Widespread anticoagulant resistance was discovered in populations of the brown rat (Rattus norvegicus Berk.) in an area of roughly 8000 km2 in north‐west Germany. Resistance testing was performed by feeding tests and/or by measuring blood clotting response after intraperitoneal injection of a sublethal testing solution. A hierarchical resistance system was found with warfarin resistance at the base followed by bromadiolone/coumatetralyl resistance to difenacoum resistance at the top. Warfarin resistance was spread over the whole area with reduced incidence towards the edges. Difenacoum resistance represented the highest level found so far and was restricted to the inner zone of the resistance area where it occurred with a frequency of 6% of all individuals tested. Breeding experiments with bromadiolone‐resistant rats showed that expression of the bromadiolone resistance gene differed in the two sexes, suggesting additional sex‐linked modifying effects to the resistance gene. Control strategy within the resistance area with respect to prevention of further selection for resistance is discussed.

The development from growing plants in field soil to soil-less culture systems has not resulted in the elimination of problems caused by plant-parasitic nematodes. Species of Meloidogyne and Radopholus have been reported to occur in soil-less culture systems, such as flower crops. The reasons for initial nematode infestation are numerous but the primary reason is likely to be infested plant material. Since nematodes are not expected in soil-less systems, they are often overlooked. However, extension specialists report an increasing occurrence of plant-parasitic nematodes in soil-less culture systems and nematodes seem to be more prevalent than is often thought likely. In an attempt to increase the awareness of the prevalence of plant-parasitic nematodes in soil-less culture systems, this short paper summarises incidences of nematode detections and reviews methods for their detection and strategies for their control.