An ant leans over an ant blueworm caterpillar as if caring for it. In fact, there are some species of butterflies whose caterpillars rely on the support of ants. Vibration rhythms play an important role.
Ants and caterpillars have a special connection. The ants carry baby caterpillars of some butterfly species to their nest, protect them from danger or even feed them. They treat them like members of the colony. To do this, the caterpillars release a sugary secretion and adapt to the ant colony. They imitate the ants visually, chemically, behaviorally or even acoustically.
Vibration signals are widespread among insects. Ants also use these for communication. A research group at the University of Warwick has now examined the rhythmic signals in more detail. To do this, the researchers looked at two species of ants and nine species of butterflies, whose caterpillars depend on ants to varying degrees. Among other things, they examined the speed of the signals and the regularity of the patterns.
The results show that caterpillars that have a particularly strong connection to ants have more regular and complex rhythms. The vibration signals are therefore similar to those of ants. There are also two key rhythms shared by ants and highly ant-dependent caterpillars: a steady pulse and a more complicated pattern that alternates long and short intervals. This combination was not observed in caterpillars, which have a weaker connection to ants. This suggests that the respective species have developed a common rhythm pattern through their close connection.
Rhythm is not only reserved for humans or animals with large brains, but also plays a major role in insects. This suggests that it is a fundamental feature of communication.