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Abstract: The association of Rhizoctonia spp. with insect-damaged and diseased tissue of the invasive perennial Lepidium draba was documented throughout the range of L. draba that was surveyed in Europe, including Hungary, Austria, Switzerland and France. Samples that could be both maintained under cooled conditions after collection and promptly processed consistently yielded Rhizoctonia solani, 11 isolates of which anastomosed with AG-4, one with AG-2-1 and one isolate was determined to be binucleate. Comparative virulence among the isolates was analyzed using nonparametric survival analysis for interval-censored data. This analysis indicated that there were significant differences among the isolates. These findings provide further evidence that both root-attacking insects and soilborne pathogens are associated with the lower density of a perennial invasive species in its native range. Prioritization of prospective biocontrol agents should include the ability to engage in insect/plant pathogen synergisms. The application of nonparametric maximum likelihood estimation to interval-censored data for the assessment of comparative virulence among several strains of a plant pathogen is more accessible than calculation of the area under the disease progress curve. [Copyright &y& Elsevier]

In order to take account of the negative effects of invasive species and pathogens on networked forest areas, we study the dynamics of stochastic closed-loop input-output systems faced with the risk of external random perturbations. The extension of previous works on robustness is carried out by introducing a negative feedback mechanism, such that the output from an element contained in the system behaves as a negative input toward elements to which it is connected. Through the study of an overall network divided into compartments barely connected to one another, we first consider the pathway pertaining to monofunctional zoning. By looking at a single aggregated structure, we then move our focus to the pathway proper to multifunctionality. Our results show that, at significant time scales, the monofunctional-zoning mode of forest governance, generally applied in Australasia, performs robustly against invasive biological threats at all levels of outbreak probability. The multifunctional mode of forest governance, further practiced in Western Europe, is mainly sturdy when the probability of invasion verges into certainty. Should this not be the case, robustness is ensured would disturbers and perturbations be uncorrelated. Accordingly, the monofunctional pathway can afford adopting control strategies for outbreak avoidance, which is only acceptable in case the expected invasion can be halted. For the sake of maintaining low likelihood of invasion, the multifunctional pathway is compelled to applying preventive strategies., (Copyright © 2018 Elsevier Ltd. All rights reserved.)