogen)