Background

Vertebrate brains can solve complex tasks with regional specialization (Kandel et al., 2000) and this may also be the case in invertebrates (Frasnelli et al., 2010). To date, experimental evidence for lateralization, a form of regional specialization, in honeybees has been documented for simple olfactory classical conditioning. For example, asymmetry in use of the antennae (Letzkus et al., 2006; Rogers and Vallortigara, 2008) with associated asymmetry of anatomy (i.e., sensilla number and electroantennographic responses of antennal neurons (Anfora et al., 2010; Frasnelli et al., 2010)). The honeybee Apis mellifera displays a clear laterality in responding to learned odors (Guo et al., 2016). By training honeybees on two different versions of the well-known proboscis extension reflex (PER) paradigm (Kuwabara et al., 1957; Bitterman et al., 1983), we demonstrated that bees respond to odors better when they are trained through their right antenna. To our knowledge, that was the first report of asymmetrical learning performance in an insect. In summary, our modified protocol can be used to further explore lateralization in invertebrates.