This parasite turns ants into zombies. Liver fluke – what is it?

Many parasites influence the behavior of their hosts. Some of them are like the famous fungi from the Cordyceae family.Cordycepetaceae), complete control of the infected organism, while others do so only partially. The results of research on the interactions of a “partial” parasite and its victim were recently published in the journal “Behavioral Ecology.”

Scientists from Wageningen University in the Netherlands and the University of Copenhagen conducted research on ant mites (Formica polyctina), inhabits the Danish Bedstrup Forest. Some individuals were carriers of liver fluke larvae (Dendritic diploid) – A parasitic bird that feeds in its life cycle on snails, ants, and mammals, especially from the deer family.

In order to grow and reproduce, the butterfly must enter the digestive system of mammals. To do this, it forces the normally active ants to climb onto grass blades and nibble on them, waiting for the host to grab them while they nibble on the plants. The insects then become motionless and numb, as if they were zombies.

The study’s lead author, Simone N. Gaske conducted field research in a Danish forest over the course of one year, tracking hundreds of ants. The 172 infected people have been marked with numbered tags so you can track their movements. During the observations, the researcher also recorded the temperature and relative humidity of the air.

Measurements have shown that ants most often climb onto grass blades and freeze on top in the morning and evening when the air temperature drops. During the day, as the weather became warmer, the insects returned to their normal behavior. As Gaskey explained, on cold fall days, ants stay stuck in the grass almost all day.

– On hot summer days, when the temperature reaches 36 degrees Celsius, ants do not behave this way or almost not at all. The parasite affects their behavior in cold times, which is crucial for their survival, because deer feed mainly in the morning and evening.

Scientists confirmed that they do not know at the present time what the precise mechanism is that allows butterfly larvae to control the behavior of ants. Gaskey said it may be related to the production of a specific protein by the larvae or to the immune process that occurs after infection with the parasite. As the researcher added, this is not the end of the “zombie ants” observations – in the future she also plans to determine the effect of sunlight on the behavior of infected insects.