Queen faeces

At emergence hindgut of queens is empty but after 24-48 hours there is 10-30 μl of faeces [1]. Young queens often release faeces during fighting. In laboratory conditions the faeces of young queen repel workers and stimulate autogrooming behaviour, but this effect is not present in case of queens older than 2-3 weeks [1]. In natural conditions workers are attracted to the faeces and imbibe it [2].

The faeces contain (accordng to [3]):

  1. ortho-aminoacetophenone
  2. decanoic acid
  3. dodecanoic acid
  4. octyl decanoate
  5. decyl decanoate
  6. decyl octanoate
  7. tetradecyl decanoate
  8. octanoic acid
  9. benzoic acid
  10. l-dodecanol
  11. octyl octanoate

The first five components are not present in faeces of workers [4]. Benzoic acid and octanoic acid were present in faeces of queens and workers [4].

The faeces of young queens have a milky yellowish-brown color and a strong floral scent. The faeces of queens older than 2-3 weeks are clear with pieces of dark solid matter and have a rancid odour [1]. The floral smell of the faeces of young queens is probably caused by presence of ortho-aminoacetophenone which smells like grapes [3]. This compound is responsible for repelling properties of the queen faeces in laboratory conditions and can be considered as a pheromone [3]. The queen faeces can be used for queen recognition or nestmate recognition [5].

A queen can be stimulated to release faeces in laboratory conditions [6] this method can be used for detection of Nosema spores without sacrificing the queen [7]. It is more difficult to stimulated workers to release feaces [8].