Changes in chemical cues of Melissococcus plutonius infected honey bee larvae

Abstract European foulbrood (EFB), caused by Melissococcus plutonius, is a globally distributed bacterial brood disease affecting Apis mellifera larvae. There some evidence, even if under debate, that spreading of the within colony prevented worker bees performing hygienic behaviour, including detection and removal infected Olfactory cues (brood pheromones, signature mixtures, diagnostic substances) emitted individuals may play central role for to initiate disease-specific behaviour. However, mechanisms cue removal, causing behaviour in EFB affected colonies, are poorly understood. Here, coupled gas chromatography-mass spectrometry (GC–MS) was used detect substances, changes cuticular hydrocarbon (CHC) profiles, ester pheromones (BEPs) honey bee larvae artificially with M. plutonius . Although no substances were found significant quantities, discriminant analysis revealed specific differences CHC BEP profiles healthy ?-Ocimene, volatile pheromone related starvation present all highest quantities young larvae; whereas oleic acid, non-volatile necromone, only old Furthermore, ?-octalactone (newly discovered A. this study) detectable trace amounts We propose deviation from olfactory profile supposed trigger bees. To confirm relevance change chemical bouquet (CHCs, BEPs, ?-octalactone, etc.), field bioassay needed, using determine elicit