In Apis Mellifera or honeybees, the Proboscis Extension Reflex, PER, is part of the honeybee’s feeding behavior. The PER is a natural behavioral reflex in which the honey bee extends its proboscis in response to antennal stimulation with a sugar solution, during normal foraging behavior, PER occurs when the honey bee finds nectar in a flower. For example, If a honeybee went out of the hive to find nectar in flowers, and then found nectar, it would stick its Proboscis out to sense and smell it. After the Proboscis senses it, the bee will collect the nectar and then bring it back to the hive. If this bee was impaired form the toxic Neonicotinoid, Imidacloprid, it wouldn’t be able to sense the nectar, collect it, nor bring it back to the hive. That is how Imidacloprid can affect a whole hive, just by infecting one honeybee and impairing its Proboscis Extension. The PER can be seen as one of the honeybees most vital tools. This is because, without it, the bee wouldn’t able to test if the substance it is retrieving is nectar, or another, poisonous, substance. Therefore the PER is vital to the honeybees survival and could mean life or death if it becomes impaired under the influence of the toxic neonicotinoid Imidacloprid. The PER happens as one swift motion in a honey bee, it is absolutely amazing to watch!
The image above, photo b and photo c, shows the Proboscis not extended, and then the Proboscis extended after floral odors. Photo b shows the normal side view of a honeybee, here the Antenna and some mouth parts are visible. Photo c shows the same side view of the honeybee, however, the bee has extended its Proboscis in response to either food or floral odors.