Resistance tests and field trials with bromadiolone for the control of Norway rats (Rattus norvegicus) on farms in Westphalia, Germany

Abstract

BCR tests based on the use of the INR and baselines are suitable for determining the incidence and for assessing the level of resistance in populations of Norway rats. The majority of rats of the Westphalian resistant strain, characterised by the Y139C marker in VKOR, are resistant to bromadiolone under practical control conditions.

Distribution of anticoagulant rodenticide resistance inRattus norvegicusin the Netherlands according toVkorc1mutations

“…Ala26Thr, Ser79Phe, Tyr139Phe, Tyr139Cys), with known resistance effects for Tyr139Cys and Tyr139Phe . Strain Tyr139Cys is resistant to warfarin, and the majority of rats are resistant to bromadiolone as well as to coumatetralyl: neither bromadiolone nor difenacoum provides a sufficient level of control . On the other hand, brodifacoum has been found to be fully effective against R. norvegicus with the Tyr139Cys mutation in Germany …”

Monitoring of Rattus norvegicus based on non-toxic bait containing encapsulated fluorescent dye: Laboratory and semi-field validation study

“…Because of the significance of R. norvegicus, this species must be systematically controlled using an integrated pest control (IPM) approach. However, efficient control of R. norvegicus is becoming increasingly difficult because of the physiological (e.g., Endepols et al, 2011;Buckle et al, 2013;Esther et al, 2014) and behavioural resistance (Brunton et al, 1993;Buckle and Prescott, 2011) of this species to toxic anticoagulant baits and because of the continuing trend of limiting various active ingredients and formulations of toxic baits in the EU.…”

The potential of coumatetralyl enhanced by cholecalciferol in the control of anticoagulant-resistant Norway rats (Rattus norvegicus)

“…Norway rats derived from livestock farms in the Münsterland area, Westphalia, have been subjected to susceptibility tests with anticoagulant rodenticides owing to problems controlling them since the early 1970s . Increased tolerance to anticoagulants in these populations was confirmed, first during the 1980s by feeding tests and later using blood clotting response tests (BCR tests) . Warfarin resistance in the Westphalia strain of the Norway rat was found to be linked to a gene on chromosome 1 .…”