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

Økologisk dyrkning fremmer den naturlige regulering af skadedyr

Naturlige svampesygdomme, som hjælper med til at regulere skadedyr i grønsager, er hyppigere i økologiske dyrkningssystemer sammenlignet med konventionelle. Samtidig er der færre overvintrende kålfluepupper. Det viser de foreløbige resultater fra den første dyrkningssæson i FØJO III-projektet VegQure

Diversitet af insekternes svampesygdomme i økologisk jordbrug - hvorledes kan den øges?

Det er et vigtigt mål i økologisk jordbrug at inddrage skadedyrenes naturlige fjender i reguleringen af skadedyrpopulationer. En vigtig gruppe af disse fjender er insekternes naturligt forekommende svampesygdomme, som blandt andet findes i jorden. Danske studier viser, at landbrugslandet rummer en stor diversitet af disse svampe, og det er en fremtidig udfordring at udnytte denne diversitet i regulering af skadedyrspopulationer

Entomopathogenic fungi infecting non-pest insects: Implications for ecosystem services and relevance of behavioural ecology

Entomopathogenic fungi infect a wide array of insects from most orders and they are among the natural enemies that contribute to the regulation of insect populations. However, only a limited number of studies have focused on the impact of fungal pathogens on populations of non-pest insects. Effects of entomopathogenic fungi on non-pest host populations should receive more attention based on the increasing interest in conservation biological control. In this strategy, founded on competition theory, non-pest host populations adjacent to cropping systems will in principle affect pest populations through shared natural enemies. We present examples of selected non-pest host-fungus systems from temperate ecosystems that are relevant for the expected ecosystem service provided by entomopathogenic fungi. Predators are among the non-pest hosts that are infected by fungi. Recent advances in our understanding of the effect of pathogens on the behaviour of predators may shed light on the significance of entomopathogenic fungi for the regulation of predator populations. We discuss what we can learn about host-pathogen interactions from behavioural ecology and which life history parameters in the host that may be important for the impacts of fungal pathogens on their host populations

Status og nye udfordringer: Biologisk bekæmpelse af skadedyr

Biologisk bekæmpelse var en succes, da det blev introduceret første gang i 1880'erne i Californien. I artiklen defineres forskellige strategier og vi gør status over den faktiske brug af biologisk bekæmpelse, både i Danmark og globalt. Der er fortsat et stort potentiale for biologisk bekæmpelse, og metoden er mere aktuel end nogensinde. Der er dog fortsat behov for at vide mere om organismerne og deres samspil med andre arter og deres omgivelser

Molecular diversity of the Metarhizium anisopliae lineage in an agricultural field

Entomopathogenic fungal isolates identified by morphology as Metarhizium anisopliae may belong to different species when identified by molecular characters. We isolated Metarhizium spp. from an experimental agricultural field under both conventional and organic farming regimes using Tenebrio molitor as bait insect to assess the molecular diversity within the soil. Isolates were analyzed using DNA sequencing and applying SSR markers. Within the former M. anisopliae lineage, we found M. brunneum (86.3%), M. robertsii (11.3%) and M. majus (3.4%) in the soil samples. Several genotypes of each species were identified based on SSR markers. Differences in abundance of the species and their genotypes suggest different adaptations to the soil environment of the agricultural field. There were no effects of conventinal or organic farming regimes on diversity of the fungi

Statistical modelling of conidial discharge of entomophthoralean fungi using a newly discovered Pandora species

Entomophthoralean fungi are insect pathogenic fungi and are characterized by their active discharge of infective conidia that infect insects. Our aim was to study the effects of temperature on the discharge and to characterize the variation in the associated temporal pattern of a newly discovered Pandora species with focus on peak location and shape of the discharge. Mycelia were incubated at various temperatures in darkness, and conidial discharge was measured over time. We used a novel modification of a statistical model (pavpop), that simultaneously estimates phase and amplitude effects, into a setting of generalized linear models. This model is used to test hypotheses of peak location and discharge of conidia. The statistical analysis showed that high temperature leads to an early and fast decreasing peak, whereas there were no significant differences in total number of discharged conidia. Using the proposed model we also quantified the biological variation in the timing of the peak location at a fixed temperature.Comment: 23 pages including supplementary materia

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

<i>Ascosphaera callicarpa</i>, a new species of bee-loving fungus, with a key to the Genus for Europe.

We studied the bee specialist fungus Ascosphaera in wild solitary bees to investigate the diversity of the genus in nature and the ecology of these fungi with their bee hosts. A new morphologically distinctive species was discovered which also has a unique nrITS sequence. This new species, here named Ascosphaera callicarpa, is common on the larval feces of the solitary bee Chelostoma florisomne which nests in the Phragmites reeds of thatched roofs in Europe. Because collections of Ascosphaera from wild bees are scarce and because little is known about the ecology and distribution of the majority of the species in the genus, a key to the species thus far reported for Europe is included