Entomology is the branch of zoology that deals with the study of insects. There is a wide spectrum within the field, because insects, making up more than 80 percent of the entire animal species, are the dominant life form on Earth. There are more than 1 million known species, and some scientists believe there may be more than 30 million species yet undiscovered.

The word "entomology" is based in the Greek language. It combines entomos, which roughly translates to "something segmented or cut into pieces" and logia, or "the study of".

Because they make up such an enormous part of the life on this planet, it goes without saying that insects play important roles in various fields: ecology, botany, biomechanics, paleontology, etc. Their study is essential to better understand the often symbiotic relationship other life forms have with insects.


FORENSIC ENTOMOLOGY
Forensic entomology is the study of insects in legal cases. Usually forensic entomology is associated with how insects feed on dead bodies, but the science may also be used in civil cases, such as the investigation of contaminated food.

Some recent criminal and medical television series feature forensic entomologists who can help determine information about a person's time of death based on the stage of insect activity in the cadaver. Two of the most popular are CSI and Bones.


MEDICAL ENTOMOLOGY
Medical entomology deals with disease-spreading insects like mosquitoes, mites, ticks and fleas. Originating in 1878 with the discovery that mosquitoes had the capability to transmit parasites, this discipline deals with other infectious diseases like malaria, typhus, and plague. Military medical entomology, separate from civilian medical entomology, helps armies determine and eradicate insect threats to troops. According to the United States Air Force, the military has been using medical entomologists since 1900 and the discovery that mosquitoes transmitted yellow fever.


RESEARCH ENTOMOLOGISTS
Research entomologists can be experts in any sub-field of entomology. Many entomologists specialize in a single order or even a family of insects, and a number of these subspecialties are given their own informal names, often derived from the scientific name of the group, for example:

- Apiology (or melittology) - bees
- Coleopterology - beetles
- Dipterology - flies
- Lepidopterology - moths and butterflies
- Myrmecology - ants
- Orthopterology - grasshoppers, crickets, etc.

The studies of research entomologists can extend to classification, conservation, toxicology and evolutionary biology of their chosen order or family.


TAXONOMIC SPECIALIZATION OF INSECTS
The more than 1 million known species of insects are currently divided into dozens of different orders. Some of the most common are shown below:

Collembola: Springtails - from the Greek: colla = glue + embolon = wedge or peg)

Thysanura: Silverfish, Firebrats, Bristletails - from the Greek: thysanos = tassel + oura = tail

Ephemeroptera: Mayflies - from the Greek: ephemeros = living but a day

Odonata: Dragonflies and Damselflies - from the Greek: odontos = tooth

Orthoptera: Grasshoppers, Crickets, Katydids - from the Greek: orthos = straight + ptera = wings

Phasmida: Walking Sticks - from the Greek: phasm = phantom

Mantodea: Praying mantids - from the Greek: mantis = soothsayer

Blattaria: Cockroaches - from the Latin: blatta = cockroach

Isoptera: Termites - from the Greek isos = equal + ptera = wings

Dermaptera: Earwigs - from the Greek: derma = skin + ptera = wings

Plecoptera: Stoneflies - from the Greek: plekos = plaited + ptera = wings

Psocoptera: Psocids, Barklice, Booklice - from the Greek: psocho = to rub or grind into small pieces + ptera = wings

Phthiraptera: Lice - from the Greek: phthir = lice + aptera = wingless

Hemiptera: True Bugs - from the Greek: hemi = half + ptera = wings

Homoptera: Aphids, Cicadas, Scales, Leafhoppers, and others - from the Greek: homos = same + ptera = wings

Thysanoptera: Thrips - from the Greek: thysanos = fringe + ptera = wing

Neuroptera: Lacewings, Dobsonflies, Antlions, others - from the Greek neura = nerves + ptera = wings

Coleoptera: Beetles - from the Greek: coleos = sheath + ptera = wings

Mecoptera: Scorpionflies and Hanging Scorpionflies - from the Greek: mecos = long + ptera = wings

Diptera: Flies, Gnats, Midges, Mosquitoes - from the Greek: di = two + ptera = wings

Siphonaptera: Fleas - from the Greek: siphon = tube + aptera = without wings

Trichoptera: Caddisflies, Caseflies - from the Greek: trichos = hair + ptera = wings

Lepidoptera: Moths, Butterflies, and Skippers - from the Greek: lepidos = scale + ptera = wings

Hymenoptera: Wasps, Bees, Ants, Sawflies, Horntails - from the Greek: hymen = membrane + ptera = wings