An improved micro-method for avidin assay (Short Communication)

A sensitive method for avidin assay was devised. Tritiated biotin is bound to avidin and this complex is then bound to bentonite. Radioactivity is converted into a gas form by combustion and counted in an automatic proportional counter with 55% efficiency and background of 3.7c.p.m. The sensitivity is 1-2ng of avidin.     

Über die Anpassung der Bäckerhefe an Galaktose

Zusammenfassung Die mit Einsporen-Kulturen der Bäckerhefe durchgeführten Versuche weisen darauf hin, daß die untersuchten homozygotischen Bäckerhefestämme durch Anpassung imstande waren, Galaktose zu vergären, so daß diese Erscheinung mit der genotypischen Variation nichts zu tun hat.     

Phylogeny of Syrphidae (Diptera) inferred from combined analysis of molecular and morphological characters

Abstract.  Syrphidae (Diptera) commonly called hoverflies, includes more than 5000 species world-wide. The aim of this study was to address the systematic position of the disputed elements in the intrafamilial classification of Syrphidae, namely the monophyly of Eristalinae and the placement of Microdontini and Pipizini, as well as the position of particular genera ( Nausigaster , Alipumilio , Spheginobaccha ). Sequence data from nuclear 28S rRNA and mitochondrial COI genes in conjunction with larval and adult morphological characters of fifty-one syrphid taxa were analysed using optimization alignment to explore phylogenetic relationships among included taxa. A species of Platypezidae, Agathomyia unicolor , was used as outgroup, and also including one representative ( Jassidophaga villosa ) of the sister-group of Syrphidae, Pipunculidae. Sensitivity of the data was assessed under six different parameter values. A stability tree summarized the results. Microdontini, including Spheginobaccha , was placed basally, and Pipizini appeared as the sister-group to subfamily Syrphinae. The monophyly of subfamily Eristalinae was supported. The results support at least two independent origins of entomophagy in syrphids, and frequent shifts between larval feeding habitats within the saprophagous eristalines.     

Effects of Metarhizium anisopliae on the pollen beetle Meligethes aeneus and its parasitoids Phradis morionellus and Diospilus capito

The efficacy of two Finnish strains of Metarhizium anisopliaeagainst the rape blossom beetle Meligethes aeneus (Coleoptera:Nitidulidae) and the effect on its parasitoids Phradismorionellus (Hymenoptera: Ichneumonidae) and Diospilus capito(Hymenoptera: Braconidae) were studied in laboratory and semi-fieldexperiments. Several bio-assays were performed using either directexposure of the host beetle to the pathogens, or pots containing soilinoculated with M. anisopliae conidia at a rate of 2 ×10⁸ per ml soil. Parasitised and unparasitised M. aeneuslarvae were collected in the field and were placed for pupation in thetest soil. The effect of treatment on M. aeneus andD. capito was estimated after adult emergence, and the effecton P. morionellus was estimated by dissecting hibernating pupae.While both of the M. anisopliae strains were highly pathogenicto M. aeneus adults and larvae upon direct exposure, soiltreatment resulted in no significant difference between the number ofinsects emerging (or found) from the treated and untreatedpots. However, the treated insects appeared to be latently infectedand the actual infection rate had to be estimated after their deathand incubation in a moist chamber. The mortality of the beetles causedby direct exposure to the fungus was 85% (range 70–88%). The rateof latent infection following indirect exposure via treated soil indeep pots in laboratory was 80% (range 49–100%), while that inP. morionellus was only 17% (range 0–85%), and inD. capito significantly higher, 76% (range 72–100%).The results indicate that M. anisopliae is a potentially usefulcandidate to be used as a bio-insecticide to control the pollenbeetle, and that at least the most abundant parasitoid, Phradismorionellus, is less affected than the target pest itself. Thepossible ecological role of latent infections in the host as well asin some of the parasitoids needs to be clarified.