HC Deb 27 October 1970 vol 805 cc11-3W
Mr. Biffen

asked the Minister of Agriculture, Fisheries and Food what plans he now has to deal with the spread of Warfarin-resistant rats; what is the present extent of the area infested by such rats; and if he will make a statement.

Mr. Anthony Stodart

Yes. I recommend farmers, occupiers and local authorities who have the statutory responsibility for controlling rats to use alternative poisons in the areas where warfarin-resistant rats are found and where necessary our staff give technical advice on their safe use.

Warfarin-resistant rats are unevenly distributed within an area of approximately 1,200 square miles in Shropshire and Montgomeryshire, but they have also been found on several small farms outside it as well as in a number of isolated places

flock sizes have only beer calculated since 1955. The figures below are therefore based on censuses taken in December and include 1954–55.

Mr. Anthony Stodart

Foul brood of bees is not a notifiable disease. The number of colonies in which foul brood has been confirmed in England and Wales as a result of inspections made under the Foul Brood Disease of Bees Orders has been as follows:—

Fisheries for Scotland and the Ministry of Agriculture for Northern Ireland were as follows:—

elsewhere in Great Britain. It is not difficult to control these rats if occupiers and local authorities follow the technical advice available, and the spread of warfarin resistance should not increase the number of rats or the risk to public health.

Mr. Biffen

asked the Minister of Agriculture, Fisheries and Food what evidence he has of mice developing Warfarin-resistant characteristics; and what proposals he has to deal with the dangers to public health deriving from Warfarin-resistant mice.

Mr. Anthony Stodart

A small percentage of mice have always possessed the inheritable characteristic that confers resistance to warfarin. The intensive use of this poison in some towns has resulted in large increases locally in the proportion of mice resistant to it, but the local authorities know how to control them by other poisons or by trapping. Such mice do not present any more danger to public health than ordinary mice.