The buzz on honeybee-hornet interactions
Posted April 11, 2012
Spring is here. Flowers are blooming, birds are flying and bees are buzzing. If those bees are Asian honeybees, however, it’s likely that their buzzing indicates more than nice weather. According to a BBC Nature News article, Asian honeybees signal to acknowledge a predator’s presence.
The hornet is one predator of the Asian honeybee. Hornets eat the bees. When a hornet lands at a hive entrance, the bees that act as guards kill the hornet by surrounding it until it suffocates or dies from the heat. This is obviously detrimental to the health of the hornet. Although this defense mechanism saves the hive’s occupants, it’s not entirely without risk for the bees and takes effort.
The honeybees have developed a signal to warn away hornets that’s beneficial to both species. When hornets approach the hive, guard honeybees shake their abdomens at the same time, creating vibrations that warn the hornets not to come closer. As the hornet nears, the bees’ vibrations intensify.
This signal is mutually beneficial because it prevents the hornet from suffering a rather nasty death and prevents the honeybees from risking any hive members from being hurt or killed in the defense of the hive or from exerting any effort. This signal has also given hornets the opportunity to develop the safer, if more difficult, attack method of hunting bees in mid-flight, rather than in the hive.
Interestingly, the bees vibrate their abdomens in a warning signal only when a hornet is approaching. When a similarly-colored butterfly nears, the bees do not react. This research about honeybee-hornet interactions might change our thoughts about the insects. Rather than assuming they’re buzzing because it’s spring, we might check to see if there is a hornet lurking.