The life of an illegal immigrant is fraught with apprehension. When caught, he/she will be imprisoned and thereafter extradited. So much time, money and effort seeking for greener pastures gone down the drain. Some have even died in the process. To survive and succeed, illegal immigrants have allowed themselves to be exploited financially, mentally and physically. The same fate could be faced by a species of Maculinea butterflies, a predatory parasite on ant colonies, the Maculinea arion.
Ants are social insects. They live in colonies with a queen ant that ensures the generational continuation of the species by giving birth to young ones, a group of worker ants who are sterile females that produce the food for the colony, defend the colony and the young. Then, there are the unfortunate male ants whose only purpose is to mate with the queen and die after a mating ritual. An ant colony is one of the most organized social structures in insects of order Hymenoptera.
There is another group of winged insects, butterflies, order Lepidoptera, who produce larva like the ants. Like I said unlike ants they are winged. One family, the Maculinea butterflies have learnt how to depend on or parasitize the ants. How does the Maculinea do this?
Maculinea can't do this, or they'll be caught!Credit: latimesblogs.latimes.com
A Maculinea lays its eggs on plants where you are likely to find an ant colony. These eggs later mature to the larval stage. When the larva falls off, it looks to the ant colonies for nutrition by corrupting the communication signals which the ants use to organize their social life in order to gain access to the colony.
The butterfly larvae hack so perfectly at the gates of the ant colony to be accepted. There are two types of larvae. Those that are socially accepted, or what are called cuckoo parasites, and those that when they have been accepted into the ants colony, go into hiding and look for opportunities to feed on the young ants, or broods, when no one is looking, the predatory parasites.
What is most interesting about these butterfly hackers is that the successful hackers are the cuckoo parasites. They emit a sound like the queen ants and become accepted by the ant colony, are treated and feted like queen ants. In brief, they achieve a high social status in the ant colony. One such butterfly is M. alcon. The predatory parasite butterflies cannot achieve this because the sound they have hacked into can only give them a gate pass into the ant colony and not social acceptance.
So, how does the predatory parasitic butterfly, M. arion, survive? Possibly by subterfuge - sneaking on broods at inopportune moments or conniving with defense worker ants to be exploited – notably, living off its wits. That wouldn’t be for long though. When found out, they would possibly be eaten or killed.
A predatory parasitic butterfly like M. arion can learn so much from illegal immigrants who have known how to evade the police. Who will do the teaching is the unanswered question.
Probably helped by Toxoplasma gondii.Credit: The New York Times (NYT)
The predator-prey rivalry between the cat and rat is famous. It inspired a popular cartoon series, Tom and Jerry Show. One parasite, Toxoplasma gondii, can bring about changes in the rat so that it forgets its natural fear and apprehension for the cat. The parasite makes the rat to love its enemy, the cat.
The preferred site of the Toxoplasma gondii parasite is the brain. When it eventually gets there and encounters the lymphocytes, cells that protect the body, it retreats and encysts itself. The parasite sleeps when encysted, awaiting when the host’s immunity is compromised.
The same story for the rat can be told for man. Yet, the behavioral changes the parasite causes in the rat have not been demonstrated with certainty for humans.
When the cyst persists until favorable conditions, it attacks the nervous system, causing behavioral changes. The rat takes to liking the odor of the cat. Eventually, it gets attracted to the cat and does not take it as an enemy. The rat becomes easy prey and is then eaten.
Having the rat eaten is advantageous to the parasite because the cat’s intestine is where it undergoes sexual reproduction. Therefore, finding a cat host is more important than living inside a rat.
What about humans? Research has discovered that humans can have behavioral changes based on gender when infected with Toxoplasma gondii. Males have been found to be introverted, suspicious and rebellious while women could exhibit extroverted, trusting and obedient behavior. Pregnant women infected with the parasite could have a miscarriage or birth defect.
Lifecylcle of Toxoplasma gondii.Credit: ScienceNews.org
As you can see from the picture above, the life cycle of the parasite involves these three hosts. Humans are not prey for the cat, but they can make themselves susceptible to parasitic invasion through unhygienic practices – not washing hands carefully after handling cat litter, eating unwashed vegetables and undercooked meat.
Scientists have not yet decided if the parasite changes human behavior to docile obedience in face of danger like the rat. Such a discovery could help in treatment of schizophrenia and helping persons infected with the disease when their immune system is compromised.
