Comparative reproduction of Varroa destructor in different types of Russian and Italian honey bee combs.

Earlier studies showed that Russian honey bees support slow growth of varroa mite population. We studied whether or not comb type influenced varroa reproduction in both Russian and Italian honey bees, and whether Russian bees produced comb which inhibited varroa reproduction. The major differences found in this study concerned honey bee type. Overall, the Russian honey bees had lower (2.44 +/- 0.18%) levels of varroa infestation than Italian honey bees (7.20 +/- 0.60%). This decreased infestation resulted in part from a reduced number of viable female offspring per foundress in the Russian (0.85 +/- 0.04 female) compared to the Italian (1.23 +/- 0.04 females) honey bee colonies. In addition, there was an effect by the comb built by the Russian honey bee colonies that reduced varroa reproduction. When comparing combs having Russian or Italian colony origins, Russian honey bee colonies had more non-reproducing foundress mites and fewer viable female offspring in Russian honey bee comb. This difference did not occur in Italian colonies. The age of comb in this study had mixed effects. Older comb produced similar responses for six of the seven varroa infestation parameters measured. In colonies of Italian honey bees, the older comb (2001 dark) had fewer (1.13 +/- 0.07 females) viable female offspring per foundress than were found in the 2002 new (1.21 +/- 0.06 females) and 1980s new (1.36 +/- 0.08 females) combs. This difference did not occur with Russian honey bee colonies where the number of viable female offspring was low in all three types of combs. This study suggests that honey bee type largely influences growth of varroa mite population in a colony.