Basic Entomology

What is Entomology?

Entomology is the branch of zoology that deals with the scientific study of insects and how they relate to humans, the environment, and other living organisms.  The word comes from the Greek word entom which means “notched”, a reference to their segmented bodies.

The origins of entomology date back to the times of Aristotle (384-322 BC) when biology became a formal field of study.  Humans have been known to make use of insects in their daily life as far back as 4700 BC when Chinese began growing silkworms.  However, it was not until the Renaissance and up to the Age of Enlightenment that the true scientific study of insects developed.  By the 18th and 19th centuries, most major universities were studying the world's insects.

What are Insects?

Insects are arthropods.  They are invertebrates (have no backbone) which as adults have exoskeletons, three body segments (head, thorax, and abdomen), and three pairs of jointed legs.  Most have a pair of compound eyes and two antennae. 

Insects are some of the oldest creatures on earth. There are over one million identified species on earth today, with estimates that some five to eight million species exist but have not yet been identified. Insects inhabit ever portion of earth except the open seas.  

Most insects are beneficial or harmless to humans.  They are instrumental in pollinated fruits, vegetables, and other plants.  Some insects prey on other harmful insects.  Insects provide food for many animals like birds.  Others provide useful products for humans like honey, wax, and silk.

However, some insects are harmful.  There are insects that cause economic destruction by destroying crops.  About 1/6th of the world’s crops is destroyed by insects as they are being grown or after their harvest.  Insects are also harmful to humans, pets, livestock, and crops because they are carriers for diseases.

Insects are a member of the phylum Arthropoda meaning “jointed legs”.  They, like spiders, ticks, crabs, and lobsters, are classified as arthropods because they have segmented bodies and their skeleton is on the outside of their body (called an exoskeleton).   Many other arthropods are mistakenly called insects.