TY  - JOUR
A1  - Schneider, Christof W.
A1  - Tautz, Jürgen
A1  - Grünewald, Bernd
A1  - Fuchs, Stefan
T1  - RFID Tracking of Sublethal Effects of Two Neonicotinoid Insecticides on the Foraging Behavior of Apis mellifera
JF  - PLoS One
N2  - The development of insecticides requires valid risk assessment procedures to avoid causing harm to beneficial insects and especially to pollinators such as the honeybee Apis mellifera. In addition to testing according to current guidelines designed to detect bee mortality, tests are needed to determine possible sublethal effects interfering with the animal's vitality and behavioral performance. Several methods have been used to detect sublethal effects of different insecticides under laboratory conditions using olfactory conditioning. Furthermore, studies have been conducted on the influence insecticides have on foraging activity and homing ability which require time-consuming visual observation. We tested an experimental design using the radiofrequency identification (RFID) method to monitor the influence of sublethal doses of insecticides on individual honeybee foragers on an automated basis. With electronic readers positioned at the hive entrance and at an artificial food source, we obtained quantifiable data on honeybee foraging behavior. This enabled us to efficiently retrieve detailed information on flight parameters. We compared several groups of bees, fed simultaneously with different dosages of a tested substance. With this experimental approach we monitored the acute effects of sublethal doses of the neonicotinoids imidacloprid (0.15-6 ng/bee) and clothianidin (0.05-2 ng/bee) under field-like circumstances. At field-relevant doses for nectar and pollen no adverse effects were observed for either substance. Both substances led to a significant reduction of foraging activity and to longer foraging flights at doses of >= 0.5 ng/bee (clothianidin) and >= 1.5 ng/bee (imidacloprid) during the first three hours after treatment. This study demonstrates that the RFID-method is an effective way to record short-term alterations in foraging activity after insecticides have been administered once, orally, to individual bees. We contribute further information on the understanding of how honeybees are affected by sublethal doses of insecticides.
KW  - memory
KW  - nicotinic acetylcholine-receptors
KW  - unpaired median neurons
KW  - honey bees
KW  - learning performances
KW  - toxicity
KW  - hymenoptera
KW  - pesticides
KW  - relevance
KW  - agonist
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131753
VL  - 7
IS  - 1
ER  - 
TY  - JOUR
A1  - Azzami, Klara
A1  - Ritter, Wolfgang
A1  - Tautz, Jürgen
A1  - Beier, Hildburg
T1  - Infection of honey bees with acute bee paralysis virus does not trigger humoral or cellular immune responses
JF  - Archives of Virology
N2  - We have studied the responses of honey bees at different life stages (Apis mellifera) to controlled infection with acute bee paralysis virus and have identified the haemolymph of infected larvae and adult worker bees as the compartment where massive propagation of ABPV occurs. Insects respond with a broad spectrum of induced innate immune reactions to bacterial infections, whereas defence mechanisms based on RNA interference play a major role in antiviral immunity. In this study, we have determined that honey bee larvae and adult workers do not produce a humoral immune reaction upon artificial infection with ABPV, in contrast to control individuals challenged with Escherichia coli. ABPV-infected bees produced neither elevated levels of specific antimicrobial peptides (AMPs), such as hymenoptaecin and defensin, nor any general antimicrobial activity, as revealed by inhibition-zone assays. Additionally, adult bees did not generate melanised nodules upon ABPV infection, an important cellular immune function activated by bacteria and viruses in some insects. Challenge of bees with both ABPV and E. coli showed that innate humoral and cellular immune reactions are induced in mixed infections, albeit at a reduced level.
KW  - chemosensory protein
KW  - bee larva
KW  - adult bee
KW  - honey bee
KW  - larva
KW  - work bee
KW  - infected bee
KW  - immune response
KW  - young work bee
KW  - capsid protein
KW  - abdominal
KW  - tergite
KW  - haemolymph
KW  - sample
KW  - Imd pathway
KW  - worker bee larva
KW  - antimicrobial
KW  - peptide
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126863
VL  - 157
IS  - 4
ER  -