Where have all the Varroa gone

摘要

I decided, for the first time, to monitor the effect of Apiguard this summer by recording the natural mite drop before application and then taking the drop of dead mites at the end of the first two weeks or so. I use a Varroa floor with full mesh andan insert that slots into the front and side members of the floor; the rear being closed with the "handle" of the insert so mites can't escape from the insert nor can anything gain access to remove them. Since Oxalic Acid became readily available I havealways used it and monitored its effect with some amazing drop numbers. The pre-Apiguard application drop period was between 15 August when the inserts were put in the floors, and 21 August (6 days later) when Apiguard trays were placed over the brood frames. The period of monitoring the Apiguard-induced drop was between 21 August and 10 September (20 days). I use a magnifying glass to make sure I count as accurately as possible and my inserts are divided into 50mm squares, marked in red to aid counting.