VARROA-JACOBSONI OUDEMANS TOLERANCE IN SELECTED STOCKS OF APIS-MELLIFERA L

The relative tolerance of four honey bee stocks to Varroa jacobsoni Ou demans was investigated in field conditions. Apis mellifera carnica fr om Yugoslavia (ARS-Y-C-1), A m carnica from Canada (Hastings), F-1 hyb rids from ARS-Y-C-1 and Hastings crosses, and a commercial Louisiana s tock of yellow honey bees were studied. All three Carniolan stocks exh ibited greater tolerance to V jacobsoni than the Louisiana stock. The Carniolan stocks survived longer with higher levels of Varroa infestat ion on both worker pupae and adult honey bees. Louisiana stock was mor e susceptible to Varroa infestation. Colonies died earlier. But, unlik e other stocks, the Louisiana stock had lower levels of infestation at death. Regardless of the stock, Varroa had similar reproductive succe ss based on the number of mites per infested pupa (1-10 mites), the nu mber of foundress Varroa per infested pupa (1-3 females), the number o f progeny per female (0-5 progeny), the number of progeny per infested pupa (0-7 progeny), and the proportion of infested pupae containing i nfertile foundresses (0-47%).