Queen fighting

Honey bee queen fighting occurs when there is two or more queens in one nest (temporary polygyny). As a result of the fighting there is only one queen left in the nest (monogyny). The fighting can occur during swarming, emergency queen rearing and possibly supersedure. In the fighting usually participate young virgin queens but during supersedure young virgin queen can fight with old mated queen. In experimental conditions also mated queens can fight [1]. There are also fights between queens and pseudoqueens [2].

The queen fighting behaviour is induced by olfactory stimulus [3], source of the stimulus is located on abdominal tergites [4][5] and it is not related to mandibular glands [4][6][7]. Queens are able to perceive each other only when there is direct contact between them [1][5]. Sometimes short contact between two young queens does not end with fight [8]. In A. m. sicula young virgin queens can tolerate each other for some time [9][10]. Queens refrain from fighting when one of their mandibles was removed [11].

During the fight queens use sting while holding each other with legs and mandibles [1]. The queen which successfully stung its rival wins the fight. Sting is usually delivered into intersegmental membrane of abdomen. The fight last from 5 seconds to 15 minutes [8]. In most cases stung queen is paralysed and dies within about 15 minutes. The stung queen can be immobilized by workers [8] and before death it can receive from the winning queen additional stings [5]. The winning queen is usually not injured. Occasional her wings can be destroyed during fighting [12].

In case of virgin queens older individuals win the fights more often [13], but in case of mated queens the opposite is true [1]. During swarming the oldest queen have advantage only in colonies without afterswarms [14]. Heavier queens won the fights more often in one study [15] but not in others [13][16]. There are suggestions that workers can affect result of the fighting [17][18][19][14]. Young queens are harassed by workers. A behaviour called "clump" occurs when a worker close her mandibles on leg or wing base of a queen [8]. Another behaviour called "grab" occurs when a workers opens and closes her mandibles against the surface of thorax and abdomen of a queen [8]. However, workers do not participate in the queen fighting by stinging the queens [1]. Queens that were vibrated by workers at higher rates won more fights [20]. Harassment of a queen by a worker is not affected by their relatedness [21] or queen quality [22].

During the fight content of hind-gut (see queen faeces) can be released by one or both queens [17][23]. This behaviour (called spraying) occurs in 67% [24] or 38% [23] of fights. After the spraying the fight is usually interrupted and queens are separated [24]. The queen covered with faeces is often immobilized by workers [8] for 15±24 minutes [23]. Queens that were immobilized in this way are less likely to survive the fighting [23]. Sometimes immobilized queen is attacked and stung by free moving queen [23]. Spraying is specific to young queens up to two weeks of age [25].

Historical references: [26][27][28][29]
Other references: [30][31]

»