Insect pathogenic fungi in biological control: status and future challenges

In Europe, insect pathogenic fungi have in decades played a significant role in biological control of insects. With respect to the different strategies of biological control and with respects to the different genera of insect pathogenic fungi, the success and potential vary, however. Classical biological control: no strong indication of potential. Inundation and inoculation biological control: success stories with the genera Metarhizium, Beauveria, Isaria/Paecilomyces and Lecanicillium (previously Verticillium). However, the genotypes employed seem to include a narrow spectrum of the many potentially useful genotypes. Conservation biological control: Pandora and Entomophthora have a strong potential, but also Beauveria has a potential to be explored further. The main bottleneck for further exploitation of insect pathogenic fungi in biological control is the limited knowledge of host pathogen interaction at the fungal genotype level

Hvem gavner hvem i marken?

I det dyrkede land ønsker vi en høj produktion af sunde fødevarer samtidig med, at økosystemets biologiske mangfoldighed er så høj som muligt. Naturlige fjender er med til at holde skadedyrene nede uden brug af pesticider. Men når nogle svampearter angriber de nyttige insekter som rovinsekterne og bierne, kan det indirekte hæmme fødevareproduktionen

Virulence of mixed fungal infections in honey bee brood

<p>Abstract</p> <p>Introduction</p> <p>Honey bees, <it>Apis mellifera</it>, have a diverse community of pathogens. Previous research has mostly focused on bacterial brood diseases of high virulence, but milder diseases caused by fungal pathogens have recently attracted more attention. This interest has been triggered by partial evidence that co-infection with multiple pathogens has the potential to accelerate honey bee mortality. In the present study we tested whether co-infection with closely related fungal brood-pathogen species that are either specialists or non-specialist results in higher host mortality than infections with a single specialist. We used a specially designed laboratory assay to expose honey bee larvae to controlled infections with spores of three <it>Ascosphaera </it>species: <it>A. apis</it>, the specialist pathogen that causes chalkbrood disease in honey bees, <it>A. proliperda</it>, a specialist pathogen that causes chalkbrood disease in solitary bees, and <it>A. atra</it>, a saprophytic fungus growing typically on pollen brood-provision masses of solitary bees.</p> <p>Results</p> <p>We show for the first time that single infection with a pollen fungus <it>A. atra </it>may induce some mortality and that co-infection with <it>A. atra </it>and <it>A. apis </it>resulted in higher mortality of honey bees compared to single infections with <it>A. apis</it>. However, similar single and mixed infections with <it>A. proliperda </it>did not increase brood mortality.</p> <p>Conclusion</p> <p>Our results show that co-infection with a closely related fungal species can either increase or have no effect on host mortality, depending on the identity of the second species. Together with other studies suggesting that multiple interacting pathogens may be contributing to worldwide honey bee health declines, our results highlight the importance of studying effects of multiple infections, even when all interacting species are not known to be specialist pathogens.</p