When attacked, they provide another service to the colony, these social insects performing housekeeping when young, but engaging in the dangerous act of defence as they get older.
It has been discovered that a particular termite species, found in the French Guiana rainforests, has evolved so that aged worker hive members – no longer able to make major contributions to hive welfare – grow sacks of toxic blue liquid.
In suicidal acts of self-sacrifice, they cause these to explode, when threatened, showering enemies with toxins to help defend their colonies. It appears that these explosive body parts, grow throughout the life-times of the worker termites – of the species Neocapritermes taracua – are filled by abdomen glands secreting the blue crystals.
The most toxic sacks are carried by older workers – those least able to forage, with dull and worn mandibles, which because can no longer be sharpened by moulting, but when attacked, they provide another service to the colony, these social insects performing housekeeping when young, but engaging in the dangerous act of defence as they get older.
This kind of suicidal behaviour is not uncommon among sterile worker castes of termites and honeybees, workers foregoing reproduction, and instead evolving behaviours benefitting the colony as a whole. A number of termite species have evolved to develop autothysis – defensive suicidal rupturing — termed — has evolved.
Many termite species attack enemies by actively squeezing their own abdominal muscles – causing specialized thin abdominal wall areas to explode – showering enemies with excrement, but this species has added to this by using a reaction to make its defensive chemical even more toxic.
Those copper-containing blue crystals are located in pouches close by salivary glands, and upon being attacked, the bites of enemies cause the rupturing of these swollen pouches, meaning that the toxic blue liquid mixes with salivary secretions, producing a dealy spray with which to shower the attackers.