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Bensaci O A, Lombarkia N, Laib D E, Initial evaluation of endophytic fungi, isolated from Nerium oleander L. for their biocontrol action against the bruchid Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae) in Algeria.

In book: Endophytes for plant protection: the state of the art, Chapter: Bensaci O A, Lombarkia N, Laib D E, Initial evaluation of endophytic fungi, isolated from Nerium oleander L. for their biocontrol action against the bruchid Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae) in Algeria., Publisher: Deutsche Phytomedizinische Gesellschaft, Braunschweig, Editors: Schneider C, Leifert C, Feldmann F, pp.162-167

ABSTRACT Insecticid activity of two endophytic fungal filtrates, isolated from leaves of oleander Nerium oleander (Apocynaceae: Gentianales) was experimentally demonstrated against the bean weevil Acanthoscelides obtectus, a serious harmful pest of beans and broad beans in Algeria. The filtrates (stock solutions) from Wickerham medium-cultivated colonies of Paecilomyces sp. and Cladosporium sp. showed variable insecticidal activities against the target insect, with an average mortality of 68% and 84% obtained with filtrates of Paecilomyces sp. and Cladosporium sp., respectively. The mortality of insects is proportionally positive with filtrate concentrations for Cladosporium sp. but it is not the case for Paecilomyces sp. The proteolytic activity is positively related to radial growth for both mycotaxons, however, for the chitinolytic activity, Cladosporium sp. exhibits an incompatibility with biomass, which implies high energy expenditure and disqualifies him to metabolize chitinous polymers, unlike Paecilomyces sp. proven his chitinolytic ability.These results, and even those relating to the relationship between the proteolytic and chitinolytic activities, show that Paecilomyces sp. can be used as contact mycoinsecticide, either in the form of filtrate or propagules, while Cladosporium sp. may reflect a different biological activity rather than enzymatic.

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