Natures wonders: ant care for the sick protects well ants (Introduction)

by David Turell , Tuesday, April 03, 2018, 20:08 (2424 days ago) @ David Turell

How the ants discover fungus infected pupas is discovered as a compound on the pupa surface:

https://www.the-scientist.com/?articles.view/articleNo/52082/title/Infected-Ants-Chemic...

"The team also noticed that workers were destroying infected pupae while the fungal infection was still in its incubation period, before it had become visible or contagious. Something other than the infectious agent was telling the workers that the ants were sick. Pull and his colleagues knew that ants communicate with their nestmates via chemical compounds called cuticular hydrocarbons (CHCs), and suspected that the infected pupae might be signaling workers in this manner.

"To test the hypothesis, the researchers washed some of the infected pupae with a solvent to remove CHCs. Presented with these pupae, the worker ants carried out their disinfection routine 72 percent less often than when they were given infected pupae that were unwashed or had been rinsed with water. The researchers then used gas chromatography to confirm that infected pupae that hadn’t been solvent treated had a unique chemical profile on their cuticles—a kind of “find-me/eat-me” signal, Pull notes, functionally similar to those released by apoptotic cells to attract phagocytic immune cells in the human body (eLife, 7:e32073, 2018).

"While this sickness cue usually leads to the death of the infected individual by stimulating disinfection behavior in workers, it protects the rest of the colony, including egg-producing queens, from fatal infection, Pull says. “[The sick ants] are performing these behaviors and putting themselves at risk, but at the end of the day it’s still to maximize genes which they carry, to ensure that genes they carry are being passed on to the next generation.'”

Comment: Automatically producing a perfume to say I'm sick certainly protects the colony and must have been developed as ants developed social colonies. This is an automatic designed protection as part of an immune response.