What is IPM?

Modern management of varroa should involve an Integrated Pest Management approach. IPM is a principle widely used in agriculture, involving the use of a combination of methods of pest control, including Chemicals and Biotechnical techniques as part of routine pest control management.

With the development of increasing resistance to currently licensed treatments, it is not possible to completely eradicate the varroa mite. Management of the mite involves keeping its population levels in our colonies down to low levels. UK researchers suggest we should aim to keep the varroa population below the harmful mite population threshold of 1000 mites/hive, (known as the economic injury level), which the Western Honeybee (Apis mellifera mellifera) seems able to tolerate without threat to the survival of the colony. However there is no clear threshold above which the mite suddenly causes harm, and levels of infestation that appear to cause no harm to one colony, may prove extremely damaging to another. This may be due to environmental factors, and variations in the resistance of bees to the effects of the mite, particularly to the various other pathogens, primarily viruses, which are vectored by the mite.

IPM for varroa in our honeybees employs the various techniques described in the linked pages. The basic necessity is good bee husbandry. Constant monitoring of the levels of varroa in our colonies and use of multiple Biotechnical techniques can reduce our use of chemical varroacides and therefore reduce the development of chemical resistance to them.

An important principle of IPM is to alter the control strategy in response to the level of infestation. So IPM programmes will vary according to prevailing circumstances, depending on such variables as levels of infestation, pyrethroid resistance, climate, proximity to other apiaries, local beekeeping practices etc. Contrary to previous advice from the NBU, we should not routinely treat with alternating pyrethroids/Thymol each Spring and Autumn. Instead, we should be monitoring the levels of mite infestation, controlling them with various Biotechnical methods, and only treating with chemicals when necessary. If treatment is required and carried out, but pyrethroid resistance is demonstrated either through continued mite monitoring, or routine resistance testing, we should then be using alternative chemical treatments which are now accepted,e.g. Oxalic acid, to keep mite levels below the harmful threshold.