Small Hive Beetles are Facultative Predators of Adult Honey Bees

Abstract

Fax: +27(0)123625242Foraging animals can choose to act as predators or not depending on the level of defensiveness of the potential prey. This requires prior evaluation of prey defensiveness, which can be variable, e.g. young insects are usually less able to defend themselves. Here we show that small hive beetles, Aethina tumida, which are scavengers and parasites of honey bee, Apis mellifera, colonies, are facultative predators of young adult host workers. Adult female beetles mounted and attacked young workers more often than their older nestmates, indicating that the beetle is assessing the defensiveness of the host and is adjusting its behaviour accordingly.Since adult female beetles need proteins to activate their ovaries, predation on defenceless young alive host workers offers another rewarding food source, which can obviously not be exploited by beetle larvae. In conclusion, adult small hive beetles seem to be able to assess the trade-off between safety and food reward.

The first detection of Nosema ceranae (Microsporidia) in the small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae)

“…The infection of Nosema ceranae in SHBs adults may confirm the transmission of pathology from original host to other species, like Deformed Wing Virus (DWV) replicative form funded in Vespa crabro (Forzan et al 2017a;Forzan et al 2017b) The presence of spores in the SHB abdomens suggests that they may have been ingested by the beetles. This is compatible with the fact that SHB adults feed on colony stores (Buchholz et al 2008;Neumann et al 2016;Pirk and Neumann 2013) and with the description of bee-collected pollen as a possible N. ceranae spore reservoir (Higes et al 2008c). Another possible contamination route may be related to the SHB ability to interact with the workers to elicit a trophallactic food transfer via antennal stimulation (Ellis 2005;Ellis et al 2002).…”

Hit‐and‐run trophallaxis of small hive beetles

“…Behavioral interactions were analyzed from the converted videos using the freeware Elan 3.6.0. Then, the SHB behavior was categorized following Neumann et al 2013's synthesis of numerous studies (Elzen et al 2001;Neumann et al 2001b;Ellis et al 2002c;Ellis et al 2004a,b;Ellis 2005;Pirk and Neumann 2013):…”

“…Series of behaviors, which started with begging and ended with trophallactic contact (=successful) or with begging, followed by a break of at least 5 sec (=unsuccessful), were defined as interactions. Interactions were excluded when (1) interactions from cages, where a bee had squeezed itself into the gap and been fed on by the SHBs (see Pirk and Neumann 2013); and (2) cases for which behaviors could not be scored unambiguously due to poor recording.…”

Behavioral responses of the small hive beetle, Aethina tumida, to odors of three meliponine bee species and honey bees, Apis mellifera scutellata

“…The beetles inflict negligible damage to its host but, upon hatching, the larvae feed on pollen and honey, putrefying hive products as they simultaneously defecate leading to comb honey contamination and sometimes colony collapse in severe cases (Figure 1). In the past two decades, it has become an invasive pest of European honey bees in the Americas, Australia, and Asia (Ellis et al, 2002;Neumann & Elzen, 2004;Ellis & Hepburn, 2006;Spiewok & Neumann, 2006;Graham et al, 2011;Pirk & Neumann, 2013;Mustafa et al, 2014), and most recently Europe (Palmeri et al, 2015). The SHB has also been found in the nests of other Apidae members such as the bumble bee Bombus impatiens Cresson (Stanghellini et al, 2000;Spiewok & Neumann, 2006;Mustafa et al, 2014) and some neotropical meliponine bee species of the genera Trigona and Dactylurina in various parts of the world, such as Latin America and sub-Saharan Africa (Greco et al, 2010;Halcroft et al, 2011;Neumann et al, 2016;Nkoba et al, 2012;Peña et al, 2014;Anguilet et al, 2017).…”