The invention relates to a device for combating the varroa mite in a bee brood, comprising at least one middle wall (15, 16) that can be inserted in particular into a beehive (1, 2) and that is provided with brood cells (17) for female bees, the device having an electrical heating device that has a resistance heating element (19) embedded in the middle wall (15, 16) and a control device (27, 28, 31) connected to the latter which is designed such that an automatically running heating process can be initiated with a temporally pre-determined heat-up phase that lasts until a temperature of 39°C to 45°C, preferably 39°C to 42°C, is reached at the bottom of the brood cells (17) in the region of the resistance heating element (19) and then with a subsequent phase of maintaining this temperature for a predetermined period of time.
