entomopathogenic fungi

yabatta's picture

Biocontrol of Almond Bark Beetle (Scolytus Amygdali Geurin-Meneville, Coleoptera: ‎Scolytidae) Using Beauveria Bassiana (Bals.) Vuill. (Deuteromycotina: ‎Hyphomycetes)‎

Journal Title, Volume, Page: 
Journal of Applied Microbiology, 103: 1406-1414.
Year of Publication: 
Batta, Y. A.
Laboratory of Plant Protection, Department of Plant Production and Protection, Faculty of Agriculture, An-Najah National University, Palestine
Current Affiliation: 
Department of Plant Production and Protection,Faculty of Agriculture and Veterinary Medicine, An Najah National University, Nablus, Palestine
Preferred Abstract (Original): 

To formulate the entomopathogenic fungus Beauveria bassiana in invert emulsion, then apply it against adults of almond bark beetle (Scolytus amygdali) under laboratory and field conditions.

Methods and Results
The effect of formulated B. bassiana in invert emulsion against S. amygdali adults was shown by comparing the mortality percentage of adults exposed to the formulated fungus using a Petri dish treatment method and by field applications to infested peach trees with mortality of adults exposed to the unformulated fungus or the untreated control. Results obtained from both exposure methods have indicated that treatment of S. amygdali adults with the formulated fungus resulted in a significantly higher mean mortality percentage (P < 0.05) when compared with the treatment with the unformulated fungus or the untreated control. This mortality ranged from 81.2 to 100%, 10 days after treatment with the formulated fungus when compared with 6.7 to 49.6% mortality, 10 days after treatment with the control or the unformulated fungus, respectively. Viability of the fungus conidia in invert emulsion was assessed by calculating the germination percentage of the conidia over time. Results indicated a high storage stability shown by a small loss of germination percentage for the formulated conidia of both strains (5.8 to 8.4% over a 12-week period) vs a low storage stability shown by a high loss of germination percentage for the unformulated conidia of the same strains (58.9 to 61.0% over the same period). The presence of B. bassiana in the galleries of beetles following the treatment of infested trees was shown in the present research.

The results obtained have demonstrated a significantly higher level of efficacy of formulated B. bassiana in invert emulsion against S. amygdali adults under laboratory and field conditions. The ingredients of invert emulsion used in the formulation of the fungus had a negligible effect on the viability of formulated conidia when compared with the unformulated.

Significance And Impact Of The Study
Results obtained in the present research are promising and may be exploited commercially to control S. amygdali adults on various species of stone fruit trees, especially peach trees. This type of biocontrol of this insect may be used as an alternative means to chemical control for management of the insect. No adverse environmental impacts of the fungus or its formulation have been observed during application.

MSShtayeh's picture

Distribution, Occurrence And Characterization of Entomopathogenic Fungi In Agricultural Soil In The Palestinian Area

Journal Title, Volume, Page: 
Mycopathologia 156: 235–244, 2002
Year of Publication: 
Mohammed S. Ali-Shtayeh
Department of Biological Sciences, An-Najah National University, Nablus, P. O. Box 7, Palestine
Current Affiliation: 
Department of Biology, Faculty of Science, An-Najah National University, Nablus. Palestine
Abdel-Basit B.M. Marai
Department of Biology, An-Najah University, Nablus
Rana M. Jamous
Biodiversity and Environmental Research Center (BERC), Til Village, Palestine
Preferred Abstract (Original): 

The occurrence of entomopathogenic fungi was investigated in irrigated vegetable fields and citrus orchards soils, over a nine-month period (April-December 1999), using the Galleria bait method (GBM). Entomopathogenic fungi were found to occur in 33.6% of the soil samples studied, with positive samples yielding 70 fungal isolates, belonging to 20 species from 13 genera. Conidiobolus coronatus was the most frequent and abundant entomopathogenic species recovered, comprising 31.4% of the total number of isolates. Soil pH, soil moisture content and the geographical location had minor or no effect on the isolation of entomopathogenic fungi in the fields studied. On the other hand, organic matter content of soil, and vegetation type were found to significantly affect the occurrence of entomopathogenic fungi in soil habitats, with orchard fields yielding larger numbers of isolates than vegetable fields. Using Koch’s postulates the pathogenicity of fungal isolates to Galleria larvae was found to range from 16–100% (mortality rate). Isolates of C. coronatus proved to be the most virulent isolates recovered. The effect of media and temperature on mycelial growth rate, conidial production and conidial germination of six entomopathogenic fungal species (C. coronatus, Entomophaga grylli, Erynia castrans, Hirsutella jonesii, Paecilomyces farinosus and Sporodiniella umbellata) was also studied.Mycelial growth rate, spore production and spore germination were significantly affected by media, temperature and isolates. In view of the present results, C. coronatus appears to be a good candidate for pest control in agricultural soils, as it has a wide tolerance to agricultural practices, has frequently been isolated from both vegetable and orchard fields, and is characterized by high mycelial growth rate, conidial production and conidial germination.

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