An entomologist is a scientist who studies insects, their biology, behavior, ecology, and relationships with other organisms and the environment. The field stretches far beyond catching butterflies with a net. Entomologists work in agriculture, public health, criminal investigations, conservation, and even engineering, applying their knowledge of the world’s most species-rich animal group to problems that affect nearly every part of human life.
Why a Whole Scientific Discipline for Insects
Insects make up the vast majority of known animal species on Earth. Estimates vary, but there are well over a million described insect species, and researchers suspect millions more remain undiscovered. That staggering diversity means insects show up everywhere: pollinating food crops, spreading diseases, decomposing dead matter, feeding other wildlife, and damaging forests and buildings. No single researcher can cover all of that, so entomology has branched into dozens of subspecialties, each focused on a different slice of insect life and its intersection with human concerns.
Identifying those species accurately is itself a major challenge. Traditional methods that rely on physical features demand specialist knowledge and are labor-intensive, which is why DNA barcoding has emerged as a practical tool for cataloging insect biodiversity more efficiently.1Forest Research Papers. DNA barcoding: A practical tool for the taxonomy and species identification of entomofauna Taxonomy may sound dry, but it underpins everything else entomologists do: you cannot protect a pollinator, control a pest, or track a disease vector if you cannot tell what species you are looking at.
Agricultural Entomology and Crop Protection
A large share of working entomologists spend their careers figuring out how to keep insects from destroying the food supply. Agricultural entomologists study pest life cycles, feeding habits, and vulnerabilities to develop strategies collectively known as integrated pest management, or IPM. The goal is to control pest damage with the least collateral harm to beneficial insects, soil health, and human safety.
One growing area within agricultural entomology is chemical ecology, which focuses on how insects use chemical signals to find food, locate mates, mark territory, and coordinate behavior.2PubMed Central. Chemical Communication in Insects: New Advances in Integrated Pest Management Strategies Pheromones, for example, are species-specific chemical signals insects rely on for mating and aggregation. Decades of research into these compounds have enabled entomologists to design precision tools like pheromone traps and slow-release dispensers that disrupt pest mating cycles without broad-spectrum pesticides.3PubMed Central. Design of Polymer Carriers for Optimized Pheromone Release in Sustainable Insect Control Strategies
Repellent-based strategies follow a similar logic. Researchers have tested naturally occurring volatile compounds to deter pest insects from laying eggs on crops. In one example, treating red raspberry fruit with certain volatiles significantly reduced egg-laying by a pest fly in both lab and field trials.4PubMed. Robust Manipulations of Pest Insect Behavior Using Repellents and Practical Application for Integrated Pest Management Work like this illustrates how entomologists translate detailed knowledge of insect sensory biology into practical crop protection.
Medical and Veterinary Entomology
Some of the deadliest diseases in human history are transmitted by insects. Malaria, dengue, Zika, Chagas disease, and leishmaniasis all depend on insect vectors to spread from host to host. Medical entomologists study the biology of these vectors, figure out where and when they breed, and develop strategies to interrupt transmission.
A key part of this work is surveillance: monitoring insect populations over time and testing whether they have developed resistance to the chemicals used to control them. In mosquito-borne disease programs, entomologists routinely collect local mosquito populations and expose them to insecticides to see whether the chemicals still work.5Borneo Journal of Medical Sciences (BJMS). Entomological Surveillance on Resistance of Aedes to Aqua K-Otherine at Taman Sri Rugading, Tuaran, Sabah, Malaysia When resistance is detected, control programs can switch chemicals or adopt alternative methods before an outbreak spirals. Veterinary entomologists do the same kind of work for livestock diseases, tackling insects that transmit pathogens to cattle, poultry, and other animals.
Forensic Entomology
When a body is found under uncertain circumstances, a forensic entomologist can help determine how long the person has been dead. The core idea is straightforward: certain insects, particularly flies and beetles, colonize remains in a predictable sequence. By identifying the species present and the developmental stage of their larvae, an entomologist can estimate the postmortem interval, which is essentially the time since death.6PubMed. Case report on Cochliomyia hominivorax and Co. macellaria myiasis prior to death: Implications on postmortem interval estimation
This technique depends on having good baseline data for the region where a body is found, because insect species composition and arrival timing vary with climate, season, and geography. Researchers build those baselines through controlled decomposition studies, often using pig carcasses as proxies for human remains. A study in southern Nigeria, for instance, documented arthropod succession on pig carrion across wet and dry seasons, providing reference data that forensic scientists in that region can use when real cases arise.7PubMed Central. Insect succession patterns on pig carrion in southern Nigeria Without that locally calibrated knowledge, postmortem interval estimates would be far less reliable.
Forensic entomology can also reveal more than just time of death. In one case, the presence of parasitic fly species that only colonize living tissue told investigators that the victim had been alive and suffering from a wound infestation before death, which altered the timeline and the interpretation of the crime scene.6PubMed. Case report on Cochliomyia hominivorax and Co. macellaria myiasis prior to death: Implications on postmortem interval estimation
Conservation Entomology and the Insect Decline Problem
Entomologists have been raising alarms about declining insect populations for years, and the evidence keeps building. Globally, insect numbers have been dropping, driven by habitat loss, pesticide use, pollution, invasive species, intensive agriculture, and climate change.8Psyche: A Journal of Entomology. A Systematic Review of Insect Decline and Discovery: Trends, Drivers, and Conservation Strategies over the past Two Decades Because insects underpin so many ecological processes, from pollination to decomposition to serving as food for birds and fish, their decline has cascading effects across ecosystems.
Conservation entomologists work to document which species and populations are declining, figure out why, and develop strategies to reverse the trend. That includes habitat restoration, promoting sustainable land management, and advocating for species-specific protections. The challenge, though, is partly political. Several roadmaps to averting biodiversity loss have been proposed at the international level, but meaningful progress has been limited, with economic and political factors consistently undermining commitments.9PubMed Central. Global insect decline is the result of wilful political failure: A battle plan for entomology One prominent paper argued bluntly that the continued decline is a result of political failure rather than scientific ignorance. Entomologists working in conservation therefore find themselves not just doing fieldwork but also engaging with policy, communicating findings to the public, and pushing for regulatory change.
Forest Entomology and Invasive Species
Forests face a particular category of threat from invasive insects, species that arrive in new regions (often via international trade in wood products) and encounter trees with no evolved defenses against them. Entomologists specializing in forest health focus heavily on early detection, because stopping an invasive insect early is far more feasible and cost-effective than trying to control it after it has established a breeding population across a wide area.10Resources. Forest Health Management and Detection of Invasive Forest Insects
This work involves setting traps near ports and shipping hubs, identifying intercepted specimens, and monitoring forests for unusual tree damage that could signal a new arrival. When an invasion is detected, entomologists help design the response: quarantine zones, targeted chemical treatments, or biological control using natural enemies of the invader. The emerald ash borer and the Asian longhorned beetle are two well-known examples where forest entomologists have led the scientific response to devastating invasive insects in North America.
Modern Tools Reshaping the Field
Entomology has traditionally been a field of hand nets, pinning boards, and microscopes. That toolkit is expanding rapidly. Computer vision systems can now identify insects from photographs or video, acoustic monitoring can detect species by their wing-beat frequencies or calls, radar technology tracks insect migration at landscape scales, and molecular methods including environmental DNA let researchers detect species from traces they leave behind in water or soil.11PubMed. Emerging technologies revolutionise insect ecology and monitoring
These technologies are particularly valuable for the insect decline question. Traditional monitoring requires trained specialists to hand-sort thousands of specimens, which limits how many sites can be surveyed and how often. Automated identification and remote sensing can massively increase the scale and frequency of monitoring, giving researchers a much clearer picture of population trends. For a young entomologist entering the field today, comfort with data science and sensor technology is becoming nearly as important as the ability to identify a beetle under a microscope.
Genetic Pest Control Strategies
One of the more innovative tools in the entomologist’s arsenal is the sterile insect technique, which has been used for over six decades as part of large-scale pest management programs worldwide.12PubMed Central. Sterile Insect Technique (SIT) and Its Applications The basic principle is to mass-rear the target pest species, sterilize the males through irradiation, and release them into wild populations. When sterile males mate with wild females, no offspring result, so the population shrinks over time without any pesticide being sprayed.
The technique has been refined considerably over the years. Modern programs use genetically sexing strains that allow factories to rear and release only males, which improves efficiency since females do not contribute to the suppression effect. One program targeting the Mediterranean fruit fly in Argentina combined sterile male releases with biological control using parasitoid wasps, achieving roughly 96% suppression of the pest population, an effect close to local eradication.13Agronomy. Combined Effect of Sterile Insect Technique and Augmentative Biological Control Use for Ceratitis capitata Control Under Field Cage Conditions Entomologists in this space work on everything from optimizing rearing conditions and radiation doses to evaluating how released sterile males perform in field conditions.14PubMed. Performance of a Genetically Modified Strain of the Mediterranean Fruit Fly for Area-Wide Integrated Pest Management With the Sterile Insect Technique
A related approach involves entomopathogenic fungi, naturally occurring fungal species that infect and kill insects. Over a thousand fungal species from eleven different phyla are known to attack insects, though their role in natural ecosystems is still poorly understood compared to their use in agriculture. A recent meta-analysis found that the median infection rate in natural settings was around 8%, suggesting fungi cause less insect mortality than predators and parasitoids do, but they remain a valuable and chemical-free tool for targeted pest management.15PubMed Central. Entomopathogenic Fungi as Mortality Agents in Insect Populations: A Review
Insects as Industrial and Environmental Resources
Not all entomological work is about killing or controlling insects. A growing branch of the field treats insects as useful biological machines. Insects have been proposed as efficient agents for converting agricultural and food waste into valuable biomass. Certain fly larvae, for example, can consume enormous quantities of organic waste and convert it into protein-rich material suitable for animal feed, while their gut microbiota play a key role in breaking down complex organic compounds during the process.16PubMed Central. Insect-based agri-food waste valorization: Agricultural applications and roles of insect gut microbiota
Entomologists working in this space study which insect species process waste most efficiently, how to optimize rearing conditions for maximum biomass output, and how the microbial communities living inside insect guts contribute to the breakdown process. It is applied ecology with a commercial and environmental payoff: diverting organic waste from landfills while producing feed ingredients that reduce pressure on conventional protein sources like fishmeal and soy.
Biomechanics and Engineering Inspiration
Some entomologists work at the intersection of biology and engineering, studying how insects move, sense, and build. Insect flight, in particular, has fascinated researchers for decades because insects achieve aerodynamic feats that seem to defy the rules governing larger aircraft. One study of a tiny fly with wings barely 1.4 millimeters long found that it beat its wings at about 265 times per second with a stroke amplitude of roughly 182 degrees, generating a mean lift coefficient of about 1.85, several times higher than that of a cruising airplane.17PubMed Central. Wing-kinematics measurement and aerodynamics in a small insect in hovering flight A “clap and fling” motion of the wings boosted lift by an additional 7%.
Findings like these feed directly into the design of micro-drones and other small flying robots. Engineers look to insect wing mechanics for solutions to problems that conventional aerodynamics cannot solve at very small scales. Entomologists who specialize in biomechanics use high-speed cameras, wind tunnels, and computational fluid dynamics to decode these systems, and the resulting insights have applications well beyond biology.
Urban Entomology
As more of the world’s population lives in cities, a distinct branch of entomology has emerged to deal with the insects that thrive alongside us in built environments. Urban entomology covers the study and management of arthropod pests in homes, restaurants, hospitals, warehouses, and other structures. Cockroaches, bed bugs, termites, and stored-product beetles are among the usual suspects. The field is expected to grow as urbanization intensifies and the global economy drives more international movement of goods, which inevitably moves pests along with them.18Annual Reviews. The Emergence and Sustainability of Urban Entomology
Urban entomologists work with pest control companies, public health departments, and building managers. Their expertise goes beyond simply recommending a pesticide: they analyze building design for pest entry points, study how insect populations develop resistance to commonly used chemicals, and develop integrated strategies that combine sanitation, exclusion, monitoring, and targeted treatment. It is one of the most commercially visible corners of the field and among the most directly relevant to everyday life.
Insects in Human Culture
There is even a subdiscipline devoted to the role insects play in human culture, spirituality, and symbolism. Ethnoentomology examines how different societies have understood and interacted with insects across history, covering everything from the use of insects as food and medicine to their symbolic significance in mythology, art, and cosmology.19PubMed Central. Ethnoentomology (1952–2024): scientific production, emerging trends and research gaps In many cultures, specific insects carry spiritual or cosmological meaning, serving as omens, symbols of social values, or elements of collective identity.
Ethnoentomologists document traditional knowledge about insects that might otherwise be lost, including indigenous pest-management practices, medicinal uses of insect products like honey and propolis, and the ecological knowledge embedded in cultural relationships with specific species. This work sometimes feeds back into applied entomology: traditional knowledge about which insects are safe to eat, for instance, is informing modern research on entomophagy and insect farming. The field sits at the boundary between natural science and anthropology, and it reminds us that humans have been amateur entomologists for far longer than the discipline has formally existed.