Entomology, fromAncient Greek ἔντομον (éntomon), meaning insect", and-logy from λόγος (lógos), meaning "study",^[1] is the branch ofzoology that focuses on insects. Those who study entomology are known as entomologists. In the past, the terminsect was less specific, and historically the definition of entomology would also include the study ofanimals in otherarthropod groups, such asarachnids,myriapods, andcrustaceans. The field is also referred to as insectology in American English, while in British English insectology implies the study of the relationships between insects and humans.^[2]

Diversity of insects from different orders

Over 1.3 million insectspecies have been described by entomology.^[3]

Entomology is rooted in nearly all humancultures fromprehistoric times, primarily in the context ofagriculture (especiallybiological control andbeekeeping). The natural Roman philosopherPliny the Elder (23–79 CE) wrote a book on the kinds of insects,^[4] while the scientistof Kufa,Ibn al-A'rābī (760–845 CE) wrote a book on flies,Kitāb al-Dabāb (كتاب الذباب). However scientific study in the modern sense began only relatively recently, in the 16th century.^[5]Ulisse Aldrovandi'sDe Animalibus Insectis (Concerning Insect Animals) was published in 1602. MicroscopistJan Swammerdam publishedHistory of Insects, correctly describing the reproductive organs of insects andmetamorphosis.^[6] In 1705,Maria Sibylla Merian published the bookMetamorphosis Insectorum Surinamensium about the tropical insects ofDutch Surinam.^[7]

Early entomological works associated with the naming and classification of species followed the practice of maintainingcabinets of curiosity, predominantly in Europe. This collecting fashion led to the formation of natural history societies, exhibitions of private collections, and journals for recording communications and the documentation of new species. Many of the collectors tended to be from the aristocracy, and there developed a trade involving collectors around the world and traders. This has been called the "era of heroic entomology".William Kirby is widely considered as the father of entomology in England. In collaboration withWilliam Spence, he published a definitive entomological encyclopedia,Introduction to Entomology, regarded as the subject's foundational text. He also helped found theRoyal Entomological Society in London in 1833, one of the earliest such societies in the world; earlier antecedents, such as theAurelian society date back to the 1740s. In the late 19th century, the growth of agriculture, and colonial trade spawned the "era of economic entomology" which created the professional entomologist associated with the rise of the university and training in the field of biology.^[8][9]

Entomology developed rapidly in the 19th and 20th centuries and was studied by large numbers of people, including such notable figures asCharles Darwin,Jean-Henri Fabre,Vladimir Nabokov,Karl von Frisch (winner of the 1973Nobel Prize in Physiology or Medicine),^[10] and twicePulitzer Prize winnerE. O. Wilson.

There has also been a history of people becoming entomologists through museum curation and research assistance,^[11] such asSophie Lutterlough at the SmithsonianNational Museum of Natural History. Insect identification is an increasingly common hobby, withbutterflies^[12] and (to a lesser extent)dragonflies being the most popular.^[13]

Most insects can easily be allocated toorder, such asHymenoptera (bees, wasps, and ants) orColeoptera (beetles). However, identifying to genus or species is usually only possible through the use ofidentification keys andmonographs. Because the classInsecta contains a very large number of species (over 330,000 species of beetles alone) and the characteristics distinguishing them are unfamiliar, and often subtle (or invisible without a microscope), this is often very difficult even for a specialist. This has led to the development ofautomated species identification systems targeted on insects, for example,Daisy, ABIS, SPIDA and Draw-wing.

In 1994, the Entomological Society of America launched a newprofessional certification program for the pest control industry called the Associate Certified Entomologist (ACE). To qualify as a "true entomologist" an individual would normally require an advanced degree, with most entomologists pursuing a PhD. While not true entomologists in the traditional sense, individuals who attain the ACE certification may be referred to as ACEs or Associate Certified Entomologists.^[14]

As such, other credential programs managed by the Entomological Society of America have varying credential requirements. These different programs are known as Public Health Entomology (PHE), Certified IPM Technicians (CITs), and Board Certified Entomologists (BCEs) (ESA Certification Corporation). To be qualified in public health entomology (PHE), one must pass an exam on the types of arthropods that can spread diseases and lead to medical complications (ESA Certification Corporation). These individuals also have to "agree to ascribe to a code of ethical behavior" (ESA Certification Corporation). Individuals who are planning to become Certified IPM Technicians (CITs), need to obtain at around 1-4 years of experience in pest management and successfully pass an exam, that is based on the information, that they are acquainted with (ESA Certification Corporation). Like in Public Health Entomology (PHE), those who want to become Certified IPM Technicians (CITs) also have to "agree to ascribe to a code of ethical behavior" (ESA Certification Corporation). These individuals must also be approved to use pesticides (ESA Certification Corporation). For those who plan on becoming Board Certified Entomologists (BCEs), individuals have to pass two exams and "agree to ascribe to a code of ethical behavior" (ESA Certification Corporation). As with this, they also have to fulfill a certain amount of educational requirements every 12 months (ESA Certification Corporation).^[15]

Forensic entomology is a branch offorensic science that studies insects found on corpses or elsewhere around crime scenes. This includes studying the types of insects commonly found oncadavers, their life cycles, their presence in different environments, and how insect assemblages change withdecomposition.^[16]

Medical entomology is focused uponinsects andarthropods that impact human health. Veterinary entomology is included in this category, because many animal diseases can "jump species" and become a human health threat, for example, bovine encephalitis. Medical entomology also includes scientific research on the behavior, ecology, andepidemiology of arthropod diseasevectors, and involves a tremendous outreach to the public, including local and state officials and other stake holders in the interest of public safety.

Many entomologists specialize in a single order or even a family of insects, and a number of these subspecialties are given their own generic names, typically (but not always) derived from the scientific name of the group:

• Coleopterology –beetles
• Dipterology –flies
• Odonatology –dragonflies and damselflies
• Hemipterology –true bugs
• Isopterology –termites
• Lepidopterology –moths andbutterflies
• Melittology (orApiology) –bees
• Myrmecology –ants
• Orthopterology –grasshoppers,crickets, etc.
• Trichopterology –caddisflies
• Vespology – socialwasps

Like other scientific specialties, entomologists have a number of local, national, and international organizations. There are also many organizations specializing in specific subareas.

• Amateur Entomologists' Society
• British Entomological and Natural History Society
• Entomological Society of America
• Entomological Society of Canada
• Entomological Society of Japan
• Entomologischer Verein Krefeld
• Royal Entomological Society
• Australian Entomological Society^[17]
• Entomological Society of New Zealand^[18]

Here is a list of selected very large insect collections, housed in museums, universities, or research institutes.

• Zoological Survey of India

• Natal Museum,Pietermaritzburg, South Africa^[19]

• Lincoln University Entomology Research Collection, Lincoln, New Zealand

• Bavarian State Collection of Zoology,Zoologische Staatssammlung München

• Academy of Natural Sciences of Philadelphia

• Canadian Museum of Nature,Ottawa,Ontario

• Capinera, JL (editor). 2008.Encyclopedia of Entomology, 2nd Edition. Springer.ISBN 1-4020-6242-7

• Chiang, H.C. and G. C. Jahn 1996. Entomology in the Cambodia-IRRI-Australia Project. (in Chinese)Chinese Entomol. Soc. Newsltr. (Taiwan) 3: 9–11.
• Davidson, E. 2006.Big Fleas Have Little Fleas: How Discoveries of Invertebrate Diseases Are Advancing Modern Science University of Arizona Press, Tucson, 208 pages,ISBN 0-8165-2544-7.
• Gillot, Cedric. Entomology. Second Edition, Plenum Press, New York, NY / London 1995,ISBN 0-306-44967-6.
• Grimaldi, David;Engel, Michael S. (2005).Evolution of the Insects. Cambridge University Press.ISBN 0-521-82149-5.

• Triplehorn, Charles A. and Norman F. Johnson (2005-05-19). Borror and DeLong's Introduction to the Study of Insects, 7th edition, Thomas Brooks/Cole.ISBN 0-03-096835-6. — a classic textbook in North America.
• Wale, Matthew.Making Entomologists: How Periodicals Shaped Scientific Communities in Nineteenth-Century Britain (U of Pittsburgh Press, 2022)online book review