Influence of Nosema ceranae and the neonicotionid Thiacloprid® on longevity and behavior of honey bees (Apis mellifera) at the colony level

Publikations-Art

Vortrag

Autoren

ODEMER, Richard, RHEINSCHMIDT, A., MÜHLHÄUSER, H., ROSENKRANZ, P.

Erscheinungsjahr

2012

Tagungsname

AG Tagung

Tagungsort

Bonn

Synergistic effects of pesticides and pathogens are considered a crucial factor for honey bee colony losses. Within the EU project “BEE DOC” we analyze such interactions at both the individual and the colony level. Here we present data on the effect of Nosema ceranae and the neonicotinoid Thiacloprid^®. Four differently treated groups, each consisting of 120 freshly hatched worker bees, were introduced into observation hives. The bees of two groups derived from colonies which had been continuously fed with Thiacloprid^® for eight weeks; the bees of the other two groups were taken from untreated control colonies headed by sister queens. The bees of two groups - one from the pesticide treated and one from the control – were individually fed with approx. 60.000 spores of N. ceranae and marked according to the 4 groups (untreated control, N. ceranae, Thiacloprid^®, N. ceranae & Thiacloprid^®). After introduction into the observation hives, flight activity, longevity and social behavior were quantified in daily intervals for a period of 4 weeks (3 repetitions). Samples, taken after 2 and 4 weeks confirmed the successful infection of bees in the Nosema-treated groups. However, no clinical symptoms could be observed in any of our hives even though high infections of the bees treated with N. ceranae were confirmed. In addition, we could not reveal any consistent effect of Nosema and/or Thiacloprid^® treatments on the longevity, flight activity, and the quantity of certain behavioral tasks. Our results are in contradiction to reports from Spain that suggest a high mortality of bees infected by N. ceranae; however, they confirm our results obtained from similar experiments in mini-hives (Larue et al., this meeting) and from a European Nosema monitoring (Rosenkranz et al., this meeting).

Supported by EU project “BEEDOC” (244956 CP-FP)