| Popis: |
Females of Psithyrus vestalis (Geoffroy in Fourcroy 1785) were introduced to free-foraging colonies of their host Bombus terrestris (Linnaeus 1758), and the interactions of parasite and host colony members during the development of the colony were studied. In three colonies observed, the B terrestris queens were found dead in their nests between six hours and six days after introduction of the parasite. In two of these colonies the host bees reproduced in males. As all host broods which were reared from eggs which had been laid by workers, only males emerged. In these cases, the Psithyrus females significantly favoured contacts to egg-laying workers, as compared to non-egg-laying workers. The number of contacts to the first group was significantly higher, even before the workers had started laying their eggs. The parasite only reproduced in the third colony, in which the host did not succeed in reproducing young queens or drones. |
