Insects call each other too.

Well, sort of.

The Environmental News Network has an article entitled Insect use Plants Like a Telephone.

A Dutch ecologist and her colleagues found out that any plant-eating insect can communicate to each other using plants.

Subterranean insects or underground insects emit chemical warning signals using the leaves of plants. When the underground insect does that, aboveground insects are warned that the plant is taken.

Herbivore insects do this to avoid unnecessary competition. Aboveground insects would rather have plants that have not yet been occupied by underground insects which have already eaten the root.

The article says that in recent years it has been found that some aboveground insects have developed slower when they eat plants that have been eaten by an underground insect.

Through this telephone, underground insects can also communicate to parasitic wasps. Aboveground insects are the unfortunate hosts of parasitic wasps who lay eggs inside of them. When signals are emitted from underground insects, it shows wasps where they can find a good host for their egg.

Because the recent studies on insect communication was done in only a few systems, ecologists don’t know how commonly widespread the green telephone is.