A food chain is simply a description of who eats what in an environment. In any
terrestrial ecosystem there are herbivorous bugs that eat plants, detritivorous
bugs that feed on leaf litter and dead animals, and carnivorous
bugsferocious predators of live animals, including other bugs.
Who Eats What
A food chain describes the transfer of energy from an organism to other
organisms. Each animal and plant can be thought of as a link in the chain.
Ants, for example, may have located a food source in an injured cricket.
Hundreds of worker ants march out in single file to bring the food back to the
nest. But there are other hungry predators, such as the thorny devil, that love
to eat ants. The food chain is:
Each arrow means ‘is eaten by’ and shows the flow of energy from one
living thing to the next. You can extend the food chain. What do crickets eat?
What would eat thorny devils?
Bugs Eating Bugs
It is said that insects are their own worst enemy. The most important predators
of bugs are other bugs. There are thousands of bug-eating bugs, more than
half of which are beetles. These include ladybirds, fireflies, tiger beetles,
ground beetles and water tigers.
Many ants are insectivorous, as are all of the social wasps and most of the
solitary ones. Other insectivorous species include dragonflies, damselflies,
robber flies, many hover flies, lacewings, antlions, ambush bugs and assassin
bugs (True Bugs). Some carnivorous bugs will eat almost anything they can
catch, while others specialise on particular types of prey.
All insectivorous bugs have special adaptations and behaviours that allow them
to trap the animals that they will eat. Praying mantids will sit motionless and
perfectly camouflaged, waiting to ambush their prey. Their forelegs are armed
with sharp spines and they strike with lightning speed. They will attack and
eat anything that comes close enough, even their mates.
Different species of spiders use either ‘web-catching’ or
‘hunting’ techniques to catch their prey. Species that are
web-catchers weave elaborate webs and wait for their victims to become
ensnared in the sticky silken threads. Spiders like the wolf spider are vagrant
hunters and actively stalk their prey on foot.