INTRODUCTION TO THE STUDY OF ENTOMOLOGY
Takumasa Kondo
Corporación Colombiana de Investigación Agropecuaria (CORPOICA), Centro de
Investigación Palmira, Valle del Cauca, Colombia.
Keywords: apiculture, applied entomology, arthropoda, arthropod-borne diseases, basic
entomology, biogeography, bugs, Chagas disease, ecological genetics, entomology, entomophagy,
entognathology, entognathologist, forest entomology, Hexapoda, Insecta, insect anatomy, insect
physiology, insect color pigments, insect molecular genetics, insect morphology, insect pets, insect
science, insect taxonomy, medical and veterinary entomology, meliponiculture, phylogenetics
population genetics, sericulture, systematic entomology, urban entomology.
Contents
1. Introduction
2. What is an insect?
3. Insects and people
4. What subjects are studied in entomology?
5. Basic entomology
5.1. Insect anatomy and insect physiology
5.2. Systematic entomology
5.3. Insect developmental biology/insect growth and development
5.4. Insect ecology
5.5. Ecological genetics, insect molecular genetics and population genetics
6. Applied entomology
6.1. Agricultural Entomology
6.2. Forest Entomology
6.3. Medical and Veterinary Entomology
6.3.1. Arthropod-borne diseases
6.3.2. Chagas disease
6.4. Urban Entomology
6.5. Apiculture and meliponiculture
6.6. Sericulture
7. Insect color pigments
8. Entomophagy
9. Insects and other arthropods as pets
10. Conclusions
Summary
Strictly defined, entomology is the study of insects, but often includes closely related arthropods as
well. The work of entomologists, the people who study insects is extremely diverse due to the high
abundance, species richness, and ecological and behavioral characteristics of insects. This chapter is
intended as an introduction to the study of entomology, giving brief explanations and definitions of
some chosen topics such as integrated pest management, Chagas disease caused by triatomine bugs,
colony collapse disorder of honey bees, red pigments derived from scale insects, the human
consumption of insects, and keeping of insects as pets. Emphasis was particularly given to some
important aspects of human association with insects.
Since early times, entomology has been a very broad subject. Oliver Wendell Holmes Sr.
(29.viii.1809 – 8.x.1894) in his book “The Poet at the Breakfast Table” (1872) wrote the following
quotes that describe the complexities of entomology:
“ ‘I suppose you are an entomologist?’ I said with a note of interrogation.”
“Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that
name! A society may call itself an Entomological Society, but the man who arrogates such a broad
title as that to himself, in the present state of science, is a pretender, sir, a dilettante, an impostor!
No man can be truly called an entomologist, sir; the subject is too vast for any single human
intelligence to grasp.”
1. Introduction
Entomology is a branch of biology that focuses on the study of insects. The word entomology
comes from the French word “entomologie” coined from the Greek word “entomon” meaning
“insect” + “logia” meaning the “study of”. “Entomon” comes from the word “entomos” which
means "having a notch or cut (at the waist)," so called by Aristotle in reference to the segmented
division of the insect body, from “en-” meaning “in” + “temnein” meaning “to cut” (Online
Etymology Dictionary, 2011).
In the strict sense, entomology is the study of insects, but entomologists often study other
arthropods such as arachnids (e.g., spiders, scorpions and mites), myriapods (e.g., millipedes and
centipedes) and even crustaceans (e.g., crabs and isopods). Nevertheless, insects (those organisms
belonging to the class Insecta) are studied by entomologists, arachnids are studied by arachnologists
and acarologists (those who specialize on mites and ticks), myriapods are studied by
myriapodologists, and crustaceans are studied by carcinologists (also known as malacostracologists
or crustaceologists). Recent phylogenetic studies have placed organisms previously included in the
class Insecta, such as diplurans (order Diplura), proturans (order Protura) and springtails (order
Collembola) into a sister group called the class Entognatha. Hexapods (six legged organisms) of the
class Entognatha have long been treated as insects, and thus are generally studied by entomologists
too. The word “entognathology” may be proposed as the study of these non-insect hexapods, and
the word “entognathologist” to describe those who study them.
2. What is an Insect?
Insects are small animals with 6 pairs of legs that range from less than 1 mm to about 30 cm long.
Within the phylum Arthropoda, the classes Insecta and Entognatha (together forming the superclass
Hexapoda) have the most developed tagmosis, that is, their body segments are arranged into welldefined functional body parts known as tagmata (singular tagma). Adult insects and entognathans
are characteristic in having three tagmata, the head, thorax and abdomen (Figs 1 & 2, left). Besides
bearing the mouthparts, the insect head contains many of the sensory organs that perceive and
process external information (e.g., antennae, eyes and ocelli). The thorax bears the locomotory
organs (i.e., legs and wings). The abdomen contains most of the organs associated with metabolism
and reproduction. The insect body is protected by a hard external “shell” or integument called the
exoskeleton, which is composed of cuticle that is secreted by the epidermis. Cuticle is formed of
chitin (an amino-sugar polysaccharide) and protein, and there are several layers that vary in
development and composition on different areas of the body to allow flexibility or strength of the
body wall.
Other arthropods have a more reduced type of body segmentation - for example, arachnids have two
tagmata, the cephalothorax (or prosoma) and the abdomen (or opisthosoma) (Fig. 2, right). Insects
have different types of metamorphosis, but all entognathans have incomplete metamorphosis (see
Section 5.3.). Some morphological differences between the Insecta and the closely related
Entognatha are as follows (features of Entognatha in parenthesis): (1) mouthparts exposed or in
technical terms ectognathous (mouthparts not exposed, entognathous); (2) adults usually with
compound eyes and ocelli (eyes and ocelli usually absent, rudimentary when present); and (3) legs
composed of six segments (legs composed of four or five segments).
Colloquially, insects are often referred to as “bugs”, however, in entomology; the word “bug” is
strictly used for insects belonging to the order Hemiptera. Insects in this order, especially those of
the suborder Heteroptera are known as “true bugs”. Although insects of the family Coccinellidae
(Fig. 11) are sometimes called ladybirds or ladybugs, these are neither birds nor true bugs, but
actually beetles, and thus the names ladybird beetles or lady beetles are preferred by entomologists.
For common names of true bugs, e.g., assassin bug, leaf-footed bug or giant water bug, the word
‘bug’ is written separately from its adjective or descriptor.
Figure 1. A colorful eumastacid grasshopper (Insecta: Orthoptera: Eumastacidae). Photo by T.
Kondo.
Figure 2. Comparison of an insect and an arachnid. Left. The fruit fly, Anastrepha striata (Insecta:
Diptera: Tephritidae) showing its three main body parts. Right. The crab spider, Gasteracantha
cancriformis (Arachnida: Araneae: Araneidae) showing its two main body parts. Photos by T.
Kondo.
Many insect common names end with the word “fly”, e.g., butterfly, dragonfly, mayfly, whitefly,
but these are really not flies; butterflies belong to the order Lepidoptera, dragonflies belong to the
order Odonata, mayflies belong to the order Ephemeroptera and whiteflies belong to the order
Hemiptera. In entomology, “flies” are insects belonging to the order Diptera, and for this group,
common names are usually written with the word fly separately, e.g., fruit fly, vinegar fly, deer fly,
house fly, etc.
3. Insects and People
The first insects appeared on Earth more than 400 million years ago, in comparison to the modern
human species that only came into existence only about 50,000 years ago. Insects have long been
associated with humans. A list of some insects and insect products that are associated with human
life are summarized in Table 1.
Table 1. Insects and insect products associated with various aspects of human life.
Topic
Arts
literature
Associated insects or insect products
and Insects are often a subject in literature works and paintings (e.g.,
butterflies, flies, beetles). In some countries in SE Asia and Brazil, art
works made of butterfly wings are commonly sold.
Clothing
Plant fiber and leather product pests (e.g., carpet beetles, clothing
moths, screw worms), silk clothes (e.g., silk moths).
Cosmetics
Ingredients in cosmetics (e.g., bee wax, cochineal dye, honey).
Educational
Insects (silk moth, cockroaches, crickets, butterflies, others) are often
material
used for teaching art, biology and other related subjects.
Energy
Caddisfly cases (e.g., Stenopsyche siamensis; Stenopsychidae) can
foul flumes in hydroelectric generators and reduce generator
efficiency.
Food and
Agricultural, storage and food product pests (e.g., aphids, army
agriculture
worms, bruchid beetles, cigarette beetles, corn borers, fruit flies, fruit
borers, inch worms, Indian meal moth, June beetles, leaf beetles, leaf
hoppers, rice weevils, scale insects, schaffers, thrips, whiteflies,
wireworms); livestock pests (e.g., house fly, stable fly, horn fly, bot
flies, deer flies, horse flies, blister beetles, moths); insects and insect
products as a food source (e.g., honey, mopane worms, beetle grubs).
Forensic
The biologies of insects and other arthropods often aid in solving
science
crimes. Insects (e.g., flesh flies, blue bottle flies, various beetles,
moths) are often studied in criminal investigations to determine the
time of death, original location of a crime, etc.
Forestry
Bark beetles, gypsy moth, woolly adelgids, and other insect pests.
Human health Stinging and urticating insects (e.g., bees, carabids, hornets, blister
and medicine
beetles, moths); blood sucking and/or disease vectors (e.g., bed bugs,
black flies, ceratopogonid flies, cockroaches, fleas, deer flies, horse
flies, house flies, kissing bugs, lice, mosquitoes, sandflies, tsetse
flies); insect products use for pharmaceutical purposes (e.g., beeswax,
pela scale insect wax, shellac as material for coating pills);
aphrodisiacs (Spanish fly).
Jewelry
and Jewel beetles (buprestid beetles); butterflies; colorful and beautiful
ornaments
insects for display (e.g., butterflies, June beetles, rhinoceros beetles).
Museum
Cleaning flesh and cartilage from bone specimens (e.g., dermestid
beetles).
Science
Many species of insects are commonly studied by scientists, but the
vinegar fly, Drosophila melanogaster, is probably the most studied
organism in biological research, particularly in genetics and
developmental biology.
Sports
Fishing bait (e.g., caddisflies, stoneflies, chironomid midges).
Transport and Disruption of visibility and slippery road surface conditions (e.g.,
communication mayflies, chironomid midges); accidents due to distraction and stings
(bees, wasps, others); shellac extracted from the Indian lac insect
Kerria lacca may be used as an electric insulator in electric wires;
damage to electric wires (powderpost beetles).
Wood building Wood boring pests (e.g., bruchid beetles, carpenter ants, carpenter
and
bees, deathwatch beetles, longhorned beetles, termites).
construction
4. What Subjects are studied in Entomology?
Entomologists may investigate any number of subjects relevant to insects. Some examples include
agriculture, anthropology, behavior, biochemistry, biomechanics, developmental biology, ecology,
forensic science, insect art (Fig. 3), genetics, molecular biology, morphology, nutrition,
paleontology, physiology, robotics, systematics, and various other fields. For example, meteorology
is applied to the study of insects as radar technology is used for studying the migratory patterns of
insects such as butterflies and dragonflies.
Figure 3. Luna moth. Ceramic plate by unknown American artist. Photo by T. Kondo.
Entomology is divided into basic and applied entomology. The former deals with the basic aspects
of insects, whereas the latter deals with the economic aspects of insects in human society.
Nevertheless both basic and applied fields are like two wheels of a cart and must go hand in hand.
5. Basic Entomology
Basic entomology (also known as general, pure, fundamental, or theoretical entomology) deals with
studies such as biochemistry, biogeography, cytology, ecology, insect development, ethology,
genetics, histology, morphology (insect anatomy), paleoentomology, physiology, reproduction,
phylogeny and taxonomy.
5.1. Insect Anatomy and Insect Physiology
Insect anatomy is the study of the structures (body parts and organs) of insects. It is often taught in
courses in general entomology and insect physiology, and is usually divided into external and
internal anatomy. The study of external anatomy is called morphology. Morphology is the branch of
biology that deals with the form and structure of organisms. In entomology, morphology is
important to understand the functions of the various insect body plans and to allow the
classification and identification of insects and their relatives. Internal anatomy deals with the
internal organs of the insect body, and is often taught along with insect physiology because of the
close association of the various organs with essential chemical and physiological processes. The
study of minute anatomical structures includes histology (the study of the organization of tissues)
and cytology (the study of cells).
5.2. Systematic Entomology
Systematic entomology or insect systematics is the study of the diversity of insects and their interrelationships. Systematics can be subdivided into two fields, i.e., taxonomy and phylogenetics.
Insect taxonomy is the science that deals with recognizing, describing, and naming species and
groups of species, and the classification of insects into a ranked and named system (e.g., species,
genus, family, order, etc.) that aims to reflect a natural evolutionary history. Phylogenetics is the
study of the relatedness of organisms or groups of organisms based on shared ancestry. The study
of the distribution of insects based on environmental, geological factors and phylogenetic
relationships is termed biogeography.
More than half of the known species on Earth are insects, with an estimate of 925,000 species
described! Within the currently recognized 29 insect orders, the most species-rich orders are the
Coleoptera (the beetles) (e.g., Figs 11 & 25) (38% of species), Lepidoptera (butterflies, moths (e.g.,
Figs 4, 8 & 26) and skippers) (16%), Hymenoptera (ants, bees (e.g., Figs 18 & 19) and wasps (e.g.,
Fig. 25)) (13%) and the Diptera (flies (e.g., Figs 2 left & 10), gnats and mosquitoes (e.g., Fig. 14))
(12%). The superorder Paraneoptera, composed of the orders Hemiptera (true bugs (e.g., Fig. 6) and
others (e.g., Fig. 21)), Psocoptera (bark lice), Phthiraptera (sucking lice) and Thysanoptera (thrips)
make up about 11% of the total known insect species. The rest of the 10% of insects are composed
by the less species-rich orders: Siphonaptera (fleas), Mecoptera (scorpion flies), Trichoptera
(caddisflies), Strepsiptera (twisted-winged parasites), Neuroptera (lacewings, mantidflies, antlions,
others), Rhapidioptera (snakeflies), Megaloptera (alderflies, dobsonflies, fishflies), Blattodea
(cockroaches, termites (e.g., Fig. 16)), Mantodea (praying mantids) (e.g., Fig. 5), Zoraptera
(zorapterans), Dermaptera (earwigs), Plecoptera (stoneflies), Orthoptera (crickets, grasshoppers
(e.g., Fig. 1), katydids, locusts), Mantophasmatodea (heel-walkers or gladiators), Grylloblattodea
(ice-crawlers or rock crawlers), Embioptera (webspinners), Phasmatodea (stick insects, walking
sticks, leaf insects), Ephemeroptera (mayflies), Odonata (damselflies, dragonflies), Zygentoma
(silverfish), Archaeognatha (jumping bristletails).
Figure 4. Two male geometrid moths. Photo by T. Kondo.
Figure 5. A praying mantis (Mantodea) showing cryptic coloration. Photo by T. Kondo.
5.3. Insect Developmental Biology/Insect Growth and Development
The study of developmental biology in insects includes such fields as cell biology, embryology,
morphology, physiology and molecular biology. Insect growth usually involves a process called
metamorphosis; those with gradual metamorphosis are called hemimetabolous insects and those
with complete metamorphosis are called holometabolous insects. Furthermore, there are
ametabolous insects such as silverfish (Fig. 6) that show no change of body form as they grow and
mature.
Figure 6. A silverfish (Insecta: Thysanura). Photo by T. Kondo.
In hemimetabolous insects, the immature individuals resemble the adults (e.g., Fig. 7), whereas in
holometabolous insects, the immatures start as larvae and then go through a pupal stage before
developing into adults that differ greatly in morphology from the immature stages (e.g., Fig. 8).
Each growth stage, or instar, is separated by a molt (or ecdysis) at which the old cuticle is sloughed
off to allow the new and initially flexible cuticle to expand and accommodate the growth of the
insect. Molting and growth occur mostly during larval or nymphal instars, and adult insects (called
imagos) never molt again, with the exception of mayflies (Ephemeroptera) that have two adult
instars. In holometabolous insects, the pupal instar is a “resting” stage during which major
anatomical changes occur in the apparently quiescent insect to transform it from its larval to adult
form. Insect life histories differ among species, and even in individuals of a single species
depending on the influence of environmental factors such as temperature and moisture. Some topics
considered in the life history of an insect may include allometry, sexual dimorphism,
polymorphism, migration, resting stages and voltinism.
Figure 7. A true bug, Antiteuchus tripterus (Hemiptera: Pentatomidae), tending her eggs and
nymphs. Notice the resemblance of the nymphs to their mother. Eggs with dark color have been
parasitized by a tiny parasitic wasp. Photo by T. Kondo.
Figure 8. The silverspot butterfly, Dione juno (Lepidoptera: Nymphalidae). Left. Larvae. Center.
Pupae. Right. Adult. Photos by T. Kondo.
5.4. Insect Ecology
Insect ecology considers the interactions of insects and their environment. Insects play an important
role in ecosystems and are among the most important organisms contributing to biodiversity. In
rainforests and other ecosystems, insects play an important role in nutrient recycling, breaking
down animal waste, carrion, leaf litter, and providing the forest floor with rich nutrients. Insects are
also important as a food source for many organisms, such as amphibians, birds, mammals, noninsect arthropods and reptiles. Insects interact with other organisms in multiple ways, by
transmitting diseases, through competition, predation, mutualisms, parasitism, etc. Insects also
interact with plants in many ways, for example, through phytophagy, pollination, seed dispersal,
and in some cases by protecting them from herbivores. Insect interactions occur at different trophic
levels. A trophic level is the position of organism in the food web (Fig. 9).
Figure 9. Trophic levels. Photos by T. Kondo.
Primary producers such as plants, algae and fungi are at the trophic level 1; herbivores (primary
consumers) are at trophic level 2; carnivores (secondary consumers) are at trophic level 3,
carnivores that eat other carnivores (tertiary consumers) are at level 4; and top carnivores are at
level 5 (not shown on Fig. 9). The food web often follows a one-way flow, with plants or primary
producers being at the base of the pyramid. Trophic paths become more complex in ecological
communities with higher biodiversity and by the presence of omnivores that can interact at more
than one trophic level.
5.5. Ecological Genetics, Insect Molecular Genetics and Population Genetics
The field of ecological genetics is the study of genetics in natural populations, often focusing on
traits related to fitness (e.g., mating behavior, polymorphism, speciation, mimicry). Insect
molecular genetics is the branch of genetics concerned with the structure and function, at the
molecular level, of the genetic material (genes) of insects and other related arthropods. It can be
used to understand genetic mutations associated with morphological features, disease, pesticide
resistance, etc. Topics studied in molecular genetics may include insect chromosome and gene
structure, DNA replication, Mendelian inheritance, molecular biology, concepts of inheritance, cell
cycles, mutation, biochemical genetics, epistasis, biochemical pathways, genetic systems, genome
evolution, genetic control of embryonic development, sex determination, and even transgenic pests
and beneficial insects for pest management programs. Advancement in molecular genetics has made
possible the wide use of molecular information to determine patterns of descent, resulting in more
accurate classifications of organisms, and giving birth to the field of insect molecular systematics.
Population genetics studies the distribution and change of allele frequency as a result of
evolutionary processes such as gene flow, genetic drift, mutation and natural selection, and aims to
explain adaptation and speciation, among other phenomena. Molecular markers are used to
determine the presence of hitherto unknown species and to develop fast identification methods, e.g.,
DNA barcoding. The common fruit fly or vinegar fly, Drosophila melanogaster, has been studied
extensively and is a model organism widely used for biological research in genetics (Fig. 10).
Figure 10. The vinegar fly, Drosophila melanogaster (Diptera: Drosophilidae), is the most
common species used in genetic studies. Photo by T. Kondo.
6. Applied Entomology
Applied entomology (also known as economic or strategic entomology) deals with the study of
insects that are beneficial or detrimental to humans, domestic animals, and agricultural crops.
Beneficial insects include the honey bee, Apis mellifera, which is reared for honey, beeswax,
propolis and pollination; the silkworm, Bombyx mori, and the tussah moth, Antheraea pernyi, which
are reared for the extraction of silk; the Indian lac insect, Kerria lacca, from which shellac and a
pigment known as ‘lake’ is extracted; the cochineal insect, Dactylopius coccus, from which
cochineal dye (known also as carminic acid) is extracted; and many insect pollinators (e.g., bumble
bees, honey bees, sweat bees, various beetles and flies) for their role in pollination of agricultural
crops. Insects that are consumed as food (e.g., grasshoppers, mopane worm, beetle grubs, others)
are considered beneficial and the eating of insects by humans is termed entomophagy (see Section
8). Insect natural enemies, such as parasitoids (e.g., parasitic wasps and flies) and predators (e.g.,
praying mantises (Fig. 6), lacewings, ladybird beetles (Fig. 11), others) are beneficial because they
play an important role in the control of insect pests. It should be noted that some ladybird beetles
are phytophagous, for example, those of the genus Epilachna are commonly known as pests of
cucurbits (e.g., melon) and solanaceous plants (e.g., eggplant); and although the Asian multicolored
lady beetle, Harmonia axyridis (Fig. 11) is commonly known as a beneficial insect because it is a
voracious predator of aphids, sometimes it is considered also a pest as is known to cause damage to
apples, grapes and peaches, and besides biting, it can cause allergic reactions to humans. An insect
may be beneficial or detrimental depending on the circumstances.
Figure 11. The multicolored Asian lady beetle, Harmonia axyridis (Coleoptera: Coccinellidae).
Photo by T. Kondo.
An insect is considered a pest when it is harmful to human life, be it directly or indirectly. Species
that cause indirect damage by spreading diseases are termed vectors. Some fields included in
applied entomology are agricultural entomology, forest entomology, medical and veterinary
entomology and urban entomology. Apiculture or apicultural science and sericulture are also
subjects dealt with in applied entomology.
6.1. Agricultural Entomology
Agricultural entomology concerns the study of insects associated with various aspects of
agriculture. Agricultural entomology deals with the study of both beneficial and detrimental insects.
Beneficial insects include insect pollinators, such as bumble bees and honey bees; those that
produce various commodities such as honey (e.g., honey bees and stingless bees; see Section 6.5.),
lac (e.g., the lac insect Kerria lacca) and silk (e.g., the silk moth; see Section 6.6.); and natural
enemies (e.g., parasitoids and predators) of agricultural pests. Insects that are detrimental to
agriculture (those that cause economic losses) are commonly known as insect pests. Agricultural
entomology includes ways to control insect pests, which either cause direct damage to agricultural
crops or farm animals by injecting toxins and/or feeding on them; or indirect damage by serving as
vectors for diseases.
The bulk of agricultural entomology deals with the control of insect pests. Half a century ago,
particularly during the time of the green revolution, the philosophy of insect control was centered
on eradication of the insect pest, especially through the use of persistent organic pesticides such as
DDT. Chemical control was the main control method for many years; however, in 1962, a book
entitled “Silent Spring”, written by Rachel Carson, raised concerns about the impact of pesticides
on the environment, including wildlife and human health. Since then, the philosophy of insect
control has switched from eradication to maintaining insect populations below an economic injury
level, that is, a point where the cost of controlling the pest equals the cost of its inflicted yield loss.
Insect pest control is now conducted through integrated pest management (IPM) principles that aim
to be sustainable in the use of resources and environmentally friendly. IPM requires plenty of
experience and knowledge and combines all available methods of control such as biological control
(e.g., use of natural enemies), cultural control (e.g., weed control, fertilization, irrigation, pruning),
and mechanical or physical control (e.g., use of barriers, traps, knocking down insect pests with
high water pressure), and chemical control, giving preference to products that are less harmful to
humans and the environment. In IPM, control begins by knowing the insects that affect the
agricultural crops. The first step in insect control is the correct identification of the insect, making
taxonomy an important part of any pest control strategy. It is very important to study also the
biology of the insect pest, since control may be more efficient at certain times of the insect life
cycle; for example, in scale insects, chemical control is generally more effective when the insects
are in their first instar (or first growth stage), just after hatching from the egg, because they are
more vulnerable as they are smaller and have not developed a protective scale cover at this time.
Once they grow older, scale insects produce a waxy cover that makes them less susceptible to
pesticides.
In IPM, control measures should be undertaken only when necessary. This can be achieved by
closely monitoring the insect populations in the field, through visual observation of crops or by the
use of monitoring traps, etc. Once the relationship between damage and pest population densities
are established, an economic threshold can be defined, where control measures should be started so
that the potential pest population will not exceed the economic injury level. An insect should be
considered a pest only when its damage exceeds the economic injury level; before that point it is a
just a potential pest. There are many insects in the field, but not all insects require control as most
do not cause harm and some are beneficial. Prevention is an important component of IPM
programs, because by preventing potential pests there is no need of control at all. Cultural control
methods such as crop rotation, the use of pest-resistant varieties, or using pest-free plantings, are
some common methods of prevention. At a larger scale, prevention can be done also at points of
entry, for example, quarantine inspections at airports and ports prevent the entrance of exotic pests
to a country. The study of agricultural entomology involves all the basic principles of agronomy,
insect ecology, life history and behavior, insect taxonomy, insect physiology, toxicology and other
fields of general and applied entomology.
6.2. Forest Entomology
Forest entomology concerns the study of insects and other arthropods associated with forest
ecosystems. It deals mostly with insect pest management, seeking to control insects that cause
crown dieback or death of trees, degradation and destruction of wood, defoliation (Fig. 12), and
other problems related to the health of a forest and wood products.
Figure 12. Defoliation of a tree caused by leaf-cutting ants, Atta cephalotes (Hymenoptera:
Formicidae). Photo by T. Kondo.
Forest entomology may include studies on biodiversity, biology and ecology of insects in natural or
cultivated forest ecosystems, and damage assessment to tree structures, forest stands and wood
products. Insects (and other arthropods) may affect the health of a tree by interrupting its normal
growth and causing stunted growth and ruining tree form.
Damage caused by insects may include perforation of tree bark, leaves and roots, which often
become an entry route for pathogens (fungi, virus, others); crown dieback which consists of a
substantial progressive decline in crown health, often resulting in tree death; degradation of wood
quality through tunneling caused by insect feeding; staining of the wood either by feeding or by
fungi carried by the tunneling insect; destruction of flowers and seeds; and decrease in
photosynthetic activity and other physiological processes due to defoliation or injection of toxins,
etc. On the other hand, in general, insect populations in forest ecosystems are in balance. But
insects are also essential in maintaining healthy forests. Some services provided by insects in a
forest include the aeration of soil through tunneling activity improving gas exchange in the root
system; decomposition of organic matter of the forest floor; pollination; biological control; food
source for other invertebrates and vertebrates that live in the forest; and production of food products
such as honey.
6.3. Medical and Veterinary Entomology
Medical entomology or human health entomology is the branch of entomology that deals with
arthropods that affect human health; veterinary entomology is that branch of entomology that deals
with arthropods affecting the health of nonhuman animals, particularly domesticated species. These
two disciplines are often combined into a single field known as “medical and veterinary
entomology”. Medical and veterinary entomology involves the study of insects and other
arthropods, especially arachnids, and is a broad science that includes studies on biology, ecology,
morphology, taxonomy and many aspects related to disease transmission. Medical and veterinary
entomology also includes pest control, parasitology, and the study of vector-borne and zoonotic
diseases (see Sections 6.3.1. and 6.3.2.).
Forensic entomology is a specialist branch of medical and veterinary entomology in which insects
are used as evidence in criminal investigations. Insects may be particularly important in establishing
the post-mortem interval (time since death) in a homicide investigation. Insects develop at
predictable rates. Since many of the insects that feed on human cadavers arrive soon after death,
information about the developmental stage of these insects can be used to estimate when death
actually occurred. Some types of problems caused to humans and other animals by insects and other
arthropods include annoyance, envenomation, allergic reactions, invasion of host tissues, arthropodborne diseases, food contamination, phobia for arthropods and delusory parasitosis. Envenomation
occurs by the injection of venom by arthropods through bites and stings.
In Japan, the giant Asian hornet, Vespa mandarinia (Fig. 25), a species native to temperate and
tropical Eastern Asia, is the world's largest hornet with a body length of approximately 5 cm, a
wingspan of about 7.5 cm, and a 1 cm long sting that can inject large amounts of a potent venom
which has a high content of acetylcholine. Each year as many as 40 people die because of allergic
reactions caused by the sting of this species.
Other problems may result when poisonous arthropods are touched or ingested; for example, the
larvae of some moths can cause allergic reactions to the skin when touched, as in the case of the
stinging rose caterpillar Parasa indetermina (Fig. 13).
Figure 13. A stinging rose caterpillar, Parasa indetermina (Lepidoptera: Limacodidae) on arm of a
volunteer. Notice mild allergic reaction on top right. Photo by T. Kondo.
Delusory parasitosis refers to the psychosis that occurs when a person has a strong delusional belief
that they are infested
with parasites, when they are actually not infested with any. Each year arthropod-borne diseases
and new strains of known pathogens are being discovered making the study of medical and
veterinary entomology an essential field in human and animal health.
6.3.1. Arthropod-borne Diseases
Numerous human diseases are transmitted by insects and other arthropods that carry pathogens,
such as bacteria, flukes, protozoa, viruses, roundworms and tapeworms, between vertebrate hosts.
Insects that carry pathogens between hosts are called “vectors”. Here are listed just a few of the
many known vectors of human pathogens. Mosquitoes of the genus Anopheles are vectors of
protozoans of the genus Plasmodium, the causal agents of malaria, which is the most deadly
arthropod-borne disease, affecting about 250 million people worldwide, with about 2 million deaths
accredited to this disease annually. Viruses that are transmitted through the bite of mosquitoes are
commonly known as “arboviruses” (a shortening of ‘arthropod-borne viruses’). The most
commonly known arboviruses are those that cause dengue, yellow fever and several kinds of
encephalitis (e.g., Venezuelan equine encephalitis, Western equine encephalitis, others). The yellow
fever mosquito, Aedes aegypti (Fig. 14), is the main vector of dengue virus, yellow fever virus, and
other diseases.
Figure 14. The yellow fever mosquito, Aedes aegypti (Diptera: Culicidae) is the main vector of
yellow fever and dengue viruses. Photo by N. Burkett-Cadena.
Fleas are capable of transmitting the bacterium, Yersinia pestis, the causal agent of plague. Three
forms of plague (bubonic, pneumonic, and septicemic) are known to occur in humans. Plague has
killed millions of people, especially in the 14th and 17th centuries and is still a problem in society,
with some 5,000 cases annually.
House flies are vectors of bacteria that cause enteric diseases. For example, typhoid fever caused by
Salmonella typhi, cholera caused by Vibrio cholera and shigellosis caused by Shigella spp. cause
dysentery and diarrhea, and Escherichia coli causes urogenital and intestinal infections. Triatomine
bugs are capable of transmitting the protozoan Trypanosoma cruzi, the causative agent of Chagas
disease (see Section 6.3.2.). Deer ticks may act as vectors of the bacterium, Borrelia burgdorferi,
which causes Lyme disease in the northern hemisphere. In some parts of Africa, the tsetse flies,
Glossina spp., are vectors of two forms of the protozoan Trypanosoma brucei, the causative agent
of sleeping sickness or African trypanosomiasis.
6.3.2. Chagas Disease
Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness
caused by a flagellate protozoan parasite, Trypanosoma cruzi. The disease was named after the
Brazilian physician Carlos R.J. Chagas who first described T. cruzi and its infection in humans in
1909. The protozoans invade the muscle cells of the digestive tract, heart, and sometimes the
skeletal muscle of their hosts. The life cycle of T. cruzi is complex, consisting of three main
developmental forms. The disease is found from the southern USA to Central America and South
America and is generally transmitted to humans by the infested feces of triatomine bugs (Fig. 15),
although there are other ways of transmission (e.g., via contact of mucosal surfaces, blood
transfusion, congenitally, or through organ transplant).
Figure 15. A triatomine bug (Hemiptera: Reduviidae: Triatomiinae), vector of the protozoan
parasite Tripanosoma cruzi, the causal agent of Chagas disease. N. Burkett-Cadena.
Triatomine bugs feeds on blood using their sucking mouthparts. As the bug feeds, it defecates in
order to expel excess liquid from its gut. The feces of a bug infected with T. cruzi will contain the
infectious parasites. The saliva of triatomine bugs contains anesthetics, anticoagulants and
vasodilators that permit the insect to feed without disturbing its host. Once satiated, the insect
leaves its human host and the effect of the anesthetic wears off. The bite begins to itch and the
sleeping human will scratch the bug bite. The act of scratching disrupts the protective layers of the
skin, allowing the protozoans found in the infected feces to penetrate the skin. Chagas disease is
typical of poor rural communities, especially among people who live in houses with thatch roofs in
areas where the protozoans and their triatomine bug vectors are endemic. Chagas disease affects
about 18 million people in Latin America.
6.4. Urban Entomology
Urban entomology is the study of insects, arachnids and other arthropods that affect people and
their property in urban environments. Some urban pests may cause direct damage to humans
through biting and stinging (e.g., ants, bed bugs, fleas, mites, spiders, wasps) and others may cause
indirect damage by eating or tunneling their homes and furniture (e.g., carpenter ants, carpenter
bees, termites (Fig. 16), damaging paper products (e.g., booklice, silverfish, termites) and fabrics
(e.g., carpet beetles, cloth moths), by consuming their food (e.g., Indian meal moths, mealworms),
by carrying diseases (e.g., cockroaches, house flies), inducing allergies (e.g., dust mites), by
affecting human pets (e.g., fleas, lice, mites), by damaging garden and house plants, etc. Similar to
other fields of applied entomology, urban entomology aims to control pests. Medical and veterinary
entomology, insect physiology, taxonomy, toxicology, and the study of pesticides and their
application are some important components of urban entomology.
Figure 16. The subterranean termite, Reticulitermes flavipes (Blattodea: Rhinotermitidae), a
common structural pest in the southeastern USA. Photo by T. Kondo.
6.5. Apiculture and Meliponiculture
Apiculture or beekeeping is the cultivation of bees for the extraction of honey, beeswax, bee
venom, pollen, propolis, royal jelly or for pollination. The nests of cultivated bees are usually called
beehives, and these are kept in places known as apiaries (Fig. 17). The collection of bee honey by
humans dates back as far as the Neolithic period. One of the earliest records of honey gathering
comes from a rock painting, dated to 6,000 B.C., that depicts a person climbing a cliff to collect
honey from a bee nest. The most commonly cultivated species of honey bee worldwide is Apis
mellifera (Figure 18), which has numerous subspecies and hybrids. A second species, Apis cerana,
with its various subspecies is cultivated in many Asian countries. The latter species is smaller in
size and produces less honey, but is known to be resistant to the mite Varroa destructor, which is a
major pest of A. mellifera.
In recent years, populations of cultivated honey bees have been affected by what is now known as
“colony collapse disorder” or “CCD”, which is a phenomenon in which worker bees of the
European honey bee abruptly disappear from their colonies. Although such disappearances have
been known to occur previously, the term colony collapse disorder was coined to refer to a drastic
rise in the number of collapses of honey bee colonies in the USA in 2006, and since then CCD has
also been reported in European countries and even in Taiwan. Colony collapse disorder has raised
attention since many agricultural crops rely on pollination by honey bees. The cause of CCD is still
not clearly understood, but a great deal of research has been conducted resulting in many
hypotheses that try to explain this phenomenon. Colony collapse disorder has been accredited to a
variety of factors such as Varroa mites, insect pathogens (e.g., the microsporidian Nosema apis, the
Israel acute paralysis virus, and others), environmental and nutritional stresses, neonicotinoid
pesticides, genetically modified (GM) crops, etc. Other studies suggest that CCD is caused by a
combination of multiple factors.
Figure 17. An apiculturist checking his beehives. Photo by T. Kondo.
Figure 18. Honey bees pollinating a flower of yellow pitaya, Selenicereus megalanthus
(Cactaceae). Photo by T. Kondo.
Besides honey bees, stingless bees (Fig. 19) are cultivated in Africa, Australia, and Latin America
for the production of honey. The cultivation of stingless bees is termed meliponiculture. Many
species of stingless bees are commonly used in Bolivia, Brazil, Colombia, Guatemala, Mexico, Peru
and Venezuela for honey production and their use dates back to the times of the Mayan culture.
Figure 19. Stingless bees (Hymenoptera: Apidae: Meliponini) at nest entrance. Photo by T. Kondo.
Honey from these stingless bees is often used for medicinal purposes such as fertility enhancers,
laxatives, for the treatment of ocular cataracts and pterygium, fatigue, gastritis, ulcers, lung
weakness, coughs, wounds and bruises.
6.6. Sericulture
Sericulture, also known as silk farming, is the cultivation of silkworms for the production of silk
(Fig. 20). Many species of silk moth are used for silk extraction, but the most commonly used
species is Bombyx mori, a species domesticated from the wild silkmoth, Bombyx mandarina, which
is distributed in northern India, China, Korea, Japan, Russia and Turkey.
Figure 20. Traditional extraction of Turkish silk. Photo by T. Kondo.
The silk thread from a cocoon of B. mori can be as long as 1,000 m. The main food of B. mori is the
leaves of the white mulberry Morus alba, however, polyphagous strains also exist that are able to
feed on apple fruit and cabbage. Silk production using B. mori began in China around 2,700 B.C.
The trade of silk was so important that a trade route called the “Silk Road” expanded from China
towards other Asian territories, the Middle East, Europe and to Africa.
7. Insect Color Pigments
Few people are aware that many color pigments and dyes come from animals such as sea snails and
insects. Seven species in four families of scale insects (Hemiptera: Coccoidea) are known as a
source of red dyes. The body of the lac insect of commerce Kerria lacca contains a dye called
“lake” which is still used in India (Fig. 21). The principal component of the dye of the lac insect is
laccaic acid. Lac dye is used extensively as a natural food additive, and can be found in baked
foods, candies, chocolate, compound seasonings, fruit and fruit-flavored beverages, ham, ice cream,
jam, sausages, soda pop, vegetable juices, and other food products; it is used also in cosmetics and
for dyeing silk and cotton.
Figure 21. The body of an individual female of the commercial lac insect, Kerria lacca (Hemiptera:
Coccoidea: Kerriidae), showing the red pigment. Photo by T. Kondo.
The oak-feeding scale insect, Kermes vermilio (Kermesidae), which lives around the Mediterranean
shores, produces a red dye that has been known for more than two thousand years. These insects
originally were mistaken for little worms, and were given the Latin name vermiculi from which the
name vermilion is derived. Another closely related species, Kermes ilicis, has a similar
geographical distribution and also is collected as a source of dye. The principal component of the
dye of these two species is kermesic acid.
There is also a dye known as Armenian red, which is the name given to the red dye obtained from
the scale insect Porphyrophora hameli (Margarodidae) that lives mainly on grass roots in Armenia
and surrounding countries and was widely used for dying silk products. In Poland and surrounding
areas, there exists a related insect, the Polish cochineal insect, Porphyrophora polonica, which also
feeds on roots; the insect was widely used in the production of a red dye and exported to Western
Europe. In China, Kazakhstan and Uzbekistan there is a third species in the same genus,
Porphyrophora sophorae, which also is used as a source of dye. These three species are commonly
known as ground pearls because they have a rounded pearl-like cyst stage that does not resemble a
typical insect, and for this reason were originally thought to be of plant origin. The principal
component of the dye of these ground pearl species is carminic acid.
Of all insect dyes, the most famous is the cochineal dye that is extracted from the cochineal insect
of commerce, Dactylopius coccus (Dactylopiidae), a species that has been used by Aztecs, Incas
and Mayans for more than a thousand years. After the Europeans arrived in the New World, the red
dye produced by this insect proved to be superior to any of the red dyes produced by other scale
insects in Asia and Europe, resulting in a drastic decline of other scale insect based dyes. It is said
that the cochineal insect was so precious that for a time the species was sold at the same price as
gold. However, with the appearance of cheap artificial dyes in Europe in the mid-19th century, the
demand for cochineal dye dropped drastically. More recently, many synthetic dyes have been found
to be carcinogenic, resulting in resurgence in the use of cochineal dye. Currently, the cochineal
insect is grown commercially in the Canary Islands, Chile, Mexico and Peru.
Figure 22. A drop of the red haemolymph of a cochineal insect, Dactylopius sp. (Hemiptera:
Coccoidea: Dactylopiidae), a source of carminic acid. Photo by T. Kondo.
The main ingredient of cochineal dye is carminic acid (Fig. 22). Cochineal dye is known by various
names, such as carmine, cochineal extract, C.I. 75470, crimson lake, E-120, natural red 4, and
natural coloring. As a food colorant, cochineal dye can be found in alcoholic drinks, artificial
flowers, bakery products, cheddar cheese and other dairy products, cookies, crimson ink, desserts,
gelatin desserts, icings, jams, juice beverages, marinades, meats, paints, pie fillings, preserves,
processed poultry products, sausages, sauces, toppings, and variety of sweets. Insoluble carmine
pigment is used in the cosmetics industry for blushes, hair-care products, lipsticks, face powders,
rouges and skin-care products. Cochineal dye is also used in microbiology for staining tissues, and
in the pharmaceutical industry to color pills and ointments.
8. Entomophagy
The word entomophagy is derived from the Greek words “entomon” meaning insect and “phagy”
meaning to eat, and refers to the consumption of insects as food, particularly by humans (Fig. 23).
The term insectivory is generally used for the consumption of insects by animals other than humans
and by some carnivorous plants. The idea of eating insects is not well accepted in Western cultures
despite the fact that every day hundreds of insect parts are found in the flour of our daily bread. In
rare cases, the consumption of certain insects can induce an anaphylactic shock reaction in
susceptible people, as is true for many other food products.
Figure 23. The young author (left) eating a fried grasshopper in Thailand.
However, recently entomophagy is gaining popularity as reflected by the high increase of
entomophagy-related publications, products and insect-eating activities. Entomophagy is common
in many parts of the World. In Mexico, for example, more than 200 species of insects are known to
be consumed. In general, ants, grasshoppers, beetle grubs (Fig. 24), bee larvae and caterpillars are
popular in many countries. Some insects are more popular than others, either because of their taste,
abundance or culture. In southern Africa, the larvae of a species of silkmoth, Imbrasia belina,
commonly known as mopani or mopane worm, are extremely popular and a good source of animal
protein. In northern Japan, wasp larvae known as “hachinoko”, caddisfly larvae “zazamushi” and
grasshoppers “inago” are commonly eaten. In Mexico, ant eggs and larvae known as “escamoles”
and various aquatic insect eggs, particularly those of the families Corixidae and Notonectidae of the
insect order Hemiptera, are very popular and often known as insect caviar. In Colombia and
northern parts of Brazil, leaf-cutting ants, Atta spp. are consumed. In Thailand, the giant water bug
Lethocerus indicus is quite popular, and a condiment extracted from this insect and known as
“mangda” is commonly used in their cuisine. Some scale insects are also used as human food. In
Australia, Aboriginal people consume the gall-inducing scale insect, Cystococcus pomiformis
(Eriococcidae), which apparently have a watery female with nutty-flavored nymphs. In Sakorn
Nakorn Province, Thailand, the giant scale insect, Nietnera sp. (Monophlebidae), is cooked together
with sticky rice and then consumed.
Insects are rich in animal protein. In general, insect protein is low in the amino acids,
methionine/cysteine, but has a high content of lysine and threonine, which tend to be deficient in
maize-based, cassava, rice, and wheat diets prevalent in the developing countries. Some insects may
have high fat and caloric values. Insects are rich in vitamins and minerals, such as calcium, copper,
iron, magnesium, niacin, pyridoxine, riboflavin, thiamin, zinc. The insect exoskeleton is made
mostly of chitin (10% of whole dried insects) making it a significant source of fiber. The larvae of
the American palm weevil, Rhynchophorus palmarum (Fig. 24), are an important protein source for
indigenous Amazonian communities, and are considered a tasty food in tropical regions of the
Amazon. These weevil larvae are a valuable resource for the indigenous population and natives
collect them from rotten palm stems and consume them boiled or raw. According to a study, the
protein content of the American palm weevil is of 7.33g/100g, surpassing that of cow milk
(3.1g/100g). The larvae of R. palmarum are also rich in Vitamin A (equivalent to 85.0g of retinol),
a value that is also higher than that found in milk (37g de retinol). Vitamin E is particularly high
(9.82 mg/100g of fresh weight of alpha-Tocopherol); 100g of R. palmarum larvae will assure 100%
the daily requirement of this nutrient for an adult person (8 to 10 mg/per capita/per day).
Figure 24. A dish of beetle grubs of the American palm weevil, Rhynchophorus palmarum
(Coleoptera: Curculionidae). Photo by T. Kondo.
Insects are not only nutritious but also tasty. In Indonesia, children usually catch dragonflies and eat
them as a snack. In Phu Phan-Park in Nakorn Sakorn province in northern Thailand, locals
essentially eat any insect that comes to light traps; the insects usually are deep fried before
consumption. Besides insects, other terrestrial arthropods such as arachnids and myriapods are also
consumed as food.
9. Insects and other arthropods as pets
When the general public hears the word pet, they often think of birds, cats and dogs, other small
mammals, fish, reptiles, and perhaps even giant snails. But insects have been kept as pets since
ancient times. It is said that in China, crickets were kept as pets for their beautiful chirps as early as
the 13th century, and later were used also for cricket fighting. Other species, such as cicadas and
grasshoppers, were also kept as insect pets in China.
In Japan, the bell cricket, Meloimorpha japonica (Orthoptera: Gryllidae), is sold during summer in
supermarkets, and Japanese buy them because their chirping is said to give a cooling sensation.
Among Japanese children, various species of stag beetles and the common Japanese rhinoceros
beetle, Allomyrina dichotoma (Coleoptera: Scarabaeidae: Dynastinae) (Fig. 25), are the most
popular. Many species are kept as pets in classrooms in elementary schools in Japan for teaching
purposes. For example, the Japanese national butterfly, Sasakia charonda (Lepidoptera:
Nymphalidae) (Fig. 26), is raised by Japanese students in many elementary schools and their food
plants are planted in order to increase their wild populations.
Figure 25. A male common Japanese rhinoceros beetle, Allomyrina dichotoma (Coleoptera:
Scarabaeidae) (top left) and The Asian giant hornet, Vespa mandarinia (Hymenoptera: Vespidae)
(bottom right) attracted to oak sap. Photo by T. Kondo.
Figure 26. The Great purple emperor, Sasakia charonda (Lepidoptera: Nymphalidae), the national
butterfly of Japan. Photo by T. Kondo.
In Australia, insect pets are becoming popular, and many species are sold for this purpose, for
example, the native giant burrowing cockroach, Macropanesthia rhinoceros (Blattodea:
Blaberidae), makes a good pet. This giant cockroach is wingless, slow-moving, easy to keep
(completely vegetarian), does not bite, can live for up to 10 years, and as it name suggests, the
insect is quite large and can grow up to 8 cm long. Furthermore, the giant burrowing cockroach is
known to be the heaviest cockroach species in the world, weighing up to 35g! Other insect species
sold as pets in Australia include rhinoceros beetles, June beetles and stick insects.
Nowadays, even in countries such as the USA and the UK, many species of insects may be found in
pet shops. Probably, the most popular pet, similar to Australia, is another species of cockroach, the
Madagascar hissing cockroach, Gromphadorhina portentosa (Blattodea: Blaberidae), a native of
Madagascar. This species can grow up to 7.6 cm at maturity, and its popularity is said to be due to it
hissing habit when disturbed. The hissing sound results when the cockroach forces air out of its
breathing tubes (called spiracles), which are found on each segment of the thorax and abdomen.
This cockroach, like its Australian counterpart is wingless, slow moving, does not bite and is easy
to keep. Other popular insect pets include various species of stick and leaf insects (Phasmatodea),
praying mantises (Mantodea), antlions (Neuroptera: Chrysopidae), darkling beetles (Coleoptera:
Tenebrionidae), June beetles and rhinoceros beetles (Coleoptera: Scarabaeidae), assasin bugs
(Hemiptera: Reduviidae), butterflies and moths (Lepidoptera), crickets, grasshoppers and katydids
(Orthoptera), and many others. The larvae of a wide range of aquatic insects, such as damselflies
and dragonflies (Odonata) and giant water bugs (Hemiptera: Belostomatidae), can be kept in
aquariums. Ants are also kept as pets in ant farms or formicariums. A formicarium is a narrow box
made of glass or plastic filled with soil or other nesting substrates that allow observation of the
various activities that occur within an ant colony. Other arthropods such as crabs, hermit crabs,
tarantulas, wolf spiders, scorpions, vinegaroons, millipedes and isopods are also kept as pets.
10. Conclusions
This chapter reviews the science of entomology or insect science as understood today. An effort
was made to explain as a manner of introduction as many of the fields and topics that are currently
studied in entomology. Great advances have been made in the fields of insect molecular genetics
and phylogenetic systematics with the development of new data, new computer programs and other
research tools, resulting in new classifications. For example, termites were previously classified in
the order Isoptera, but now they are classified in the order Blattodea, the same group as
cockroaches.
An emphasis was made to highlight the close association of insects and people, from both positive
and negative aspects. Insects are better known as “pests” because they often cause direct damage to
humans and their food crops, and serve as vectors of diseases. But the benefits we gain from insects
are infinite, beginning with pollination, their role in maintaining healthy ecosystems, the various
insect products including honey, silk, shellac, color pigments, and because of their beauty.
The field of entomology is in a constant flux, always evolving like the insects themselves. For
example, radar technology is used to study migrating patterns of insects; insects are often used as
models in the field of robotics; and the implementation of GPS and computer modeling have
allowed easy mapping of insect distributional patterns. Entomology is in the true sense a
multidisciplinary discipline.
Acknowledgments
The author thanks Dr. Gary Mullen (Auburn University) and Dr. Nathan Burkett-Cadena
(University of South Florida) for checking the section on medical and veterinary entomology; to Dr.
Nathan Burkett-Cadena for providing the wonderful photos of the yellow fever mosquito (Fig. 14)
and a triatomine bug (Fig. 15) and for checking the content of Chagas disease; to Dr. James T. (JT)
Vogt (USDA, Forest Service), Dr. Penny Gullan and Dr. Peter Cranston (both at the Australian
National University, Canberra), Dr. Bora M. Kaydan (Çukurova University, Turkey) and Dr. Kris
A.G. Wyckhuys (CIRAD) for reviewing the text and for providing valuable comments.
Glossary
Allometry: The study of the relative size and shape of organs or parts of organisms in accordance to growth.
Beeswax: A natural wax produced by honey bees in the construction of their hive; often purified and sold commercially
for making candles, crayons, and polishes.
Cochineal dye: A crimson red dye composed of carminic acid and extracted from female cochineal insects, especially
Dactylopius coccus (Hemiptera: Dactylopiidae).
Cryptic coloration: Also known as crypsis, refers to ability of an insect to blend with the environment, through
different color patterns and shapes.
Sexual dimorphism: Inherited morphological and color differences between males and females of the same species.
DNA barcoding: A molecular method that uses a short genetic marker of the mitochondrial DNA to identify an
organism as a particular species.
Green revolution: A time period between the 1940s and the late 1970s of agricultural development and technology.
The green revolution resulted in a high increase in agricultural production and was aimed at reducing world starvation.
Some technologies used to achieve high yields involved the development of high-yielding varieties of cereal grains,
implementation of better irrigation methods and infrastructure, new management techniques, hybridized seeds,
synthetic fertilizers and pesticides.
Gypsy moth: Lymantria dispar (Lepidoptera: Lymantriidae) is a serious forest pest of Eurasian origin.
Indian meal moth: Plodia interpunctella (Lepidoptera: Pyralidae) is a common grain-feeding pest worldwide.
Instar: The stage between molts in an arthropod’s life.
Metamorphosis: The conspicuous and marked morphological changes during an insect´s development, often
accompanied by a change of habitat or behavior.
Mopane worm: The large caterpillars of the saturnid moth Imbrasia belina (Lepidoptera: Saturniidae), usually known
as mopani or mopane worm, are an important source of protein in southern African countries.
Shellac: A natural resin secreted by female lac insects, especially the species Kerria lacca (Hemiptera: Kerriidae).
Shellac is produced in China, India, Indonesia, Thailand and Vietnam, and has many uses, e.g., as a varnish for
furniture and musical instruments, for coating pills and candies, and often used to give glaze to food products.
Pela scale insect wax: A high quality wax secreted by the males of the Chinese wax scale Ericerus pela (Hemiptera:
Coccidae). The wax is used to make candles, coatings for pills, polishing furniture, sizing paper, and as a shining agent
for paper, leather and food products, etc.
Polymorphism: In biology, polymorphism refers to the occurrence of different morphs (forms or types) in the same
population of a species, independent of sexual variation.
Propolis: A resinous mixture produced by honey bees from plant resins and saps and used as a sealant for cracks in the
hive. It is commonly sold as a natural health product for various purposes, and also used in varnishes of musical
instruments.
Royal jelly: A viscous substance secreted by worker honey bees from special glands and used for feeding adult queens
and also larvae chosen to become queens. It is sold commercially as a health product that claims to reduce physical and
mental exhaustion, increase physical strength, and improve metabolism, digestive problems, etc.
Spanish fly: The blister beetle Lytta vesicatoria (Coleoptera: Meloidae), commonly known as "Spanish fly", produces a
strong irritant vesicant substance called cantharidin which is claimed to have aphrodisiac properties at small doses.
Spiracle: Most hexapods and some spiders breathe from small holes in the exoskeleton, called spiracles, from where air
enters into the tracheae, a network of internal tubes that carry air inside the body.
Tussah moth: Antheraea pernyi (Lepidoptera: Saturniidae) is a tropical Asian species used for the production of a wild
silk called tussah silk.
Vinegaroons: Also known as vinegarroons or whip scorpions are arachnids of the order Thelyphonida.
Voltinism: Refers to the number of generations of an organism per year. Species with one generation a year are termed
univoltine; those with two generations a year are bivoltine; and those with several generations a year are polyvoltine.
Zoonotic disease: Any infectious disease transmitted (often through insect vectors) from non-human animals to
humans or vice versa.
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Biographical Sketch
Takumasa Kondo (Demian Takumasa Kondo Rodríguez), born in Colombia in 1968, obtained a B.Sc. degree in
International Agricultural Development from Tokyo University of Agriculture (Japan) in 1994 for his thesis entitled:
“The scale insect fauna of Okinawa” (In Japanese), and in 1996 he was awarded a M.Sc. degree from the same
university for his thesis entitled: “The Scale Insects on Mango in the World” (In English). While studying his
undergraduate degree in Japan, he traveled to the USA where he was an exchange student at the Department of
Entomology at Michigan State University (1992-1993). In 1997 he moved to the Department of Entomology (now
Department of Entomology and Plant Pathology) of Auburn University and obtained his Ph.D. degree in 2003. His
dissertation was entitled: “A taxonomic review of the subfamily Myzolecaniinae (Homoptera: Coccoidea: Coccidae)”.
As soon as he received his doctorate’s degree he moved to the University of California, Davis, where he was a
postdoctoral researcher until December 2007. Since January 2008 he has been working in the area of integrated pest
management at the Corporación Colombiana de Investigación Agropecuaria (Corpoica), in Palmira, Colombia. During
his career, he has participated in many field expeditions, traveling to countries such as Argentina, Brazil, Chile,
Colombia, Ghana, India, Indonesia, Jamaica, Japan (Okinawa), Mexico, and other regions. He is section editor in the
area of systematics for the journal Neotropical Entomology (2007-present), member of the editorial board of the
International Journal of Insect Science (2008-present), and topic editor of systematics for the Journal of Insect Science
(2010-present). He is member of: The Honor Society of Agriculture: Gamma Sigma Delta, Auburn University Chapter
(Inducted May 1, 2003). He is an active member of the Entomological Society of America, The Entomological Society
of Japan, The Entomological Society of Colombia (SOCOLEN), The Entomological Society of Brazil, the International
Organization for Biological Control (IOBC), Neotropical Regional Section (NTRS) and ASIAVA (Association of
Agricultural Engineers of the Valle del Cauca region, Colombia). He has experience supervising or co-supervising
Ph.D., M.Sc. and undergraduate students, and has published over 80 research papers. His research has dealt mostly with
the systematics of several scale insect groups, including the lac insects (Kerriidae), mealybugs (Pseudococcidae), giant
scales (Monophlebidae), ground pearls (Margarodidae), the felt scales (Eriococcidae), and the soft scale insects
(Coccidae), especially those species associated with ants and stingless bees. He is also working on a molecular level
phylogenetic study of the family Coccidae. At Corpoica, he has lead three research projects, namely, two projects on
integrated pest management of two lonchaeid fly species, Dasiops inedulis (Steyskal) on passionfruit, and D. saltans
(Townsend) on yellow pitaya, Selenicereus megalanthus (Cactaceae), and a third project on a faunistic survey of mites
and scale insects and their natural enemies on avocado in Colombia. Currently he is conducting research on the
integrated pest management of the Asian citrus psyllid, Diaphorina citri (Psyllidae), with emphasis on biological
control, and is involved in a classical biological control program on San Andres Island, Colombia, to control two
invasive scale insect species, namely the pink hibiscus mealybug Maconellicoccus hirsutus (Pseudococcidae) and the
multicicatrices fluted scale Crypticerya multicicatrices (Monophlebidae).
This article is for personal use only.
To cite this chapter:
Takumasa Kondo (2012). INTRODUCTION TO THE STUDY OF ENTOMOLOGY, Animal and
Plant Productivity [Eds. UNESCO-EOLSS Joint Committee]. In: Encyclopedia of Life Support
Systems(EOLSS), Developed under the Auspices of the UNESCO, Eolss Publishers, Oxford, UK,
[http://www.eolss.net] [Retrieved January 31, 2013].