A study published inSciencereveals thatwhen the female fly Drosophila melanogaster sees a wasparound,lays its eggs in food that contains toxic levels of alcohol, not supported by the parasite, toprevent your offspring from being infected. This act by which individuals, in the presence of pathogens, adopt certain behaviors to prevent contact with them, is called by researchers“immune behavioral response”. “There are many examples of this type of behavior in different species,” explains Todd Schlenke, one of the authors of the article, in statements to the SINC agency. “Some examples are chimpanzees, which eat certain antibacterial plants when they have stomach infections, or monarch butterflies, which lay their eggs in milkweed (a toxic plant),” he adds.
In their experiments with flies, the researchers from Emory University (USA) placed two dishes of food for the deposition of eggs: one with alcohol and one without it. In the absence of wasps, the females preferred the dish without alcohol for their larvae. However, when they saw wasps around, the vast majority preferred the dish with a high level of alcohol, assuming the damage that this can cause to their larvae. They take advantage of that, althoughthe fruit fly has developed a tolerance to alcohol as it feeds on decaying food, the wasps do not tolerate high levels of alcohol and cannot infect the larvae located in these dishes.
The study also shows that the flies are able to remember the presence of the wasp up to four days after it has disappeared, during which time they continue to deposit their eggs on the plate of food with high alcohol content. This means thatflies store information on the presence of the wasp in long-term memory.
On the other hand, the researchers affirm that the flies literally see the wasps, but not only that, but they are able to differentiate some species from others and the males from the females. When the flies were exposed to female wasps from parasitic families, they deposited their larvae in the alcohol dish, but this did not occur when the wasps were male – which are not parasitic – or individuals of non-parasitic species.
Theinnately recognizing imagesit is important for most organisms, which need to be able to recognize predators, food, and other conspecifics. “The fruit fly, being a laboratory model animal, can be used to understand how these images are generated and stored in the brain,” says Schlenke.
