Suicidal termites use chemical weapons to defend colony

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Old-aged termites go out with a bang, it appears. While ageing, the insects brew a backpack of deadly chemicals, which they use to self-destruct when under attack, taking out any enemies with them.


When Jan Šobotník from the Academy of Sciences of the Czech Republic and Thomas Bourguignon from the Free University of Brussels in Belgium were examining termites (Neocapriterme taracua) in French Guiana, they were surprised to see that some individuals had pale blue spots on their abdomens. But the real shock came when the pair picked up the spotted insects – they exploded in their hands.

To investigate whether the suicides might be part of a defence strategy, Šobotník, Bourguignon and their colleagues pitted spotted and non-spotted termites against two rival species of termite – known to compete with the others for land and food. When the spotted termites were physically unable to defend themselves with their jaws, they would commit the ultimate sacrifice and burst a pouch on their backs, releasing a toxic liquid that quickly paralysed and killed any other termites it touched.

While non-spotted termites would also burst when they were threatened, they appeared more reluctant to do so. Their poison was less potent too: liquid extracted from spotted workers was five times more effective at killing attackers than that of non-spotted insects.

On closer inspection, the team found that the blue spotted termites’ jaws weren’t as sharp as those of their non-spotted counterparts, indicating that they were older. Team member Robert Hanus, also from the Academy of Sciences of the Czech Republic, thinks the insects develop their spotted toxicity once they’re too old to forage for food.

“To ensure that they remain of use to the colony, the older workers take on a defensive role,” Hanus says. “The younger workers will do anything to avoid exploding because they know they are not very toxic so their suicide is a waste to the colony.”

Under the microscope, the spots appear to be crystals encased in pouches that sit on top of the insects’ salivary glands, says Hanus. When the pouch bursts, it’s the mix of crystals, saliva and haemolymph – a liquid similar to blood – that makes the resulting liquid so toxic, he reckons. “Some unknown chemistry must take place,” he says.

Self-detonation as a defensive tool is known to be used by social insects like termites, but it has never been seen accompanied by this type of chemistry. Most insects simply compress their abdominal muscles to release the contents of their intestine, which normally disturbs their attackers rather than killing them.

Written By: Jessica Griggs
continue to source article at newscientist.com

15 COMMENTS

  1.   While non-spotted termites would also burst when they were threatened,
    they appeared more reluctant to do so. Their poison was less potent too:
    liquid extracted from spotted workers was five times more effective at
    killing attackers than that of non-spotted insects.

    More species, with chemical weapons! 
    It would be interesting to find their source for the chemicals.  Are they formed in the termite’s body, or derived from a food source over time as they age?

  2. I don’t know. Kinda sounds like the termites just die during the involuntary release of chemicals when threatened. The chemicals, of course, have the byproduct effect of killing the host termite and possibly other termites; maybe even other insects or more. We know human contact can trigger the chemical release. If this article is any indication, I must tip my hat at the termite. I had no idea they were so fucking brave. What will and determination these hyper-thoughtful creatures posses.

    I scanned the article and saw this beauty.

    “To ensure that they remain of use to the colony, the older workers take on a defensive role,”

    No, no, no, no… I would have thought that impossible, surely not! Kinda sounds to me like the older workers are of use to the colony because they have the byproduct effect of a defensive role. Before this article, I wouldn’t have accepted that any termite had taken on anything in this situation. I tip my boot to you Mr. termite. Once again you have shown yourself quite the impressive little creature. If the Jessica is correct, a strategist!

    Damn it’s hard for them to write like the termite isn’t a hero. I know I don’t know shit but this is how a creationist would write it.

  3. “When the pouch bursts, it’s the mix of crystals, saliva, and haemolymph (oh my!) that makes the resulting liquid so toxic.”

    I almost didn’t read the article ’cause termites (and the photo) give me the heebie jeebies.  But damn if this isn’t interesting stuff.  

  4.  Calling any remark PC always sounds belittling if not insulting. It was partly a joke, but in fact, it does introduce the question in an abstract kind of way.. From the standpoint of the other termites, the exploding ones are ‘patriotic’ but to the termite enemies, they are terrorists. I don’t see why this observation causes you to label it PC.

  5. > “To ensure that they remain of use to the colony, the older workers take on a defensive role,”

    Yes it’s hard to rein in this kind of writing.  I can see the animated version now, where the Old TImer Termite says something like

     “I’m gettin too old for this foraging shit, reckon its time for me to sign up for the Security Detail.  Nothin to do, and I still get fed.  Unless we’re attacked.  But then, a Termite’s Gotta Do What A Termite’s Gotta Do…   Now, run along kids, and don’t forget to save a few tasty bits for the Old Timers…”

  6. “To investigate whether the suicides might be part of a defence strategy…”
    If it was not “part of a defence strategy” (for the colony) then evolution by NS would not make sense, given the eusocial nature of termites. 

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