As discussed in the previous chapters, plants are the producers of forest ecosystems. All animals belong either to the consumers or the decomposers of the forest. They need make use of the chemical energy produced by green plants in order to grow and develop. To do this, they must consume other organisms.

Consumers can be divided into herbivores and predators. The larvae of many insect species are herbivores. Butterfly larvae, for example, can sometimes devour all the leaves of a broadleaf tree. These larvae are examples of first degree consumers. As they eat and gain energy, the insect larvae gradually grow bigger and pupate. Finally, an adult butterfly emerges from the pupa.

Many insect species are predators. They gain their energy by preying on other insects. They are second degree consumers. The ladybug is an example of a predator insect species.

Some invertebrates act as decomposers. They use parts of dead organisms, such as plant leaves and insects, as their source of energy. Some species of beetle are examples of decomposer insects.


Insect larvae are first degree consumers.