We investigated the occurrence and pathogenicity of Beauveria spp. (Hypocreales: Cordycipitaceae) in forest soils in Poland, in outbreak areas of cockchafers (Coleoptera: Scarabaeidae): Melolontha melolontha L. and M. hippocastani F. We also examined the occurrence of Beauveria in relation to soil pH. Beauveria spp. isolates were characterised at species and genotype levels using ITS and microsatellite markers. Beauveria spp., which were detected at over 80% of sites, were sensitive to pH, preferring neutral or alkaline soils. This suggests that the acidity of forest soils in Poland can affect their efficacy as biological control agents (BCAs). B. brongniartii (Sacc.) Petch as a pathogen of cockchafers occurred at 41% of sites, but often at densities below the threshold values for infection, and it infected only 1.3% of cockchafer grubs. Our results suggest that B. brongniartii genotype isolated from cockchafers in forest soils can potentially expand the pool of BCAs in this environment.
This paper treats the stability of two superposed gravitating streams rotating about the axis transverse to the horizontal magnetic field. The critical wave number for instability is found to be affected by rotation for propagation perpendicular to the axis about which the system rotates. The critical wave number for instability is not affected by rotation when waves propagate along the axis of rotation. The critical wave number is affected by both the magnetic field and the streaming velocity in both cases. Both the magnetic field and the rotation are stabilizing, while the streaming velocity is destabilizing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.