Seasonality of honey bee colony invasion by Varroa jacobsoni Oud

Invasion of Varroa jacobsoni into Apis mellifera colonies was monitored using Bayvarol-strips for 2 years from April to October. The seasonal profile of mite invasion was similar in all colonies. Invasion was low in spring and increased considerably during summer when it remained at high levels until autumn. Mite invasion into the monitored colonies correlated closely with the infestation level of the apiaries, but varied considerably between monitor colonies

Fcdcral Republic of Germany

Summary. Colonies and smaller social groups of honeybees (lpl.l mellif aru c'arnicct L.) show distinct free-running circadian rhythms similar to that of individuai organisms. Thc workers of a colony synchronize their individual rhythms to one overall group rhythm. Caste plays an important role in this synchronization process. Queens were introduced into worker groups which were entrained to a phase-shifted light/dark cycle. The introduction of the queen caused a shift in the free-running phase under constant dark conditions. Single introduced workers had no effect on the free-running rhythms. This indicates that the queen plays an important role in the synchronization of circadian rhythms of honeybee colonies