VARROA DEFENSE MECHANISMS

Bees have several defense mechanisms which they use to cope with varroa.  It seems hives exhibit most of these defense mechanisms to some degree; usually at a very low level.

One mechanism is the chewing on the varroa. Chewed varroa essentially bleed to death.   The Purdue Mite Biter is an example of this bee type.

Next using chemical ques some bees decap, clean out and then recap cells containing varroa.  Finally some hives open the cells with bee larvae that are either being attacked or killed by varroa and remove the larvae and varroa inside.  These are known as VSH bees.

Various beekeeping authorities have tried to increase the efficiency of these defense mechanisms by breeding.  To date they have had limited success in making these mechanisms strong enough and also permanent.

It is also reported that feral bees have also, via natural selection, strengthened the chewing attribute as part of their coping mechanisms.  It is reported that feral bees in Kentucky and Ohio are damaging/killing 60% of the varroa that are on the bottom board.  Hives with these feral bees have been reported to have survived 5 years without chemical varroa treatments.  It has been reported that some crosses of the Kentucky/Ohio bees are chewing at an 80% rate.

Perhaps a cross which has all three types of coping mechanisms will solve the varroa problem.

Almost all bees purchased in packages do not have these enhanced attributes.

Chewing damage on the leg of a varroa mite