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

Use and impact of point-of-care ultrasonography in general practice:a prospective observational study

Objectives To describe how general practitioners (GPs) use point-of-care ultrasonography (POCUS) and how it influences the diagnostic process and treatment of patients.Design Prospective observational study using an online questionnaire before and after POCUS.Setting Office-based general practice.Participants Twenty GPs consecutively recruited all patients examined with POCUS in 1 month.Primary and secondary outcome measures We estimated the use of POCUS through the indication for use, the frequency of use, the time consumption, the extent of modification of the examination and the findings.The influence on the diagnostic process was estimated through change in the tentative diagnoses, change in confidence, the ability to produce ultrasound images and the relationship between confidence and organs scanned or tentative diagnoses.The influence of POCUS on patient treatment was estimated through change in plan for the patient, change in patient’s treatment and the relationship between such changes and certain findings.Results The GPs included 574 patients in the study. POCUS was used in patient consultations with a median frequency of 8.6% (IQR: 4.9–12.6). Many different organs were scanned covering more than 100 different tentative diagnoses. The median time taken to perform POCUS was 5 min (IQR: 3–8). Across applications and GPs, POCUS entailed a change in diagnoses in 49.4% of patients; increased confidence in a diagnosis in 89.2% of patients; a change in the management plan for 50.9% of patients including an absolute reduction in intended referrals to secondary care from 49.2% to 25.6%; and a change in treatment for 26.5% of patients.Conclusions The clinical utilisation of POCUS was highly variable among the GPs included in this study in terms of the indication for performing POCUS, examined scanning modalities and frequency of use. Overall, using POCUS altered the GPs’ diagnostic process and clinical decision-making in nearly three out of four consultations.Trial registration number NCT03375333

Honeybees Tolerate Cyanogenic Glucosides from Clover Nectar and Flowers.

Honeybees (Apis mellifera) pollinate flowers and collect nectar from many important crops. White clover (Trifolium repens) is widely grown as a temperate forage crop, and requires honeybee pollination for seed set. In this study, using a quantitative LC-MS (Liquid Chromatography-Mass Spectrometry) assay, we show that the cyanogenic glucosides linamarin and lotaustralin are present in the leaves, sepals, petals, anthers, and nectar of T. repens. Cyanogenic glucosides are generally thought to be defense compounds, releasing toxic hydrogen cyanide upon degradation. However, increasing evidence indicates that plant secondary metabolites found in nectar may protect pollinators from disease or predators. In a laboratory survival study with chronic feeding of secondary metabolites, we show that honeybees can ingest the cyanogenic glucosides linamarin and amygdalin at naturally occurring concentrations with no ill effects, even though they have enzyme activity towards degradation of cyanogenic glucosides. This suggests that honeybees can ingest and tolerate cyanogenic glucosides from flower nectar. Honeybees retain only a portion of ingested cyanogenic glucosides. Whether they detoxify the rest using rhodanese or deposit them in the hive should be the focus of further research

Morphological and Molecular Characterization of Entomophthorales (Entomophthoromycota: Entomophthoromycotina) from Argentina

We characterized 17 insect-pathogenic entomophthoralean fungal isolates (Entomophthoromycotina: Entomophthorales) using morphological and molecular techniques. We identified four species from various insect hosts: (i) Entomophthora planchoniana, six specimens from aphids; (ii) Pandora neoaphidis, three specimens from aphids; (iii) Zoophthora phalloides from an aphid; and (iv) Z. radicans, seven specimens from insects in the orders Diptera, Hemiptera, and Lepidoptera. Analysis of ITS1 data from E. planchoniana showed clustering in accordance to aphid host species. Entomophthora planchoniana from Macrosiphum euphorbiae clustered together, separate from the isolate from Myzus persicae. The P. neoaphidis specimens clustered with sequences from other aphid-pathogenic Pandora species in GenBank. In this study, Z. phalloides from Brevicoryne brassicae and Z. radicans from an unidentified species of Chironomidae (Diptera) in Argentina were characterized for the first time. The present study was initiated to elucidate the taxonomy of the entomophthoralean fungi in Argentina according to their morphological and molecular characters. The presented results emphasize the significance of the combination of molecular data and information on morphology, ecology, and host range for accurate identification of entomophthoralean and allied genera.Centro de Estudios Parasitológicos y de VectoresCentro de Investigaciones en Fitopatologí

The distribution of Aspergillus spp. opportunistic parasites in hives and their pathogenicity to honey bees

Stonebrood is a disease of honey bee larvae caused by fungi from the genus Aspergillus. As very few studies have focused on the epidemiological aspects of stonebrood and diseased brood may be rapidly discarded by worker bees, it is possible that a high number of cases go undetected. Aspergillus spp. fungi are ubiquitous and associated with disease in many insects, plants, animals and man. They are regarded as opportunistic pathogens that require immunocompromised hosts to establish infection. Microbiological studies have shown high prevalences of Aspergillus spp. in apiaries which occur saprophytically on hive substrates. However, the specific conditions required for pathogenicity to develop remain unknown. In this study, an apiary was screened to determine the prevalence and diversity of Aspergillus spp. fungi. A series of dose–response tests were then conducted using laboratory reared larvae to determine the pathogenicity and virulence of frequently occurring isolates. The susceptibility of adult worker bees to Aspergillus flavus was also tested. Three isolates (A. flavus, Aspergillus nomius and Aspergillus phoenicis) of the ten species identified were pathogenic to honey bee larvae. Moreover, adult honey bees were also confirmed to be highly susceptible to A. flavus infection when they ingested conidia. Neither of the two Aspergillus fumigatus strains used in dose–response tests induced mortality in larvae and were the least pathogenic of the isolates tested. These results confirm the ubiquity of Aspergillus spp. in the apiary environment and highlight their potential to infect both larvae and adult bees