Multitrophic interaction facilitates parasite–host relationship between an invasive beetle and the honey bee

Abstract

Colony defense by honey bees, Apis mellifera, is associated with stinging and mass attack, fueled by the release of alarm pheromones. Thus, alarm pheromones are critically important to survival of honey bee colonies. Here we report that in the parasitic relationship between the European honey bee and the small hive beetle, Aethina tumida, the honey bee's alarm pheromones serve a negative function because they are potent attractants for the beetle. Furthermore, we discovered that the beetles from both Africa and the United States vector a strain of Kodamaea ohmeri yeast, which produces these same honey bee alarm pheromones when grown on pollen in hives. The beetle is not a pest of African honey bees because African bees have evolved effective methods to mitigate beetle infestation. However, European honey bees, faced with disease and pest management stresses different from those experienced by African bees, are unable to effectively inhibit beetle infestation. Therefore, the environment of the European honey bee colony provides optimal conditions to promote the unique bee-beetle-yeast-pollen multitrophic interaction that facilitates effective infestation of hives at the expense of the European honey bee.alarm pheromone ͉ kairomone ͉ small hive beetle

Small hive beetle,Aethina tumida, populations I: Infestation levels of honeybee colonies, apiaries and regions

“…The strong bouquet of a whole colony might not enable any quantitative discrimination by SHB. Furthermore, fermentation products of beetle-associated yeast are attractive to SHB and might cause aggregations (Torto et al, 2007). However, it remains to be shown to which extent fermentation actually takes place in SHB infested but otherwise healthy colonies, especially in the absence of feeding SHB larvae.…”

“…To overcome host defence, SHB might use a mass attack strategy as is known in Scolytidae, such as the bark or pine beetles (Person, 1931;Thalenhorst, 1958), by using pheromones or invading as swarms (Tribe, 2000). However, despite intensive research, such pheromones have not yet been identified (Torto et al, 2007).…”

The Signaling Pathway of Caenorhabditis elegans Mediates Chemotaxis Response to the Attractant 2-Heptanone in a Trojan Horse-like Pathogenesis

“…Potent volatile organic compounds produced by this bacterium are more attractive to worms than those from ordinary dietary bacteria, luring the nematode and permitting successful infection. Among volatile organic compounds, 2-heptanone belonging to methyl ketone, a compound found widely in nature, has been reported to serve as a biological pheromone in some species (15). Our previous work has revealed an interesting phenomenon: the fatal pathogenic bacterium B. nematocida 16 can imitate this beneficial signal to trap animals.…”

Standard methods for chemical ecology research inApis mellifera

“…As such, the collection, analyses, bioactivity of identified honey bee odours is vital to understanding how social cohesion is maintained, regulated and influenced by various biotic factors such as foreign intruders (Torto et al, 2005(Torto et al, , 2007a(Torto et al, , 2007b and pathogens (Swanson et al, 2009). Odours associated with honey bees have been used to improve colony vigour and to manage certain pest such as the small hive beetle Aethina tumida, (Teal et al, 2006;Arbogast et al, 2007;Torto et al, 2007b).…”

“…A specialized method that provides information on honey bee detection and sensitivity to specific compounds is coupled Gas Chromatography-ElectroAntennographic Detection (GC-EAD) (Schneider, 1957;Baker et al, 1985;Torto et al, 2007a;Swanson et al, 2009). This coupled system uses an insect antenna in tandem with a flame ionization detector (FID) This section focuses on methods to collect honey bee odours outside of the colony environment (ex-situ volatile collection) and to carry out electrophysiological recordings using antenna or other chemosensory body parts of the honey bee.…”